Manufacturing method of flexible circuit board and flexible circuit board thereof

Abstract

The invention discloses a manufacturing method of a flexible circuit board and the flexible circuit board. The method comprises the following steps: carrying out laser drilling on a roll-shaped flexible insulating base film which is arranged in a roll-to-roll continuous processing mode to obtain micropores; performing deposition treatment on the surface of the roll-shaped flexible insulating base film and the inner walls of the micropores according to a physical vapor deposition method to obtain a continuous metal seed layer; electroplating the metal seed layer according to a preset electroplating thickness parameter to obtain an electroplated metal layer corresponding to the preset electroplating thickness parameter; an anti-corrosion layer is attached to the surface of the electroplated metal layer, an anti-corrosion pattern is formed, the electroplated metal layer on which the anti-corrosion pattern is formed is sequentially subjected to etching and anti-corrosion layer removing treatment, and a target circuit substrate is obtained; and post-processing the target circuit substrate to obtain a target flexible circuit board. According to the invention, the technical problems of low manufacturing efficiency, low reliability and poor environmental protection of the manufacturing method of the flexible circuit board in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of electronic circuit board manufacturing, and more specifically, to a method for manufacturing a flexible circuit board and the flexible circuit board thereof. Background Technology

[0002] Flexible printed circuit boards (PCBs), also known as flexible printed circuit boards, are key components for achieving lightweighting, miniaturization, and three-dimensional assembly in modern electronic devices. The core of PCB manufacturing lies in the precise processing of flexible substrates and conductive lines to create a bendable, thin circuit carrier. The core process revolves around "substrate treatment, circuit forming, and encapsulation protection." Currently, most mainstream PCB manufacturing employs a "subtractive" process: on a copper-clad laminate, excess copper foil is removed through metallization, pattern transfer, and chemical etching to form the circuitry. However, this manufacturing method has several drawbacks: First, severe lateral etching: the lateral corrosion of the etching solution results in poor circuit precision, making it difficult to achieve fine circuits with a line width / spacing of less than 15μm. Second, reliability bottlenecks: the use of adhesives to bond copper foil and the base film reduces heat resistance, bending resistance, and dimensional stability. Third, environmental pressures: the chemical copper plating process necessary for manufacturing through-hole interconnects generates wastewater containing heavy metal complexes, resulting in high treatment costs.

[0003] To overcome the aforementioned problems, the electronic circuit board manufacturing industry has explored a semi-additive manufacturing process. The semi-additive method first forms a thin seed layer on an insulating substrate, then thickens it through electroplating, and finally etches it. However, how to efficiently, uniformly, and environmentally friendly form a high-quality seed layer on a flexible substrate, especially to achieve reliable metallization of microvias, remains a technological bottleneck. For example, while chemical copper plating can deposit a seed layer, it suffers from complex processes, unstable solutions, and significant pollution. In summary, existing flexible circuit board manufacturing methods suffer from low manufacturing efficiency, low reliability, and poor environmental performance.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This invention provides a method for manufacturing a flexible circuit board and a flexible circuit board thereof, so as to at least solve the technical problems of low manufacturing efficiency, low reliability and poor environmental performance of existing flexible circuit board manufacturing methods.

[0006] According to one aspect of the present invention, a method for manufacturing a flexible circuit board is provided, the method comprising: laser drilling a roll of flexible insulating substrate film arranged in a roll-to-roll continuous processing manner to obtain micropores;

[0007] The surface of the roll-shaped flexible insulating substrate and the inner wall of the micropores are deposited using physical vapor deposition to obtain a continuous metal seed layer. The metal seed layer is then electroplated according to a preset electroplating thickness parameter to obtain an electroplated metal layer corresponding to the preset electroplating thickness parameter. A resist layer is attached to the surface of the electroplated metal layer to form a resist pattern. The electroplated metal layer with the resist pattern is then etched and the resist layer is removed sequentially to obtain a target circuit board. The target circuit board is then post-processed to obtain a target flexible circuit board.

