Manufacturing method of metal foil antenna

Abstract

According to the manufacturing method, through a Roll to Roll continuous production mode, traditional 19 procedures are reduced to 12 procedures, the production speed is increased to 5 m / min, the dielectric constant of a composite PI film doped with nanometer aluminum oxide is smaller than or equal to 3.2 and is reduced by 15% compared with that of a traditional PI film, a micro-arc oxidation insulating layer of copper / magnesium alloy foil is combined, the signal loss of the antenna in the frequency band of 28-300 GHz is reduced by 30%, and the antenna performance is improved. The sheet resistance of the graphene / silver nanowire composite conductive adhesive is smaller than or equal to 0.1 omega / sq, the bending life is larger than or equal to 100,000 times, the performance is improved by 10 times compared with that of traditional silver paste, the long-term dynamic use requirement of wearable equipment is met, no chemical etching liquid is used in the whole process, waste is subjected to magnetic separation and low-temperature pyrolysis, waste discharge is reduced by 90% compared with a traditional process, and the graphene / silver nanowire composite conductive adhesive is environmentally friendly. The carbon-based particles generated through pyrolysis meet the RoHS standard and can be directly used for 3D printing consumables, the antenna produced through the method can adapt to the leading-edge fields of 6G base stations, flexible intelligent watches, implantable medical sensors and the like, and the technology of the Internet of Things and high-frequency communication is promoted.

Description

Technical Field

[0001] The present invention relates to the field of antennas, and specifically to a manufacturing method of a metal foil antenna. Background Art

[0002] With the rapid development of mobile communication technology, the evolution from 2G to 5G has put forward higher requirements for the performance of antennas, especially in aspects such as high frequency bands (such as millimeter waves), miniaturization, flexibility, and environmentally friendly production. Traditional antenna manufacturing technologies have gradually revealed various limitations: 1. In the early stage, external antennas were used in mobile devices (such as in the 2G era), which had problems such as large volume and inconvenient installation. With the popularization of smart phones, the second-generation antenna technology (such as FPCB flexible circuit board antennas, LDS laser direct structuring antennas) realized the embedding of antennas. However, the FPCB process requires 19 complex processes such as cutting, drilling, copper plating, and etching, with a long production cycle and high cost. In addition, the copper-containing wastewater and acidic waste liquid generated during the chemical etching process cause serious pollution to the environment. Taking FPCB as an example, a large amount of photoresist and etching solution are required for its production, and the waste treatment cost accounts for more than 15% of the total production cost; 2. 5G and future 6G communications (operating frequencies of 28 - 300 GHz) require antennas to have extremely low dielectric losses and higher dimensional accuracy. The dielectric constant of traditional polyimide (PI) films (usually ≥3.5) is difficult to meet the requirements of millimeter wave transmission, and the interfacial bonding strength between the metal foil and the PI film is insufficient, resulting in impedance mismatch during high-frequency signal transmission. For example, although the multi-layer composite antenna structure mentioned in patent WO2021040226A1 improves the performance, it still relies on complex exposure and etching processes and does not solve the environmental protection problem; 3. Emerging scenarios such as wearable devices and Internet of Things sensors require antennas to have excellent flexibility and bending life. Existing conductive adhesive materials (such as silver paste) have a relatively high sheet resistance (≥0.5 Ω / sq) and are prone to cracking after repeated bending, resulting in signal attenuation. For example, the LDS antenna of a certain brand of smart watch can only withstand 10,000 bends at a curvature radius of 3 mm, which is difficult to meet the long-term use requirements; In view of the above problems, there is an urgent need for a new antenna manufacturing method that can achieve green production while simplifying the process and improving accuracy, and meet the requirements of 6G high-frequency communication and flexible devices. Summary of the Invention

[0003] Therefore, in order to solve the above deficiencies, the present invention provides a manufacturing method of a metal foil antenna herein.

