Processing method for generating insulating layer on edge and back surface of stainless steel plate
By generating a chemically bonded polyethylene layer on the surface of the stainless steel plate, the insulation problem of the edge and back of the stainless steel substrate is solved, and strong insulation and compatibility with the electroplating process are achieved, providing excellent insulation effect and service life.
Patent Information
- Application Number
- CN202510877518.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-09-16
AI Technical Summary
In the existing technology, the metal residue on the edge and back of the stainless steel substrate is difficult to peel off during the electroplating process, and the commonly used insulating coatings or films have problems such as poor bonding, easy falling off or contamination of the bath liquid, making it difficult to achieve effective insulation.
By carrying out olefin polymerization on the surface of the stainless steel plate, a chemically bonded polyethylene layer is generated, forming an insulating layer with controllable thickness. The bonding is strong and suitable for electroplating process, avoiding contamination of the bath liquid.
It achieves firm insulation on the edge and back of the stainless steel plate to prevent it from falling off, is compatible with the electroplating process, provides excellent insulation effect and service life, and is compatible with the electroplating bath liquid.
Smart Images
Figure CN120644355A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of insulating stainless steel plate processing, and in particular to a processing method for generating an insulating layer on the edge and back of a stainless steel plate. Background Art
[0002] Electroformed stencils are widely used in SMT, semiconductor, and photovoltaic applications. They are typically grown on the surface of a stainless steel substrate. Lamination, exposure, and development create an opening pattern. After electroplating, the patterned portion is peeled from the stainless steel substrate, and the mesh is stretched to form the electroformed stencil. Due to the high cost of stainless steel substrates, they are often reused. After peeling the stencil pattern, residual electroplated metal remains on the edges and back of the stainless steel substrate. This residual metal must be removed before the stainless steel substrate can be reused. Due to edge effects during the electroplating process, the plating layer near the edges is typically thicker and adheres to the sides of the substrate, making it difficult to peel and easily scratching the substrate surface in the patterned area.
[0003] While it's possible to create an insulating layer on the surface of a stainless steel substrate by covering it with plastic film or insulating coating, the thickness of the plastic film itself is in the tens of microns, exceeding the thickness of many thin dry films. Applying the plastic film to the front of the substrate can affect lamination. The plastic film also has weak adhesion to the substrate and is prone to falling off during repeated use. Furthermore, it's difficult to evenly wrap the sides of the stainless steel substrate with the plastic film. Insulating coatings, due to their complex composition, can contaminate the bath solution when the coated substrate is immersed, making them unsuitable for insulating the edges and backs of stainless steel substrates. Summary of the Invention
[0004] The purpose of the present invention is to address the defects and shortcomings of the existing technology and provide a processing method for generating an insulating layer on the edge and back of a stainless steel plate. Through olefin polymerization reaction, a hexene layer with controllable thickness is chemically bonded on the surface of the stainless steel plate to achieve insulation on the edge and back of the stainless steel substrate. The method has the advantages of firm bonding, controllable thickness, and compatibility with electroplating process.
[0005] To achieve the above object, the present invention adopts the following operating steps: Step 1: Degrease, pickle, and ultrasonically wash the stainless steel plate, and then perform surface hydroxylation to form a layer of chemical structure rich in hydroxyl (-OH) groups (such as Figure 1 ) (All surfaces of the stainless steel plate are hydroxylated); Step 2: Use a laminating machine to press a plastic film (such as Figure 2 and Figure 3 ); Step 3: Immerse the stainless steel plate treated in step 2 in a 0.01 mol / L to 0.05 mol / L chloroform solution of olefin trimethoxysilane for 60 min to 120 min. Trimethoxysilane reacts with the hydroxyl groups on the surface of the peripheral area of the stainless steel plate that is not protected by the plastic film, thereby chemically bonding the groups containing carbon-carbon double bonds to the peripheral area (such as Figure 4 ); Step 4: Immerse the stainless steel plate treated in step 3 in a n-hexene toluene solution containing a Ziegler-Natta catalyst to perform an olefin polymerization reaction, thereby forming a polyhexene layer on the surface of the stainless steel plate chemically bonded with carbon-carbon double bonds; the concentration of n-hexene in the n-hexene toluene solution is 0.75 mol / L to 1.25 mol / L, and the temperature of the solution is 50° to 55° (such as Figure 5-Figure 7 ); Step 5: Remove the plastic film on the working area of the front of the stainless steel plate, degrease the stainless steel plate, and soak it in a 0.1mol / L to 0.3mol / L hydrochloric acid solution for 3min to 5min to remove the hydroxyl groups on the surface of the stainless steel metal in the working area. After washing with water, obtain a stainless steel plate with insulation on the back and edges (such as Figure 8 ).