[0008] Furthermore, the above-mentioned laser drilling of the roll-shaped flexible insulating base film arranged in a roll-to-roll continuous processing method to obtain micropores includes: laser drilling the roll-shaped flexible insulating base film arranged in a roll-to-roll continuous processing method according to a preset type of laser and preset aperture parameters to obtain the micropores, wherein the preset type of laser is an ultraviolet laser or an ultrafast laser, and the preset aperture parameters range from 30μm to 150μm.

[0009] Furthermore, the above method also includes: performing laser drilling on the roll-shaped flexible insulating base film according to the drilling design parameters of the preset computer-aided manufacturing software to obtain the micropores.

[0010] Furthermore, the above-mentioned deposition treatment of the surface of the roll-shaped flexible insulating base film and the inner wall of the micropores by physical vapor deposition to obtain a continuous metal seed layer includes: depositing the surface of the roll-shaped flexible insulating base film and the inner wall of the micropores by magnetron sputtering to obtain the continuous metal seed layer, wherein the metal seed layer is a copper layer or a composite metal layer, the composite metal layer is composed of at least a bonding layer and a conductive layer, and the thickness of the metal seed layer ranges from 50 nm to 500 nm.

[0011] Further, the above-mentioned electroplating of the metal seed layer according to the preset electroplating thickness parameters to obtain the electroplated metal layer corresponding to the preset electroplating thickness parameters includes: performing copper electroplating on the metal seed layer according to the preset electroplating thickness parameters to obtain the electroplated metal layer corresponding to the preset electroplating thickness parameters, wherein the parameter range of the preset electroplating thickness parameters is 1um to 30um.

[0012] Furthermore, the post-processing of the target circuit board to obtain the target flexible circuit board includes: post-processing the target circuit board according to a preset post-processing method to obtain the target flexible circuit board, wherein the preset post-processing method includes at least one of the following: lamination of cover film, surface treatment, bonding reinforcement, electrical testing, and shape processing.

[0013] Furthermore, the aforementioned roll-shaped flexible insulating base film is one of the following: a polyimide film, a liquid crystal polymer film, or a polyester film.

[0014] Further, the above-mentioned process of attaching a resist layer to the surface of the electroplated metal layer and forming a resist pattern, and sequentially etching and removing the resist layer on the electroplated metal layer forming the resist pattern to obtain the target circuit substrate includes: sequentially etching and removing the resist layer on the electroplated metal layer forming the resist pattern using a rapid etching method to obtain the target circuit substrate.

[0015] Furthermore, the above method also includes: forming the above-mentioned anti-corrosion pattern on the surface of the above-mentioned electroplated metal layer by means of film application, exposure, development and imaging.

[0016] According to another aspect of the present invention, a flexible circuit board is also provided, which is manufactured according to any of the above-described methods for manufacturing flexible circuit boards.

[0017] In this embodiment of the invention, micropores are obtained by laser drilling on a roll-to-roll flexible insulating base film arranged in a roll-to-roll continuous processing manner; then, a continuous metal seed layer is obtained by physical vapor deposition on the surface of the roll-to-roll flexible insulating base film and the inner wall of the micropores; the metal seed layer is electroplated according to a preset electroplating thickness parameter to obtain an electroplated metal layer corresponding to the preset electroplating thickness parameter; by attaching a resist layer to the surface of the electroplated metal layer and forming a resist pattern, the electroplated metal layer with the resist pattern is etched and the resist layer is removed in sequence to obtain the target circuit board; the purpose of post-processing the target circuit board to obtain the target flexible circuit board is achieved, thereby realizing the technical effects of improving the manufacturing efficiency, reliability, and environmental friendliness of the manufacturing method of flexible circuit boards, and thus solving the technical problems of low manufacturing efficiency, low reliability, and poor environmental friendliness of the existing flexible circuit board manufacturing methods. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0019] Figure 1 This is a schematic flowchart of an optional flexible circuit board manufacturing method according to an embodiment of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] Example 1

[0023] According to an embodiment of the present invention, an embodiment of a method for manufacturing a flexible circuit board is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0024] Figure 1 This is a schematic flowchart of an optional flexible circuit board manufacturing method according to an embodiment of the present invention, as shown below. Figure 1 As shown, the method includes the following steps:

[0025] Step S102: Laser drilling is performed on the roll-shaped flexible insulating base film arranged in a roll-to-roll continuous processing method to obtain micropores;

[0026] Step S104: The surface of the roll-shaped flexible insulating substrate and the inner wall of the micropores are deposited according to the physical vapor deposition method to obtain a continuous metal seed layer.

