Method for preventing post-laser gold oxidation of fpc plug by pre-lasered gold

Abstract

This application relates to the field of flexible printed circuit board (FPC) manufacturing technology, and provides a pre-laser gold plating method for preventing oxidation of the gold surface of FPC connectors after laser processing. The method includes: sequentially performing bonding, encapsulation, lamination, and surface treatment on the flexible circuit board; then applying polyimide reinforcement, followed by a second lamination and surface treatment; printing reinforcement marking lines and text on the flexible circuit board, and after curing; laser-cutting the connector finger positions on the flexible circuit board, with laser cutting only extending to the tips of the connector fingers and both sides of the polyimide reinforcement, controlling the cutout size to avoid affecting subsequent grinding and sandblasting processes; performing a third surface treatment on the laser-cut flexible circuit board, thoroughly removing carbon powder residue generated during laser cutting through sandblasting to prevent carbon powder contamination of the subsequent electroless plating tank; and finally, electroless nickel-gold plating on the surface-treated flexible circuit board to complete subsequent conventional production processes.

Description

Technical Field

[0001] This application relates to the field of flexible printed circuit board (FPC) manufacturing technology, and more particularly to a pre-laser gold plating method for preventing oxidation of the gold surface of FPC connectors after laser treatment. Background Technology

[0002] Flexible printed circuit boards (FPCs) are widely used in consumer electronics, automotive electronics, and communication equipment due to their advantages such as thinness, flexibility, and high wiring density. Among them, the connector fingers (gold fingers) are the core functional areas of FPCs that enable electrical connection with external devices, and their surface quality directly determines the electrical connection performance, service life, and reliability of the product.

[0003] Currently, the common production process for FPC products with plugs and fingers in the industry is as follows: lamination and encapsulation → pressing → curing → surface treatment → electroless nickel plating → flying probe testing → PI reinforcement → text printing → laser cutting of the plug shape → oxidation and wiping repair → subsequent routine processes. This process path is a long-established and common technical solution in this field. There is a general consensus among those skilled in the art that an electroless nickel plating process must be completed first to form a stable gold protective layer before laser cutting of the plug shape. This avoids substrate debris and carbon powder from laser cutting entering the electroless plating tank and causing contamination, while also preventing the electroless plating process from affecting the dimensional accuracy of the plug shape and ensuring the fitting accuracy between the plug and connector. This understanding has become a common technical bias in the field, causing relevant personnel to consistently optimize the technology around the fixed process path of "electroless nickel plating first, then laser cutting," never deviating from this limitation. Summary of the Invention

[0004] This application provides a pre-laser gold plating method for preventing oxidation of the gold surface after laser treatment of FPC plugs. It aims to solve the problem that existing technologies have always focused on optimizing the fixed process path of "gold plating first, then laser treatment" and have never broken out of the limitations of this path.

[0005] In a first aspect, embodiments of this application provide a pre-laser gold plating method for preventing oxidation of the gold surface after laser treatment of an FPC connector, the method comprising: After sequentially completing bonding, encapsulation, lamination, and surface treatment of the flexible circuit board, polyimide reinforcement is applied, and secondary lamination and secondary surface treatment are completed. Reinforcing markings and text are printed on the flexible circuit board. After curing, the plug finger positions on the flexible circuit board are laser-cut. The laser cutting is only processed to the top of the plug finger and both sides of the polyimide reinforcement. The size of the cut is controlled to avoid affecting the subsequent grinding and sandblasting process. The flexible circuit board that has undergone laser cutting undergoes a third surface treatment, which involves sandblasting to thoroughly remove any carbon powder residue generated during laser cutting, thus preventing carbon powder from contaminating the subsequent electroless plating tank. The flexible circuit board that has undergone surface treatment is then electroless nickel-gold plated to complete the subsequent routine production process.

[0006] In some embodiments, the process of sequentially bonding, encapsulating, pressing, and surface treating the flexible circuit board includes: bonding and encapsulating the substrate of the flexible circuit board after circuit fabrication; pressing and curing the encapsulation layer and the substrate using a pressing device; grinding and sandblasting the pressed flexible circuit board; and simultaneously identifying the flatness and foreign matter residue on the board surface in real time using a visual inspection algorithm. Board surfaces that do not meet preset standards undergo secondary surface treatment until the board surface parameters meet the process requirements.

[0007] In some embodiments, the application of polyimide reinforcement, completing secondary lamination and secondary surface treatment, includes: identifying the reinforcement area corresponding to the plug fingers on the flexible circuit board using a positioning algorithm, accurately applying the polyimide reinforcement material to the corresponding area, completing the secondary lamination of the polyimide reinforcement and the flexible circuit board using a lamination device, then grinding and sandblasting the laminated board surface, and confirming that there is no excess adhesive or foreign matter residue in the reinforcement area using a visual inspection algorithm, thus completing the secondary surface treatment.

[0008] In some embodiments, the step of printing reinforcing marking lines and text on the flexible circuit board and completing the curing includes: printing reinforcing marking lines and production traceability text in a preset area of ​​the flexible circuit board using a character printing device; verifying the integrity and positional accuracy of the printed content using a visual recognition algorithm after printing; and sending the qualified flexible circuit board into a curing device for heat curing treatment to completely cure the printing ink and adhere it to the board surface.

[0009] In some embodiments, the laser cutting of the plug finger position on the flexible circuit board, wherein the laser cutting is only processed to the tip of the plug finger and both sides of the polyimide reinforcement, includes: identifying the boundary between the plug finger area and the polyimide reinforcement on the flexible circuit board through a visual positioning algorithm, generating a corresponding laser cutting path, and controlling the laser equipment to cut the plug finger position along the cutting path so that the cutting range only covers the tip of the plug finger and both sides of the polyimide reinforcement, without exceeding the preset cutting boundary.

[0010] In some embodiments, controlling the size of the cut cutout to avoid affecting subsequent grinding and sandblasting processes includes: during the laser cutting process, collecting the cutout depth and size data of the cutting area in real time through a laser ranging algorithm, comparing the collected real-time data with a preset size threshold, and when the real-time data exceeds the threshold range, adjusting the output power and cutting speed of the laser equipment in real time to control the cut cutout size within a preset range, so as to avoid excessively large cutouts that could cause wrinkles on the plate surface in subsequent grinding and sandblasting processes.

[0011] In some embodiments, the third surface treatment of the laser-cut flexible circuit board includes: first cleaning and dust removal of the board surface, then uniformly grinding the board surface using a grinding equipment, while simultaneously using a visual detection algorithm to identify residual laser-cut debris on the board surface in real time, adjusting the brush pressure and travel speed of the grinding equipment, and completing the third surface treatment of the board surface.

[0012] In some embodiments, the step of thoroughly removing carbon powder residue generated by laser cutting through sandblasting to avoid carbon powder contamination of the subsequent electroplating tank includes: performing sandblasting on the flexible circuit board after grinding; using an image recognition algorithm to identify the distribution of carbon powder residue in the laser-cut area of ​​the plug fingers in real time; adjusting the sandblasting pressure and target area of ​​the sandblasting equipment accordingly; performing targeted sandblasting on the areas where carbon powder residue is concentrated; and visually verifying that there is no carbon powder residue in the cut area after completion to prevent residual carbon powder from entering the subsequent electroplating process and contaminating the tank.

[0013] In some embodiments, the process of electroless nickel-gold plating on the flexible circuit board after surface treatment includes: after pretreatment of the flexible circuit board after the third surface treatment, such as degreasing, micro-etching and activation, the board is sent into an electroless nickel plating tank and an electroless gold plating tank to complete the nickel plating and gold plating operations in sequence. During the process, the parameters of the plating solution are monitored in real time by a liquid level and concentration detection algorithm, and the corresponding reagents are automatically replenished to maintain the stability of the plating solution parameters, so as to form a uniform nickel-gold protective layer on the metal contact surface of the plug fingers.

[0014] In some embodiments, the completion of subsequent routine production processes includes: sequentially performing flying probe electrical testing, full appearance inspection, and packaging on the flexible circuit boards that have undergone chemical nickel-gold plating. During the process, a visual inspection algorithm is used to perform full inspection of the gold surface appearance of the plug fingers, screening out products with oxidation and blackening defects on the gold surface, and completing the final production and shipment of qualified products.

[0015] This application breaks through the common technical bias in the field of "first gold plating, then laser cutting," and revolutionarily moves the laser cutting process forward to before the nickel-gold plating operation. The laser cutting operation will not come into contact with the subsequently formed gold surface throughout the entire process, fundamentally eliminating the damage to the gold surface caused by the high temperature of the laser, debris and carbon powder, completely eliminating the defect of gold surface oxidation and blackening, eliminating the need for additional manual wiping and repair processes, greatly shortening the production cycle, and effectively ensuring the delivery schedule of the product.

[0016] This invention completely avoids the problems of scratches on the gold surface and wear of the plating caused by manual wiping. The gold surface plating after molding is complete, has high flatness and good consistency. The electrical connection performance, corrosion resistance and service life of the plug are significantly improved, and the product yield is qualitatively improved.

[0017] This invention eliminates the need for extensive manual cleaning and repair, significantly reduces product scrap rates due to gold surface defects, minimizes material waste, and improves production efficiency while significantly reducing the overall cost of mass production.