[0006] Furthermore, the hydroxylation treatment in step 1 uses a Piranha solution (the volume ratio of concentrated sulfuric acid to concentrated hydrogen peroxide is 7:3 to 8:3), and the stainless steel plate after ultrasonic water washing is immersed in the Piranha solution for 15 minutes to 30 minutes. After soaking, it is taken out and washed with water, dried with cold air, and placed in a drying oven to dry overnight.
[0007] Furthermore, in the step 2, the thickness of the plastic film is between 20 μm and 200 μm, and the material is polyethylene, polypropylene or polytetrafluoroethylene.
[0008] Furthermore, the working area in step 2 is an area that is symmetrical with respect to the center of the front surface of the stainless steel plate, and whose length and width are 1 mm to 100 mm smaller than the length and width of the entire stainless steel plate.
[0009] Furthermore, the olefin trimethoxysilane in step 3 is allyl trimethoxysilane, butyl trimethoxysilane, pentyl trimethoxysilane, hexyl trimethoxysilane or heptyl trimethoxysilane ( Figure 4 Allyltrimethoxysilane was used.
[0010] Furthermore, the molar ratio of titanium tetrachloride to triethylaluminum in the Ziegler-Natta catalyst in step 4 is 1:10 to 1:20, and the concentration of titanium tetrachloride in toluene is 10 to 20 μmol / L.
[0011] Furthermore, the polymerization reaction time in step 4 is 3.5 min to 65 min, and the thickness of the generated polyethylene layer is 0.5 μm to 10 μm.
[0012] Compared with the prior art, the present invention has the following beneficial effects: The back and sides of the stainless steel plate are insulated by a polyethylene layer by chemical bonding, which has the advantage of being firmly bonded and will not fall off during use; The thickness of the insulating layer can be freely adjusted by changing the time of the olefin polymerization reaction, and the growth thickness per minute is between 0.1 and 0.2 μm. Depending on the thickness and opening requirements of the electroformed steel mesh, the thickness of the dry film selected during the steel mesh production process ranges from 10 μm to 100 μm. In order not to affect the film application effect, the thickness of the insulating polypropylene layer should be less than 1 / 10 of the dry film thickness. However, at the same time, a thicker insulating polypropylene layer can provide better insulation effect. The insulating polypropylene layer of the present invention can be adjusted accordingly according to the thickness of the dry film to achieve better insulation effect and longer service life. For example, when the selected dry film thickness is 100 μm, a 10 μm thick polypropylene layer can be generated on the stainless steel core mold to provide better insulation effect and longer service life. In order to be compatible with the electroplating bath liquid and prevent contamination of the bath liquid, the plastic material in the electroplating equipment is generally polypropylene or polyvinyl chloride. The insulating layer of the present invention is polyethylene, which is a material of the same family as polypropylene. Therefore, it has the advantage of being compatible with the electroplating bath liquid. Compared with propylene, the monomer of polypropylene, polyethylene is liquid at room temperature, and the conditions for the polymerization reaction are relatively simpler and easier to operate. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is a structural diagram of a product subjected to surface hydroxylation treatment according to the present invention.
[0014] Figure 2 This is a product structure diagram of the present invention using a laminating machine to press a plastic film on the working area on the front of a stainless steel plate.
[0015] Figure 3 yes Figure 2 side view.