[0027] Step S106: Electroplating the metal seed layer according to the preset electroplating thickness parameters to obtain an electroplated metal layer corresponding to the preset electroplating thickness parameters.

[0028] Step S108: A resist layer is attached to the surface of the electroplated metal layer to form a resist pattern. The electroplated metal layer with the resist pattern is then etched and the resist layer is removed sequentially to obtain the target circuit board.

[0029] Step S110: Post-process the target circuit board to obtain the target flexible circuit board.

[0030] In this embodiment of the invention, micropores are obtained by laser drilling on a roll-to-roll flexible insulating base film arranged in a roll-to-roll continuous processing manner; then, a continuous metal seed layer is obtained by physical vapor deposition on the surface of the roll-to-roll flexible insulating base film and the inner wall of the micropores; the metal seed layer is electroplated according to a preset electroplating thickness parameter to obtain an electroplated metal layer corresponding to the preset electroplating thickness parameter; by forming a resist pattern on the electroplated metal layer, the electroplated metal layer with the resist pattern is etched and the resist layer is removed sequentially to obtain the target circuit board; the purpose of post-processing the target circuit board to obtain the target flexible circuit board is achieved, thereby realizing the technical effects of improving the manufacturing efficiency, reliability, and environmental friendliness of the manufacturing method of flexible circuit boards, and thus solving the technical problems of low manufacturing efficiency, low reliability, and poor environmental friendliness in the existing flexible circuit board manufacturing methods.

[0031] Optionally, the purpose of this invention is to provide a method for manufacturing a flexible circuit board and the flexible circuit board thereof, to solve the problems of low circuit accuracy due to side etching, poor reliability due to the use of adhesives and chemical copper plating, and environmental pollution in existing subtractive processes. This invention innovatively combines roll-to-roll continuous production technology, high-precision laser micro-via processing technology, and physical vapor deposition technology to construct a novel "semi-additive" flexible circuit board manufacturing process. This method fundamentally abandons traditional copper-clad laminate and chemical copper plating processes.

[0032] Optionally, flexible insulating base film is a key material for electronic devices such as flexible printed circuit boards (FPCs). It possesses insulating and flexible properties, enabling circuits to be bent and made thinner. Flexible insulating base film is an important component of flexible copper-clad laminates. It is typically laminated with adhesives and release paper to form a cover film, which is then applied to the surface of the flexible circuit board. This film isolates the circuit from the external environment, prevents oxidation and short circuits, and prevents solder bridging during soldering. It also improves the bending lifespan of the flexible circuit board.

[0033] Optionally, the manufacturing method of the flexible circuit board in the embodiments of the present invention realizes the manufacturing of ultra-fine lines: since the total copper thickness of the final etching is about 10um, the side etching amount is very small, and it can stably manufacture circuits with line width / line spacing ≤15μm, thus solving the precision bottleneck of traditional processes.

[0034] Optionally, step S102, which involves laser drilling of a roll-shaped flexible insulating base film arranged in a roll-to-roll continuous processing manner to obtain micropores, includes: laser drilling of the roll-shaped flexible insulating base film arranged in a roll-to-roll continuous processing manner according to a preset type of laser and preset aperture parameters to obtain micropores, wherein the preset type of laser is an ultraviolet laser or an ultrafast laser, and the preset aperture parameters range from 30μm to 150μm.

[0035] Optionally, the manufacturing method of the flexible circuit board in the embodiments of the present invention may further include: laser drilling the roll-shaped flexible insulating base film according to the drilling design parameters of the preset computer-aided manufacturing software CAM (Computer Aided Manufacturing) to obtain micropores.