[0004] The present invention is implemented as follows. A manufacturing method of a metal foil antenna is constructed, including the following steps; Step S1: Raw material slitting: Use a laser slitter to perform high-precision slitting on the metal foil coil, with a slitting accuracy error ≤ 0.05 mm; Step S2: TOP Removal layer treatment: Apply an anti-scratch protective film (TOP Removal layer) to the surface of the slit metal foil, and perform stamping through a cylindrical mold to form positioning holes, a handle structure, and a signal transmission area; Step S3: PI film lamination: Laminate multiple layers of polyimide (PI) film on the material after TOP Removal treatment, and use a hot pressing process (temperature 100 - 150 °C, pressure 5 - 10 MPa) to ensure seamless bonding between the PI film and the metal foil; Step S4: Laser fine-tuning: Use an ultraviolet laser to perform micro-hole processing on the PI film to form antenna radiation units and feeding points, with a hole diameter accuracy of ±5 μm; Step S5: Metal pattern stamping: Selectively etch the metal foil through a cylindrical mold to form an antenna radiation pattern, with an etching depth of 80% - 95% of the metal foil thickness; Step S6: Flexible adhesive layer lamination: Coat a flexible conductive adhesive (adhesion force ≥ 8 N / cm²) on the metal pattern surface, and laminate a double-sided tape with a thickness of 50 - 150 μm; Step S7: MFA outer shape forming: Use a high-speed rotating mold to perform three-dimensional curved surface stamping to form an antenna three-dimensional structure, and simultaneously correct the shape error through real-time optical inspection (AOI); Step S8: Bottom layer gasket treatment: Bond a non-sticky hot melt gasket to the bottom of the material, and perform four-corner positioning stamping through a mold. The gasket material is biodegradable polylactic acid (PLA); Step S9: Roll to Roll continuous pressing: Use a multi-stage pressing device (pressure 10 - 25 MPa, temperature 80 - 120 °C) to perform 3 - 6 times of dynamic pressing on the composite layer, with a single pressing time ≤ 30 seconds; Step S10: Conductive ink printing: Print antenna contacts using nano-silver conductive ink (resistivity ≤ 10⁻ 7 Ω·m), with a printing accuracy error ≤ 0.02 mm; Step S11: Scrap recycling and environmental protection treatment: Separate the metal and non-metal components of the stamping scrap through magnetic separation, with a metal recovery rate ≥ 98%. The non-metal scrap is subjected to low-temperature pyrolysis treatment to generate harmless particles; Step S12: Full-automatic inspection: Use an AI vision system to perform impedance matching, radiation efficiency, and defect detection on the finished product, and automatically reject defective products; Among them, the method realizes real-time optimization of process parameters through a cloud production management system, and no chemical etching solution is used throughout the process.

[0005] Preferably, the PI film in step 3 is a composite polyimide film doped with nano-aluminum oxide, with a dielectric constant ≤ 3.2, a thickness of 25 - 80 μm, and a tensile strength ≥ 300 MPa.

[0006] Preferably, the etching process in step 5 uses plasma-assisted dry etching, and the etching gas is a CF4 / O2 mixed gas, with an etching rate ≥ 5 μm / min and a sidewall perpendicularity ≥ 85°.

[0007] Preferably, the flexible conductive adhesive in step 6 contains a graphene / silver nanowire composite conductive material, with a sheet resistance ≤ 0.1 Ω / sq and a bending life ≥ 100,000 times (curvature radius 3 mm).

[0008] Preferably, the three-dimensional curved surface stamping in step 7 uses a shape memory alloy mold, and the mold surface is coated with a diamond-like carbon coating (DLC), with a hardness ≥ 3000 HV and a stamping repeat positioning accuracy ≤ 2 μm.

[0009] Preferably, the low-temperature pyrolysis treatment in step 11 is carried out in an inert atmosphere (nitrogen or argon), with a pyrolysis temperature ≤ 300 °C, generating particle sizes ≤ 10 μm and meeting the RoHS standard.

[0010] Preferably, the AI vision system in step 12 is based on a convolutional neural network (CNN) model, and the training data contains 100,000 sets of antenna defect samples, with a detection accuracy ≥ 99.5%.

[0011] Preferably, the metal foil is a copper / magnesium alloy foil, with a thickness of 15 - 60 μm, and a dense insulating layer is formed on the surface by micro-arc oxidation treatment, with an insulation resistance ≥ 10¹² Ω·cm.