[0018] This invention avoids the problem of wrinkles on the surface of the plate after grinding and sandblasting due to excessive cutting cuts by precisely controlling the laser cutting range. At the same time, the surface sandblasting treatment after laser cutting completely removes carbon powder residue and completely avoids the risk of carbon powder contaminating the electroplating tank. The process has strong controllability and stability and can be directly adapted to existing FPC mass production lines without large-scale equipment modification, and has extremely high mass production and promotion value.

[0019] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic flowchart of the steps of a pre-laser gold plating method for preventing oxidation of the gold surface of an FPC plug after laser treatment, provided in an embodiment of this application. Figure 2 This is a schematic diagram illustrating the principle of a pre-laser gold plating method for preventing oxidation of the gold surface of an FPC plug after laser treatment, provided in an embodiment of this application. Figure 3 This is a schematic block diagram of a pre-laser gold plating system for preventing oxidation of the gold surface of an FPC plug after laser treatment, provided in one embodiment of this application. Figure 4This is a schematic block diagram of the structure of a computer device provided in an embodiment of this application.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0025] It should be understood that, in order to clearly describe the technical solutions of the embodiments of the present invention, the terms "first" and "second" are used in the embodiments of the present invention to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0026] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0027] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] Flexible printed circuit boards (FPCs) are widely used in consumer electronics, automotive electronics, and communication equipment due to their advantages such as thinness, flexibility, and high wiring density. Among them, the connector fingers (gold fingers) are the core functional areas of FPCs that enable electrical connection with external devices, and their surface quality directly determines the electrical connection performance, service life, and reliability of the product.

[0029] Currently, the common production process for FPC products with plugs and fingers in the industry is as follows: lamination and encapsulation → pressing → curing → surface treatment → electroless nickel plating → flying probe testing → PI reinforcement → text printing → laser cutting of the plug shape → oxidation and wiping repair → subsequent routine processes. This process path is a long-established and common technical solution in this field. There is a general consensus among those skilled in the art that an electroless nickel plating process must be completed first to form a stable gold protective layer before laser cutting of the plug shape. This avoids substrate debris and carbon powder from laser cutting entering the electroless plating tank and causing contamination, while also preventing the electroless plating process from affecting the dimensional accuracy of the plug shape and ensuring the fitting accuracy between the plug and connector. This understanding has become a common technical bias in the field, causing relevant personnel to consistently optimize the technology around the fixed process path of "electroless nickel plating first, then laser cutting," never deviating from this limitation.

[0030] In actual mass production, the aforementioned conventional process has inherent defects that cannot be overcome: laser cutting generates instantaneous high temperatures and a large amount of molten substrate debris and carbon powder. These high temperatures and contaminants directly affect the already formed gold surface, causing oxidation and blackening defects. In actual production, the incidence of this defect is as high as 70%-80%. To solve this problem, manufacturers can only invest a lot of manpower to wipe and repair the oxidized and blackened gold surfaces one by one. This not only significantly increases labor costs but also severely prolongs the production cycle, directly affecting the product delivery schedule. At the same time, the manual wiping process is very easy to cause scratches on the gold surface and wear of the nickel-gold plating, which in turn leads to poor product contact, reduced corrosion resistance, and the inability to guarantee product yield and quality stability, posing serious electrical performance risks.

[0031] To solve the above problem, please refer to Figure 1 and Figure 2 This application provides a pre-laser gold plating method for preventing oxidation of the gold surface of an FPC connector after laser treatment, applicable to computer equipment. The computer equipment can be deployed on a single server or server cluster. It can also be deployed on handheld terminals, laptops, wearable devices, or robots, etc. It should be noted that all information involved in the method provided in this application is extracted with the authorization of the relevant users and in accordance with relevant regulations, and will not infringe on user privacy.

[0032] The provided pre-laser gold plating method for preventing oxidation of the gold surface after laser treatment of FPC connectors includes steps S101 to S103. Details are as follows: Step S101. After completing the bonding, encapsulation, pressing and surface treatment of the flexible circuit board in sequence, polyimide reinforcement is applied, and secondary pressing and secondary surface treatment are completed.

[0033] Specifically, the core purpose of this step is to complete the circuit encapsulation protection and structural shaping of the FPC substrate, and to accurately apply and fix the reinforcement structure in the plug area. This provides a flat, clean, and structurally stable processing substrate for subsequent laser cutting and electroless nickel plating processes, and avoids the adverse effects of excess adhesive and foreign matter on the board surface on subsequent processes.

[0034] The bonding and encapsulation process involves pre-forming the FPC substrate using basic circuitry steps such as material cutting, drilling, circuit etching, and solder mask fabrication. The substrate is made of flexible polyimide, and the copper foil circuit layer thickness meets product design requirements. A fully automated CCD vision alignment and bonding machine precisely bonds the polyimide cover film with an epoxy adhesive layer to the non-plug, non-electrical connection areas of the FPC substrate, exposing only the metal pads where plug fingers will be fabricated later, thus achieving encapsulation and protection of the circuit layer. The bonding process uses CCD vision positioning to control the bonding offset to ≤±0.05mm, preventing the cover film from obscuring the plug pads.

[0035] The first pressing process involves placing the laminated and encapsulated FPC sheets into a vacuum high-pressure press for pressing. The pressing parameters are set as follows: temperature 170-190℃, pressure 25-35 kgf / cm². 2 The vacuum degree is ≤-95kPa, and the pressing time is 120-180s, which ensures that the adhesive layer of the cover film is completely melted and cured, and tightly bonded to the substrate without delamination, bubbles, or excess adhesive. After pressing, the board is allowed to cool naturally to room temperature in a dust-free environment to avoid warping caused by thermal expansion and contraction.

[0036] The first surface treatment process involves a combination of grinding and sandblasting on the pressed sheets. First, an 800-1000 grit nylon brush grinding machine is used, with a brushing pressure of 0.8-1.2 kgf / cm². 2 The sheet material travels at a speed of 2.5-3.5 m / min to remove the oxide layer, excess adhesive residue, and burrs from the surface. It is then subjected to sandblasting with 1200-1500 mesh ceramic abrasive at a pressure of 1.5-2.0 kgf / cm². 2 The process involves moving at a speed of 3-4 m / min to slightly roughen the board surface and remove residual debris. After treatment, an ion air cleaner removes dust, and the board surface cleanliness is tested with a dyne pen to ensure it is ≥38 dyn, free of oil, foreign matter, and oxide layer.

[0037] The polyimide reinforcement application process utilizes a fully automated reinforcement bonding machine to apply polyimide reinforcement sheets to the corresponding areas of the FPC plug fingers. The thickness of the reinforcement sheet is selected from 0.1-0.3mm according to the bending requirements, and its shape matches the design dimensions of the plug area. During the bonding process, CCD vision positioning identifies the target on the board, and the bonding offset is controlled within ±0.03mm. The reinforcement sheet completely covers the stress area of ​​the plug fingers, preventing subsequent bending and breakage.

[0038] The second pressing process involves placing the reinforced and coated boards back into a vacuum high-pressure press for secondary pressing. The parameters are set as follows: temperature 160-180℃, pressure 20-30 kgf / cm². 2 The vacuum degree is ≤-95kPa, and the pressing time is 90-150s to ensure that the adhesive layer of the reinforcing sheet is completely cured and tightly bonded to the board, without any warping, delamination, or excess adhesive, and the bonding strength is ≥1.5N / mm. After pressing, allow it to cool naturally to room temperature, controlling the board surface warpage to ≤0.5% to avoid subsequent positioning deviations.

[0039] The second surface treatment process involves a second grinding and sandblasting treatment of the laminated board. The process parameters are matched with the first process, focusing on removing excess glue from the edges of the reinforcing sheet and removing foreign matter from the lamination. The joint between the reinforcing sheet and the board surface is slightly roughened to improve the adhesion of subsequent inks. After treatment, the board is cleaned with ion air, achieving a dyn value ≥38 dyn, free of excess glue, foreign matter, and oxide layer, thus completing this step.

[0040] Step S102. Print reinforcing marking lines and text on the flexible circuit board. After curing, laser cut the plug finger positions on the flexible circuit board. The laser cutting is only processed to the top of the plug finger and both sides of the polyimide reinforcement. Control the cutting cutout size to avoid affecting the subsequent grinding and sandblasting process.

[0041] Specifically, the core purpose of this step is to complete the printing and curing of product identification, providing a positioning benchmark for subsequent processes; the plug shape is processed by precise laser cutting, and the cutting range and hollow size are strictly controlled to ensure the dimensional accuracy of the plug and avoid affecting the subsequent grinding and sandblasting process. The entire process does not come into contact with the subsequent gold surface, thus avoiding damage to the gold surface by the laser from the source.

[0042] The reinforcing markings and text printing process utilizes a fully automated screen printing machine to print reinforcing markings, product models, production batches, traceability QR codes, and other information on the pre-set areas of the FPC. UV-curable character ink is used, with a screen mesh count of 300-350 and a squeegee pressure of 3-5 kgf / cm². 2 The squeegee angle is 60-70°, and the printing speed is 2-3 m / min to ensure clear printing content, no ink breaks or omissions, and a positional deviation of ≤±0.05mm. The reinforcing marking line is printed on the edge of the polyimide reinforcement, with a line width of 0.15-0.2mm and a distance of 0.1mm from the reinforcement edge, providing a visual positioning reference for subsequent laser cutting.

