High temperature lamination method for pet hinge positioned passport pages

Abstract

The application discloses a PET hinge positioning passport page high-temperature laminating method and relates to the technical field of electronic passport manufacturing. Breakthrough is realized by innovating laminated steel plate structure and optimizing process. Core improvements include: a special laminated steel plate is designed, a convex step is arranged on the surface of the steel plate, the dam height of the top plate is 0.13 mm on a single side, the dam height of the bottom plate is 0.17 mm on a single side, the dam height of the middle plate is 0.17 mm and 0.13 mm on two sides respectively, the dam width is 20-40 mm, and the roughness is strictly controlled to be Ra0.5+ / -0.1 mu m; during lamination, the PET hinge is accurately attached to the step, and a high-temperature and high-pressure environment of 180 DEG C and 180 N / cm2 is maintained for 20 minutes. The design effectively inhibits the overflow deformation of the melted PC material and the PET hinge, especially solves the edge distortion problem caused by the fact that the hinge area cannot be cut, the straightness of the finished product is less than 0.2 mm, and the appearance quality and structural reliability of the electronic passport are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of electronic passport manufacturing technology, and in particular to a high-temperature lamination method for passport pages with PET hinge positioning. Background Technology

[0002] In the manufacturing process of the electronic passport information page, the PET hinge and the polycarbonate (PC)-based information page inlay layer need to be permanently bonded through high-temperature lamination. Current technology generally employs a process of directly laminating multiple layers of PC material (protective layer, embedded wire layer) with the PET hinge and then hot-pressing the entire assembly. For example, the PET hinge is sandwiched between two layers of PC material and fused under a pressure of 170-190℃ and 150-200 N / cm² for 15-25 minutes. While this method achieves basic bonding, the difference in thermal expansion coefficients between PET and PC materials (PET is 65 × 10⁻⁶ N / cm²) limits its application. / ℃, PC is 70× The mismatch between the lamination temperature (°C) and the melt rheological properties causes the molten material to overflow from the edge of the laminate during lamination, resulting in irreversible deformation.

[0003] The typical scheme of the "Electronic Passport Component Layer Manufacturing Method" disclosed in Chinese Patent CN102622639B includes: cutting, cutting various raw materials to obtain the carrier layer substrate, leveling layer substrate, base layer, and center seam layer of the electronic passport; punching, punching positioning holes and chip mounting holes on the carrier layer substrate and leveling layer substrate, and punching positioning holes on the base layer; cutting strips, cutting the carrier layer substrate and leveling layer substrate into carrier layer and leveling layer; filling, encapsulating the chip into the chip mounting hole of the carrier layer; embedding and welding, embedding an antenna on the carrier layer substrate, and welding the two ends of the antenna to the two fins of the chip respectively; arranging and laminating, arranging the carrier layer, leveling layer, center seam layer, and base layer together according to a specific positional relationship and pressing them together using a laminating device. This invention's electronic passport component layer manufacturing method can improve production efficiency and the accuracy of chip positioning during the packaging process.

[0004] In summary, existing technologies have not yet solved three major technical problems: 1) directional and controllable sealing of the molten PC material in the PET hinge area under high-temperature lamination; 2) precise suppression of deformation in uncuttable areas (target straightness ≤ 0.2mm); and 3) maintaining the long-term stability of the laminated steel sheet surface. This directly leads to industry bottlenecks such as the electronic passport hinge area peel strength being less than 5N / cm and product yield being less than 85%. Summary of the Invention

[0005] In view of the aforementioned existing problems, the present invention is proposed.

[0006] Therefore, this invention provides a high-temperature lamination method for passport pages with PET hinge positioning to solve the problems of existing electronic passports.

[0007] The technical challenge of material overflow and deformation due to high temperature and pressure during the lamination of information pages and PET hinges, and the inability to cut and repair the hinge area.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0009] In a first aspect, the present invention provides a high-temperature lamination method for passport pages with PET hinge positioning, which includes the following steps:

[0010] Step 1: Prepare a special laminated steel plate. The surface of the steel plate is provided with a raised step structure, including a single step height of 0.13mm on the top plate, a single step height of 0.17mm on the bottom plate, and double step heights of 0.17mm on side A and 0.13mm on side B of the middle plate. The step width is 20~40mm and the surface roughness is Ra0.5±0.1μm.

[0011] Step 2: Stack the electronic passport inlay layers in the following order: first protective layer, compensation layer, PET hinge layer, embedded wire layer, and second protective layer. The PET hinge layer is placed between the compensation layer and the embedded wire layer, and a 7mm bonding area is reserved on each side of the hinge.

[0012] Step 3: Fix the laminate to the PET hinge using an ultrasonic welding head, ensuring that the distance between the long side of the hinge and the edge of the embedded wire layer is strictly controlled at 13±0.05mm;

[0013] Step 4: Place the assembly on the laminated steel plate, precisely aligning the PET hinge with the edge of the steel plate step, with a gap ≤ 0.05mm;

[0014] Step 5: Laminate continuously for 20 minutes at 180℃ and 180N / cm² pressure to physically prevent the material from melting and overflowing.

[0015] As a preferred embodiment of the high-temperature lamination method for PET hinge positioning of passport pages according to the present invention, the special lamination steel plate is made of 430 stainless steel substrate and is formed by five-axis CNC precision grinding. Its external dimensions are strictly controlled within the range of length 690mm±0.1mm, width 540mm±0.1mm, and thickness 0.8mm±0.01mm.

[0016] The stepped structure is continuously distributed along the entire edge of the operating surface of the top plate. The step height is fixed at 0.13mm ± 0.005mm, the step width is 20mm ± 0.05mm, and the non-operating surface of the top plate remains absolutely flat.

[0017] The steps of the middle plate are extended to a width of 40mm±0.1mm and are centered along the long axis of the steel plate. The height of the step on side A is set to 0.17mm±0.005mm, and the height of the step on side B is set to 0.13mm±0.005mm. The double-sided steps form a closed frame on the four sides of the steel plate.

[0018] The steps on the bottom slab are mirror-symmetrically distributed with the top slab, and the step height is fixed at 0.17mm±0.005mm, and the width is 20mm±0.05mm.

[0019] The angle between the sidewalls and the surface of all steps is 90°±0.5°, and the transition edges between the top and bottom surfaces of the steps are rounded with a radius of 0.05mm.

[0020] The surface roughness of the steps was achieved by polishing with diamond wheels in stages. Three grinding passes were performed using 400-mesh, 800-mesh, and 1500-mesh wheels to ensure a consistent roughness of Ra0.5±0.1μm. A sampling point was taken every 10mm for roughness testing.

[0021] The non-step areas of the steel plate are subjected to shot peening strengthening treatment. 304 stainless steel shot with a diameter of 0.2 mm is used to impact the surface with a pressure of 0.25 MPa to form a residual compressive stress layer to suppress high-temperature deformation.

[0022] As a preferred embodiment of the high-temperature lamination method for PET hinge positioning of passport pages according to the present invention, the through-hole processing of the compensation layer and the embedded wire layer adopts ultraviolet laser perforation process, with the laser wavelength set to 355nm, pulse frequency 80kHz, single pulse energy 0.8mJ, and focused spot diameter 15μm.

[0023] Before perforation, the PC material is placed on a constant temperature vacuum adsorption platform, with the temperature maintained at 25±0.5℃ and the vacuum degree at -90kPa to ensure that the material is flat and free from deformation.

[0024] The machining of positioning holes and chip holes is completed in two stages: the first stage is contour cutting at a speed of 500 mm / s with a 5 μm allowance; the second stage adopts a finishing mode, with the speed reduced to 100 mm / s, and the laser is repeatedly scanned 3 times to remove slag, and the final hole diameter tolerance is controlled within ±5 μm.

[0025] When the copper wire in the buried layer is wound, the enameled wire passes through the closed-loop tension control system and a constant tension of 0.5N±0.02N is applied. The tension sensor feeds back the data to the PLC in real time. If the tension exceeds the tolerance by 0.05N, the machine will be stopped for calibration.

[0026] The winding path is controlled by a vector interpolation algorithm, the positioning accuracy of the embedding machine's motion axis is ±1μm, the angle between the copper wire and the surface of the embedding layer is maintained at 90°±0.5°, and the spacing error between adjacent wires is ≤2μm;

[0027] Before chip soldering, the pads are cleaned with argon plasma. The processing parameters are: power 300W, argon flow rate 20sccm, duration 30s, to remove the oxide layer on the surface of the copper wire.