[0012] Preferably, the method is applicable to the manufacturing of embedded antennas for 6G millimeter-wave communication (frequency 28 - 300 GHz), flexible wearable devices, and Internet of Things (IoT) sensors.

[0013] Preferably, the cloud production management system collects pressure, temperature, and stamping speed data in real time through a 5G network, and uses digital twin technology to simulate the process optimization path, resulting in a ≥ 15% increase in the good product rate.

[0014] The present invention has the following advantages: The present invention provides a method for manufacturing a metal foil antenna by improvement. Compared with the same type of equipment, the following improvements are made: The method for manufacturing a metal foil antenna according to the present invention reduces the traditional 19 processes to 12 through a Roll to Roll continuous production mode, increases the production speed to 5 m / min, and has full automation control. For example, plasma-assisted dry etching replaces chemical wet etching, reducing the single-link time consumption by 60%, and increasing the good product rate from 85% to 98.5%; The composite PI film doped with nano-aluminum oxide has a dielectric constant ≤ 3.2, which is 15% lower than that of the traditional PI film. Combined with the micro-arc oxidation insulation layer of copper / magnesium alloy foil (insulation resistance ≥ 10¹² Ω·cm), the signal loss of the antenna in the 28 - 300 GHz frequency band is reduced by 30%, making it suitable for 6G millimeter-wave communication; The sheet resistance of the graphene / silver nanowire composite conductive adhesive ≤ 0.1 Ω / sq, and the bending life ≥ 100,000 times (curvature radius 3 mm), with its performance being 10 times higher than that of the traditional silver paste (0.5 Ω / sq, 10,000 times), meeting the long-term dynamic use requirements of wearable devices; No chemical etching solution is used throughout the process. The waste materials are separated by magnetic separation (metal recovery rate ≥ 98%) and low-temperature pyrolysis (non-metal waste harmless rate 100%). Compared with the traditional process, the waste emissions are reduced by 90%, and the carbon-based particles generated by pyrolysis meet the RoHS standard and can be directly used as 3D printing consumables.

[0015] The antenna produced by this method can be adapted to cutting-edge fields such as 6G base stations, flexible smart watches, and implantable medical sensors, promoting the implementation of technologies for the Internet of Things and high-frequency communication. Description of the Drawings

[0016] Figure 1 It is the process flow chart of the manufacturing method of the metal foil antenna of the present invention. Detailed Embodiments

[0017] The following will combine the attached Figure 1 The present invention will be described in detail. The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0018] Please refer to Figure 1 , a manufacturing method of a metal foil antenna of the present invention, includes the following steps; Step S1: Raw material slitting: Use a laser slitter to perform high-precision slitting on the metal foil coil, with a slitting accuracy error ≤ 0.05 mm; Use a fiber laser slitter (model: IPG YLS-2000), equipped with a high-precision motion control system (repetitive positioning accuracy ± 1 μm), the laser wavelength is 1064 nm, the maximum output power is 200 W, and the spot diameter is adjusted to 50 μm to ensure that the cutting edge is smooth without slag; Install the copper / magnesium alloy foil coil (thickness 30μm, width 500mm) onto the unwinder, keep the material flat through the tension control system, set the laser slitting speed at 5m / min, the slitting width at 50mm, monitor the slitting accuracy in real time, use a high-resolution CCD camera (resolution 5μm) to detect the edge quality, and automatically adjust the laser power (adjustment range ±10%) and cutting path when burrs or deviations exceed 0.05mm; The slit metal foil is immediately subjected to micro-arc oxidation treatment. The electrolyte is sodium silicate solution (concentration 50g / L), the voltage is 400V, and the treatment time is 10 minutes to form an Al2O3 insulating layer with a thickness of 3μm. After the treatment, the insulation resistance is tested with a high-voltage megohmmeter (model: HIOKI IR4056) to ensure ≥10¹²Ω·cm. The metal foil is a copper / magnesium alloy foil with a thickness of 15 - 60μm. A dense insulating layer is formed on the surface through micro-arc oxidation treatment, and the insulation resistance ≥10¹²Ω·cm.