[0036] Optionally, step S104, depositing a continuous metal seed layer on the surface of the roll-shaped flexible insulating base film and the inner walls of the micropores using physical vapor deposition, includes: depositing a continuous metal seed layer on the surface of the roll-shaped flexible insulating base film and the inner walls of the micropores using magnetron sputtering, wherein the metal seed layer is a copper layer or a composite metal layer, and the composite metal layer comprises at least a bonding layer and a conductive layer, with a thickness ranging from 50 nm to 500 nm. Specifically, magnetron sputtering is used to achieve direct bonding between copper and the base film, eliminating the adhesive layer, and the resulting flexible circuit board has higher heat resistance, better dimensional stability, and excellent bending fatigue resistance. For example, a uniform and dense metal seed layer is deposited on the surface of the base film and the inner walls of the micropores using magnetron sputtering technology. Preferably, a titanium / copper composite layer is used to enhance bonding and conductivity.

[0037] Optionally, the manufacturing method of the flexible circuit board in this embodiment of the invention is environmentally friendly and efficient, completely avoiding the highly polluting chemical copper plating process. Magnetron sputtering is a dry, low-pollution technology, and combined with roll-to-roll production, it achieves full-process automation and high efficiency, significantly reducing production costs. The manufacturing method of the flexible circuit board in this embodiment of the invention is particularly suitable for high-quality metallization of microvias. Magnetron sputtering has excellent step coverage capabilities, forming a continuous and uniform conductive layer on the inner wall of microvias with high aspect ratios, ensuring the reliability of high-density interconnects.

[0038] Optionally, step S106, which involves electroplating the metal seed layer according to a preset electroplating thickness parameter to obtain an electroplated metal layer corresponding to the preset electroplating thickness parameter, includes: electroplating the metal seed layer with copper according to the preset electroplating thickness parameter to obtain an electroplated metal layer corresponding to the preset electroplating thickness parameter, wherein the preset electroplating thickness parameter ranges from 1µm to 30µm. Specifically, electroplating is performed using the metal seed layer as the cathode to thicken the copper layer to the required thickness.

[0039] Optionally, post-processing the target circuit board to obtain the target flexible circuit board includes: post-processing the target circuit board according to a preset post-processing method to obtain the target flexible circuit board, wherein the preset post-processing method includes at least one of the following: applying a cover film, surface treatment, bonding reinforcement, electrical testing, and shape processing.

[0040] Optionally, lamination of the cover film is a core process for circuit protection. A 25μm thick polyimide cover film (15μm adhesive layer) is used, precisely aligned with the target circuit board's circuit surface, and then hot-pressed at 180℃ and 0.5MPa pressure for 60 seconds. This ensures a completely bubble-free, airtight fit, leaving only the solder pad area exposed. This effectively isolates the cover film from the external environment, preventing circuit oxidation and short circuits, while also improving the substrate's bending resistance. Surface treatment can employ a chemical nickel-gold process, depositing a 5μm nickel layer and a 0.05μm gold layer on the solder pad surface. This enhances solder adhesion and significantly improves oxidation resistance, ensuring the reliability of subsequent component assembly. For reinforcement, a 0.3mm thick FR-4 reinforcement plate is hot-pressed onto areas subject to installation stress to strengthen local mechanical strength and prevent substrate deformation or breakage during assembly or use. Electrical testing can be performed using a flying probe tester at 500V voltage and ±1% accuracy to comprehensively check for circuit continuity and insulation defects, strictly rejecting defective products. The shape processing can be carried out using laser cutting technology, which can accurately cut according to the preset size, ensuring that there are no burrs on the edges and that the dimensional tolerance is controlled within ±0.1mm. Ultimately, this allows the product to adapt to actual installation needs and has both good flexibility and structural stability.

[0041] Optionally, FR-4 is the industry standard designation for fiberglass reinforced epoxy copper clad laminate (FCL), which is also the most commonly used rigid reinforcement material in flexible circuit board bonding and reinforcement processes. Its core function is to improve the mechanical strength of key areas of the flexible substrate.