[0028] Welding was performed using a high-frequency ultrasonic spot welder with a welding head frequency of 60kHz, an amplitude of 8μm, a pressure of 15N, and a welding time of 50ms. X-ray inspection was conducted immediately after weld formation. The weld diameter was ≤100μm and the rate of incomplete welds had to be less than 0.1%.

[0029] The welded embedded wire layer and compensation layer are superimposed using an infrared alignment system, with the center of the positioning hole as the reference, and the coaxiality error is ≤3μm. After superposition, they are fixed by a negative pressure adsorption fixture with a vacuum pressure of -50kPa.

[0030] As a preferred embodiment of the high-temperature lamination method for passport pages with PET hinge positioning described in this invention, the optical alignment system consists of a high-resolution CCD camera, a ring LED array light source, and a piezoelectric fine-tuning platform. The CCD camera is equipped with a 5-megapixel CMOS sensor and a 10x telecentric lens, with a pixel size of 2.4μm and a working distance of 150mm.

[0031] During system initialization, a standard step gauge is used for calibration. Reference lines are laid on the edge of the laminated steel plate step, with a width of 10μm and a depth of 5μm. A three-dimensional coordinate system is established by sampling at 9 points, and the coordinate transformation error is ≤±1μm.

[0032] During the positioning process, the CCD camera acquires images of the PET hinge edge at a rate of 30 frames per second. The image processing adopts a sub-pixel edge extraction algorithm: first, a 5×5 Gaussian filter is used to reduce noise, then the Sobel operator is used to calculate the gradient field, and finally, cubic spline interpolation is used to improve the edge positioning accuracy to the 0.1 pixel level.

[0033] The offset between the long side of the hinge and the steel plate step is calculated in real time. When the offset exceeds 0.05mm, the piezoelectric fine-tuning platform starts the correction within 20ms: the X / Y direction uses a piezoelectric ceramic actuator with a stroke range of ±1mm and a resolution of 10nm, and the Z direction uses a voice coil motor to provide a constant contact pressure of 0.5N.

[0034] The calibration process is performed in two stages: the first stage uses a coarse positioning speed of 50 μm / ms to locate the target position within ±5 μm; the second stage switches to nanostepping mode and uses a precise positioning speed of 1 μm / ms to ultimately stabilize the gap between the hinge and the step at 0.03~0.05 mm.

[0035] After each calibration is completed, the system automatically records the offset data and generates a compensation curve. When the calibration amount exceeds ±0.1mm three times in a row, an audible and visual alarm is triggered, prompting the replacement of the laminated steel plate.

[0036] The positioned stack is immediately fixed with a vacuum suction cup. The surface of the suction cup is equipped with a micropore array with a pore diameter of 100μm and a pore spacing of 1mm. The vacuum pressure is -70kPa. After adsorption, the flatness change of the stack is ≤0.005mm.

[0037] As a preferred embodiment of the high-temperature lamination method for passport pages with PET hinge positioning described in this invention, the three-stage temperature control of the lamination process is achieved through an embedded temperature-pressure coupling system. This system integrates 12 sets of K-type thermocouples and 24 piezoresistive sensors. The thermocouples are embedded in the lamination steel plate at a depth of 0.2 mm and are distributed in a matrix with a spacing of 50 mm.

[0038] When the first stage of heating is started, the upper heating plate of the laminator increases the temperature at a linear rate of 10℃ / s, while the lower heating plate follows synchronously with a lag of 0.5s. When the surface temperature of the steel plate reaches 120℃±0.5℃, the system automatically applies a pre-pressure of 50N / cm² and starts a 60s countdown.

[0039] During the pre-compression period, the temperature fluctuation is controlled within ±0.3℃. The power of the heating tube is dynamically adjusted through a PID algorithm with a power adjustment accuracy of ±5W. At this time, the material undergoes a glass transition but has not yet reached a flow state.

[0040] Before the second stage of heating, the system immediately switches the control mode after detecting the pre-pressure end signal: the temperature rises to 180℃ in a gradient of 5℃ / s, and the pressure increases by 30N / cm² for every 10℃ increase during the heating process, until the total pressure of 180N / cm² is reached.

[0041] When the temperature rises to 175℃, the pressure holding program is activated, the hydraulic system switches to closed-loop servo control, and the pressure fluctuation range is compressed to ±1.5N / cm². During this stage, the material is completely melted and fills the interlayer gaps.

[0042] The third stage of constant temperature and pressure maintenance is initiated, and the system locks the temperature value at 180℃±0.2℃. The temperature data is cross-validated by three redundant thermocouples, and compensation heating is triggered if any measuring point exceeds the tolerance.

[0043] During the pressure maintenance phase, an adaptive attenuation algorithm is used to release 5 N / cm² of interference pressure every 30 seconds and then restore it to the set value. A total of 6 pulse-type pressure relief operations are performed to eliminate residual stress inside the material.

[0044] After the 20-minute pressure holding period, the heat source is immediately cut off, and the stepped cooling process begins. The hot plate separation speed of the laminator is controlled at 0.5 mm / s.

[0045] As a preferred embodiment of the high-temperature lamination method for PET hinge positioning of passport pages according to the present invention, the stepped cooling process is started immediately after the hot plate of the laminator is separated, and the nitrogen injection system is equipped with annular array nozzles with a nozzle diameter of 0.8 mm, a spacing of 15 mm, and a distance of 20 ± 0.5 mm from the surface of the steel plate.

[0046] The initial spraying stage uses -30℃ liquid nitrogen vaporized gas with a pressure of 0.25MPa and a flow rate of 120L / min. It covers the entire steel plate at a 45° angle and forcibly reduces the steel plate temperature from 180℃ to 80℃±1℃ within 60 seconds. The cooling rate is strictly controlled at 1.5℃ / s.

[0047] Temperature monitoring is achieved through real-time feedback from 12 PT100 platinum resistance thermometers embedded in the steel plate. The temperature measurement point is located at the boundary between the stepped area and the non-stepped area, with a data sampling frequency of 10Hz. When the detected temperature difference in the area is greater than 2℃, the flow rate of the corresponding nozzle is automatically adjusted, with a flow rate adjustment accuracy of ±0.5L / min.

[0048] During the natural cooling stage, the assembly is moved into a constant temperature inert environment chamber, which is filled with 99.999% high-purity nitrogen and has an oxygen content of <10ppm. The temperature is uniformly reduced from 80℃ to 40℃, with a cooling gradient of 0.67℃ / min. An airflow field with a laminar flow velocity of 0.2m / s is set in the chamber to eliminate heat accumulation.

[0049] During the cooling process, the shape change of the stack is recorded every 5 minutes. The laser displacement sensor has a measurement accuracy of 0.1μm. When the warpage of the PET hinge area is detected to be >0.05mm, the auxiliary flattening mechanism is triggered. The pressure head applies a local pressure of 5N / cm² for 30 seconds for correction.

[0050] When the temperature drops to 40℃±0.5℃, vacuum demolding is initiated. The demolding force increases linearly to the maximum value of 50N and is held for 3 seconds. The separation speed is 0.1mm / s. Immediately after demolding, the finished product is placed in a 23℃ / 50%RH constant humidity chamber for 24 hours to equilibrate.

[0051] After demolding, the laminated steel sheet enters the surface regeneration process. First, dry ice blasting is used to remove residual polymer, followed by sandblasting. The steel sheet temperature must be cooled to below 25°C before the regeneration cycle can begin.

[0052] As a preferred embodiment of the high-temperature lamination method for passport pages with PET hinge positioning described in this invention, the surface regeneration treatment is carried out in a dedicated sandblasting chamber, the sandblasting medium is 120-mesh white corundum abrasive with a Mohs hardness of 9.0 and a particle size distribution of 150~180μm, and the abrasive moisture content is strictly controlled to be below 0.3%.

[0053] Before sandblasting, the laminated steel plate is fixed on the magnetic platform, the platform temperature is maintained at 25±1℃, the spray gun is tilted at a 30° angle to the steel plate surface, the moving speed is 0.5m / s, the working distance is 100±5mm, the compressed air pressure is 0.3MPa±0.01MPa, and the flow rate is 60L / min.

[0054] The sandblasting process is carried out in three stages: the first stage is parallel sweeping along the long axis of the steel plate, the second stage is vertical sweeping with a 90° rotation, and the third stage is diagonal sweeping at 45°. Each sweep is spaced 10 seconds apart to allow for dust settling, and the total abrasive consumption is 400g / m².

[0055] Plasma cleaning is performed in a vacuum reaction chamber. After the chamber is evacuated to a vacuum level of 5×10⁻³Pa, argon gas is introduced with a purity of 99.999%, a flow rate of 20 sccm, and a working pressure of 10Pa.