[0043] The curing process involves feeding the printed boards into a UV curing oven for curing, with the UV energy set to 800-1200 mJ / cm². 2The curing temperature is 60-80℃, and the board travel speed is 3-4m / min, which ensures complete cross-linking and curing of the ink, achieving an adhesion level of 5B in the cross-cut adhesion test, with no peeling or scratching. For high-temperature curing inks, a hot air curing oven can be used at 150℃ for 30 minutes to ensure complete curing.

[0044] Before laser cutting, the pre-positioning process involves feeding the cured sheet material into the UV laser cutting machine platform, where it is flattened and fixed using a vacuum adsorption device to prevent displacement during cutting. The machine's CCD vision positioning system identifies the positioning target on the sheet material and the printed reinforcing lines to complete coordinate positioning with an accuracy of ≤±0.01mm. The system automatically matches the preset laser cutting path to ensure the cutting position perfectly matches the design drawings.

[0045] The laser cutting process uses a 355nm ultraviolet nanosecond laser cutting machine. The laser parameters are set as follows: power 8-12W, pulse frequency 30-50kHz, cutting speed 100-200mm / s, and repeated cutting 2-3 times to ensure complete severing of the substrate and reinforcing sheet, resulting in a smooth cut without burrs or scorched edges. The cutting path strictly follows the edge of the plug's finger tips and the left and right edges of the polyimide reinforcement, completely covering the plug's outline and not exceeding the reinforcement boundary by more than 0.1mm to avoid cutting beyond the designated area.

[0046] The cutting and hollowing-out size control process involves the system controlling the inward shrinkage of the cutting path in real time during the cutting process. This ensures the hollowing-out size in the plug area is strictly controlled within the design range, with each side of the hollowing-out area not exceeding 1 / 5 of the plug finger width, and the maximum hollowing-out width ≤ 0.3mm. This ensures the board material retains sufficient support strength in the plug area after cutting, preventing wrinkles, deformation, and tearing during subsequent sandblasting. After cutting, a visual inspection system checks the cutting and hollowing-out dimensions online. Dimensional deviations are ≤ ±0.02mm; boards exceeding this threshold are automatically rejected, completing this step of the process.

[0047] Step S103. Perform a third surface treatment on the flexible circuit board that has been laser-cut. Thoroughly remove the carbon powder residue generated by laser cutting by sandblasting to avoid carbon powder contamination of the subsequent electroless plating tank. Perform electroless nickel-gold plating on the flexible circuit board that has been surface-treated to complete the subsequent conventional production process.

[0048] Specifically, the core purpose of this step is to thoroughly remove the carbon powder and molten debris generated by laser cutting, so as to avoid contamination of the subsequent electroless plating tank and cause poor plating; to complete the electroless nickel-gold plating on the clean plug pad surface, forming a uniform and dense nickel-gold protective layer that is free from oxidation and blackening, and finally complete the entire product production process to ensure product quality and yield.

[0049] The third surface treatment pre-cleaning process involves pre-cleaning the laser-cut board material using a high-pressure ion air cleaner. The high-pressure air pressure is 0.4-0.6MPa, and the ion air balance voltage is ≤±50V. This process removes loose debris and dust from the board surface and cut seams, preventing large particles of contaminants from affecting the subsequent grinding and sandblasting effect.

[0050] The third surface treatment grinding process is carried out using a 1000-1200 grit nylon brush grinding machine, with a brushing pressure of 0.6-1.0 kgf / cm. 2 The board travels at a speed of 3-4 m / min, performing light grinding to remove minor oxide layers and laser residue from the board surface, and to remove burrs from the cut edges. During the grinding process, an online vision inspection system identifies residual debris on the board surface in real time and dynamically adjusts the brush pressure to avoid over-grinding that could damage the board surface or expose copper traces.

[0051] The carbon removal process involves sandblasting the plate after grinding, focusing on the plug area and cut crevices of laser-cut surfaces. The sandblasting medium is 1500-1800 mesh ultrafine ceramic abrasive, and the sandblasting pressure is 1.2-1.8 kgf / cm². 2 The sheet material travels at a speed of 2.5-3.5 m / min, with a sandblasting angle of 45-60° to ensure the sandblasting medium fully enters the cutting kerf and thoroughly removes carbonized dust and molten substrate residue generated during laser cutting. After sandblasting, the sheet is cleaned in a three-stage countercurrent pure water washing machine at a water temperature of 25-30℃ and a pure water conductivity ≤5μS / cm. It is then dried in a hot air dryer at a temperature of 80-100℃ for 5-10 minutes to ensure the surface is free of moisture and sandblasting medium residue.

[0052] After drying, the toner residue verification process involves sampling and testing using a 200x high-magnification optical microscope, along with full inspection using online AOI equipment, to confirm that there is no toner residue or foreign matter on the cut area and board surface. This prevents residual toner from falling off during the electroplating process, contaminating the plating solution, and causing poor plating.

[0053] The electroless nickel-gold plating process, using qualified sheet metal, sequentially completes the entire process of degreasing, water washing, micro-etching, water washing, pre-immersion, activation, water washing, electroless nickel plating, water washing, electroless gold plating, water washing, and drying. For electroless nickel plating, a medium-phosphorus nickel plating solution is used, with a nickel layer thickness of 3-5 μm, a solution pH of 4.6-4.8, a temperature of 85-88℃, and a plating time of 15-20 min. For electroless gold plating, a neutral gold plating solution is used, with a gold layer thickness of 0.05-0.1 μm, a solution pH of 6.8-7.2, a temperature of 80-85℃, and a plating time of 8-12 min, forming a uniform, dense, and well-adhesive nickel-gold protective layer on the surface of the connector copper pads.

[0054] Subsequent routine production processes involve using nickel-plated gold alloys to complete the following steps: flying probe electrical testing, full appearance inspection, performance testing, and packaging and warehousing. The flying probe testing checks circuit continuity and insulation performance to ensure electrical performance meets standards. The full appearance inspection, conducted via AOI and manual re-inspection, involves a complete inspection of the gold-plated surface of the plug to confirm the absence of oxidation, blackening, and scratches. Finally, qualified products are vacuum-packed, completing the entire production process.

[0055] In some embodiments, the process of sequentially bonding, encapsulating, pressing, and surface treating the flexible circuit board includes: bonding and encapsulating the substrate of the flexible circuit board after circuit fabrication; pressing and curing the encapsulation layer and the substrate using a pressing device; grinding and sandblasting the pressed flexible circuit board; and simultaneously identifying the flatness and foreign matter residue on the board surface in real time using a visual inspection algorithm. Board surfaces that do not meet preset standards undergo secondary surface treatment until the board surface parameters meet the process requirements.

[0056] This embodiment provides a high-precision processing method with visual closed-loop control for FPC bonding and encapsulation, initial lamination and initial surface treatment processes. The method uses visual inspection algorithms to monitor the processing quality of the board surface in real time, realizes closed-loop rework of unqualified boards, ensures that the flatness and cleanliness of the board surface in the previous process meet the requirements, avoids defective products from flowing into the subsequent process, and improves the product yield.

[0057] The substrate pretreatment process involves cutting, CNC drilling, copper plating, circuit etching, and solder mask fabrication of the FPC substrate to be processed. The substrate thickness is 25-125μm, the copper foil thickness is 18-35μm, and the circuit etching accuracy meets the design requirements, with no open circuits, short circuits, or deviations in line width and spacing.

[0058] The lamination and encapsulation process utilizes a fully automated CCD vision alignment and cover film laminating machine. The polyimide cover film is laminated onto the non-electrical connection areas of the FPC, exposing only the copper solder pads of the connectors. During lamination, the machine's 5-megapixel industrial camera captures real-time images of four positioning targets on the board. Image recognition algorithms calculate the target coordinates and automatically adjust the lamination nozzle position, achieving an alignment accuracy of ≤±0.05mm to ensure the cover film does not obstruct the connector solder pads. After lamination, the machine automatically performs a preliminary inspection, rejecting defective products with misaligned lamination or damaged cover film.

[0059] Vacuum lamination involves placing the laminated boards into a vacuum high-speed press for lamination, with a high-temperature resistant release film inserted between each layer to prevent adhesion. The lamination parameters are set as follows: temperature 180℃, pressure 30 kgf / cm², vacuum degree -98 kPa, and lamination time 150 s. After lamination, the boards are allowed to cool naturally to room temperature in a dust-free environment for at least 10 minutes to prevent warping.

[0060] The initial surface treatment involves feeding the cooled sheet material into a fully automated grinding and sandblasting production line. First, the sheet is ground with an 800-mesh nylon brush at a pressure of 1.0 kgf / cm² and a travel speed of 3 m / min to remove excess adhesive and oxide layer from the surface. Then, it is sandblasted with 1200-mesh ceramic sand at a pressure of 1.8 kgf / cm² and a travel speed of 3.5 m / min to slightly roughen the surface.

[0061] After surface treatment, the boards undergo closed-loop visual inspection. A 2-megapixel line scan camera scans the entire board surface at 3 m / min. A flatness detection algorithm calculates warpage and flatness based on grayscale differences and 3D contour data, with a flatness threshold set to ≤0.2 mm / m. Simultaneously, a foreign object detection algorithm identifies residual dust, excess glue, burrs, etc., with a detection accuracy ≥0.02 mm. Boards that do not meet standards are automatically sent to a rework station for secondary processing until parameters meet requirements. Unrepairable defective products are automatically rejected, ensuring 100% qualification of boards flowing into the next process.

