Preparation method of high-precision printing electroplating mask material

Abstract

The invention discloses a preparation method of a high-precision printing electroplating mask material, and belongs to the technical field of metal plate strip continuous local electroplating and PTC (Positive Temperature Coefficient) heating films. The method is realized by the following steps of: manufacturing a precise polyester or steel wire screen printing plate with 300 meshes or more and a film thickness of 10-20 microns; after positioning holes are punched in the metal plate strip, single-face or double-face silk-screen printing is completed through a roll-to-roll silk-screen printing machine by using UV shielding glue according to the step pitch of the positioning holes, and instant curing is conducted through a UV drying furnace (the time is about 2 seconds); and continuously electroplating the cured plate strip, removing glue within 15 seconds by using a dispergator after electroplating, and then carrying out heating alkali washing (with the concentration of 5% and the water temperature of 60-80 DEG C), weak acid washing (with 3% sulfuric acid), pure water washing, drying and the like. According to the method, mold opening is avoided, the silk screen printing plate is low in cost, high in precision (the highest size precision is +-0.05 mm) and short in period, the silk screen printing speed reaches 6 m / min, compared with a traditional process, the cost is reduced, the efficiency is improved, and the method is suitable for short-frequency and fast precision electroplating scenes.

Description

Technical Field

[0001] The invention belongs to the technical field of continuous local electroplating of metal plates and strips and PTC heating films, and particularly relates to a method for preparing a high-precision printed electroplating mask material. Background Art

[0002] In the fields of continuous local electroplating of metal sheets and strips, PTC heating films, etc., the traditional continuous local electroplating process has the pain points of low efficiency, high cost and long development cycle. Among them, when using spot plating molds, the molds are made of acid and alkali resistant PP plates, fluoroplastics or silicone materials, and are made through complex CNC engraving. The processing cycle exceeds 7 days and the cost is 8,000 to 200,000 yuan; the use of die-cutting local adhesive backing process requires opening more than 2 cutting dies, the cost is more than 1,000 yuan (complex patterns at least 3,000 yuan), the cycle exceeds 5 days, and the film material cost is high and tearing the film is troublesome. The investment in die-cutting machines is higher than that of screen printing machines.

[0003] To address the above technical deficiencies, the present invention provides a method for preparing high-precision printed electroplating mask materials. Using roll-to-roll precision screen printing equipment, the method involves preparing film and precision screen printing stencils, punching positioning holes in metal strips, screen printing with UV shielding glue and curing, electroplating, and then debonding and cleaning. This method allows for rapid production of electroplating mask materials without requiring a mold. This method costs 300-1000 yuan, produces the screen printing stencils the same day, and can be used the next day. Printing speeds can reach 6 meters per minute, and debonding and stripping are fast without damaging the metal substrate or the coating, significantly reducing costs and improving efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing high-precision printed electroplating mask materials, aiming to provide a mold-free, low-cost, high-efficiency continuous local electroplating mask material preparation method, which replaces the traditional mold / die-cutting process with a roll-to-roll precision silk screen printing process to reduce costs, shorten cycles and improve precision.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing a high-precision printed electroplating mask material, comprising:

[0007] S1. Make film according to masking requirements, and prepare precision polyester or steel silk screen printing screen with mesh size of 300 or above and thickness of 10-20 microns based on the film;

[0008] S2. Punch the positioning holes on the metal strip, unwind the metal strip coil onto the printing table of the screen printing machine, and complete single-sided or double-sided screen printing according to the positioning hole pitch using the screen printing screen and UV shielding glue;

[0009] S3, sending the silk-screened metal strip into the UV drying oven for instant curing;

[0010] S4, continuously electroplating the cured plate strip;

[0011] S5, removing glue, cleaning, drying and winding the electroplated plate strip using a debonding agent.

[0012] As a preferred scheme of the present application, the UV shielding glue comprises the following components in mass percentage: isobornyl acrylate 20-45%, trimethylolpropane triacrylate 3-10%, polyurethane acrylate 1-hydroxy-cyclohexyl-phenyl ketone 1-2%, and phenyl bis (2, 4, 6-trimethylbenzoyl) phosphine oxide <1.5%.