[0016] Figure 4 This is a product structure diagram of the present invention in which a group containing a carbon-carbon double bond is chemically bonded to the peripheral area of a stainless steel plate.
[0017] Figure 5 This is a product structure diagram of the present invention in which a polyethylene layer is formed on the surface of a stainless steel plate having carbon-carbon double bonds.
[0018] Figure 6 yes Figure 5 side view.
[0019] Figure 7 yes Figure 6 Enlarged view of part A in the middle.
[0020] Figure 8 It is the final product structure diagram of the present invention.
[0021] Figure 9 It is a test experiment data table.
[0022] Description of reference numerals: Stainless steel plate 1, chemical structure rich in hydroxyl groups 2, working area 3, plastic film 4, peripheral area 5, carbon-carbon double bonds 6, polyhexene layer 7. DETAILED DESCRIPTION
[0023] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. The preferred embodiments described are only used as examples. All other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present invention. Example 1:
[0024] like Figures 1-9 As shown, this embodiment adopts the following technical solutions: Step 1: Degrease, pickle, and ultrasonically clean the stainless steel plate 1. Then, use Piranha solution (the volume ratio of concentrated sulfuric acid to concentrated hydrogen peroxide is 7:3) to perform surface hydroxylation on the stainless steel plate 1 to form a layer of chemical structure 2 rich in hydroxyl (-OH) groups (such as Figure 1 ) (all surfaces of the stainless steel plate 1 are hydroxylated); specifically: the stainless steel plate 1 after ultrasonic water washing is immersed in the Piranha solution for 15 minutes, and then taken out after soaking, washed with water, dried with cold air, and placed in a drying oven to dry overnight; Step 2: Use a laminating machine to press a plastic film 4 (such as Figure 2 and Figure 3 ), the thickness of the plastic film 4 is 20 μm, and the material is polyethylene, polypropylene or polytetrafluoroethylene; the working area 3 is symmetrical with respect to the center of the front surface of the stainless steel plate 1, and the length and width are 1 mm smaller than the length and width of the entire stainless steel plate 1; Step 3: Immerse the stainless steel plate 1 treated in step 2 in a 0.01 mol / L chloroform solution of olefin trimethoxysilane for 60 minutes. Trimethoxysilane reacts with the hydroxyl groups on the surface of the peripheral area 5 of the stainless steel plate 1 that is not protected by the plastic film 4, thereby chemically bonding the groups containing carbon-carbon double bonds 6 to the peripheral area 5 (e.g., Figure 4 ); The above-mentioned olefin trimethoxysilane is allyl trimethoxysilane, butyl trimethoxysilane, pentyl trimethoxysilane, hexyl trimethoxysilane or heptyl trimethoxysilane ( Figure 4 Allyltrimethoxysilane is used); Step 4: Immerse the stainless steel plate 1 treated in step 3 in a n-hexene toluene solution containing a Ziegler-Natta catalyst to perform an olefin polymerization reaction for 3.5 minutes, and form a polyhexene layer 7 on the surface of the stainless steel plate 1 chemically bonded with a carbon-carbon double bond 6; the concentration of n-hexene in the n-hexene toluene solution is 0.75 mol / L, and the temperature of the solution is 50° (such as Figure 5-Figure 7 ); The molar ratio of titanium tetrachloride to triethylaluminum in the above-mentioned Ziegler-Natta catalyst is 1:10, and the concentration of titanium tetrachloride in toluene is 10 μmol / L; Step 5: Remove the plastic film 4 attached to the working area 3 on the front of the stainless steel plate 1, degrease the stainless steel plate 1, and soak it in a 0.1 mol / L hydrochloric acid solution for 3 minutes to remove the hydroxyl groups on the surface of the stainless steel metal in the working area 3. After washing with water, obtain the stainless steel plate 1 with insulation on the back and edges (such as Figure 8 ).