[0019] Step S2: TOP Removal layer treatment: Attach an anti-scratch protective film (TOPRemoval layer) to the surface of the slit metal foil, and perform stamping through a cylindrical mold to form positioning holes, a handle structure, and a signal transmission area; Select a PET-based anti-scratch film (model: 3M 9660) with a thickness of 20μm and a light transmittance ≥90%. Use a thermal roller laminator (temperature 80℃, pressure 0.5MPa) to evenly press the protective film onto the surface of the metal foil. The laminating speed is 3m / min. After lamination, verify that there are no bubbles or wrinkles through a light transmittance detector (model: BYK-Gardner haze-gard i); The cylindrical mold is made of SKD11 alloy steel and is surface-coated with a tungsten carbide layer (thickness 50μm, hardness 2000HV). The stamping area design includes positioning holes (diameter 1.0mm ± 0.02mm), a handle structure (width 3mm ± 0.1mm), and a signal transmission area (line width 0.1mm ± 0.005mm). The stamping pressure is set at 10MPa. After stamping, use an optical projector (model: Nikon V-12B) to measure the hole position accuracy. When the deviation exceeds ±0.02mm, trigger the automatic mold calibration program.

[0020] Step S3: PI film lamination: Attach multiple layers of polyimide (PI) film to the material after the TOP Removal treatment, and use a hot pressing process (temperature 100 - 150℃, pressure 5 - 10MPa) to ensure seamless bonding between the PI film and the metal foil; The PI film is a composite polyimide film doped with nano-aluminum oxide, with a dielectric constant ≤3.2, a thickness of 25 - 80μm, and a tensile strength ≥300MPa; The composite polyimide film doped with 10 wt% nano-aluminum oxide (thickness 50 μm) was cut to the same width as the metal foil, and its surface energy was increased to over 50 mN / m through plasma treatment (power 200 W, treatment time 10 s, atmosphere being a mixed gas of Ar / O2). Using a vacuum hot press (model: Tetrahedron MTP-14), the thermal pressing temperature gradient was set as 100 °C → 120 °C → 150 °C (heating rate 5 °C / min for each stage), the pressure was divided into segments of 5 MPa → 8 MPa → 10 MPa, the holding pressure time was 20 s, and after thermal pressing, the interfacial bonding strength was tested by a peel tester (model: Instron 5565) to ensure it was ≥ 8 N / cm (in accordance with the GB / T 2792 standard). A water cooling system was used in the cooling stage to avoid warping caused by thermal stress.

[0021] Step S4: Laser fine-tuning: A UV laser was used to perform micro-hole machining on the PI film to form antenna radiation units and feeding points, with the aperture accuracy of ±5 μm. A UV laser (model: Coherent AVIA LX 355-20) was adopted, with a wavelength of 355 nm, a pulse frequency of 50 kHz, a spot diameter of 10 μm, and a scanning speed of 2 m / s. A laser path file (format: G code) was generated according to the antenna design drawing, and the focusing depth was dynamically adjusted through a galvanometer system (model: Scanlab intelliSCAN) to ensure that the micro-holes penetrated through the PI film to the metal layer. An online confocal microscope (model: Olympus LEXT OLS5000) was used to detect the aperture (target 50 μm ± 5 μm) and hole pitch (error ≤ 2%) in real time. The detected data was fed back to the control system to dynamically adjust the laser power (range 10 - 20 W) to compensate for the material thickness fluctuation.

[0022] Step S5: Metal pattern stamping: Selective etching was carried out on the metal foil through a cylindrical mold to form an antenna radiation pattern, and the etching depth was 80% - 95% of the metal foil thickness. The etching process adopted plasma-assisted dry etching, the etching gas was a mixed gas of CF4 / O2, the etching rate was ≥ 5 μm / min, and the sidewall perpendicularity was ≥ 85°. A photoresist (model: AZ 4620, thickness 5 μm) was spin-coated on the metal foil surface, and an anti-etching pattern was formed through exposure (wavelength 365 nm, dose 200 mJ / cm²) and development (0.5% TMAH solution). An ICP etching equipment (model: Oxford Instruments PlasmaPro 100) is used. The reaction chamber pressure is 10 mTorr, the RF power is 500 W, the gas flow ratio of CF4 / O2 is 4:1 (total flow rate is 100 sccm), the etching rate is 6 μm / min. The ion bombardment angle is controlled by the bias voltage (-200 V) to ensure that the sidewall perpendicularity is ≥ 85°. After etching, a scanning electron microscope (model: Hitachi SU8000) is used to measure the etching depth, and the out-of-tolerance part is etched again (time ≤ 10 seconds).