[0056] The RF power supply is 300W±5W, the excitation frequency is 13.56MHz, the processing time is 30 minutes, the electrode spacing is 50mm, and the steel plate temperature is controlled below 40℃ during the processing by a water cooling system.

[0057] The nano-zirconia coating was applied by sol-gel spraying. The precursor solution was zirconium oxychloride ethanol solution with 3% yttrium nitrate stabilizer added. The atomization pressure was 0.15 MPa and the spray gun moving speed was 1 m / s.

[0058] The coating is applied in two layers: after the first layer is sprayed, it is preheated at 120℃ for 60 seconds to form a porous substrate; after the second layer is sprayed, it is cured at 150℃ for 30 minutes. The final coating thickness is 1.0~1.2μm, and the thickness uniformity deviation is ≤±0.05μm.

[0059] The recycled steel plates must pass three tests: white light interferometer to measure the roughness Ra value of the step area, contact angle tester to verify that the surface energy is >72mN / m, and XRD to detect that the tetragonal zirconium oxide content is >85%;

[0060] Each batch of recycled steel sheets must undergo process verification testing. Take three steel sheets and laminate five standard samples on each sheet. The proportion of samples with straightness exceeding 0.15mm in the PET hinge area must not exceed 1 / 1000.

[0061] As a preferred embodiment of the high-temperature lamination method for PET hinge positioning of passport pages described in this invention, the finished product inspection adopts a dual-laser profilometer synchronous scanning system, the main laser is a helium-neon laser with a wavelength of 632.8nm and a line scanning frequency of 10kHz, the auxiliary laser is a 405nm blue laser, and the dot density is 500 dots / mm².

[0062] Before scanning, a reference marking tape with a bandwidth of 0.5 mm and containing chrome lines spaced 10 μm apart was pasted on the PET hinge area as an optical positioning reference. The marking tape was peeled off non-destructively with ethanol after the inspection.

[0063] The main laser continuously scans along the long side of the hinge, with the scanning path 0.3mm ± 0.02mm from the edge. 200 contour points are collected every millimeter. The system fits a straight line using the least squares method and calculates the deviation value. When the straightness deviation is > 0.2mm, the system automatically sprays red UV marking paint on the defect area.

[0064] A secondary laser synchronously scans the chip packaging area to detect the coplanarity of the copper wires and the chip. A yellow marker is triggered when the coplanarity exceeds the tolerance by more than 5μm.

[0065] Peel strength tests were conducted on samples marked as qualified, using a custom pneumatic clamp to hold the exposed end of the PET hinge. The clamping area was 10×20mm, the pneumatic pressure was 0.6MPa, the peel angle was 180°, and the tensile speed was 100mm / min.

[0066] During testing, the force-displacement curve is recorded in real time. When the peel strength first reaches 8 N / cm², the displacement value L1 is recorded. When the strength decreases by 20%, the displacement value L2 is recorded. If L2-L1>0.5mm, the interface is judged to be in failure.

[0067] All test data are uploaded to the MES system. Products that fail to meet the straightness standard are directly crushed and recycled with a particle size ≤0.5mm. Products that fail the peel strength standard but meet the straightness standard enter the rework process: first, the adhesive layer is softened with 120℃ hot air at a speed of 5m / s for 30 seconds, then the residual adhesive is removed with a precision scraper with a blade radius of 50μm. After removal, the epoxy film is recoated.

[0068] Returned products need to undergo secondary lamination. The lamination parameters are adjusted to: temperature 170℃, pressure 150N / cm², and time 15 minutes. After secondary lamination, the peel strength meets the standard rate >99.2%.

[0069] The final qualified products are sealed in nitrogen gas with an oxygen content of less than 100 ppm. They are also accompanied by a laser-etched process traceability code containing the steel plate batch number, lamination timeline, and test data hash value.

[0070] As a preferred embodiment of the high-temperature lamination method for passport pages with PET hinge positioning as described in this invention, the width of the embedded wire layer is strictly limited to 174±0.05mm, and its edge forms a stepped sealing structure with the PET hinge bonding area. This structure is formed by precision die-cutting process, with a die-cutting blade angle of 22° and a blade radius ≤5μm.

[0071] The overlapping area between the exposed part of the PET hinge and the laminated steel plate step is designed as a three-level sealing strip: the first level is a physical contact sealing strip with a width of 1.0±0.02mm, a surface processing depth of 10μm and a micro-groove array with a spacing of 50μm, and the groove direction is at a 45° angle to the lamination pressure direction;

[0072] The second stage is a molten material flow-blocking zone with a width of 1.5±0.03mm. This area is pre-coated with a silicone-based sealant with a matching coefficient of thermal expansion before lamination. The sealant contains glass microspheres with a diameter of 5~8μm as spacer particles.

[0073] The third level is a dynamic compensation band with a width of 0.5±0.01mm. It has a built-in pressure-sensitive color-changing film. When the local pressure exceeds 190N / cm², the film changes from transparent to red, indicating the pressure distribution status in real time.

[0074] During the lamination process, the microgrooves of the physical contact sealing strip capture the first wave of molten PC material to form a primary seal. The sealant of the flow-blocking strip expands by 35% at 120°C to fill the gaps, and the glass microspheres are broken in a controlled manner to release silica to enhance the bonding strength.

[0075] The dynamic compensation belt triggers pressure feedback through a pressure-sensitive color change signal: when the red area is detected to be greater than 30%, the laminator automatically reduces the pressure in that area by 5 N / cm² and extends the holding time by 10 seconds.

[0076] The total width of the overlapping area is controlled at 3.0±0.05mm. After lamination, the seal integrity is verified by micro-CT scanning. The porosity is required to be <0.01%, and the thickness change of the transition zone at the interface of the three-level sealing strip is ≤0.5μm.

[0077] The finished product's edge undergoes a helium mass spectrometry leak test; after introducing 0.6 MPa of helium gas, the leakage rate must be <1×10⁻⁻⁻⁶. 9 For parts that do not meet the standard (Pa·m³ / s), a local laser remelting process is used for repair: a 1064nm fiber laser with a power of 80W, a spot diameter of 0.1mm, a scanning speed of 10mm / s, and a remelting depth of 50±5μm is used.

[0078] As a preferred embodiment of the passport page high-temperature lamination method for PET hinge positioning described in this invention, the partition pressure control is achieved through a piezoelectric ceramic actuator array, which consists of 576 independent drive units, each unit measuring 10×10mm. Each unit integrates a pressure sensor and a temperature compensation module, and the total array thickness is 1.8mm, embedded in the surface of the laminator hot plate.

[0079] The pressure zoning strategy is based on the precise division of the laminated steel plate step position: the unit corresponding to the PET hinge bonding area is defined as the high pressure zone, with a width of 20±0.1mm; the non-hinge area is the reference pressure zone; the boundary between the high pressure zone and the reference zone is located by laser projection, with a positioning accuracy of ±0.05mm;

[0080] When lamination starts, all units are subjected to a base pressure of 180 N / cm²; when the temperature reaches 120℃ in the pre-melting stage, the high-pressure zone units increase the pressure to 200 N / cm² at a rate of 5 N / cm² per second, while the base zone remains unchanged at 180 N / cm².

[0081] Dynamic pressure adjustment and pressure-sensitive color-changing signal linkage: When the area of ​​the red region in the dynamic compensation zone is greater than 30%, the system automatically reduces the pressure of the corresponding coordinate point unit by 5 N / cm², and returns to the set value in three steps within 10 seconds, with each return being 1.67 N / cm².

[0082] The actuator control adopts an adaptive pulse drive mode: the piezoelectric ceramic drive voltage is adjustable from 0 to 150V, the voltage resolution is 2mV, and the pressure output linearity error is ≤0.3%; the high-pressure zone unit applies a 220N / cm² pulse pressure for 50ms every 15 seconds to overcome the material flow resistance;

[0083] The temperature compensation module monitors the unit temperature rise in real time. When the local temperature exceeds 185℃, it automatically reduces the driving voltage by 0.5V / N / cm² to prevent thermal depolarization of the piezoelectric ceramic.

[0084] Five minutes before the end of lamination, the pressure equalization program is initiated: the high-pressure zone decreases to 185 N / cm² at a rate of 0.8 N / cm² per second, and the reference zone decreases to 175 N / cm² simultaneously, so that the internal stress gradient of the material is released gradually.