[0025] The thickness of the polyhexene insulation layer prepared in this embodiment is 0.5 μm. The test results of the bonding strength between the insulation layer and the stainless steel plate 1 are listed in the following performance test section. Example 2:
[0026] This embodiment adopts the following technical solutions: Step 1: Degrease, pickle, and ultrasonically clean the stainless steel plate 1. Then, use Piranha solution (the volume ratio of concentrated sulfuric acid to concentrated hydrogen peroxide is 7.5:3) to perform surface hydroxylation on the stainless steel plate 1 to form a layer of chemical structure 2 rich in hydroxyl (-OH) groups (such as Figure 1 ) (all surfaces of the stainless steel plate 1 are hydroxylated); specifically: the stainless steel plate 1 after ultrasonic water washing is immersed in the Piranha solution for 20 minutes, and then taken out after soaking, washed with water, dried with cold air, and placed in a drying oven to dry overnight; Step 2: Use a laminating machine to press a plastic film 4 (such as Figure 2 and Figure 3 ), the thickness of the plastic film 4 is 100 μm, and the material is polyethylene, polypropylene or polytetrafluoroethylene; the working area 3 is symmetrical with respect to the center of the front surface of the stainless steel plate 1, and the length and width are 10 mm less than the length and width of the entire stainless steel plate 1; Step 3: Immerse the stainless steel plate 1 treated in step 2 in a 0.02 mol / L chloroform solution of olefin trimethoxysilane for 90 minutes. Trimethoxysilane reacts with the hydroxyl groups on the surface of the peripheral area 5 of the stainless steel plate 1 that is not protected by the plastic film 4, thereby chemically bonding the groups containing carbon-carbon double bonds 6 to the peripheral area 5 (e.g., Figure 4 ); The above-mentioned olefin trimethoxysilane is allyl trimethoxysilane, butyl trimethoxysilane, pentyl trimethoxysilane, hexyl trimethoxysilane or heptyl trimethoxysilane ( Figure 4 Allyltrimethoxysilane is used); Step 4: Immerse the stainless steel plate 1 treated in step 3 in a n-hexene toluene solution containing a Ziegler-Natta catalyst to perform an olefin polymerization reaction for 6.5 minutes, and form a polyhexene layer 7 on the surface of the stainless steel plate 1 chemically bonded with a carbon-carbon double bond 6; the concentration of n-hexene in the n-hexene toluene solution is 1 mol / L, and the temperature of the solution is 53° (such as Figure 5-Figure 7 ); The molar ratio of titanium tetrachloride to triethylaluminum in the above-mentioned Ziegler-Natta catalyst is 1:15, and the concentration of titanium tetrachloride in toluene is 13 μmol / L; Step 5: Remove the plastic film 4 attached to the working area 3 on the front of the stainless steel plate 1, degrease the stainless steel plate 1, and soak it in a 0.2 mol / L hydrochloric acid solution for 4 minutes to remove the hydroxyl groups on the surface of the stainless steel metal in the working area 3. After washing with water, obtain the stainless steel plate 1 with insulation on the back and edges (such as Figure 8 ).