[0013] As a preferred scheme of the present application, the debonding agent comprises the following components in content: trichloroethane 3-50%, dimethyl sulfate 0.05-25%, organic solvent 0.3-15%, and chemical reagent 0.1-10%.

[0014] As a preferred scheme of the present application, the parameters of the UV drying furnace include: UV mercury lamp power 6KW, light emitting area 330MM, waveband 395NM, and 20%-100% of the electrodeless dimming; or LED light source power 14000MW / cm, light emitting area 300MM, main peak wave 365NM, and water-cooled dimming system and air-cooled shutter lampshade are adopted. 2

[0015] As a preferred scheme of the present application, the screen printing machine is a roll-to-roll precise screen printing equipment, which comprises a take-up and pay-off system, a precise screen printing table, a CCD alignment system, a tension control system, a UV drying furnace and an exhaust device, and the CCD alignment system is used to realize step pitch alignment of the plate strip and the screen printing plate based on the positioning hole.

[0016] As a preferred scheme of the present application, the curing time of the UV drying furnace is about 1-3 seconds, the debonding time of the debonding agent is within 15 seconds, the heating and alkali washing adopts 5% concentration lye and 60-80℃ temperature, the cleaning time is 2-4 minutes, the weak acid washing adopts 3% concentration sulfuric acid normal temperature neutralization, the cleaning time is 2-4 minutes, and the pure water washing time is 2 minutes.

[0017] As a preferred scheme of the present application, the speed of the screen printing process can reach 6m / min, and the pattern is checked online after screen printing, and the material is inspected after electroplating.

[0018] ​As a preferred solution of the present invention, the unwinding system is used to load metal sheet and strip coils and release them at a uniform speed, and is connected to an unwinding buffer pool to stabilize the transmission tension; the unwinding buffer pool is arranged between the unwinding system and the screen printing host platform, and includes a tension sensor, which monitors the sheet and strip tension in real time and feeds back to the tension control system for dynamic adjustment; the screen printing host platform integrates a precision screen printing table and a CCD alignment system, and the precision screen printing table supports the fixation and precise movement of screen printing screens above 300 meshes. The CCD alignment system realizes ±0.05mm precision registration printing of the sheet and strip and the screen through visual recognition of positioning holes; the tension control system is linked with the unwinding system and the winding system, and adjusts the sheet and strip transmission speed through a servo motor to ensure that the tension fluctuation during printing is ≤5N; the exhaust device is arranged above the UV drying furnace and the vertical oven, and adopts a negative pressure exhaust design to effectively discharge the volatile gases generated during the curing process; the winding system includes a winding buffer pool and a winding roller, which performs tension-controlled winding on the cured sheet and strip, and an accompanying online detection device monitors the integrity of the mask pattern in real time.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention uses a roll-to-roll precision silk screen printing process that does not require opening a mold to quickly form an electroplating shielding mask. The cost of a precision silk screen screen is only 300-1000 yuan including tax, and the drawing can be produced on the same day and can be used the next day. Compared with traditional point plating molds (at least 8000 yuan, cycle ≥7 days) and die-cutting molds (complex graphics ≥2000 yuan, cycle ≥5 days), the cost is greatly reduced. The silk screen printing speed can reach up to 6 meters / minute, no waste discharge is required, and the degumming and film stripping are fast (glue removal time is within 15 seconds). It can be added to the electroplating line to improve efficiency. It has significant advantages for short-frequency, high-precision and short-cycle projects. After verification in small batches of multiple projects, it is found that the cost is reduced and the efficiency is doubled compared with traditional processes. The film stripping speed is fast and does not damage the metal substrate and the coating, and it has both technical and economic advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 Flow chart of the method of the present invention;

[0023] Figure 2 This is a top view of the roll-to-roll precision screen printing equipment of the present invention.