[0085] Pressure data is recorded throughout the entire cycle, with a sampling frequency of 100Hz. The generated pressure-position-time three-dimensional map is used for process traceability. The actuator array needs to be calibrated for its piezoelectric constant every 50 hours of operation, with a calibration accuracy of ±0.5%.

[0086] In a second aspect, the present invention provides a computer device including a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program is executed by the processor, it implements any step of the high-temperature lamination method for passport pages with PET hinge positioning as described in the first aspect of the present invention.

[0087] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, it implements any step of the high-temperature lamination method for passport page positioning by PET hinge as described in the first aspect of the present invention.

[0088] The beneficial effects of this invention are:

[0089] This invention achieves zero overflow control of molten material in the PET hinge area for the first time by combining the synergistic effect of innovatively designed differentiated stepped laminated steel plates (top plate 0.13mm / bottom plate 0.17mm / middle plate 0.17mm~0.13mm on both sides) and a three-level dynamic sealing system (physical contact band - flow blocking band - compensation band), completely eliminating the need for edge trimming caused by material deformation in traditional processes. Experiments show that the straightness of the finished hinge area is stably controlled within the range of 0.12±0.03mm (industry standard ≤0.2mm), and the pass rate jumps from 82% of the traditional process to over 99.5%. The zoned pressure control technology (200N / cm² in the hinge area / 180N / cm² in the non-hinge area) combined with the millisecond-level response of the piezoelectric ceramic actuator array increases the PET / PC interface peel strength to 10.2±1.3N / cm (compared to 5.3±2.1N / cm in the existing technology), reducing the strength fluctuation range by 60% and significantly improving the mechanical durability of the electronic passport. The surface regeneration process, through the synergistic treatment of a nano-zirconia coating (1.2μm thick) and plasma cleaning, enhances the laminated steel... The lifespan of the board has been extended from the traditional 10 cycles to over 200 cycles, with a roughness stability Ra of over 99% and a single lamination cost reduction of 41%. The combined application of an optical alignment system (±0.05mm accuracy) and a pulsed pressure relief process (releasing 5N / cm² interference pressure every 30 seconds) effectively suppresses the cumulative stress during the hot pressing process of multilayer materials, reducing the warpage deformation of the finished product from 0.25mm to below 0.04mm, completely solving the curling problem of passport pages after long-term use. The composite design of the microgroove array (10μm deep / 50μm spacing) and the thermal expansion sealant (containing 5~8μm glass microspheres) in the three-level sealing structure reduces the edge helium leak detection rate to 5× The technology achieves performance in the Pa·m³ / s range, improving waterproof and moisture-proof capabilities by three orders of magnitude and significantly extending the lifespan of electronic chips. The overall technology frees electronic passport manufacturing from reliance on manual trimming, increasing production line automation to 98% and reducing energy consumption per passport by 37%, demonstrating significant industrial implementation value. Attached Figure Description

[0090] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0091] Figure 1 This is a flowchart of the high-temperature lamination method for passport pages with PET hinge positioning in Example 1. Detailed Implementation

[0092] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0093] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0094] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0095] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides a high-temperature lamination method for passport pages with PET hinge positioning, including the following steps:

[0096] Step 1: Prepare a special laminated steel plate. The surface of the steel plate is provided with a raised step structure, including a single step height of 0.13mm on the top plate, a single step height of 0.17mm on the bottom plate, and double step heights of 0.17mm on side A and 0.13mm on side B of the middle plate. The step width is 20~40mm and the surface roughness is Ra0.5±0.1μm.

[0097] Step 2: Stack the electronic passport inlay layers in the following order: first protective layer, compensation layer, PET hinge layer, embedded wire layer, and second protective layer. The PET hinge layer is placed between the compensation layer and the embedded wire layer, and a 7mm bonding area is reserved on each side of the hinge.

[0098] Step 3: Fix the laminate to the PET hinge using an ultrasonic welding head, ensuring that the distance between the long side of the hinge and the edge of the embedded wire layer is strictly controlled at 13±0.05mm;

[0099] Step 4: Place the assembly on the laminated steel plate, precisely aligning the PET hinge with the edge of the steel plate step, with a gap ≤ 0.05mm;

[0100] Step 5: Laminate continuously for 20 minutes at 180℃ and 180N / cm² pressure to physically prevent the material from melting and overflowing.

[0101] The special laminated steel sheet is made of 430 stainless steel substrate and is formed by five-axis CNC precision grinding. Its external dimensions are strictly controlled within the range of length 690mm±0.1mm, width 540mm±0.1mm, and thickness 0.8mm±0.01mm.

[0102] The stepped structure is continuously distributed along the entire edge of the operating surface of the top plate. The step height is fixed at 0.13mm±0.005mm, and the step width is 20mm±0.05mm. The non-operating surface of the top plate remains absolutely flat.

[0103] The steps of the middle plate are extended to a width of 40mm±0.1mm and are centered along the long axis of the steel plate. The height of the step on side A is set to 0.17mm±0.005mm, and the height of the step on side B is set to 0.13mm±0.005mm. The double-sided steps form a closed frame on the four sides of the steel plate.

[0104] The steps on the bottom slab are mirror-symmetrically distributed with the top slab, and the step height is fixed at 0.17mm±0.005mm, and the width is 20mm±0.05mm.

[0105] The angle between the sidewalls and the surface of all steps is 90°±0.5°, and the transition edges between the top and bottom surfaces of the steps are rounded with a radius of 0.05mm.

[0106] The surface roughness of the steps was achieved by polishing with diamond wheels in stages. Three grinding passes were performed using 400-mesh, 800-mesh, and 1500-mesh wheels to ensure a consistent roughness of Ra0.5±0.1μm. A sampling point was taken every 10mm for roughness testing.

[0107] The non-step areas of the steel plate are subjected to shot peening strengthening treatment. 304 stainless steel shot with a diameter of 0.2 mm is used to impact the surface with a pressure of 0.25 MPa to form a residual compressive stress layer to suppress high-temperature deformation.

[0108] The through-hole processing of the compensation layer and the buried wire layer adopts the ultraviolet laser perforation process, with the laser wavelength set at 355nm, the pulse frequency at 80kHz, the single pulse energy at 0.8mJ, and the focused spot diameter at 15μm.

[0109] Before perforation, the PC material is placed on a constant temperature vacuum adsorption platform, with the temperature maintained at 25±0.5℃ and the vacuum degree at -90kPa to ensure that the material is flat and free from deformation.

[0110] The machining of positioning holes and chip holes is completed in two stages: the first stage is contour cutting at a speed of 500 mm / s with a 5 μm allowance; the second stage adopts a finishing mode, with the speed reduced to 100 mm / s, and the laser is repeatedly scanned 3 times to remove slag, and the final hole diameter tolerance is controlled within ±5 μm.

[0111] When the copper wire in the buried layer is wound, the enameled wire passes through the closed-loop tension control system and a constant tension of 0.5N±0.02N is applied. The tension sensor feeds back the data to the PLC in real time. If the tension exceeds the tolerance by 0.05N, the machine will be stopped for calibration.

[0112] The winding path is controlled by a vector interpolation algorithm, the positioning accuracy of the embedding machine's motion axis is ±1μm, the angle between the copper wire and the surface of the embedding layer is maintained at 90°±0.5°, and the spacing error between adjacent wires is ≤2μm;

[0113] Before chip soldering, the pads are cleaned with argon plasma. The processing parameters are: power 300W, argon flow rate 20sccm, duration 30s, to remove the oxide layer on the surface of the copper wire.

[0114] Welding was performed using a high-frequency ultrasonic spot welder with a welding head frequency of 60kHz, an amplitude of 8μm, a pressure of 15N, and a welding time of 50ms. X-ray inspection was conducted immediately after weld formation. The weld diameter was ≤100μm and the rate of incomplete welds had to be less than 0.1%.

[0115] The welded embedded wire layer and compensation layer are superimposed using an infrared alignment system, with the center of the positioning hole as the reference, and the coaxiality error is ≤3μm. After superposition, they are fixed by a negative pressure adsorption fixture with a vacuum pressure of -50kPa.

[0116] The optical alignment system consists of a high-resolution CCD camera, a ring-shaped LED array light source, and a piezoelectric fine-tuning platform. The CCD camera is equipped with a 5-megapixel CMOS sensor and a 10x telecentric lens, with a pixel size of 2.4μm and a working distance of 150mm.

[0117] During system initialization, a standard step gauge is used for calibration. Reference lines are laid on the edge of the laminated steel plate step, with a width of 10μm and a depth of 5μm. A three-dimensional coordinate system is established by sampling at 9 points, and the coordinate transformation error is ≤±1μm.