[0027] The thickness of the polyhexene insulation layer prepared in this embodiment is 1.1 μm. The test results of the bonding strength between the insulation layer and the stainless steel plate 1 are listed in the following performance test section. Example 3:
[0028] This embodiment adopts the following technical solutions: Step 1: Degrease, pickle, and ultrasonically clean the stainless steel plate 1. Then, use Piranha solution (the volume ratio of concentrated sulfuric acid to concentrated hydrogen peroxide is 8:3) to perform surface hydroxylation on the stainless steel plate 1 to form a layer of chemical structure 2 rich in hydroxyl (-OH) groups (such as Figure 1 ) (all surfaces of the stainless steel plate 1 are hydroxylated); specifically: the stainless steel plate 1 after ultrasonic water washing is immersed in the Piranha solution for 30 minutes, then taken out after soaking, washed with water, dried with cold air, and placed in a drying oven to dry overnight; Step 2: Use a laminating machine to press a plastic film 4 (such as Figure 2 and Figure 3 ), the thickness of the plastic film 4 is 200 μm, and the material is polyethylene, polypropylene or polytetrafluoroethylene; the above-mentioned working area 3 is a region that is symmetrical with respect to the center of the front surface of the stainless steel plate 1, and the length and width are 100 mm less than the length and width of the entire stainless steel plate 1; Step 3: Immerse the stainless steel plate 1 treated in step 2 in a 0.05 mol / L chloroform solution of olefin trimethoxysilane for 120 min. Trimethoxysilane reacts with the hydroxyl groups on the surface of the peripheral area 5 of the stainless steel plate 1 that is not protected by the plastic film 4, thereby chemically bonding the groups containing carbon-carbon double bonds 6 to the peripheral area 5 (e.g., Figure 4 ); The above-mentioned olefin trimethoxysilane is allyl trimethoxysilane, butyl trimethoxysilane, pentyl trimethoxysilane, hexyl trimethoxysilane or heptyl trimethoxysilane ( Figure 4 Allyltrimethoxysilane is used); Step 4: Immerse the stainless steel plate 1 treated in step 3 in a n-hexene toluene solution containing a Ziegler-Natta catalyst to perform an olefin polymerization reaction for 65 minutes, and form a polyhexene layer 7 on the surface of the stainless steel plate 1 chemically bonded with a carbon-carbon double bond 6; the concentration of n-hexene in the n-hexene toluene solution is 1.25 mol / L, and the temperature of the solution is 55° (such as Figure 5-Figure 7 ); The molar ratio of titanium tetrachloride to triethylaluminum in the above-mentioned Ziegler-Natta catalyst is 1:20, and the concentration of titanium tetrachloride in toluene is 20 μmol / L; Step 5: Remove the plastic film 4 attached to the working area 3 on the front of the stainless steel plate 1, degrease the stainless steel plate 1, and soak it in a 0.3 mol / L hydrochloric acid solution for 5 minutes to remove the hydroxyl groups on the surface of the stainless steel metal in the working area 3. After washing with water, the back and edge of the stainless steel plate 1 (such as Figure 8 ).
[0029] The thickness of the polyhexene insulating layer prepared in this embodiment is 10 μm. The test results of the bonding strength between the insulating layer and the stainless steel plate 1 are listed in the following performance test section.
[0030] Performance testing: The test method is a cross-cut test to test the strength of the insulation layer and the stainless steel plate 1. Specifically, 3M No. 600 tape is applied to the surface of the insulation layer, and then the tape is removed. The tape is applied and removed repeatedly a certain number of times. Then, the stainless steel plate 1 is electroformed. The area ratio of the metal on the electroformed steel sheet protected by the insulation layer in the cross-cut area is calculated and graded according to the ISO 2409 standard. Figure 9 .
[0031] Compared with the prior art, the present invention has the following beneficial effects: The back and sides of the stainless steel plate are insulated by a polyethylene layer by chemical bonding, which has the advantage of being firmly bonded and will not fall off during use; The thickness of the insulating layer can be freely adjusted by changing the time of the olefin polymerization reaction, and the growth thickness per minute is between 0.1 and 0.2 μm. Depending on the thickness and opening requirements of the electroformed steel mesh, the thickness of the dry film selected during the steel mesh production process ranges from 10 μm to 100 μm. In order not to affect the film application effect, the thickness of the insulating polypropylene layer should be less than 1 / 10 of the dry film thickness. However, at the same time, a thicker insulating polypropylene layer can provide better insulation effect. The insulating polypropylene layer of the present invention can be adjusted accordingly according to the thickness of the dry film to achieve better insulation effect and longer service life. For example, when the selected dry film thickness is 100 μm, a 10 μm thick polypropylene layer can be generated on the stainless steel core mold to provide better insulation effect and longer service life. In order to be compatible with the electroplating bath liquid and prevent contamination of the bath liquid, the plastic material in the electroplating equipment is generally polypropylene or polyvinyl chloride. The insulating layer of the present invention is polyethylene, which is a material of the same family as polypropylene. Therefore, it has the advantage of being compatible with the electroplating bath liquid. Compared with propylene, the monomer of polypropylene, polyethylene is liquid at room temperature, and the conditions for the polymerization reaction are relatively simpler and easier to operate.