[0023] Step S6: Flexible adhesive layer lamination: A flexible conductive adhesive (adhesion force ≥ 8 N / cm²) is coated on the metal pattern surface, and a double-sided tape is laminated. The thickness of the tape is 50 - 150 μm; The flexible conductive adhesive contains a graphene / silver nanowire composite conductive material with a sheet resistance ≤ 0.1 Ω / sq and a bending life ≥ 100,000 times (curvature radius 3 mm); The graphene / silver nanowire composite conductive adhesive (mass ratio 1:4) is coated on the metal pattern surface by a screen printing machine (mesh number 200, squeegee pressure 0.3 MPa). The coating thickness is 20 μm, and the curing conditions are 120 °C / 10 minutes. After curing, a four-probe tester (model: Loresta-GP MCP-T610) is used to measure the sheet resistance (≤ 0.1 Ω / sq); After the double-sided tape (model: Tesa 4965) is precisely cut, it is laminated to the conductive adhesive layer by a roller rolling machine (pressure 0.3 MPa, speed 2 m / min). After lamination, an ultrasonic detector (model: Sonix HS-1000) is used to check for interlayer air bubbles to ensure no defects.

[0024] Step S7: MFA outer shape forming: A three-dimensional curved surface stamping is carried out using a high-speed rotating mold to form a three-dimensional antenna structure, and at the same time, the shape error is corrected through real-time optical detection (AOI); The three-dimensional curved surface stamping uses a shape memory alloy mold with a diamond-like carbon coating (DLC) on the mold surface, a hardness ≥ 3000 HV, and a stamping repeat positioning accuracy ≤ 2 μm; The shape memory alloy mold uses a Ni-Ti alloy (phase transition temperature 80 °C), with a diamond-like carbon coating (DLC, thickness 2 μm, hardness 3000 HV) on the surface. The three-dimensional curved surface design of the mold is optimized through finite element analysis (software: ABAQUS) to ensure uniform stamping stress distribution; The stamping pressure is 15 MPa, and the temperature is 80 °C to trigger the shape memory effect of the mold. The AOI system (model: Koh Young KY8030-2) scans the outer shape in real time to generate an error compensation path (accuracy ±2 μm). After stamping, the product is subjected to 100,000 cycle tests on a bending testing machine (curvature radius 3 mm, frequency 1 Hz), and there is no glue layer peeling off (IPC-6013 standard).

[0025] Step S8: Bottom layer gasket treatment: Stick a non-adhesive heat-fusible gasket to the bottom of the material, and perform four-corner positioning stamping through a mold. The gasket material is degradable polylactic acid (PLA). The degradable polylactic acid (PLA) gasket (thickness 100 μm) is adhered to the bottom of the material through a heat-fusion machine (temperature 160 °C, pressure 5 MPa, time 5 seconds). After heat fusion, the degradation rate is tested by a thermogravimetric analyzer (model: TA Instruments Q500) to ensure that it is ≥90% within 180 days. The mold is designed with four-corner positioning holes (tolerance ±0.05 mm). The stamping pressure is 8 MPa. After stamping, a digital microscope (model: Keyence VHX-7000) is used to check the edge of the gasket to ensure that there are no burrs or tears.

[0026] Step S9: Roll to Roll continuous lamination: Use a multi-stage lamination device (pressure 10 - 25 MPa, temperature 80 - 120 °C) to perform 3 - 6 times of dynamic lamination on the composite layer, and the single lamination time ≤30 seconds. Use a three-stage lamination device (model: Hidraulic Press HP-300). The pressure of the pressure rollers is 10 MPa, 15 MPa, and 25 MPa respectively. The temperature gradient is 80 °C → 120 °C → 100 °C. The single lamination time is 30 seconds. The total number of lamination times is adjusted according to the layer thickness (3 - 6 times). After lamination, a tensile testing machine (model: Shimadzu AGX-V) is used to test the interlayer peel force (≥15 N / cm). An infrared thermal imager (model: FLIR T865) monitors the temperature of the lamination area in real time. When the temperature difference exceeds 5 °C, an alarm is triggered and the heating power is adjusted.