[0062] Finally, the boards that pass the inspection are cleaned by a high-pressure ion air cleaner with an ion air pressure of 0.5 MPa to remove residual dust from the board surface. The board surface dyn value is ≥38 dyn, thus completing all the processes in this embodiment.

[0063] In some embodiments, the application of polyimide reinforcement, completing secondary lamination and secondary surface treatment, includes: identifying the reinforcement area corresponding to the plug fingers on the flexible circuit board using a positioning algorithm, accurately applying the polyimide reinforcement material to the corresponding area, completing the secondary lamination of the polyimide reinforcement and the flexible circuit board using a lamination device, then grinding and sandblasting the laminated board surface, and confirming that there is no excess adhesive or foreign matter residue in the reinforcement area using a visual inspection algorithm, thus completing the secondary surface treatment.

[0064] This embodiment provides a high-precision positioning reinforcement processing method for the polyimide reinforcement lamination, secondary lamination and secondary surface treatment processes. The positioning algorithm accurately identifies the reinforcement area to achieve precise lamination of the reinforcement sheet. At the same time, the visual inspection algorithm controls the processing quality of the reinforcement area to avoid problems such as glue overflow, edge lifting and lamination misalignment, ensuring the stability of the reinforcement structure and providing a precise boundary reference for subsequent laser cutting.

[0065] The reinforcement area is located by feeding the processed board material into a fully automated reinforcement bonding machine platform, where it is vacuum-adsorbed and flattened. The equipment's CCD vision system acquires images of the board material and, through a template matching positioning algorithm, identifies the reinforcement area corresponding to the plug and the positioning mark within the area, calculating the coordinates for the reinforcement patch application, with a positioning accuracy of ≤±0.03mm.

[0066] The precise application of the reinforcing sheet involves using an algorithm-calculated coordinate system. The equipment's nozzle picks up a pre-sized polyimide reinforcing sheet, 0.2mm thick, with a 25μm thick high-temperature resistant epoxy adhesive layer. The nozzle precisely applies the reinforcing sheet to the reinforced area with a pressure of 1.5kgf / cm² and a time of 2 seconds, ensuring initial adhesion between the reinforcing sheet and the board surface, without any lifting or air bubbles. After application, the equipment performs a preliminary visual inspection; any boards with misalignment exceeding ±0.03mm are automatically rejected.

[0067] The second vacuum pressing involves placing the laminated sheet material into a vacuum high-pressure press for secondary pressing. The parameters are set as follows: temperature 170℃, pressure 25 kgf / cm². 2 The vacuum level is -98 kPa, and the pressing time is 120 seconds. Silicone buffer pads are placed on both sides of the sheet during pressing to ensure even stress on the reinforcing sheet and prevent displacement or damage. After pressing, the sheet is allowed to cool naturally to room temperature for at least 8 minutes, controlling the warpage to be ≤0.3%.

[0068] The secondary surface treatment involves feeding the cooled sheet material into a sandblasting production line using 1000-grit nylon brushes with a brushing pressure of 0.8 kgf / cm². 2 The travel speed is 3.5 m / min, with a focus on polishing and reinforcing the edges to remove excess adhesive; then it is sandblasted with 1500-mesh ceramic sand at a pressure of 1.5 kgf / cm. 2 The travel speed is 4m / min, which slightly roughens the joint between the reinforcement and the board surface, improving the adhesion of subsequent inks.

[0069] After surface treatment, the online visual inspection system performs a full inspection of the reinforcing board. Edge detection algorithms identify defects such as excess glue, warping, and delamination. Template matching algorithms check the accuracy of the bonding position, and foreign object detection algorithms confirm the absence of dust residue on the board surface. Defective boards are sent to the rework station; those that cannot be repaired are automatically rejected.

[0070] Cleaning and verification: The qualified boards are cleaned by an ion air cleaner to remove dust. The cleanliness of the board surface is tested by a dyne pen and is ≥38dyn. The bonding strength of the reinforcing sheet is tested by a tensile tester and is ≥1.5N / mm to ensure that the reinforcement quality meets the standards. This completes all the procedures in this embodiment.

[0071] In some embodiments, the step of printing reinforcing marking lines and text on the flexible circuit board and completing the curing includes: printing reinforcing marking lines and production traceability text in a preset area of ​​the flexible circuit board using a character printing device; verifying the integrity and positional accuracy of the printed content using a visual recognition algorithm after printing; and sending the qualified flexible circuit board into a curing device for heat curing treatment to completely cure the printing ink and adhere it to the board surface.

[0072] This embodiment provides a high-precision printing and curing control method for the printing and curing process of reinforcing marking lines and text. It uses a visual recognition algorithm to verify the integrity and positional accuracy of the printed content, ensuring that the printed reinforcing marking lines provide a precise positioning reference for subsequent laser cutting, while also ensuring the adhesion and durability of the printed text to prevent the markings from falling off in subsequent processes.

[0073] Before printing, the processed board is fed into the feeding station of the fully automatic screen printing machine to make a special screen printing stencil. The stencil uses 300 mesh polyester mesh to make reinforcing marking lines, product model, traceability QR code and other patterns and text that match the design drawings. The reinforcing marking lines are 0.2mm wide and designed to be 0.1mm away from the edge of the reinforcing sheet, which will serve as the positioning reference for subsequent laser cutting.

[0074] The printing process involves mounting a screen on a printing press and aligning it with the printing plate, achieving an alignment accuracy of ≤±0.02mm. UV-curable black character ink is used, with an ink viscosity adjusted to 150-200 dPa. The printing squeegee is made of 70 ShoreA polyurethane material, with a squeegee pressure of 4 kgf / cm², a squeegee angle of 65°, a return ink blade pressure of 2 kgf / cm², and a printing speed of 2.5 m / min to complete the printing operation. A first-piece inspection is performed every 50 pieces during the printing process to check the printing clarity.

[0075] The printing quality visual inspection involves immediately sending the printed boards to an online visual inspection station. A 5-megapixel industrial camera captures the printed images, and an OCR text recognition algorithm verifies the completeness and accuracy of the text and QR code content, ensuring no ink breaks, omissions, or misprints. A sub-pixel edge detection algorithm identifies the position and width of reinforcing lines, calculates the actual distance between the lines and the reinforcing edges, and verifies a positional deviation of ≤±0.05mm. Simultaneously, ink overflow, pinholes, and trailing defects are detected. Boards that fail inspection are automatically rejected.

[0076] The curing process involves feeding the calibrated boards into a UV curing oven, using three 8kW high-pressure mercury lamps, with the curing energy set at 1000mJ / cm². 2 The oven temperature is controlled at 70℃, and the board travel speed is 3.5m / min to ensure complete ink curing. For boards requiring high temperature resistance, a hot air curing oven is used to cure at 150℃ for 30 minutes, with a heating rate ≤5℃ / min to prevent board warping.

[0077] Post-curing quality inspection involves cooling the cured board to room temperature and then conducting adhesion and appearance tests. A 1mm x 1mm cross-cut test is performed; after removing the 3M 600 tape, the ink adhesion reaches a 5B level with no peeling. Simultaneously, visual inspection confirms that the printed content is free from yellowing, cracking, and discoloration, and that reinforcing lines are clear and complete, thus completing all procedures in this embodiment.

[0078] In some embodiments, the laser cutting of the plug finger position on the flexible circuit board, wherein the laser cutting is only processed to the tip of the plug finger and both sides of the polyimide reinforcement, includes: identifying the boundary between the plug finger area and the polyimide reinforcement on the flexible circuit board through a visual positioning algorithm, generating a corresponding laser cutting path, and controlling the laser equipment to cut the plug finger position along the cutting path so that the cutting range only covers the tip of the plug finger and both sides of the polyimide reinforcement, without exceeding the preset cutting boundary.

[0079] This embodiment provides a high-precision visual positioning laser cutting method for the laser cutting process of the plug finger position. The visual positioning algorithm accurately identifies the boundary between the plug area and the polyimide reinforcement, generates the optimal cutting path, strictly controls the cutting range, ensures the accuracy of the plug's external dimensions, and avoids cutting beyond the range, which would affect subsequent processes.

[0080] Before cutting, the plate is fixed and positioned. The processed plate is sent into the marble processing platform of the ultraviolet laser cutting machine. The platform is equipped with an array of vacuum adsorption holes. The vacuum adsorption device is turned on, and the vacuum degree is ≤-90kPa. The plate is flat and fixed by adsorption to avoid displacement and warping during the cutting process.

[0081] Visual positioning and cutting path generation are achieved by activating the 12-megapixel coaxial vision camera of the laser cutting machine to acquire images of the sheet material. Through a deep learning feature recognition algorithm, the system accurately identifies the positioning target, plug outline, reinforcement edges, and reinforcement marking lines on the sheet material, establishing a processing coordinate system with a positioning accuracy of ≤±0.01mm. Based on the identified boundary coordinates, the system automatically generates the laser cutting path. The cutting path is strictly set along the top edge of the plug and the left and right edges of the reinforcement, with an inward reduction of 0.05mm to ensure that the cutting range only covers the top of the plug and the two sides of the reinforcement, not exceeding the reinforcement boundary by 0.1mm, and avoiding cutting non-target areas.