[0024] Figure 2 Middle: 1. Screen printing host platform; 2. Rewinding buffer tank; 3. Vertical oven; 4. UV drying oven; 5. Unwinding buffer tank; 6. Unwinding mechanism. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Example 1

[0027] See also Figure 1-Figure 2 , the present invention provides the following technical solutions:

[0028] A method for preparing a high-precision printed electroplating mask material, comprising:

[0029] S1. Generate a vector graphics file based on the design drawings of the electroplating masking area (such as the circuit pattern of the PTC heating film and the metal electrode pattern of the electronic tag). The graphics must include positioning hole marks. The positioning hole diameter is usually 1-3mm, and the hole pitch is consistent with the subsequent silk screen pitch (such as 50mm, 100mm and other standard pitches). Output the vector graphics to film and use a laser imagesetter to produce the film. The accuracy must reach 20,000 DPI or above, ensuring that the line edge roughness is ≤1μm and the minimum line width can be resolved to 0.05mm. The film needs to be tested for light transmittance. The transmittance of the transparent area must be ≥90%, and the light shielding area must be ≥99% to avoid ghosting during exposure.

[0030] S2. Stamping the metal strip (such as aluminum strip, copper strip) with positioning holes according to the design drawing. The positioning holes are used for the pitch alignment of the silk screen printing process. The stamped strip coil is sent to the screen printing machine through the unwinding system to ensure the position accuracy of the strip and the silk screen to avoid the deviation of the mask pattern due to positioning deviation.

[0031] S3. Unwind the metal sheet coil onto the screen printing machine's ink pad. Use a 300-mesh screen or larger and UV-shielding glue (containing 20-45% isobornyl acrylate, 3-10% trimethylolpropane triacrylate, polyurethane acrylate, 1-2% 1-hydroxy-cyclohexyl-phenyl ketone, and <1.5% phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide) to screen print on one or both sides, depending on the positioning hole pitch. Screen printing speeds can reach up to 6 meters per minute. Immediately after printing, perform online inspection to eliminate defective products with pattern offset or missing prints.

[0032] S4. The printed strip is sent to the UV drying oven for instant curing. The drying oven is equipped with a 6KW UV mercury lamp (luminous area 330MM, band 395NM, stepless dimming 20%-100%) or a 14000MW / cm 2LED light source (lighting area 300MM, main peak wave 365NM, water-cooled dimming system), curing time is about 2 seconds, so that the UV glue quickly forms an acid and alkali resistant mask layer, and after curing, it is rolled up and put into the continuous electroplating production line;

[0033] S5. The cured sheet coils are placed on a continuous electroplating line for local electroplating. Electroplating processes such as acid copper plating and nickel plating are selected based on demand. After electroplating, the coating thickness and bonding strength are inspected to ensure uniform coating without defects such as missing plating and burrs, and to keep the defect rate at a low level.

[0034] S6: After electroplating, the coiled material enters the debonding and cleaning line, where a debonding agent (containing 3-50% trichloroethane, 0.05-25% dimethyl sulfate, 0.3-15% organic solvent, and 0.1-10% chemical reagent) is used to remove the adhesive within 15 seconds. This is followed by an ultrasonic 5% concentration alkaline wash (approximately 3 minutes) and a pure water wash (approximately 2 minutes). Finally, the coiled material is dried and reeled. After passing the appearance inspection and dimensional testing, it is packaged and shipped. The entire process is efficient and does not damage the metal substrate or the plating.

[0035] Specifically, the unwinding system is equipped with a magnetic powder brake, which can adjust the initial tension to 10-15N to ensure the smooth release of the plate and strip. The buffer pool is 3-5 meters long and has multiple sets of guide rollers built in. The tension of the plate and strip is monitored in real time through a tension sensor, and the fluctuation range is controlled within ±1N to avoid stretching and deformation of the plate and strip during printing. Silk screen printing host platform: integrated with a precision silk screen printing table (flatness ≤0.02mm / m) and a CCD alignment system. The silk screen printing table can move laterally with a stroke accuracy of ±0.01mm; the CCD camera has a resolution of 12 million pixels and is combined with visual processing software to achieve ±0.05mm precision positioning of the positioning holes and screen marks. The scraper system uses a polyurethane scraper with a hardness of 70-80ShoreA, a scraper angle of 45-60°, and an adjustable pressure range of 1-3kg / cm 2 , ensuring that the glue evenly penetrates the screen. The winding system is equipped with a servo motor, and the winding tension is 2-3N higher than the unwinding tension, ensuring that the strip is wound smoothly.