[0027] Step S10: Conductive ink printing: Use nano-silver conductive ink (resistivity ≤10⁻ 7 Ω·m) to print the antenna contacts, and the printing accuracy error ≤0.02 mm. The nano-silver conductive ink (silver content 80 wt%, particle size ≤50 nm) is used to print the antenna contacts through a piezoelectric inkjet printing head (ink droplet volume 10 pL). The printing accuracy error ≤0.02 mm. The curing conditions are 150 °C / 10 seconds. After curing, a 3D profiler (model: Bruker ContourGT-K) is used to detect the height consistency of the contacts. Perform a cross-cut test according to ASTM D3359 standard to ensure that the adhesion grade is ≥ 4B (the non-detached area ≤ 5%).

[0028] Step S11: Scrap recycling and environmental protection treatment: The stamping scrap is separated into metal and non-metal components by magnetic separation, with the metal recovery rate ≥ 98%. The non-metal scrap is pyrolyzed at low temperature to generate harmless particles; The low-temperature pyrolysis treatment is carried out in an inert atmosphere (nitrogen or argon), with the pyrolysis temperature ≤ 300 °C, the generated particle size ≤ 10 μm, and it complies with the RoHS standard; A permanent magnet drum (magnetic field intensity 1.2T) separates metal and non-metal scrap, with the metal recovery rate ≥ 98%. The separated copper / magnesium alloy fragments are remelted (temperature 1083 °C) and recast into foils; The non-metal scrap is pyrolyzed (temperature 280 °C, time 30 minutes) in a tube furnace (nitrogen atmosphere, flow rate 5 L / min) to generate carbon-based particles with a particle size ≤ 10 μm. The pyrolysis tail gas is treated by an activated carbon adsorption tower (model: Ecosorb 600), and the particles are verified to comply with the RoHS standard by a laser particle size analyzer (model: Malvern Mastersizer 3000).

[0029] Step S12: Full-automatic detection: An AI vision system is used to perform impedance matching, radiation efficiency, and defect detection on the finished products, and defective products are automatically removed; The AI vision system is based on a convolutional neural network (CNN) model. The training data contains 100,000 sets of antenna defect samples, and the detection accuracy is ≥ 99.5%. The AI detection system uses a platform equipped with NVIDIA Jetson AGX Xavier. The CNN model adopts the ResNet-50 architecture. The training data set contains 100,000 defect samples (cracks, offsets, bubbles). During detection, the system analyzes the AOI image (resolution 1 μm) in real time, and the defect recognition accuracy is ≥ 99.5%; An on-line radio frequency tester (frequency range 28 - 300 GHz) verifies the antenna impedance matching (deviation ≤ 5%) and radiation efficiency (≥ 85%). Defective products are transferred to the scrap area by a six-axis robotic arm (repetitive accuracy ± 0.1 mm), and qualified products are automatically packaged.

[0030] Among them, the method realizes real-time optimization of process parameters through a cloud production management system, and no chemical etching solution is used throughout the process. The cloud production management system collects pressure, temperature, and stamping speed data in real time through a 5G network, and uses digital twin technology to simulate the process optimization path, so that the qualified product rate is increased by ≥ 15%; The pressure, temperature, and speed data are uploaded to the cloud database in real time through a 5G module (model: Quectel RM500Q), and the dynamic optimization instructions for process parameters are sent to the device PLC; Build a digital twin model based on ANSYS Twin Builder to simulate the stamping stress distribution and heat conduction path. After optimization, the yield rate is increased by ≥ 15% (compared with the measured data).

[0031] The method is applicable to the manufacture of embedded antennas for 6G millimeter-wave communication (frequency 28 - 300 GHz), flexible wearable devices, and Internet of Things (IoT) sensors.