[0082] Laser parameters and cutting operations utilize a 355nm ultraviolet nanosecond laser, with the following settings: average power 10W, pulse frequency 40kHz, single pulse energy 0.25mJ, cutting speed 150mm / s, focal point set on the upper surface of the board, and cutting repeated 3 times to ensure complete severing of the substrate and reinforcing sheet, resulting in a clean cut free of burrs and scorched edges. During cutting, a coaxial dust removal device is activated at a dust removal airflow of 15m³ / min to continuously remove cutting dust and fumes, preventing dust from adhering to the board surface.

[0083] After cutting, the vision system re-captures the board image and uses an edge detection algorithm to measure the plug's external dimensions and the distance between the cutting boundary and the reinforcement edge. The dimensional deviation is verified to be ≤±0.02mm, confirming that the cutting range only covers the top of the plug and both sides of the reinforcement, with no cutting beyond the acceptable range. Boards with dimensions exceeding the tolerance are automatically rejected, completing all processes in this embodiment.

[0084] In some embodiments, controlling the size of the cut cutout to avoid affecting subsequent grinding and sandblasting processes includes: during the laser cutting process, collecting the cutout depth and size data of the cutting area in real time through a laser ranging algorithm, comparing the collected real-time data with a preset size threshold, and when the real-time data exceeds the threshold range, adjusting the output power and cutting speed of the laser equipment in real time to control the cut cutout size within a preset range, so as to avoid excessively large cutouts that could cause wrinkles on the plate surface in subsequent grinding and sandblasting processes.

[0085] This embodiment provides a real-time closed-loop cutting size control method for the laser cutting cutout size control process. It uses a laser ranging algorithm to collect the cutout depth and size data of the cutting area in real time, compares it with a preset threshold, and adjusts the laser parameters in real time to control the cutout size within a reasonable range, avoiding excessive cutouts that could cause wrinkles and deformation on the plate surface during subsequent grinding and sandblasting.

[0086] The preset size threshold and parameter model, based on the FPC sheet thickness, reinforcement thickness, and plug width in the laser cutting system, presets the maximum width of the single side of the hollow area to ≤0.3mm, and the hollow depth to be consistent with the sheet thickness. At the same time, a correspondence model between laser parameters and hollow size is established to clarify the relationship between laser power, cutting speed, pulse frequency and hollow size, providing data support for real-time adjustment.

[0087] Real-time data acquisition involves activating a laser rangefinder during the laser cutting process. Using the triangulation principle, the rangefinder collects data on the depth, width, and boundary dimensions of the cut area at a sampling frequency of 1000 times per second. Simultaneously, a coaxial vision camera captures images of the cut area in real time. An image segmentation algorithm is then used to identify the cut contour and calculate the actual dimensions of the cut, achieving dual acquisition and verification of dimensional data.

[0088] Data comparison and closed-loop adjustment: The system compares the real-time collected cutout size data with preset thresholds. When the cutout width exceeds the threshold by 80%, the system triggers an alarm and automatically adjusts the laser parameters according to the parameter model: reducing laser power by 5%-10%, increasing cutting speed by 10%-15%, reducing the number of repeated cuts by 1, narrowing the cutting path range, and reducing the cutout size. When the cutout depth does not reach the thickness of the board and there is a risk of incomplete cutting, the system automatically increases laser power by 3%-5% and reduces cutting speed by 5%-10% to ensure complete cutting of the board without expanding the cutout size.

[0089] After cutting, a full dimensional inspection is performed on each board. The cut dimensions are checked using online AOI (Automated Optical Inspection) equipment at 50x magnification with an accuracy of ±0.01mm, confirming that all cut dimensions are within a preset threshold range. Boards exceeding the threshold are automatically rejected to prevent them from entering the subsequent grinding and sandblasting processes.

[0090] The process verification involved conducting a simulated sandblasting test on the cut and qualified boards. After processing with conventional process parameters, visual inspection confirmed that the boards were free of wrinkles, tears, and deformation, thus verifying the effectiveness of the cutout size control and completing all the processes in this embodiment.

[0091] In some embodiments, the third surface treatment of the laser-cut flexible circuit board includes: first cleaning and dust removal of the board surface, then uniformly grinding the board surface using a grinding equipment, while simultaneously using a visual detection algorithm to identify residual laser-cut debris on the board surface in real time, adjusting the brush pressure and travel speed of the grinding equipment, and completing the third surface treatment of the board surface.

[0092] This embodiment provides a grinding method with visual adaptive adjustment for the third surface treatment process after laser cutting. The method uses a visual detection algorithm to identify residual laser cutting debris on the plate surface in real time and dynamically adjusts the operating parameters of the grinding equipment to achieve precise grinding. This method thoroughly removes residue from the plate surface while avoiding damage caused by excessive grinding.

[0093] Pre-cleaning treatment: Based on the processed boards, they are first sent to a high-pressure ion air cleaner for pre-cleaning. The high-pressure air pressure is 0.5MPa, the ion air balance voltage is ±30V, and the cleaning time is 3s / board. This removes loose debris and dust from the board surface and cutting gaps, preventing large particles of contaminants from entering the grinding machine and scratching the board surface.

[0094] After pre-cleaning, the board material is sent to the pre-visual inspection station of the grinding machine. The line scan camera scans the entire board surface and uses a target detection algorithm to identify the location, size, and distribution density of residual laser cutting debris, scorch marks, and burrs on the board surface in real time. At the same time, it identifies the circuit area, plug pad area, and reinforcement area of ​​the board material and divides the grinding priority. The cutting edge area is given high priority and the circuit area is given low priority to avoid damaging the circuit during grinding.

[0095] Based on the results of the front-end vision inspection, the adaptive grinding operation automatically adjusts the grinding parameters of the grinding machine: for cutting edge areas with concentrated debris and scorch marks, the brush pressure is increased to 1.0 kgf / cm², and the board travel speed is reduced to 3 m / min; for circuit areas without residue, the brush pressure is reduced to 0.6 kgf / cm², and the board travel speed is increased to 4 m / min. The grinding machine uses a 1000-grit nylon brush at a speed of 1200 rpm, ensuring the removal of cutting residue while avoiding over-grinding that could lead to copper foil thinning or surface scratches.

[0096] After grinding, the board passes quality inspection. The board then passes through a post-grinding visual inspection station for a full-width scan to confirm the absence of cutting debris, scorch marks, burrs, and smooth, even cut edges. The station also confirms the absence of exposed copper, scratches, and excessive grinding defects in the circuit layers. Any remaining boards are automatically transported to the rework station for secondary grinding, and any defective boards with surface damage are automatically rejected.

[0097] After the boards pass the inspection, they are cleaned by a high-pressure pure water washing machine to remove the grinding dust. Then they are dried in a hot air dryer at a temperature of 90°C for 8 minutes to ensure that there is no moisture or dust residue on the board surface, thus completing all the processes in this embodiment.

[0098] In some embodiments, the step of thoroughly removing carbon powder residue generated by laser cutting through sandblasting to avoid carbon powder contamination of the subsequent electroplating tank includes: performing sandblasting on the flexible circuit board after grinding; using an image recognition algorithm to identify the distribution of carbon powder residue in the laser-cut area of ​​the plug fingers in real time; adjusting the sandblasting pressure and target area of ​​the sandblasting equipment accordingly; performing targeted sandblasting on the areas where carbon powder residue is concentrated; and visually verifying that there is no carbon powder residue in the cut area after completion to prevent residual carbon powder from entering the subsequent electroplating process and contaminating the tank.

[0099] This embodiment provides a targeted sandblasting method for removing carbon powder residue in the sandblasting process. By using an image recognition algorithm to identify the distribution of carbon powder residue in real time and dynamically adjusting the sandblasting parameters, the method targets and treats areas with concentrated carbon powder, thoroughly removing carbon powder residue generated by laser cutting and preventing carbon powder from contaminating the subsequent plating tank from the source.

[0100] Before sandblasting, carbon powder residue detection involves feeding the processed board into the feeding station of the fully automatic sandblasting equipment. A high-magnification line array camera scans the entire laser-cut area of ​​the board at 100x magnification. Using a grayscale threshold image recognition algorithm, carbon powder residue in the cutting gaps, edges, and board surface is identified, and the location, area, and distribution density of the residue are marked. A carbon powder distribution heat map is generated to provide coordinate basis for targeted sandblasting.

[0101] Based on the carbon powder distribution thermal map, the sandblasting equipment control system automatically adjusts the sandblasting parameters, using 1500-mesh ultrafine ceramic abrasive as the sandblasting medium. For areas without carbon powder residue, the sandblasting pressure is set at 1.2 kgf / cm². 2 The sheet material travels at a speed of 3.5 m / min, and conventional sandblasting is performed. For areas with concentrated carbon powder, such as cutting gaps and edges, the sandblasting gun target area coordinates are automatically adjusted, and the gun moves to the corresponding area. The sandblasting pressure is increased to 1.8 kgf / cm², the sheet material travel speed is reduced to 2.5 m / min, and the sandblasting angle is adjusted to 60° for targeted sandblasting. This ensures that the sandblasting medium enters the cutting gaps and thoroughly removes the attached carbon powder.