[0042] Optionally, the roll-shaped flexible insulating base film can be one of the following: polyimide film, liquid crystal polymer film, or polyester film. Polyimide film is the preferred material, possessing excellent high-temperature resistance (long-term temperature resistance above 200℃, capable of withstanding 260℃ reflow soldering), high mechanical strength and bending resistance, a low dielectric constant of 3.2, and strong chemical stability. It is suitable for high-frequency signal transmission and use in complex environments, making it a core substrate for high-end flexible circuit boards in consumer electronics, medical devices, and other applications. Liquid crystal polymer film offers superior dielectric properties (Dk≤2.9, where Dk is the abbreviation for dielectric constant, a core parameter for measuring the insulation performance and signal transmission characteristics of a material), excellent dimensional stability, low coefficient of thermal expansion, and no hygroscopicity. It can meet the high-frequency, high-speed transmission requirements of 5G communication and millimeter-wave equipment, and is particularly suitable for precision micro-hole processing scenarios. Polyester film has lower cost, lower dielectric loss, and good flexibility, but slightly weaker temperature resistance (long-term temperature resistance ≤120℃). It is suitable for ordinary flexible circuit boards in medium- and low-temperature environments where cost is sensitive, such as simple consumer electronics connection cables. The three materials can be flexibly selected according to the product's temperature resistance, signal transmission, cost budget, and other requirements.

[0043] Optionally, a resist layer is attached to the surface of the electroplated metal layer to form a resist pattern. The electroplated metal layer with the resist pattern is then sequentially etched and the resist layer is removed to obtain the target circuit board. This process involves using a rapid etching method to sequentially etch and remove the resist layer from the electroplated metal layer with the resist pattern to obtain the target circuit board. The main function of this etching process is to quickly and selectively remove the exposed thin seed layer with almost no damage to the thickened electroplated lines protected by the resist, thereby greatly suppressing lateral etching.

[0044] Optionally, the manufacturing method of the flexible circuit board in the embodiments of the present invention may further include: forming a resist pattern on the surface of the electroplated metal layer by means of film lamination, exposure, and development imaging.

[0045] Optionally, embodiments of the present invention also provide a flexible circuit board, which is manufactured according to the manufacturing method of the flexible circuit board in the above embodiments.

[0046] Optionally, when manufacturing a high-density single-sided flexible circuit board using the flexible circuit board manufacturing method according to the embodiments of the present invention, a 12.5 μm thick polyimide film can be selected as the flexible insulating base film. First, laser drilling is employed: using an ultraviolet laser, through-holes with a diameter of 50 μm are drilled in roll-to-roll mode; then, magnetron sputtering is employed: a 30 nm thick titanium layer and a 200 nm thick copper layer are successively sputtered to form a composite seed layer; next, electroplating is employed to thicken the copper layer to 8 μm using an acidic copper sulfate electroplating solution; then, pattern transfer is employed: using LDI (Laser Direct Imaging) technology, a circuit pattern with a linewidth / spacing of 18 μm is formed on the dry film, and then etched using an acidic copper chloride etching solution; finally, post-processing steps are performed: sequentially applying a cover film lamination, electroless nickel-palladium-gold plating, and laser cutting of the outline, etc. The flexible circuit board products obtained by the above-mentioned flexible circuit board manufacturing method are tested and found to have clear line edges, steep sidewalls, line width accuracy error of ±1.5μm, low and concentrated resistance values ​​of vias, and can achieve more than 100,000 bending tests without failure.

[0047] Optionally, in the case of manufacturing a glue-free double-sided flexible circuit board using the flexible circuit board manufacturing method according to the embodiments of the present invention, after laser drilling, double-sided magnetron sputtering and electroplating are performed to thicken the board, thereby forming a double-layer circuit structure and realizing interlayer interconnection. The entire process does not require bonding sheets, achieving a truly glue-free structure. The flexible circuit board manufacturing method and the flexible circuit board provided by the embodiments of the present invention can be widely used in electronic devices that require high-density wiring, high reliability, and thin and flexible characteristics, such as flexible circuit boards in the hinge area of ​​folding screens of smartphones, camera module cables, high-end wearable devices, medical devices, and aerospace electronic systems, etc., with broad market prospects.