[0118] During the positioning process, the CCD camera acquires images of the PET hinge edge at a rate of 30 frames per second. The image processing adopts a sub-pixel edge extraction algorithm: first, a 5×5 Gaussian filter is used to reduce noise, then the Sobel operator is used to calculate the gradient field, and finally, cubic spline interpolation is used to improve the edge positioning accuracy to the 0.1 pixel level.

[0119] The offset between the long side of the hinge and the steel plate step is calculated in real time. When the offset exceeds 0.05mm, the piezoelectric fine-tuning platform starts the correction within 20ms: the X / Y direction uses a piezoelectric ceramic actuator with a stroke range of ±1mm and a resolution of 10nm, and the Z direction uses a voice coil motor to provide a constant contact pressure of 0.5N.

[0120] The calibration process is performed in two stages: the first stage uses a coarse positioning speed of 50 μm / ms to locate the target position within ±5 μm; the second stage switches to nanostepping mode and uses a precise positioning speed of 1 μm / ms to ultimately stabilize the gap between the hinge and the step at 0.03~0.05 mm.

[0121] After each calibration is completed, the system automatically records the offset data and generates a compensation curve. When the calibration amount exceeds ±0.1mm three times in a row, an audible and visual alarm is triggered, prompting the replacement of the laminated steel plate.

[0122] The positioned stack is immediately fixed with a vacuum suction cup. The surface of the suction cup is equipped with a micropore array with a pore diameter of 100μm and a pore spacing of 1mm. The vacuum pressure is -70kPa. After adsorption, the flatness change of the stack is ≤0.005mm.

[0123] The three-stage temperature control of the lamination process is achieved through an embedded temperature-pressure coupling system, which integrates 12 sets of K-type thermocouples and 24 piezoresistive sensors. The thermocouples are embedded in the laminated steel plate at a depth of 0.2 mm and are distributed in a matrix with a spacing of 50 mm.

[0124] When the first stage of heating is started, the upper heating plate of the laminator increases the temperature at a linear rate of 10℃ / s, while the lower heating plate follows synchronously with a lag of 0.5s. When the surface temperature of the steel plate reaches 120℃±0.5℃, the system automatically applies a pre-pressure of 50N / cm² and starts a 60s countdown.

[0125] During the pre-compression period, the temperature fluctuation is controlled within ±0.3℃. The power of the heating tube is dynamically adjusted through a PID algorithm with a power adjustment accuracy of ±5W. At this time, the material undergoes a glass transition but has not yet reached a flow state.

[0126] Before the second stage of heating, the system immediately switches the control mode after detecting the pre-pressure end signal: the temperature rises to 180℃ in a gradient of 5℃ / s, and the pressure increases by 30N / cm² for every 10℃ increase during the heating process, until the total pressure of 180N / cm² is reached.

[0127] When the temperature rises to 175℃, the pressure holding program is activated, the hydraulic system switches to closed-loop servo control, and the pressure fluctuation range is compressed to ±1.5N / cm². During this stage, the material is completely melted and fills the interlayer gaps.

[0128] The third stage of constant temperature and pressure maintenance is initiated, and the system locks the temperature value at 180℃±0.2℃. The temperature data is cross-validated by three redundant thermocouples, and compensation heating is triggered if any measuring point exceeds the tolerance.

[0129] During the pressure maintenance phase, an adaptive attenuation algorithm is used to release 5 N / cm² of interference pressure every 30 seconds and then restore it to the set value. A total of 6 pulse-type pressure relief operations are performed to eliminate residual stress inside the material.

[0130] After the 20-minute pressure holding period, the heat source is immediately cut off, and the stepped cooling process begins. The hot plate separation speed of the laminator is controlled at 0.5 mm / s.

[0131] The stepped cooling process is started immediately after the hot plate of the laminator is separated. The nitrogen injection system is equipped with a ring array nozzle with a nozzle diameter of 0.8 mm, a spacing of 15 mm, and a distance of 20 ± 0.5 mm from the steel plate surface.

[0132] The initial spraying stage uses -30℃ liquid nitrogen vaporized gas with a pressure of 0.25MPa and a flow rate of 120L / min. It covers the entire steel plate at a 45° angle and forcibly reduces the steel plate temperature from 180℃ to 80℃±1℃ within 60 seconds. The cooling rate is strictly controlled at 1.5℃ / s.

[0133] Temperature monitoring is achieved through real-time feedback from 12 PT100 platinum resistance thermometers embedded in the steel plate. The temperature measurement point is located at the boundary between the stepped area and the non-stepped area, with a data sampling frequency of 10Hz. When the detected temperature difference in the area is greater than 2℃, the flow rate of the corresponding nozzle is automatically adjusted, with a flow rate adjustment accuracy of ±0.5L / min.

[0134] During the natural cooling stage, the assembly is moved into a constant temperature inert environment chamber, which is filled with 99.999% high-purity nitrogen and has an oxygen content of <10ppm. The temperature is uniformly reduced from 80℃ to 40℃, with a cooling gradient of 0.67℃ / min. An airflow field with a laminar flow velocity of 0.2m / s is set in the chamber to eliminate heat accumulation.

[0135] During the cooling process, the shape change of the stack is recorded every 5 minutes. The laser displacement sensor has a measurement accuracy of 0.1μm. When the warpage of the PET hinge area is detected to be >0.05mm, the auxiliary flattening mechanism is triggered. The pressure head applies a local pressure of 5N / cm² for 30 seconds for correction.

[0136] When the temperature drops to 40℃±0.5℃, vacuum demolding is initiated. The demolding force increases linearly to the maximum value of 50N and is held for 3 seconds. The separation speed is 0.1mm / s. Immediately after demolding, the finished product is placed in a 23℃ / 50%RH constant humidity chamber for 24 hours to equilibrate.

[0137] After demolding, the laminated steel sheet enters the surface regeneration process. First, dry ice blasting is used to remove residual polymer, followed by sandblasting. The steel sheet temperature must be cooled to below 25°C before the regeneration cycle can begin.

[0138] Surface regeneration treatment is carried out in a dedicated sandblasting chamber. The sandblasting medium is 120-mesh white corundum abrasive with a Mohs hardness of 9.0 and a particle size distribution of 150~180μm. The abrasive moisture content is strictly controlled to be below 0.3%.

[0139] Before sandblasting, the laminated steel plate is fixed on the magnetic platform, the platform temperature is maintained at 25±1℃, the spray gun is tilted at a 30° angle to the steel plate surface, the moving speed is 0.5m / s, the working distance is 100±5mm, the compressed air pressure is 0.3MPa±0.01MPa, and the flow rate is 60L / min.

[0140] The sandblasting process is carried out in three stages: the first stage is parallel sweeping along the long axis of the steel plate, the second stage is vertical sweeping with a 90° rotation, and the third stage is diagonal sweeping at 45°. Each sweep is spaced 10 seconds apart to allow for dust settling, and the total abrasive consumption is 400g / m².

[0141] Plasma cleaning is performed in a vacuum reaction chamber. After the chamber is evacuated to a vacuum level of 5×10⁻³Pa, argon gas is introduced with a purity of 99.999%, a flow rate of 20 sccm, and a working pressure of 10Pa.

[0142] The RF power supply is 300W±5W, the excitation frequency is 13.56MHz, the processing time is 30 minutes, the electrode spacing is 50mm, and the steel plate temperature is controlled below 40℃ during the processing by a water cooling system.

[0143] The nano-zirconia coating was applied by sol-gel spraying. The precursor solution was zirconium oxychloride ethanol solution with 3% yttrium nitrate stabilizer added. The atomization pressure was 0.15 MPa and the spray gun moving speed was 1 m / s.

[0144] The coating is applied in two layers: after the first layer is sprayed, it is preheated at 120℃ for 60 seconds to form a porous substrate; after the second layer is sprayed, it is cured at 150℃ for 30 minutes. The final coating thickness is 1.0~1.2μm, and the thickness uniformity deviation is ≤±0.05μm.

[0145] The recycled steel plates must pass three tests: white light interferometer to measure the roughness Ra value of the step area, contact angle tester to verify that the surface energy is >72mN / m, and XRD to detect that the tetragonal zirconium oxide content is >85%;

[0146] Each batch of recycled steel sheets must undergo process verification testing. Take three steel sheets and laminate five standard samples on each sheet. The proportion of samples with straightness exceeding 0.15mm in the PET hinge area must not exceed 1 / 1000.

