Preparation process of composite electroformed printing screen plate

Abstract

The application relates to the field of printing screen plate manufacturing, and particularly discloses a preparation process of a composite electroformed printing screen plate, which comprises the following specific steps: a metal wire is woven into a net structure to form a metal wire skeleton, a mask layer is compounded on one side of the metal wire skeleton, a nickel alloy is used as an anode for electroplating with the metal wire skeleton as a cathode, the nickel alloy is electroplated and deposited on the surface of the metal wire skeleton and the opening area, an initial printing screen plate is formed, the initial printing screen plate is used as a cathode, an electroplating solution is added, secondary electroplating is carried out, an electroplated metal layer is formed, the mask is removed, the mask layer is peeled off, and the composite electroformed printing screen plate is prepared; the electroplated metal layer and the mask layer are both provided with penetrating pattern openings which correspond to the mesh holes in the metal wire skeleton; and the printing screen plate prepared by the application can have good mechanical strength and printing precision.

Description

Technical Field

[0001] This application relates to the field of printing screen manufacturing, and in particular to a process for preparing a composite electroforming printing screen. Background Technology

[0002] Printing screens are the core component of screen printing, widely used in high-precision graphic printing of electronic components, solar cells, circuit boards, and other products. Currently, there are two main types of common printing screens: The desired patterns and openings are directly formed onto thin stainless steel sheets using electroforming or etching processes. The advantages are simple processing, low cost, high precision, and clear pattern lines. However, when complex patterns are required, dense slots must be drilled into the steel sheet, resulting in the metal sheet being divided into multiple isolated areas, significantly reducing the overall structural strength. To prevent sheet breakage, the conventional practice is to retain tiny connecting bridges inside the metal sheet; however, these connecting bridges have limited strength and are prone to breakage during printing, causing the screen to be scrapped.

[0003] The second type is a composite plate made of wire mesh and polyimide (PI) film. The polyimide film is hot-pressed onto the surface of a metal wire mesh, and then laser-drilled holes in the PI film to create the pattern. This structure uses the wire mesh as a framework, resulting in high strength and resistance to breakage. However, due to the inherent thermal stability of the PI film and limitations in laser processing precision, the fineness and positional accuracy of the pattern are not as good as those of a pure steel plate, and the bonding force between the PI film and the wire mesh is sometimes insufficient, affecting its service life. Summary of the Invention

[0004] To address the shortcomings of existing printing screens, this application provides a process for preparing a composite electroforming printing screen.

[0005] This application provides a process for preparing a composite electroforming printing screen, using the following technical solution: A process for preparing a composite electroforming printing screen includes the following specific steps: Metal wires are woven into a mesh structure to form a metal mesh skeleton. A mask layer is laminated on one side of the metal mesh skeleton. Then, using the metal mesh skeleton as the cathode and nickel alloy as the anode, nickel alloy is electroplated onto the surface ribs and opening areas of the metal mesh skeleton to form a preliminary printing screen. The preliminary printing screen is then used as the cathode, and an electroplating solution is added for a second electroplating to form an electroplated metal layer. The mask is then removed, and the mask layer is peeled off to produce a composite electroformed printing screen. The electroplated metal layer has through-hole patterned openings, and the mask layer also has through-hole patterned openings, which correspond to the mesh openings in the metal mesh skeleton.

[0006] By employing the above technical solution, using metal mesh as a framework, the prepared printing screen can achieve high overall mechanical strength, reducing the likelihood of breakage even with complex patterns and dense openings. Electroplating is then performed on the surface of the metal mesh framework and the mesh opening areas, combining the electroplated metal with the mesh to form an integrated composite structure. This reduces delamination and peeling, while ensuring high precision of the printing screen pattern, neat line edges, and dimensional stability. Pattern openings are etched on both the electroplated metal layer and the mask layer, and the position and size of these openings correspond to the mesh openings of the metal mesh framework. This ensures that each pattern opening corresponds to at least one mesh gap, allowing for smooth ink flow. Furthermore, the presence of the mesh helps disperse the ink, improving printing uniformity.

[0007] Preferably, the nickel alloy is one of a nickel-cobalt alloy and a nickel-copper alloy.

[0008] Preferably, the content of each raw material in the electroplating solution is as follows: nickel sulfate 60-80 g / L, amino acid nickel 20-30 g / L, citric acid 10-20 g / L, activator 5-10 g / L, chelating agent 5-8 g / L, and butynediol diethoxy ether 0.5-1 g / L.

[0009] By employing the above technical solution, the combination of nickel sulfate and amino acid nickel can form a dense metallic nickel plating layer under the action of an electric field. The amino acid nickel reduces the internal stress of the electroplated layer, promoting the formation of a uniform and smooth electroplated metal layer. Citric acid maintains the activity of the anode, reduces anode passivation, and helps refine the grains. The chelating agent complexes impurity metal ions, reducing the co-deposition of impurity metal ions with nickel, minimizing the discharge of impurity ions, and promoting uniform composition of the electroplated layer.