[0036] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a high-precision printed electroplating mask material, characterized in that: The following steps are involved: S1. Make film according to masking requirements, and prepare precision polyester or steel silk screen printing screen with mesh size of 300 or above and thickness of 10-20 microns based on the film; S2. Punch the positioning holes on the metal strip, unwind the metal strip coil onto the printing table of the screen printing machine, and complete single-sided or double-sided screen printing according to the positioning hole pitch using the screen printing screen and UV shielding glue; S3, sending the silk-screened metal strip into the UV drying oven for instant curing; S4, performing continuous electroplating processing on the solidified strip; S5. Use a debonding agent to remove glue, clean, dry and rewind the electroplated strip.

2. The method for preparing a high-precision printed electroplating mask material according to claim 1, characterized in that: The UV shielding glue comprises the following components in proportion by mass: 20-45% of isobornyl acrylate, 3-10% of trimethylolpropane triacrylate, 1-2% of polyurethane acrylate 1-hydroxy-cyclohexyl-phenyl ketone, and <1.5% of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide.

3. The method for preparing a high-precision printed electroplating mask material according to claim 1, wherein: The debonding agent comprises the following components: 3-50% of trichloroethane, 0.05-25% of dimethyl sulfate, 0.3-15% of organic solvent and 0.1-10% of chemical reagent.

4. The method for preparing a high-precision printed electroplating mask material according to claim 3, characterized in that: The parameters of the UV drying oven include: UV mercury lamp power 6KW, luminous area 330MM, band 395NM, stepless dimming 20%-100%; or LED light source power 14000MW / cm 2 , luminous area 300MM, main peak wave 365NM, adopts water-cooled dimming system and air-cooled shutter lampshade.

5. The method for preparing a high-precision printed electroplating mask material according to claim 4, characterized in that: The screen printing machine is a roll-to-roll precision screen printing equipment, including a reel-up and reel-out system, a precision screen printing table, a CCD alignment system, a tension control system, a UV drying furnace and an exhaust device. The CCD alignment system is used to achieve step alignment between the plate strip and the screen printing screen based on positioning holes.

6. The method for preparing a high-precision printed electroplating mask material according to claim 5, characterized in that: The curing time of the UV drying furnace is 1-3 seconds, the degumming time of the degumming agent is within 15 seconds, the heated alkali washing adopts 5% concentration alkali solution and 60-80°C temperature, and the cleaning time is about 2-4 minutes, the weak acid washing adopts 3% concentration sulfuric acid at room temperature for neutralization, and the cleaning time is 2-4 minutes, and the pure water washing time is 2 minutes.

7. The method for preparing a high-precision printed electroplating mask material according to claim 6, characterized in that: The speed of the screen printing process can reach 6 meters per minute, and the pattern is inspected online after screen printing, and the coil is quality inspected after electroplating.

8. The method for preparing a high-precision printed electroplating mask material according to claim 7, characterized in that: The unwinding system is used to load metal sheet and strip coils and release them at a uniform speed, and is connected to the unwinding buffer pool to stabilize the transmission tension; the unwinding buffer pool is arranged between the unwinding system and the screen printing host platform, and includes a tension sensor, which monitors the sheet and strip tension in real time and feeds back to the tension control system for dynamic adjustment; the screen printing host platform integrates a precision screen printing table and a CCD alignment system, and the precision screen printing table supports the fixation and precise movement of screen printing screens above 300 meshes. The CCD alignment system uses visual recognition of positioning holes to achieve ±0.05mm precision registration printing of the sheet and screen; the tension control system is linked with the unwinding system and the winding system, and the servo motor adjusts the sheet and strip transmission speed to ensure that the tension fluctuation during printing is ≤5N; the exhaust device is arranged above the UV drying furnace and the vertical oven, and adopts a negative pressure exhaust design to effectively discharge the volatile gases generated during the curing process; the winding system includes a winding buffer pool and a winding roller, which performs tension control and winding on the cured sheet and strip, and is equipped with an online detection device to monitor the integrity of the mask pattern in real time.

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