[0147] The finished product inspection adopts a dual-laser profilometer synchronous scanning system. The main laser is a helium-neon laser with a wavelength of 632.8nm and a line scanning frequency of 10kHz. The auxiliary laser is a 405nm blue laser with a dot density of 500 dots / mm².

[0148] Before scanning, a reference marking tape with a bandwidth of 0.5 mm and containing chrome lines spaced 10 μm apart was pasted on the PET hinge area as an optical positioning reference. The marking tape was peeled off non-destructively with ethanol after the inspection.

[0149] The main laser continuously scans along the long side of the hinge, with the scanning path 0.3mm ± 0.02mm from the edge. 200 contour points are collected every millimeter. The system fits a straight line using the least squares method and calculates the deviation value. When the straightness deviation is > 0.2mm, the system automatically sprays red UV marking paint on the defect area.

[0150] A secondary laser synchronously scans the chip packaging area to detect the coplanarity of the copper wires and the chip. A yellow marker is triggered when the coplanarity exceeds the tolerance by more than 5μm.

[0151] Peel strength tests were conducted on samples marked as qualified, using a custom pneumatic clamp to hold the exposed end of the PET hinge. The clamping area was 10×20mm, the pneumatic pressure was 0.6MPa, the peel angle was 180°, and the tensile speed was 100mm / min.

[0152] During testing, the force-displacement curve is recorded in real time. When the peel strength first reaches 8 N / cm², the displacement value L1 is recorded. When the strength decreases by 20%, the displacement value L2 is recorded. If L2-L1>0.5mm, the interface is judged to be in failure.

[0153] All test data are uploaded to the MES system. Products that fail to meet the straightness standard are directly crushed and recycled with a particle size ≤0.5mm. Products that fail the peel strength standard but meet the straightness standard enter the rework process: first, the adhesive layer is softened with 120℃ hot air at a speed of 5m / s for 30 seconds, then the residual adhesive is removed with a precision scraper with a blade radius of 50μm. After removal, the epoxy film is recoated.

[0154] Returned products need to undergo secondary lamination. The lamination parameters are adjusted to: temperature 170℃, pressure 150N / cm², and time 15 minutes. After secondary lamination, the peel strength meets the standard rate >99.2%.

[0155] The final qualified products are sealed in nitrogen gas with an oxygen content of less than 100 ppm. They are also accompanied by a laser-etched process traceability code containing the steel plate batch number, lamination timeline, and test data hash value.

[0156] The width of the embedded wire layer is strictly limited to 174±0.05mm. Its edge forms a stepped sealing structure with the PET hinge bonding area. This structure is formed by precision die-cutting process with a die-cutting blade angle of 22° and a blade radius of ≤5μm.

[0157] The overlapping area between the exposed part of the PET hinge and the laminated steel plate step is designed as a three-level sealing strip: the first level is a physical contact sealing strip with a width of 1.0±0.02mm, a surface processing depth of 10μm and a micro-groove array with a spacing of 50μm, and the groove direction is at a 45° angle to the lamination pressure direction;

[0158] The second stage is a molten material flow-blocking zone with a width of 1.5±0.03mm. This area is pre-coated with a silicone-based sealant with a matching coefficient of thermal expansion before lamination. The sealant contains glass microspheres with a diameter of 5~8μm as spacer particles.

[0159] The third level is a dynamic compensation band with a width of 0.5±0.01mm. It has a built-in pressure-sensitive color-changing film. When the local pressure exceeds 190N / cm², the film changes from transparent to red, indicating the pressure distribution status in real time.

[0160] During the lamination process, the microgrooves of the physical contact sealing strip capture the first wave of molten PC material to form a primary seal. The sealant of the flow-blocking strip expands by 35% at 120°C to fill the gaps, and the glass microspheres are broken in a controlled manner to release silica to enhance the bonding strength.

[0161] The dynamic compensation belt triggers pressure feedback through a pressure-sensitive color change signal: when the red area is detected to be greater than 30%, the laminator automatically reduces the pressure in that area by 5 N / cm² and extends the holding time by 10 seconds.

[0162] The total width of the overlapping area is controlled at 3.0±0.05mm. After lamination, the seal integrity is verified by micro-CT scanning. The porosity is required to be <0.01%, and the thickness change of the transition zone at the interface of the three-level sealing strip is ≤0.5μm.

[0163] The finished product's edge undergoes a helium mass spectrometry leak test; after introducing 0.6 MPa of helium gas, the leakage rate must be <1×10⁻⁻⁻⁶. 9 For parts that do not meet the standard (Pa·m³ / s), a local laser remelting process is used for repair: a 1064nm fiber laser with a power of 80W, a spot diameter of 0.1mm, a scanning speed of 10mm / s, and a remelting depth of 50±5μm is used.

[0164] Zoned pressure control is achieved through a piezoelectric ceramic actuator array, which consists of 576 independent drive units, each unit measuring 10×10mm. Each unit integrates a pressure sensor and a temperature compensation module. The total thickness of the array is 1.8mm, and it is embedded in the surface of the laminator hot plate.

[0165] The pressure zoning strategy is based on the precise division of the laminated steel plate step position: the unit corresponding to the PET hinge bonding area is defined as the high pressure zone, with a width of 20±0.1mm; the non-hinge area is the reference pressure zone; the boundary between the high pressure zone and the reference zone is located by laser projection, with a positioning accuracy of ±0.05mm;

[0166] When lamination starts, all units are subjected to a base pressure of 180 N / cm²; when the temperature reaches 120℃ in the pre-melting stage, the high-pressure zone units increase the pressure to 200 N / cm² at a rate of 5 N / cm² per second, while the base zone remains unchanged at 180 N / cm².

[0167] Dynamic pressure adjustment and pressure-sensitive color-changing signal linkage: When the area of ​​the red region in the dynamic compensation zone is greater than 30%, the system automatically reduces the pressure of the corresponding coordinate point unit by 5 N / cm², and returns to the set value in three steps within 10 seconds, with each return being 1.67 N / cm².

[0168] The actuator control adopts an adaptive pulse drive mode: the piezoelectric ceramic drive voltage is adjustable from 0 to 150V, the voltage resolution is 2mV, and the pressure output linearity error is ≤0.3%; the high-pressure zone unit applies a 220N / cm² pulse pressure for 50ms every 15 seconds to overcome the material flow resistance;

[0169] The temperature compensation module monitors the unit temperature rise in real time. When the local temperature exceeds 185℃, it automatically reduces the driving voltage by 0.5V / N / cm² to prevent thermal depolarization of the piezoelectric ceramic.

[0170] Five minutes before the end of lamination, the pressure equalization program is initiated: the high-pressure zone decreases to 185 N / cm² at a rate of 0.8 N / cm² per second, and the reference zone decreases to 175 N / cm² simultaneously, so that the internal stress gradient of the material is released gradually.

[0171] Pressure data is recorded throughout the entire cycle, with a sampling frequency of 100Hz. The generated pressure-position-time three-dimensional map is used for process traceability. The actuator array needs to be calibrated for its piezoelectric constant every 50 hours of operation, with a calibration accuracy of ±0.5%.

[0172] Example 2 is the second embodiment of the present invention. The workflow of the high-temperature lamination method for PET hinge positioning passport pages in this embodiment is as follows:

[0173] In the preparation of the special laminated steel plate in step 1, 430 stainless steel plate (thickness 0.8mm) is selected and processed by five-axis CNC grinding: First, the step contour is rough ground with a 400-grit diamond grinding wheel, and the step width is set in sections of 20mm for the top plate, 40mm for the middle plate, and 20mm for the bottom plate; in the finishing stage, the grinding wheel is switched to 1500-grit, and the step height of the top plate is controlled at 0.13±0.005mm, the A side of the middle plate is 0.17±0.005mm / B side is 0.13±0.005mm, and the bottom plate is 0.17±0.005mm; then shot peening is performed, using 0.2mm diameter stainless steel shot at 0.25MPa to impact the non-step areas; finally, a white light interferometer is used to inspect the roughness to ensure that the Ra value is stable in the range of 0.4~0.6μm, and qualified steel plates are engraved with a unique batch code.

[0174] Step 2, the inlay layer stacking operation, is performed in a temperature-controlled cleanroom (23℃±1℃, humidity 45%): The first protective layer (0.03mm thick PC film, 310×188mm) is laid flat on the vacuum adsorption table; a compensation layer (0.15mm thick PC, with a pre-drilled first positioning hole φ2.00±0.05mm and a 6×6mm chip hole) is then placed; the PET hinge layer (20mm wide, 310mm long) is placed in the center, with its long side 13.00±0.05mm from the edge of the compensation layer; the embedded wire layer (0.105mm thick PC, 174±0.05mm wide, including wound copper wire and a second through-hole) is then laid; finally, the second protective layer is placed on top. During stacking, the coaxiality of the through-holes is checked using an infrared alignment instrument; if the deviation exceeds 3μm, an audible and visual alarm is triggered for repositioning.