[0102] After sandblasting, the boards are immediately fed into a three-stage counter-current pure water washing line: the first stage is a high-pressure spray wash at 0.3 MPa to remove residual ceramic sand and loose carbon powder from the board surface; the second stage is an ultrasonic wash at 40 kHz for 30 seconds to remove residual contaminants from the cut seams; the third stage is a pure water wash with a conductivity ≤2 μS / cm to ensure no ion residue remains on the board surface. After washing, the boards are dried in a hot air circulating dryer at 100℃ for 10 minutes to ensure complete drying.

[0103] After the toner residue was fully verified and dried, each board was inspected using AOI (Automated Optical Inspection) equipment with a magnification of 200x and a detection accuracy of ≥0.005mm to confirm the absence of toner residue and sandblasting medium residue on the board surface and in the cut seams. Five boards from each batch were randomly selected and their cut areas were microscopically inspected using a scanning electron microscope to confirm the absence of nano-sized toner adhesion. Boards that failed the inspection were re-sandblasted and cleaned to ensure 100% toner residue removal, thus completing all procedures in this embodiment.

[0104] In some embodiments, the process of electroless nickel-gold plating on the flexible circuit board after surface treatment includes: after pretreatment of the flexible circuit board after the third surface treatment, such as degreasing, micro-etching and activation, the board is sent into an electroless nickel plating tank and an electroless gold plating tank to complete the nickel plating and gold plating operations in sequence. During the process, the parameters of the plating solution are monitored in real time by a liquid level and concentration detection algorithm, and the corresponding reagents are automatically replenished to maintain the stability of the plating solution parameters, so as to form a uniform nickel-gold protective layer on the metal contact surface of the plug fingers.

[0105] This embodiment provides a method for real-time control of plating solution parameters in the electroless nickel-gold plating process. By using a liquid level and concentration detection algorithm to monitor the plating solution parameters in real time, the method automatically replenishes the reagents to maintain the stability of the plating solution, ensuring the formation of a uniform, dense, oxidation-free, and blackening-free nickel-gold protective layer on the plug surface, thereby improving the electrical performance and corrosion resistance of the product.

[0106] Pretreatment before electroless plating: After the plating process is completed, the standard pretreatment steps are performed sequentially, including: (1) Chemical degreasing: Alkaline degreasing agent, temperature 55℃, time 5min, removes oil stains and fingerprints from the board surface; (2) Secondary countercurrent water washing: pure water conductivity ≤5μS / cm, 2min / stage, to remove residual degreasing agent; (3) Micro-etching: Sodium persulfate + sulfuric acid system micro-etching solution, micro-etching amount 1.0-1.5μm, temperature 25℃, time 90s, to slightly roughen the copper surface and improve the adhesion of the coating; (4) Secondary countercurrent water rinse: 2 min / stage, to remove residual micro-etching solution; (5) Pre-soaking: Pre-soaking solution in sulfuric acid system for 60 seconds to protect the subsequent palladium activation solution; (6) Activation: Palladium ion activation solution, palladium ion concentration 20ppm, temperature 30℃, time 3min, to form catalytic active centers on copper surface; (7) Secondary countercurrent water wash: 2 min / stage to remove residual activating solution.

[0107] In the electroless nickel plating process, pre-treated plates are fed into the electroless nickel plating bath. The plating solution is a medium-phosphorus system with a phosphorus content of 6-8%. Preset parameters are: pH 4.7, temperature 86℃, nickel ion concentration 5.8-6.2 g / L, and sodium hypophosphite concentration 28-32 g / L. During the nickel plating process, online sensors collect real-time data on the plating solution level, nickel ion concentration, pH value, and temperature at a frequency of once every 10 seconds. A PID control algorithm compares this data with the preset parameters. If the nickel ion concentration falls below the lower limit, the replenishment pump automatically starts to add nickel salt and reducing agent; if the pH value deviates from the range, ammonia or sulfuric acid is automatically added for adjustment; if the temperature falls below the set value, the heating device automatically starts to raise the temperature, ensuring the stability of the plating solution parameters throughout the process. The nickel plating time is 18 minutes, forming a uniform nickel layer 4 μm thick on the copper pad surface.

[0108] After nickel plating, the plate is rinsed with three-stage countercurrent pure water for 3 minutes per stage. The conductivity of the pure water is ≤2μS / cm. This process thoroughly removes residual nickel plating solution and prevents nickel ions from being carried into the gold plating bath and contaminating the plating solution.

[0109] The electroless gold plating process involves washing the substrate and then immersing it in a plating bath. The plating solution is a neutral, cyanide-free system with preset parameters: pH 7.0, temperature 82℃, and gold ion concentration of 1.8-2.2 g / L. During the plating process, online monitoring equipment collects the plating solution parameters in real time, and the replenishment amount is adjusted in real time through a control algorithm to maintain stable plating solution parameters. The plating time is 10 minutes, forming a uniform gold layer with a thickness of 0.08 μm on the nickel layer surface.

[0110] After gold plating, the final washing and drying process involves a five-stage counter-current pure water wash, with the last stage using 18.2MΩ water. Use ultrapure water (5000 ml) to rinse thoroughly for 5 minutes to completely remove residual gold plating solution and prevent salt precipitation and whitening on the board surface. After rinsing, dry in a hot air dryer at 110℃ for 15 minutes to ensure the board surface is completely dry.

[0111] After drying, the coating quality was inspected and the thickness of the nickel-gold layer was measured by an X-ray coating thickness gauge to meet the design requirements; the coating adhesion was tested by cross-cut adhesion test and reached level 5B with no peeling; the 48-hour neutral salt spray test showed no oxidation or corrosion; visual inspection confirmed that the gold surface was uniform and bright, without oxidation, blackening, pinholes, or scratches, thus completing all the processes in this embodiment.

[0112] In some embodiments, the completion of subsequent routine production processes includes: sequentially performing flying probe electrical testing, full appearance inspection, and packaging on the flexible circuit boards that have undergone chemical nickel-gold plating. During the process, a visual inspection algorithm is used to perform full inspection of the gold surface appearance of the plug fingers, screening out products with oxidation and blackening defects on the gold surface, and completing the final production and shipment of qualified products.

[0113] This embodiment provides a production method for full-process quality control in the subsequent conventional production processes after nickel plating and gold plating. It uses a visual inspection algorithm to fully inspect the gold surface of the plug, screen out defective products, and ensure that the electrical performance and appearance quality of the final shipped products meet 100% standards, while also enabling full-process product traceability.

[0114] The processed boards are fed into a fully automated flying probe tester. Based on the product's circuit network design documents, a test program is written. Four sets of flying probes sequentially contact the test pads and connector fingers according to the program to test the continuity and insulation resistance of the circuit. The test voltage is 100V, and the insulation resistance threshold is ≥100MΩ, ensuring that the circuit has no open circuits, short circuits, or leakage, and that the electrical performance meets design requirements. During testing, the system automatically records the test data for each board and links it to the product traceability QR code, enabling traceability of electrical data. Boards that fail the test are automatically marked and rejected.

[0115] After passing the electrical tests, the metal sheets undergo a full visual inspection of the gold-plated surfaces. These sheets are then sent to the full visual inspection station. First, an AOI (Automated Optical Inspection) visual inspection system is used. A 20-megapixel high-resolution camera, combined with ring and coaxial light sources, scans each connector's gold surface at 100x magnification. A deep learning defect detection algorithm identifies defects such as oxidation, blackening, scratches, pinholes, exposed copper, and uneven plating, with a detection accuracy of ≥0.01mm. After AOI inspection, products flagged as potentially defective by the algorithm are manually inspected by quality control personnel using a high-magnification microscope to confirm the defect type and remove defective products. This ensures that products flowing into the next process are free of oxidation and blackening defects on the gold surface.

[0116] Reliability testing is conducted on samples taken from each batch of products according to AQL sampling standards. These tests include: bending life test (bending radius 0.8mm, bending angle 180°, bending times ≥1000 times without wire breakage), insertion and removal life test (insertion and removal with matching connector ≥1000 times, contact resistance change ≤10mΩ), and high temperature and humidity resistance test (85℃ / 85%RH, 96h, no oxidation on the gold surface, no peeling of the plating). This ensures that product reliability meets industry standards and customer requirements.

[0117] Product traceability and packaging: For products that pass inspection, a traceability QR code is scanned using a barcode scanner. Information such as the product production batch, equipment parameters, test data, and operators is entered into the production traceability system, achieving full lifecycle traceability. Subsequently, vacuum packaging is used, where the product and desiccant are placed in an anti-static aluminum foil bag and vacuum-sealed. The outer packaging box is labeled with information such as product model, batch, quantity, and production date to prevent oxidation, moisture, and static electricity damage during transportation and storage.

[0118] Warehouse inspection: After the packaged products are inspected by quality inspectors according to the sampling standards before warehousing. After confirming that the product model, quantity, appearance and packaging meet the requirements, the warehousing procedures are completed, and all production processes of the product are completed, thus completing all processes in this embodiment.

[0119] Please see Figure 3 As shown, Figure 3 This is a schematic diagram of a pre-laser gold plating system 200 for preventing oxidation of the gold surface after laser treatment of FPC connectors, provided in an embodiment of this application. This pre-laser gold plating system 200 is used to perform the steps of the pre-laser gold plating method for preventing oxidation of the gold surface after laser treatment of FPC connectors as shown in the above embodiments. This pre-laser gold plating system 200 can be a single server or a server cluster, or it can be a terminal, such as a handheld terminal, laptop computer, wearable device, or robot.