[0048] Optionally, the manufacturing method of the flexible circuit board in this embodiment of the invention includes: firstly, laser drilling is performed on the flexible insulating base film using a roll-to-roll method; then, a metal seed layer is formed on the surface of the base film and inside the holes by magnetron sputtering; then, electroplating is performed to thicken the layer to form a conductive layer; then, circuit patterns are formed by lamination, exposure, development, etching, and film removal; finally, post-processing such as lamination and surface treatment is performed. This invention replaces the traditional "copper clad laminate + chemical copper plating" with "laser drilling + magnetron sputtering", achieving environmentally friendly manufacturing without glue or chemical copper plating, and solving the side etching problem in the traditional subtractive process. The manufacturing method of the flexible circuit board in this embodiment of the invention can manufacture ultra-fine lines with a line width / spacing of less than 20μm, significantly improving the precision, reliability, and production efficiency of flexible circuit board manufacturing, and providing the electronic circuit board manufacturing industry with a new flexible circuit board manufacturing method that can balance high precision, high reliability, high efficiency, and environmental protection.

[0049] Optionally, the flexible circuit board manufacturing method in this embodiment of the invention achieves a synergistic improvement in manufacturing efficiency, product reliability, and environmental protection through process innovation and full-process optimization, such as roll-to-roll continuous production, laser drilling, magnetron sputtering, and semi-additive processes. The core technology has significant effects. In terms of production efficiency, the entire process adopts a roll-to-roll continuous processing mode, with seamless connection between laser drilling, magnetron sputtering, electroplating, etching, and other processes. This avoids the time-consuming material change and positioning of traditional single-sheet processing. Combined with the high-efficiency drilling of ultraviolet / ultrafast lasers (precise forming of 30μm-150μm hole diameter) and the pattern transfer of LDI laser direct imaging, the production efficiency is increased by more than 30% compared with the traditional subtractive method, making it suitable for the needs of large-scale mass production.

[0050] Optionally, the flexible circuit board in this embodiment of the invention achieves multiple breakthroughs in product performance: First, the line accuracy is greatly improved. The 50nm-500nm continuous metal seed layer formed by magnetron sputtering works in conjunction with the 2μm-20μm electroplated metal layer, combined with a rapid etching process, to effectively suppress side etching. The line width / spacing can be stably controlled within 15μm with an error of no more than ±1.5μm, meeting the requirements of high-density wiring. Second, the reliability is significantly enhanced. The adhesive-free composite structure (magnetron sputtering directly combines the base film and the metal layer) eliminates the shortcomings of heat resistance and bending resistance caused by adhesives. Combined with the 25μm polyimide cover film lamination and FR-4 reinforcement design in the post-processing, the product can withstand more than 100,000 bending cycles and can still maintain structural stability in high-temperature environments (260℃). Third, the interconnect reliability is optimized. The combination of laser drilling and magnetron sputtering ensures that the metal layer on the inner wall of the micro-hole (minimum 30μm) is continuous and dense, with low and uniform hole resistance. The interlayer interconnect stability far exceeds that of traditional chemical copper plating processes.

[0051] Optionally, the manufacturing method of the flexible circuit board in this embodiment of the invention has significant advantages in terms of environmental protection and cost control: it abandons the highly polluting chemical copper plating process and adopts magnetron sputtering dry deposition technology, generating no heavy metal wastewater and reducing environmental treatment costs by more than 60%; continuous roll-to-roll production reduces material loss, and with precise control of process parameters (such as electroplating thickness and etching rate), the product yield can be increased to over 95%, and the unit product manufacturing cost can be reduced by 20%-25%. In summary, the flexible circuit board produced by this method can meet the stringent requirements of high precision, high reliability, and thinness in consumer electronics, medical devices, aerospace and other fields, demonstrating significant technical practicality and market competitiveness.

[0052] In this embodiment of the invention, micropores are obtained by laser drilling on a roll-to-roll flexible insulating base film arranged in a roll-to-roll continuous processing manner; then, a continuous metal seed layer is obtained by physical vapor deposition on the surface of the roll-to-roll flexible insulating base film and the inner wall of the micropores; the metal seed layer is electroplated according to a preset electroplating thickness parameter to obtain an electroplated metal layer corresponding to the preset electroplating thickness parameter; by attaching a resist layer to the surface of the electroplated metal layer and forming a resist pattern, the electroplated metal layer with the resist pattern is etched and the resist layer is removed in sequence to obtain the target circuit board; the purpose of post-processing the target circuit board to obtain the target flexible circuit board is achieved, thereby realizing the technical effects of improving the manufacturing efficiency, reliability, and environmental friendliness of the manufacturing method of flexible circuit boards, and thus solving the technical problems of low manufacturing efficiency, low reliability, and poor environmental friendliness of the existing flexible circuit board manufacturing methods.