[0175] Step 3, ultrasonic fixation, is performed using a 40kHz welding machine: the welding head pressure is set to 80N, the amplitude to 15μm, and the welding time to 0.5 seconds; the welding points are arranged at 10mm intervals along the long side of the PET hinge, for a total of 31 welding points; after welding, the hinge position is checked using a laser rangefinder. If the distance between the hinge and the edge of the buried wire layer exceeds 13.05mm, the offset area is corrected by welding, and the total number of welding repairs does not exceed 2.

[0176] The precise positioning in step 4 is achieved using an optical alignment system: the assembly is placed in the center of the laminated steel plate, and the CCD camera (5 megapixels) is activated to scan the gap between the edge of the PET hinge and the step of the steel plate; when a local gap > 0.05 mm is detected, the piezoelectric fine-tuning platform pushes the assembly at a speed of 50 μm / ms until the gap is evenly distributed in the range of 0.03~0.05 mm throughout the entire circumference; after positioning is completed, the vacuum chuck (-70 kPa) immediately adsorbs and fixes it, and the adsorption force is maintained until the lamination is completed.

[0177] Step 5, high-temperature lamination, is controlled in three stages: After the laminator is closed, the temperature is increased to 120°C at a rate of 10°C / s, and a pre-pressure of 50 N / cm² is applied and held for 60 seconds. In the second stage, the temperature is increased to 180°C at a rate of 5°C / s, and the pressure is increased by 30 N / cm² for every 10°C increase until it reaches 180 N / cm². After reaching 180°C, a 20-minute constant pressure stage is initiated, during which 5 N / cm² interference pressure is released every 30 seconds and then returned, for a total of 40 pulse pressure reliefs. Five minutes before the end, a pressure equalization program is initiated, reducing the high-pressure area (the area corresponding to the hinge) to 185 N / cm² and the non-hinge area to 175 N / cm². After the heat source is cut off, the nitrogen injection system reduces the steel plate temperature from 180°C to 80°C within 60 seconds, and finally, the plate is moved into a nitrogen chamber to cool naturally to 40°C for demolding.

[0178] Example effect verification:

[0179] Following the above procedure, 1000 electronic passport pages were produced on a trial basis and inspected using a laser profilometer.

[0180] The maximum deviation of straightness in the PET hinge area is 0.15mm (standard ≤0.2mm), with a pass rate of 99.7%.

[0181] The average helium leak detection rate is 3.7 × 10⁻¹ 0 Pa·m³ / s (standard < 1×10⁻) 9 );

[0182] Peel strength test value: 10.5 ± 1.1 N / cm (standard ≥ 8 N / cm);

[0183] After 50 consecutive uses, the step height of the laminated steel sheet decreased by less than 0.002 mm, and the roughness Ra value remained at 0.52±0.08 μm, verifying the stability of the process.

[0184] This embodiment also provides a computer device applicable to the high-temperature lamination method for passport pages with PET hinge positioning, comprising: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the high-temperature lamination method for passport pages with PET hinge positioning as proposed in the above embodiment.

[0185] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0186] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the high-temperature lamination method for PET hinge positioning of a passport page as proposed in the above embodiments. The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0187] In summary, this invention, through the synergistic effect of innovatively designed differentiated stepped laminated steel plates (top plate 0.13mm / bottom plate 0.17mm / middle plate double-sided 0.17mm~0.13mm) and a three-level dynamic sealing system (physical contact band - flow-blocking band - compensation band), achieves zero overflow control of molten material in the PET hinge area for the first time, completely eliminating the edge trimming requirements caused by material deformation in traditional processes. Experiments show that the straightness of the finished hinge area is stably controlled within the range of 0.12±0.03mm (industry standard ≤0.2mm), and the pass rate jumps from 82% of the traditional process to over 99.5%. The zoned pressure control technology (200N / cm² in the hinge area / 180N / cm² in the non-hinge area) combined with the millisecond-level response of the piezoelectric ceramic actuator array increases the PET / PC interface peel strength to 10.2±1.3N / cm (compared to 5.3±2.1N / cm in the existing technology), reducing the strength fluctuation range by 60% and significantly improving the mechanical durability of the electronic passport. The surface regeneration process, through the synergistic treatment of a nano-zirconia coating (1.2μm thick) and plasma cleaning, enhances the laminated steel... The lifespan of the board has been extended from the traditional 10 cycles to over 200 cycles, with a roughness stability Ra of over 99% and a single lamination cost reduction of 41%. The combined application of an optical alignment system (±0.05mm accuracy) and a pulsed pressure relief process (releasing 5N / cm² interference pressure every 30 seconds) effectively suppresses the cumulative stress during the hot pressing process of multilayer materials, reducing the warpage deformation of the finished product from 0.25mm to below 0.04mm, completely solving the curling problem of passport pages after long-term use. The composite design of the microgroove array (10μm deep / 50μm spacing) and the thermal expansion sealant (containing 5~8μm glass microspheres) in the three-level sealing structure reduces the edge helium leak detection rate to 5× The technology achieves performance in the Pa·m³ / s range, improving waterproof and moisture-proof capabilities by three orders of magnitude and significantly extending the lifespan of electronic chips. The overall technology frees electronic passport manufacturing from reliance on manual trimming, increasing production line automation to 98% and reducing energy consumption per passport by 37%, demonstrating significant industrial implementation value.

[0188] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method of high temperature lamination of a passport page with PET hinge positioning, characterized in that, Includes the following steps: Step 1: Prepare a special laminated steel plate. The surface of the steel plate is provided with a raised step structure, including a single step height of 0.13mm on the top plate, a single step height of 0.17mm on the bottom plate, and double step heights of 0.17mm on side A and 0.13mm on side B of the middle plate. The step width is 20~40mm and the surface roughness is Ra0.5±0.1μm. Step 2: Stack the electronic passport inlay layers in the following order: first protective layer, compensation layer, PET hinge layer, embedded wire layer, and second protective layer. The PET hinge layer is placed between the compensation layer and the embedded wire layer, and a 7mm bonding area is reserved on each side of the hinge. Step 3: Fix the laminate to the PET hinge using an ultrasonic welding head, ensuring that the distance between the long side of the hinge and the edge of the embedded wire layer is strictly controlled at 13±0.05mm; Step 4: Place the assembly on the laminated steel plate, precisely aligning the PET hinge with the edge of the steel plate step, with a gap ≤ 0.05mm; Step 5: Lamination is carried out continuously at 180℃ and 180N / cm² pressure for 20 minutes to physically prevent the material from melting and overflowing using the stepped structure; The special laminated steel plate is made of 430 stainless steel substrate and is formed by five-axis CNC precision grinding. Its external dimensions are strictly controlled within the range of length 690mm±0.1mm, width 540mm±0.1mm, and thickness 0.8mm±0.01mm. The stepped structure is continuously distributed along the entire edge of the operating surface of the top plate. The step height is fixed at 0.13mm ± 0.005mm, the step width is 20mm ± 0.05mm, and the non-operating surface of the top plate remains absolutely flat. The steps of the middle plate are extended to a width of 40mm±0.1mm and are centered along the long axis of the steel plate. The height of the step on side A is set to 0.17mm±0.005mm, and the height of the step on side B is set to 0.13mm±0.005mm. The double-sided steps form a closed frame on the four sides of the steel plate. The steps on the bottom slab are mirror-symmetrically distributed with the top slab, and the step height is fixed at 0.17mm±0.005mm, and the width is 20mm±0.05mm. The angle between the sidewalls and the surface of all steps is 90°±0.5°, and the transition edges between the top and bottom surfaces of the steps are rounded with a radius of 0.05mm. The surface roughness of the steps was achieved by polishing with diamond wheels in stages. Three grinding passes were performed using 400-mesh, 800-mesh, and 1500-mesh wheels to ensure a consistent roughness of Ra0.5±0.1μm. A sampling point was taken every 10mm for roughness testing. The non-step areas of the steel plate are subjected to shot peening strengthening treatment. 304 stainless steel shot with a diameter of 0.2 mm is used to impact the surface with a pressure of 0.25 MPa to form a residual compressive stress layer to suppress high-temperature deformation. The width of the embedded wire layer is strictly limited to 174±0.05mm, and its edge forms a stepped sealing structure with the PET hinge bonding area. This structure is formed by precision die-cutting process with a die-cutting blade angle of 22° and a blade radius of ≤5μm. The overlapping area between the exposed part of the PET hinge and the laminated steel plate step is designed as a three-level sealing strip: the first level is a physical contact sealing strip with a width of 1.0±0.02mm, a surface processing depth of 10μm and a micro-groove array with a spacing of 50μm, and the groove direction is at a 45° angle to the lamination pressure direction; The second stage is a molten material flow-blocking zone with a width of 1.5±0.03mm. This area is pre-coated with a silicone-based sealant with a matching coefficient of thermal expansion before lamination. The sealant contains glass microspheres with a diameter of 5~8μm as spacer particles. The third level is a dynamic compensation band with a width of 0.5±0.01mm. It has a built-in pressure-sensitive color-changing film. When the local pressure exceeds 190N / cm², the film changes from transparent to red, indicating the pressure distribution status in real time. During the lamination process, the microgrooves of the physical contact sealing strip capture the first wave of molten PC material to form a primary seal. The sealant of the flow-blocking strip expands by 35% at 120°C to fill the gaps, and the glass microspheres are broken in a controlled manner to release silica to enhance the bonding strength. The dynamic compensation belt triggers pressure feedback through a pressure-sensitive color change signal: when the red area is detected to be greater than 30%, the laminator automatically reduces the pressure in that area by 5 N / cm² and extends the holding time by 10 seconds. The total width of the overlapping area is controlled at 3.0±0.05mm. After lamination, the seal integrity is verified by micro-CT scanning. The porosity is required to be <0.01%, and the thickness change of the transition zone at the interface of the three-level sealing strip is ≤0.5μm. The finished product edge is subjected to helium mass spectrometry leak detection test, and the leakage rate after 0.6 MPa helium is introduced must be <1×10⁻ 9 Pa·m³ / s, and the unqualified parts are repaired by local laser remelting process: using 1064 nm fiber laser, power 80 W, spot diameter 0.1 mm, scanning speed 10 mm / s, and remelting depth 50±5 μm.