[0120] like Figure 3 As shown, the pre-laser gold plating system 200 for preventing oxidation of the gold surface after laser treatment of the FPC connector includes: The surface treatment unit 201 is used to sequentially perform bonding, encapsulation, pressing and surface treatment on the flexible circuit board, then apply polyimide reinforcement, and complete secondary pressing and secondary surface treatment. The laser cutting unit 202 is used to print reinforcing marking lines and text on the flexible circuit board. After curing, it performs laser cutting on the plug finger position of the flexible circuit board. The laser cutting is only processed to the top of the plug finger and both sides of the polyimide reinforcement. The size of the cut is controlled to avoid affecting the subsequent grinding and sandblasting process. The nickel-gold treatment unit 203 is used to perform a third surface treatment on the flexible circuit board that has been laser-cut. It thoroughly removes the carbon powder residue generated by laser cutting through sandblasting to avoid carbon powder contamination of the subsequent electroless plating tank. The flexible circuit board that has been surface-treated is then electroless plated with nickel-gold to complete the subsequent conventional production process.

[0121] In some embodiments, the process of sequentially bonding, encapsulating, pressing, and surface treating the flexible circuit board includes: bonding and encapsulating the substrate of the flexible circuit board after circuit fabrication; pressing and curing the encapsulation layer and the substrate using a pressing device; grinding and sandblasting the pressed flexible circuit board; and simultaneously identifying the flatness and foreign matter residue on the board surface in real time using a visual inspection algorithm. Board surfaces that do not meet preset standards undergo secondary surface treatment until the board surface parameters meet the process requirements.

[0122] In some embodiments, the application of polyimide reinforcement, completing secondary lamination and secondary surface treatment, includes: identifying the reinforcement area corresponding to the plug fingers on the flexible circuit board using a positioning algorithm, accurately applying the polyimide reinforcement material to the corresponding area, completing the secondary lamination of the polyimide reinforcement and the flexible circuit board using a lamination device, then grinding and sandblasting the laminated board surface, and confirming that there is no excess adhesive or foreign matter residue in the reinforcement area using a visual inspection algorithm, thus completing the secondary surface treatment.

[0123] In some embodiments, the step of printing reinforcing marking lines and text on the flexible circuit board and completing the curing includes: printing reinforcing marking lines and production traceability text in a preset area of ​​the flexible circuit board using a character printing device; verifying the integrity and positional accuracy of the printed content using a visual recognition algorithm after printing; and sending the qualified flexible circuit board into a curing device for heat curing treatment to completely cure the printing ink and adhere it to the board surface.

[0124] In some embodiments, the laser cutting of the plug finger position on the flexible circuit board, wherein the laser cutting is only processed to the tip of the plug finger and both sides of the polyimide reinforcement, includes: identifying the boundary between the plug finger area and the polyimide reinforcement on the flexible circuit board through a visual positioning algorithm, generating a corresponding laser cutting path, and controlling the laser equipment to cut the plug finger position along the cutting path so that the cutting range only covers the tip of the plug finger and both sides of the polyimide reinforcement, without exceeding the preset cutting boundary.

[0125] In some embodiments, controlling the size of the cut cutout to avoid affecting subsequent grinding and sandblasting processes includes: during the laser cutting process, collecting the cutout depth and size data of the cutting area in real time through a laser ranging algorithm, comparing the collected real-time data with a preset size threshold, and when the real-time data exceeds the threshold range, adjusting the output power and cutting speed of the laser equipment in real time to control the cut cutout size within a preset range, so as to avoid excessively large cutouts that could cause wrinkles on the plate surface in subsequent grinding and sandblasting processes.

[0126] In some embodiments, the third surface treatment of the laser-cut flexible circuit board includes: first cleaning and dust removal of the board surface, then uniformly grinding the board surface using a grinding equipment, while simultaneously using a visual detection algorithm to identify residual laser-cut debris on the board surface in real time, adjusting the brush pressure and travel speed of the grinding equipment, and completing the third surface treatment of the board surface.

[0127] In some embodiments, the step of thoroughly removing carbon powder residue generated by laser cutting through sandblasting to avoid carbon powder contamination of the subsequent electroplating tank includes: performing sandblasting on the flexible circuit board after grinding; using an image recognition algorithm to identify the distribution of carbon powder residue in the laser-cut area of ​​the plug fingers in real time; adjusting the sandblasting pressure and target area of ​​the sandblasting equipment accordingly; performing targeted sandblasting on the areas where carbon powder residue is concentrated; and visually verifying that there is no carbon powder residue in the cut area after completion to prevent residual carbon powder from entering the subsequent electroplating process and contaminating the tank.

[0128] In some embodiments, the process of electroless nickel-gold plating on the flexible circuit board after surface treatment includes: after pretreatment of the flexible circuit board after the third surface treatment, such as degreasing, micro-etching and activation, the board is sent into an electroless nickel plating tank and an electroless gold plating tank to complete the nickel plating and gold plating operations in sequence. During the process, the parameters of the plating solution are monitored in real time by a liquid level and concentration detection algorithm, and the corresponding reagents are automatically replenished to maintain the stability of the plating solution parameters, so as to form a uniform nickel-gold protective layer on the metal contact surface of the plug fingers.

[0129] In some embodiments, the completion of subsequent routine production processes includes: sequentially performing flying probe electrical testing, full appearance inspection, and packaging on the flexible circuit boards that have undergone chemical nickel-gold plating. During the process, a visual inspection algorithm is used to perform full inspection of the gold surface appearance of the plug fingers, screening out products with oxidation and blackening defects on the gold surface, and completing the final production and shipment of qualified products.

[0130] It should be noted that those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the pre-laser gold plating system and its modules for preventing oxidation of the gold surface after laser treatment of FPC plugs described above can be referred to the corresponding content in the various embodiments of the pre-laser gold plating method for preventing oxidation of the gold surface after laser treatment of FPC plugs, and will not be repeated here.

[0131] The aforementioned pre-laser gold plating method for preventing oxidation of the gold surface after laser treatment of FPC connectors can be implemented as a computer program, which can be used in various ways, such as... Figure 3 It runs on the device shown.

[0132] Please see Figure 4 , Figure 4 This is a schematic block diagram of the structure of a computer device provided in an embodiment of this application. The computer device includes a processor, a memory, and a network interface connected via a device bus, wherein the memory may include a storage medium and internal memory.

[0133] The storage medium may store operating devices and computer programs. The computer program includes program instructions that, when executed, cause the processor to perform any pre-laser gold plating method for preventing oxidation of the gold surface after laser treatment of the FPC connector.

[0134] The processor provides computing and control capabilities, supporting the operation of the entire computer device.

[0135] The internal memory provides an environment for the execution of computer programs in non-volatile storage media. When executed by a processor, the computer program can enable the processor to perform any pre-laser gold plating method to prevent oxidation of the gold surface after laser treatment of the FPC connector.

[0136] This network interface is used for network communication, such as sending assigned tasks. Those skilled in the art will understand that... Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the terminal to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0137] It should be understood that the processor can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among these, a general-purpose processor can be a microprocessor or any conventional processor.

[0138] In one embodiment, the processor is configured to run a computer program stored in memory to perform the following steps: After sequentially completing bonding, encapsulation, lamination, and surface treatment of the flexible circuit board, polyimide reinforcement is applied, and secondary lamination and secondary surface treatment are completed. Reinforcing markings and text are printed on the flexible circuit board. After curing, the plug finger positions on the flexible circuit board are laser-cut. The laser cutting is only processed to the top of the plug finger and both sides of the polyimide reinforcement. The size of the cut is controlled to avoid affecting the subsequent grinding and sandblasting process. The flexible circuit board that has undergone laser cutting undergoes a third surface treatment, which involves sandblasting to thoroughly remove any carbon powder residue generated during laser cutting, thus preventing carbon powder from contaminating the subsequent electroless plating tank. The flexible circuit board that has undergone surface treatment is then electroless nickel-gold plated to complete the subsequent routine production process.

[0139] In some embodiments, the process of sequentially bonding, encapsulating, pressing, and surface treating the flexible circuit board includes: bonding and encapsulating the substrate of the flexible circuit board after circuit fabrication; pressing and curing the encapsulation layer and the substrate using a pressing device; grinding and sandblasting the pressed flexible circuit board; and simultaneously identifying the flatness and foreign matter residue on the board surface in real time using a visual inspection algorithm. Board surfaces that do not meet preset standards undergo secondary surface treatment until the board surface parameters meet the process requirements.

[0140] In some embodiments, the application of polyimide reinforcement, completing secondary lamination and secondary surface treatment, includes: identifying the reinforcement area corresponding to the plug fingers on the flexible circuit board using a positioning algorithm, accurately applying the polyimide reinforcement material to the corresponding area, completing the secondary lamination of the polyimide reinforcement and the flexible circuit board using a lamination device, then grinding and sandblasting the laminated board surface, and confirming that there is no excess adhesive or foreign matter residue in the reinforcement area using a visual inspection algorithm, thus completing the secondary surface treatment.