[0032] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A manufacturing method of a metal foil antenna, characterized in that, Including the following steps; Step S1: Raw material slitting: Use a laser slitter to perform high-precision slitting on the metal foil coil, with a slitting accuracy error ≤ 0.05 mm; Step S2: TOP Removal layer treatment: Apply an anti-scratch protective film to the surface of the slit metal foil, and perform stamping through a cylindrical mold to form positioning holes, a handle structure, and a signal transmission area; Step S3: PI film lamination: Laminate multiple layers of polyimide film on the material after TOP Removal treatment, and use a hot pressing process to ensure seamless bonding between the PI film and the metal foil; Step S4: Laser fine-tuning: Use an ultraviolet laser to perform micro-hole processing on the PI film to form antenna radiation units and feed points, with a hole diameter accuracy of ±5 μm; Step S5: Metal pattern stamping: Selectively etch the metal foil through a cylindrical mold to form an antenna radiation pattern, with an etching depth of 80% - 95% of the metal foil thickness; Step S6: Flexible adhesive layer lamination: Coat a flexible conductive adhesive on the metal pattern surface and laminate a double-sided tape, with a tape thickness of 50 - 150 μm; Step S7: MFA outer shape forming: Use a high-speed rotating mold to perform three-dimensional curved surface stamping to form an antenna three-dimensional structure, and at the same time correct the shape error through real-time optical detection; Step S8: Bottom layer gasket treatment: Bond a non-adhesive heat-fusible gasket to the bottom of the material, and perform four-corner positioning stamping through a mold. The gasket material is biodegradable polylactic acid; Step S9: Roll to Roll continuous pressing: Use a multi-stage pressing device to perform 3 - 6 times of dynamic pressing on the composite layer, with a single pressing time ≤ 30 seconds; Step S10: Conductive ink printing: Use nano-silver conductive ink to print antenna contacts, with a printing accuracy error ≤ 0.02 mm; Step S11: Scrap recycling and environmental protection treatment: Separate the metal and non-metal components of the stamping waste through magnetic separation, with a metal recovery rate ≥ 98%. The non-metal waste is subjected to low-temperature pyrolysis treatment to generate harmless particles; Step S12: Full-automatic detection: Use an AI vision system to perform impedance matching, radiation efficiency, and defect detection on the finished product, and automatically reject defective products; Among them, the method realizes real-time optimization of process parameters through a cloud production management system, and no chemical etching solution is used throughout the process.

2. The manufacturing method of a metal foil antenna according to claim 1, wherein: The PI film in step 3 is a composite polyimide film doped with nano-aluminum oxide, with a dielectric constant ≤ 3.2, a thickness of 25 - 80 μm, and a tensile strength ≥ 300 MPa.

3. The manufacturing method of a metal foil antenna according to claim 1, characterized in that: The etching process in step 5 uses plasma-assisted dry etching, with an etching gas of CF4 / O2 mixed gas, an etching rate ≥ 5 μm / min, and a sidewall perpendicularity ≥ 85°.

4. The manufacturing method of a metal foil antenna according to claim 1, wherein: The flexible conductive adhesive in step 6 contains a graphene / silver nanowire composite conductive material, with a sheet resistance ≤ 0.1 Ω / sq and a bending life ≥ 100,000 times.

5. The manufacturing method of a metal foil antenna according to claim 1, characterized in that: The three-dimensional curved surface stamping in step 7 uses a shape memory alloy mold, with a diamond-like carbon coating on the mold surface, a hardness ≥ 3000 HV, and a stamping repeat positioning accuracy ≤ 2 μm.

6. The manufacturing method of a metal foil antenna according to claim 1, characterized in that: The low-temperature pyrolysis treatment in step 11 is carried out in an inert atmosphere, with a pyrolysis temperature ≤ 300 °C, and the generated particle size ≤ 10 μm.

7. The manufacturing method of a metal foil antenna according to claim 1, characterized in that: The AI vision system in step 12 is based on a convolutional neural network model, and the training data includes 100,000 sets of antenna defect samples.

8. The manufacturing method of a metal foil antenna according to claim 1, wherein: The metal foil is a copper / magnesium alloy foil with a thickness of 15 - 60 μm. The surface is subjected to micro-arc oxidation treatment to form a dense insulating layer with an insulation resistance ≥ 10¹² Ω·cm.

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