[0010] Preferably, the activator is at least one of sodium aminosulfate and sodium dodecyl sulfate, and the chelating agent is sodium gluconate.

[0011] Preferably, the chelating agent is sodium gluconate.

[0012] Preferably, the mask layer material is photoresist, and the photoresist forms patterned openings on the surface of the metal mesh skeleton through exposure and development.

[0013] By adopting the above technical solution, the photoresist can transfer the pattern onto the metal mesh skeleton with high fidelity through exposure, and can perform chemical imaging through the developer to form a flat photosensitive surface on the metal mesh skeleton.

[0014] Preferably, the photoresist comprises the following raw materials in parts by weight: 30-40 parts acrylic resin, 1-3 parts photoinitiator, 10-15 parts solvent, and 5-8 parts reactive diluent.

[0015] By employing the above technical solution, using acrylic resin as the main component of the photoresist, and in conjunction with other additives, a strong chemical adsorption can be achieved between the prepared photoresist and the surface of the metal mesh framework, ensuring that the mask layer will not detach under subsequent high-speed electroplating bath rinsing. Simultaneously, the acrylic resin provides appropriate flexibility, allowing it to withstand slight deformation of the mesh without breaking.

[0016] Preferably, the photoinitiator is 2-isopropylthioxanthone, and the reactive diluent is at least one of hydroxyethyl methacrylate, trimethylolpropane triacrylate, and pentaerythritol triacrylate.

[0017] Preferably, the method for making a mask layer from photoresist includes the following specific steps: mixing acrylic resin, photoinitiator, solvent, and reactive diluent, filtering to obtain a photoresist mixture, coating the photoresist mixture onto a metal mesh skeleton, pre-baking by heating, and then exposing and developing to form a mask layer.

[0018] Preferably, the heating and pre-baking temperature is 110-120℃.

[0019] In summary, this application has the following beneficial effects: 1. Because this application employs electroplating on the surface of the metal mesh skeleton and the mesh opening area, combining the electroplated metal with the mesh to form an integral composite structure, it can reduce delamination and peeling. The position and size of the pattern openings are consistent with the mesh openings of the metal mesh skeleton, ensuring that each pattern opening corresponds to at least one mesh gap, allowing ink to pass smoothly. The presence of the mesh helps to disperse the ink, improving printing uniformity and printing accuracy.

[0020] 2. This application uses a composite of nickel sulfate and amino acid nickel, which can form a dense metallic nickel plating layer under the action of an electric field, reducing the internal stress of the electroplated layer and promoting the formation of a uniform and smooth electroplated metal layer. Citric acid and chelating agents can help refine the grains, reduce the discharge phenomenon of impurity ions, and promote the uniformity of the composition of the electroplated layer. Detailed Implementation

[0021] The present application will be further described in detail below with reference to the embodiments.

[0022] All raw materials used in the examples are commercially available. Example Example 1

[0023] This embodiment provides a process for preparing a composite electroforming printing screen, including the following specific steps: S1: Mix 35 kg of acrylic resin, 2 kg of photoinitiator, 13 kg of solvent, and 7 kg of reactive diluent. The acrylic resin is ACR101 type acrylic resin, the photoinitiator is 2-isopropylthioxanthone, the reactive diluent is hydroxyethyl methacrylate, and the solvent is propylene glycol methyl ether. Filter to obtain a photoresist mixture. Add 70 g / L of nickel sulfate, 25 g / L of amino acid nickel, 15 g / L of citric acid, 8 g / L of activator, 7 g / L of chelating agent, and 0.8 g / L of butynediol diethoxy ether to water and mix. The activator is sodium aminosulfate, and the chelating agent is sodium gluconate. Stir evenly to form an electroplating solution.

[0024] S2: A metal mesh skeleton is made by weaving metal wires into a mesh structure. The photoresist mixture is applied to the metal mesh skeleton, pre-baked at 115℃ for 90 seconds, and then exposed and developed to form a mask layer. The pattern openings on the mask layer correspond to and penetrate the mesh openings in the metal mesh skeleton. The metal mesh skeleton with the mask is used as the cathode, and a nickel-cobalt alloy is used as the anode for electroplating. The mass ratio of nickel to cobalt in the nickel-cobalt alloy is 9:1. Nickel alloy is electroplated and deposited on the ribs and opening areas of the metal mesh skeleton. The thickness of the nickel alloy is 10μm. The nickel alloy fills the opening areas of the metal mesh skeleton to form the initial printing screen.