[0032] For those skilled in the art, they can modify the technical solutions described in the aforementioned embodiments and make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for forming an insulating layer on the edge and back of a stainless steel plate, characterized by: The operating steps adopted: Step (1), degreasing, pickling, ultrasonic water washing, and then performing surface hydroxylation treatment on the stainless steel plate (1) to form a layer of chemical structure rich in hydroxyl groups (2); Step (2): pressing a plastic film (4) onto the working area (3) on the front side of the stainless steel plate (1) using a laminating machine; Step (3), immersing the stainless steel plate (1) treated in step (2) in a 0.01 mol / L to 0.05 mol / L chloroform solution of olefin trimethoxysilane for 60 min to 120 min, wherein the trimethoxysilane reacts with the hydroxyl groups on the surface of the peripheral region (5) of the stainless steel plate (1) that is not protected by the plastic film (4), thereby chemically bonding the group containing the carbon-carbon double bond (6) to the peripheral region (5); Step (4): immersing the stainless steel plate (1) treated in step (3) in an n-hexene toluene solution containing a Ziegler-Natta catalyst to carry out an olefin polymerization reaction, thereby forming a polyhexene layer (7) on the surface of the stainless steel plate (1) chemically bonded with a carbon-carbon double bond (6); the concentration of n-hexene in the n-hexene toluene solution is 0.75 mol / L to 1.25 mol / L, and the temperature of the solution is 50° to 55°; Step (5): removing the plastic film (4) attached to the working area (3) on the front of the stainless steel plate (1), degreasing the stainless steel plate (1), and soaking it in a 0.1 mol / L to 0.3 mol / L hydrochloric acid solution for 3 minutes to 5 minutes to remove the hydroxyl groups on the surface of the stainless steel metal in the working area (3). After washing with water, the stainless steel plate (1) with an insulated back and edge is obtained.
2. The method for forming an insulating layer on the edge and back of a stainless steel plate according to claim 1, characterized in that: The hydroxylation treatment in step (1) adopts Piranha solution, wherein the volume ratio of concentrated sulfuric acid to concentrated hydrogen peroxide is 7:3 to 8:
3. The stainless steel plate (1) after ultrasonic water washing is immersed in the Piranha solution for 15 minutes to 30 minutes. After soaking, it is taken out for water washing, dried with cold air, and placed in a drying oven to dry overnight.
3. The method for forming an insulating layer on the edge and back of a stainless steel plate according to claim 1, characterized in that: The thickness of the plastic film (4) in step (2) is between 20 μm and 200 μm, and the material is polyethylene, polypropylene or polytetrafluoroethylene.
4. The method for forming an insulating layer on the edge and back of a stainless steel plate according to claim 1, wherein: The working area (3) in step (2) is an area that is symmetrical with respect to the center of the front surface of the stainless steel plate (1), and whose length and width are 1 mm to 100 mm smaller than the length and width of the entire stainless steel plate (1).
5. The method for forming an insulating layer on the edge and back of a stainless steel plate according to claim 1, characterized in that: The olefin trimethoxysilane in the step (iii) is allyl trimethoxysilane, butyl trimethoxysilane, pentyl trimethoxysilane, hexyl trimethoxysilane or heptyl trimethoxysilane.
6. The method for forming an insulating layer on the edge and back of a stainless steel plate according to claim 1, characterized in that: The molar ratio of titanium tetrachloride to triethylaluminum in the Ziegler-Natta catalyst in step (iv) is 1:10 to 1:20, and the concentration of titanium tetrachloride in toluene is 10 to 20 μmol / L.
7. The method for forming an insulating layer on the edge and back of a stainless steel plate according to claim 1, characterized in that: The polymerization reaction time in the step (iv) is 3.5 min to 65 min, and the thickness of the generated polyhexene layer is 0.5 μm to 10 μm.