[0141] In some embodiments, the step of printing reinforcing marking lines and text on the flexible circuit board and completing the curing includes: printing reinforcing marking lines and production traceability text in a preset area of ​​the flexible circuit board using a character printing device; verifying the integrity and positional accuracy of the printed content using a visual recognition algorithm after printing; and sending the qualified flexible circuit board into a curing device for heat curing treatment to completely cure the printing ink and adhere it to the board surface.

[0142] In some embodiments, the laser cutting of the plug finger position on the flexible circuit board, wherein the laser cutting is only processed to the tip of the plug finger and both sides of the polyimide reinforcement, includes: identifying the boundary between the plug finger area and the polyimide reinforcement on the flexible circuit board through a visual positioning algorithm, generating a corresponding laser cutting path, and controlling the laser equipment to cut the plug finger position along the cutting path so that the cutting range only covers the tip of the plug finger and both sides of the polyimide reinforcement, without exceeding the preset cutting boundary.

[0143] In some embodiments, controlling the size of the cut cutout to avoid affecting subsequent grinding and sandblasting processes includes: during the laser cutting process, collecting the cutout depth and size data of the cutting area in real time through a laser ranging algorithm, comparing the collected real-time data with a preset size threshold, and when the real-time data exceeds the threshold range, adjusting the output power and cutting speed of the laser equipment in real time to control the cut cutout size within a preset range, so as to avoid excessively large cutouts that could cause wrinkles on the plate surface in subsequent grinding and sandblasting processes.

[0144] In some embodiments, the third surface treatment of the laser-cut flexible circuit board includes: first cleaning and dust removal of the board surface, then uniformly grinding the board surface using a grinding equipment, while simultaneously using a visual detection algorithm to identify residual laser-cut debris on the board surface in real time, adjusting the brush pressure and travel speed of the grinding equipment, and completing the third surface treatment of the board surface.

[0145] In some embodiments, the step of thoroughly removing carbon powder residue generated by laser cutting through sandblasting to avoid carbon powder contamination of the subsequent electroplating tank includes: performing sandblasting on the flexible circuit board after grinding; using an image recognition algorithm to identify the distribution of carbon powder residue in the laser-cut area of ​​the plug fingers in real time; adjusting the sandblasting pressure and target area of ​​the sandblasting equipment accordingly; performing targeted sandblasting on the areas where carbon powder residue is concentrated; and visually verifying that there is no carbon powder residue in the cut area after completion to prevent residual carbon powder from entering the subsequent electroplating process and contaminating the tank.

[0146] In some embodiments, the process of electroless nickel-gold plating on the flexible circuit board after surface treatment includes: after pretreatment of the flexible circuit board after the third surface treatment, such as degreasing, micro-etching and activation, the board is sent into an electroless nickel plating tank and an electroless gold plating tank to complete the nickel plating and gold plating operations in sequence. During the process, the parameters of the plating solution are monitored in real time by a liquid level and concentration detection algorithm, and the corresponding reagents are automatically replenished to maintain the stability of the plating solution parameters, so as to form a uniform nickel-gold protective layer on the metal contact surface of the plug fingers.

[0147] In some embodiments, the completion of subsequent routine production processes includes: sequentially performing flying probe electrical testing, full appearance inspection, and packaging on the flexible circuit boards that have undergone chemical nickel-gold plating. During the process, a visual inspection algorithm is used to perform full inspection of the gold surface appearance of the plug fingers, screening out products with oxidation and blackening defects on the gold surface, and completing the final production and shipment of qualified products.

[0148] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the steps of the pre-laser gold plating method for preventing oxidation of the gold surface of an FPC plug after laser treatment, as provided in any embodiment of this application.

[0149] The computer-readable storage medium may be an internal storage unit of the computer device described in the foregoing embodiments, such as the hard disk or memory of the computer device. The computer-readable storage medium may also be an external storage device of the computer device, such as a plug-in hard disk, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the computer device.

[0150] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A pre-laser gold plating method for preventing oxidation of the gold surface after laser treatment of FPC connectors, characterized in that, include: After sequentially completing bonding, encapsulation, lamination, and surface treatment of the flexible circuit board, polyimide reinforcement is applied, and secondary lamination and secondary surface treatment are completed. Reinforcing markings and text are printed on the flexible circuit board. After curing, the plug finger positions on the flexible circuit board are laser-cut. The laser cutting is only processed to the top of the plug finger and both sides of the polyimide reinforcement. The size of the cut is controlled to avoid affecting the subsequent grinding and sandblasting process. The flexible circuit board that has undergone laser cutting undergoes a third surface treatment, which involves sandblasting to thoroughly remove any carbon powder residue generated during laser cutting, thus preventing carbon powder from contaminating the subsequent electroless plating tank. The flexible circuit board that has undergone surface treatment is then electroless nickel-gold plated to complete the subsequent routine production process.

2. The method according to claim 1, characterized in that, The process of sequentially bonding, encapsulating, pressing, and surface treating the flexible circuit board includes: After the circuit fabrication is completed on the substrate of the flexible circuit board, a bonding and encapsulation operation is performed. The encapsulation layer and the substrate are bonded and cured using a laminating equipment. Then, the laminated flexible circuit board is ground and sandblasted. At the same time, a visual inspection algorithm is used to identify the flatness and foreign matter residue on the board surface in real time. Board surfaces that do not meet the preset standards are subjected to secondary surface treatment until the board surface parameters meet the process requirements.

3. The method according to claim 1, characterized in that, The polyimide reinforcement is applied to complete the secondary lamination and secondary surface treatment, including: The positioning algorithm identifies the corresponding reinforcement areas of the plug fingers on the flexible circuit board, and the polyimide reinforcement material is accurately applied to the corresponding areas. The polyimide reinforcement and the flexible circuit board are then pressed together using a laminating device. The laminated board surface is then ground and sandblasted. A visual inspection algorithm is used to confirm that there is no excess glue or foreign matter residue in the reinforcement area, thus completing the secondary surface treatment.

4. The method according to claim 1, characterized in that, The process of printing reinforcing marking lines and text on the flexible circuit board and completing the curing includes: Reinforcing marking lines and production traceability text are printed on a preset area of ​​a flexible circuit board using a character printing device. After printing, the integrity and positional accuracy of the printed content are verified by a visual recognition algorithm. The flexible circuit boards that pass the verification are then sent to a curing device for heat curing treatment, so that the printing ink is completely cured and adhered to the board surface.

5. The method according to claim 1, characterized in that, The laser cutting of the plug finger positions on the flexible circuit board, where the laser cutting only extends to the tips of the plug fingers and both sides of the polyimide reinforcement, includes: The visual positioning algorithm identifies the boundary between the plug finger area and the polyimide reinforcement on the flexible circuit board, generates the corresponding laser cutting path, and controls the laser equipment to cut the plug finger position along the cutting path, so that the cutting range only covers the top of the plug finger and the two sides of the polyimide reinforcement, without exceeding the preset cutting boundary.

6. The method according to claim 1, characterized in that, The control of the cutting and hollowing size to avoid affecting the subsequent grinding and sandblasting process includes: During the laser cutting process, the laser ranging algorithm collects the cut depth and size data of the cutting area in real time. The collected real-time data is compared with the preset size threshold. When the real-time data exceeds the threshold range, the output power and cutting speed of the laser equipment are adjusted in real time to control the cut cut size within the preset range, so as to avoid the problem of wrinkles on the board surface caused by excessive cuts.

7. The method according to claim 1, characterized in that, The third surface treatment of the laser-cut flexible circuit board includes: The flexible circuit board that has undergone laser cutting is first cleaned and dust removed. Then, the board surface is uniformly ground by a grinding machine. At the same time, a visual detection algorithm is used to identify the laser cutting residue on the board surface in real time, and the brush pressure and travel speed of the grinding machine are adjusted to complete the third surface treatment of the board surface.

8. The method according to claim 7, characterized in that, The process of thoroughly removing carbon powder residue generated during laser cutting through sandblasting to prevent carbon powder contamination of the subsequent electroplating tank includes: The flexible circuit board that has completed the grinding process is subjected to sandblasting. The distribution of carbon powder residue in the laser-cut area of ​​the plug fingers is identified in real time by image recognition algorithm. The sandblasting pressure and target area of ​​the sandblasting equipment are adjusted accordingly. The areas with concentrated carbon powder residue are targeted by sandblasting. After completion, visual verification is used to confirm that there is no carbon powder residue in the cut area, so as to avoid residual carbon powder entering the subsequent chemical plating process and contaminating the tank.

9. The method according to claim 1, characterized in that, The process of performing electroless nickel-gold plating on the surface-treated flexible circuit board includes: After the flexible circuit board that has completed the third surface treatment undergoes degreasing, micro-etching and activation pretreatment, it is sent into the electroless nickel plating tank and electroless gold plating tank to complete the nickel plating and gold plating operations in sequence. During the process, the parameters of the plating solution are monitored in real time through liquid level and concentration detection algorithms, and the corresponding agents are automatically replenished to maintain the stability of the plating solution parameters, forming a uniform nickel-gold protective layer on the metal contact surface of the plug fingers.

10. The method according to claim 1, characterized in that, The completion of subsequent routine production processes includes: Flexible circuit boards that have undergone electroless nickel-gold plating are subjected to flying probe electrical testing, full appearance inspection, and packaging. During the process, a visual inspection algorithm is used to fully inspect the appearance of the gold surface of the connector fingers, screening out products with oxidation and blackening defects on the gold surface, and completing the final production and shipment of qualified products.

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