[0025] S3: Using the initial printing screen as the cathode, add electroplating solution for secondary electroplating to cover the surface of the initial printing screen and form an electroplated metal layer with a thickness of 10μm. The electroplated metal layer has patterned openings that correspond to and penetrate the mesh openings in the metal wire skeleton. Remove the mask, peel off the mask layer, and produce a composite electroformed printing screen.

[0026] Example 2

[0027] The difference between Example 2 and Example 1 is that the amount of acrylic resin used in the photoresist raw material is 30 kg, the amount of photoinitiator is 1 kg, the amount of solvent is 15 kg, and the amount of reactive diluent is 5 kg.

[0028] Example 3 The difference between Example 3 and Example 1 is that the amount of acrylic resin used in the photoresist raw material is 40 kg, the amount of photoinitiator is 3 kg, the amount of solvent is 10 kg, and the amount of reactive diluent is 8 kg.

[0029] Example 4 The difference between Example 4 and Example 1 is that the content of each raw material in the electroplating solution is as follows: nickel sulfate 60g / L, amino acid nickel 30g / L, citric acid 20g / L, activator 10g / L, chelating agent 5g / L, and butynediol diethoxy ether 0.5g / L.

[0030] Example 5 The difference between Example 5 and Example 1 is that the content of each raw material in the electroplating solution is as follows: nickel sulfate 80g / L, amino acid nickel 20g / L, citric acid 10g / L, activator 5g / L, chelating agent 8g / L, and butynediol diethoxy ether 1g / L.

[0031] Example 6 The difference between Example 6 and Example 1 is that the nickel alloy used in the preparation process of the composite electroforming printing screen is a nickel-copper alloy, and the mass ratio of nickel to copper in the nickel-copper alloy is 9:1.

[0032] Example 7 The difference between Example 7 and Example 1 is that no chelating agent is used in the electroplating solution raw materials.

[0033] Comparative Example Comparative Example 1 A process for preparing a composite electroforming printing screen includes the following specific steps: S1: Mix 35 kg of acrylic resin, 2 kg of photoinitiator, 13 kg of solvent, and 7 kg of reactive diluent. The acrylic resin is ACR101 type acrylic resin, the photoinitiator is 2-isopropylthioxanthone, the reactive diluent is hydroxyethyl methacrylate, and the solvent is propylene glycol methyl ether. Filter to obtain a photoresist mixture. Add 70 g / L of nickel sulfate, 25 g / L of amino acid nickel, 15 g / L of citric acid, 8 g / L of activator, 7 g / L of chelating agent, and 0.8 g / L of butynediol diethoxy ether to water and mix. The activator is sodium aminosulfate, and the chelating agent is sodium gluconate. Stir evenly to form an electroplating solution.

[0034] S2: A metal mesh skeleton is made by weaving metal wires into a mesh structure. The photoresist mixture is applied to the metal mesh skeleton, pre-baked at 115℃ for 90 seconds, and then exposed and developed to form a mask layer. The pattern openings on the mask layer correspond to and penetrate the mesh openings in the metal mesh skeleton. The metal mesh skeleton with the mask is used as the cathode. Electroplating solution is added and electroplating is performed to cover the surface of the metal mesh skeleton and form an electroplated metal layer with a thickness of 10μm. The electroplated metal layer has pattern openings that correspond to and penetrate the mesh openings in the metal mesh skeleton. The mask is removed and the mask layer is peeled off to make a composite electroforming printing screen.

[0035] Comparative Example 2 A process for preparing a composite electroforming printing screen includes the following specific steps: S1: Mix 35 kg of acrylic resin, 2 kg of photoinitiator, 13 kg of solvent, and 7 kg of reactive diluent. The acrylic resin is ACR101 type acrylic resin, the photoinitiator is 2-isopropylthioxanthone, the reactive diluent is hydroxyethyl methacrylate, and the solvent is propylene glycol methyl ether. Filter to obtain the photoresist mixture.

[0036] S2: A metal mesh skeleton is made by weaving metal wires into a mesh structure. The photoresist mixture is applied to the metal mesh skeleton, pre-baked at 115℃ for 90 seconds, and then exposed and developed to form a mask layer. The pattern openings on the mask layer correspond to and penetrate the mesh openings in the metal mesh skeleton. The metal mesh skeleton with the mask is used as the cathode, and a nickel-cobalt alloy is used as the anode for electroplating. The mass ratio of nickel to cobalt in the nickel-cobalt alloy is 9:1. Nickel alloy is electroplated and deposited on the ribs and opening areas of the metal mesh skeleton. The thickness of the nickel alloy is 10μm. The nickel alloy fills the opening areas of the metal mesh skeleton. The mask is removed, and the mask layer is peeled off to form a printing screen.