[0053] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0054] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0055] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0056] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0057] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0058] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0059] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for manufacturing a flexible circuit board, characterized in that, include: Laser drilling was performed on a roll-to-roll flexible insulating base film arranged in a roll-to-roll continuous processing method to obtain micropores; The surface of the rolled flexible insulating substrate and the inner wall of the micropores are deposited using physical vapor deposition to obtain a continuous metal seed layer. The metal seed layer is electroplated according to the preset electroplating thickness parameters to obtain an electroplated metal layer corresponding to the preset electroplating thickness parameters. A resist layer is attached to the surface of the electroplated metal layer to form a resist pattern. The electroplated metal layer with the resist pattern is then etched and the resist layer is removed sequentially to obtain the target circuit board. The target circuit board is post-processed to obtain the target flexible circuit board.

2. The method for manufacturing a flexible circuit board according to claim 1, characterized in that, The process of laser drilling micropores in a roll-to-roll flexible insulating base film arranged using a roll-to-roll continuous processing method includes: Laser drilling is performed on the roll-shaped flexible insulating base film arranged in a roll-to-roll continuous processing method according to a preset type of laser and preset aperture parameters to obtain the micropores. The preset type of laser is an ultraviolet laser or an ultrafast laser, and the preset aperture parameters range from 30μm to 150μm.

3. The method for manufacturing a flexible circuit board according to claim 2, characterized in that, The method further includes: The roll-shaped flexible insulating base film is laser-drilled according to the preset drilling design parameters of the computer-aided manufacturing software to obtain the micropores.

4. The method for manufacturing a flexible circuit board according to claim 1, characterized in that, The step of depositing a continuous metal seed layer on the surface of the rolled flexible insulating substrate and the inner wall of the micropores using physical vapor deposition (PVD) includes: The surface of the roll-shaped flexible insulating substrate and the inner wall of the micropores are deposited by magnetron sputtering to obtain the continuous metal seed layer, wherein the metal seed layer is a copper layer or a composite metal layer, the composite metal layer is composed of at least a bonding layer and a conductive layer, and the thickness of the metal seed layer ranges from 50 nm to 500 nm.

5. The method for manufacturing a flexible circuit board according to claim 1, characterized in that, The step of electroplating the metal seed layer according to a preset electroplating thickness parameter to obtain an electroplated metal layer corresponding to the preset electroplating thickness parameter includes: The metal seed layer is electroplated with copper according to the preset electroplating thickness parameter to obtain the electroplated metal layer corresponding to the preset electroplating thickness parameter, wherein the parameter range of the preset electroplating thickness parameter is 1um to 30um.

6. The method for manufacturing a flexible circuit board according to claim 1, characterized in that, The post-processing of the target circuit board to obtain the target flexible circuit board includes: The target circuit board is post-processed according to a preset post-processing method to obtain the target flexible circuit board. The preset post-processing method includes at least one of the following: lamination of cover film, surface treatment, bonding reinforcement, electrical testing, and shape processing.

7. The method for manufacturing a flexible circuit board according to claim 1, characterized in that, The roll-shaped flexible insulating base film is one of the following: polyimide film, liquid crystal polymer film, or polyester film.

8. The method for manufacturing a flexible circuit board according to claim 1, characterized in that, The process involves attaching a resist layer to the surface of the electroplated metal layer to form a resist pattern, and then sequentially etching and removing the resist layer from the electroplated metal layer to obtain the target circuit board, comprising: The electroplated metal layer of the formed resist pattern is etched and the resist layer is removed sequentially using a rapid etching method to obtain the target circuit substrate.

9. The method for manufacturing a flexible circuit board according to claim 8, characterized in that, The method further includes: The resist pattern is formed on the surface of the electroplated metal layer using a film application, exposure, and development imaging method.

10. A flexible circuit board, characterized in that, The flexible circuit board is manufactured by the method of manufacturing a flexible circuit board according to any one of claims 1 to 9.

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