[0037] Performance testing The composite electroforming printing screens provided in Examples 1-7 and Comparative Examples 1-2 of this application were subjected to the following performance tests, and the specific test results are shown in Table 1.

[0038] Detection methods I. Interface Bonding Strength Referring to ISO 4624-2023 "Paints and varnishes - Pull-out method for adhesion testing", the maximum pull-out stress between the interfaces of the prepared composite electroforming printing screen was tested using the pull-out method, with n=5 per batch and a pull-out rate of approximately 1 MPa / s.

[0039] II. Dimensional Stability Referring to IEC 60068-2-14 "Environmental testing - Part 2-14: Test N: Temperature variation", the screen was cycled 100 times between 20 and 80°C, with each cycle lasting 30 minutes. Before and after each cycle, ≥50 line widths and the screen mesh pitch were measured at the same coordinate. The output line width drift was recorded, and the dimensional stability of the printing screen was determined.

[0040] III. Salt spray resistance According to ISO 9227:2022, the time until pitting / blistering / warping occurs is recorded under neutral salt spray (35°C, 5% NaCl), and the quality change and appearance are measured after immersion in typical ink solvents for 24 h.

[0041] Table 1: Performance Test Results Data Table

[0042] The performance test results show that the composite electroformed printing screen prepared in this application has good bonding strength, thermal stability, and durability. A comparison between Comparative Examples 1-2 and Example 1 reveals that in Comparative Example 1, without electroplating nickel alloy onto the surface ribs and opening areas of the metal mesh skeleton, the bonding strength between the interfaces of the prepared printing screen is significantly reduced. Furthermore, under thermal cycling, the dimensional stability is significantly reduced due to the large number of openings in the metal mesh skeleton, affecting the thickness of the printing. In Comparative Example 2, reducing the use of the electroplated metal layer significantly reduces the interfacial bonding strength and dimensional stability of the printing screen, because relying solely on the metal mesh skeleton cannot achieve high mechanical strength, and its service life is also significantly reduced during subsequent printing processes.

[0043] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A preparation process for a composite electroforming printing screen, characterized in that, The specific steps include the following: Metal wires are woven into a mesh structure to form a metal mesh skeleton. A mask layer is composited on one side of the metal mesh skeleton. The metal mesh skeleton is then used as the cathode and nickel alloy as the anode for electroplating. Nickel alloy is electroplated and deposited on the ribs and opening areas of the metal mesh skeleton to form the initial printing screen. Using the initial printing screen as the cathode, an electroplating solution is added for secondary electroplating to form an electroplated metal layer. The mask is then removed, and the mask layer is peeled off to produce a composite electroformed printing screen. The electroplated metal layer has through-hole patterned openings, and the mask layer also has through-hole patterned openings. These patterned openings correspond to the mesh openings in the metal wire skeleton.

2. The preparation process of the composite electroforming printing screen according to claim 1, characterized in that, The nickel alloy is one of a nickel-cobalt alloy and a nickel-copper alloy.

3. The preparation process of the composite electroforming printing screen according to claim 1, characterized in that, The content of each raw material in the electroplating solution is as follows: nickel sulfate 60-80g / L, amino acid nickel 20-30g / L, citric acid 10-20g / L, activator 5-10g / L, chelating agent 5-8g / L, and butynediol diethoxy ether 0.5-1g / L.

4. The preparation process of the composite electroforming printing screen according to claim 3, characterized in that, The active agent is at least one of sodium aminosulfate and sodium dodecyl sulfate.

5. The preparation process of the composite electroforming printing screen according to claim 3, characterized in that, The chelating agent is sodium gluconate.

6. The preparation process of the composite electroforming printing screen according to claim 1, characterized in that, The mask layer material is photoresist, which forms patterned openings on the surface of a metal mesh skeleton through exposure and development.

7. The preparation process of the composite electroforming printing screen according to claim 6, characterized in that, The photoresist comprises the following raw materials in parts by weight: 30-40 parts acrylic resin, 1-3 parts photoinitiator, 10-15 parts solvent, and 5-8 parts reactive diluent.

8. The preparation process of the composite electroforming printing screen according to claim 7, characterized in that, The photoinitiator is 2-isopropylthioxanthone, and the reactive diluent is at least one of hydroxyethyl methacrylate, trimethylolpropane triacrylate, and pentaerythritol triacrylate.

9. The preparation process of the composite electroforming printing screen according to claim 7, characterized in that, The method for making a mask layer from photoresist includes the following specific steps: mixing acrylic resin, photoinitiator, solvent, and reactive diluent, filtering to obtain a photoresist mixture, coating the photoresist mixture onto a metal mesh skeleton, pre-baking by heating, and then exposing and developing to form a mask layer.

10. The preparation process of the composite electroforming printing screen according to claim 9, characterized in that, The heating and pre-baking temperature is 110-120℃.

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