2. The PET hinge registered passport page high temperature lamination method of claim 1 wherein: The through-hole processing of the compensation layer and the buried wire layer adopts ultraviolet laser perforation technology, with the laser wavelength set at 355nm, pulse frequency at 80kHz, single pulse energy at 0.8mJ, and focused spot diameter at 15μm. Before perforation, the PC material is placed on a constant temperature vacuum adsorption platform, with the temperature maintained at 25±0.5℃ and the vacuum degree at -90kPa to ensure that the material is flat and free from deformation. The machining of positioning holes and chip holes is completed in two stages: the first stage is contour cutting at a speed of 500 mm / s with a 5 μm allowance; the second stage adopts a finishing mode, with the speed reduced to 100 mm / s, and the laser is repeatedly scanned 3 times to remove slag, and the final hole diameter tolerance is controlled within ±5 μm. When the copper wire in the buried layer is wound, the enameled wire passes through the closed-loop tension control system and a constant tension of 0.5N±0.02N is applied. The tension sensor feeds back the data to the PLC in real time. If the tension exceeds the tolerance by 0.05N, the machine will be stopped for calibration. The winding path is controlled by a vector interpolation algorithm, the positioning accuracy of the embedding machine's motion axis is ±1μm, the angle between the copper wire and the surface of the embedding layer is maintained at 90°±0.5°, and the spacing error between adjacent wires is ≤2μm; Before chip soldering, the pads are cleaned with argon plasma. The processing parameters are: power 300W, argon flow rate 20sccm, duration 30s, to remove the oxide layer on the surface of the copper wire. Welding was performed using a high-frequency ultrasonic spot welder with a welding head frequency of 60kHz, an amplitude of 8μm, a pressure of 15N, and a welding time of 50ms. X-ray inspection was conducted immediately after weld formation. The weld diameter was ≤100μm and the rate of incomplete welds had to be less than 0.1%. The welded embedded wire layer and compensation layer are superimposed using an infrared alignment system, with the center of the positioning hole as the reference, and the coaxiality error is ≤3μm. After superposition, they are fixed by a negative pressure adsorption fixture with a vacuum pressure of -50kPa.

3. The PET hinge registered passport page high temperature lamination method of claim 2, wherein: The optical alignment system consists of a high-resolution CCD camera, a ring-shaped LED array light source, and a piezoelectric fine-tuning platform. The CCD camera is equipped with a 5-megapixel CMOS sensor and a 10x telecentric lens, with a pixel size of 2.4μm and a working distance of 150mm. During system initialization, a standard step gauge is used for calibration. Reference lines are laid on the edge of the laminated steel plate step, with a width of 10μm and a depth of 5μm. A three-dimensional coordinate system is established by sampling at 9 points, and the coordinate transformation error is ≤±1μm. During the positioning process, the CCD camera acquires images of the PET hinge edge at a rate of 30 frames per second. The image processing adopts a sub-pixel edge extraction algorithm: first, a 5×5 Gaussian filter is used to reduce noise, then the Sobel operator is used to calculate the gradient field, and finally, cubic spline interpolation is used to improve the edge positioning accuracy to the 0.1 pixel level. The offset between the long side of the hinge and the steel plate step is calculated in real time. When the offset exceeds 0.05mm, the piezoelectric fine-tuning platform starts the correction within 20ms: the X / Y direction uses a piezoelectric ceramic actuator with a stroke range of ±1mm and a resolution of 10nm, and the Z direction uses a voice coil motor to provide a constant contact pressure of 0.5N. The calibration process is performed in two stages: the first stage uses a coarse positioning speed of 50 μm / ms to locate the target position within ±5 μm; the second stage switches to nanostepping mode and uses a precise positioning speed of 1 μm / ms to ultimately stabilize the gap between the hinge and the step at 0.03~0.05 mm. After each calibration is completed, the system automatically records the offset data and generates a compensation curve. When the calibration amount exceeds ±0.1mm three times in a row, an audible and visual alarm is triggered, prompting the replacement of the laminated steel plate. The positioned stack is immediately fixed with a vacuum suction cup. The surface of the suction cup is equipped with a micropore array with a pore diameter of 100μm and a pore spacing of 1mm. The vacuum pressure is -70kPa. After adsorption, the flatness change of the stack is ≤0.005mm.

4. The PET hinge registered passport page high temperature lamination method of claim 3, wherein: The three-stage temperature control of the lamination process is achieved through an embedded temperature-pressure coupling system, which integrates 12 sets of K-type thermocouples and 24 piezoresistive sensors. The thermocouples are embedded in the laminated steel plate at a depth of 0.2 mm and are distributed in a matrix with a spacing of 50 mm. When the first stage of heating is started, the upper heating plate of the laminator increases the temperature at a linear rate of 10℃ / s, while the lower heating plate follows synchronously with a lag of 0.5s. When the surface temperature of the steel plate reaches 120℃±0.5℃, the system automatically applies a pre-pressure of 50N / cm² and starts a 60s countdown. During the pre-compression period, the temperature fluctuation is controlled within ±0.3℃. The power of the heating tube is dynamically adjusted through a PID algorithm with a power adjustment accuracy of ±5W. At this time, the material undergoes a glass transition but has not yet reached a flow state. Before the second stage of heating, the system immediately switches the control mode after detecting the pre-pressure end signal: the temperature rises to 180℃ in a gradient of 5℃ / s, and the pressure increases by 30N / cm² for every 10℃ increase during the heating process, until the total pressure of 180N / cm² is reached. When the temperature rises to 175℃, the pressure holding program is activated, the hydraulic system switches to closed-loop servo control, and the pressure fluctuation range is compressed to ±1.5N / cm². During this stage, the material is completely melted and fills the interlayer gaps. The third stage of constant temperature and pressure maintenance is initiated, and the system locks the temperature value at 180℃±0.2℃. The temperature data is cross-validated by three redundant thermocouples, and compensation heating is triggered if any measuring point exceeds the tolerance. During the pressure maintenance phase, an adaptive attenuation algorithm is used to release 5 N / cm² of interference pressure every 30 seconds and then restore it to the set value. A total of 6 pulse-type pressure relief operations are performed to eliminate residual stress inside the material. After the 20-minute pressure holding period, the heat source is immediately cut off, and the stepped cooling process begins. The hot plate separation speed of the laminator is controlled at 0.5 mm / s.

5. The PET hinge registered passport page high temperature lamination method of claim 4, wherein: The stepped cooling process is started immediately after the hot plate of the laminator is separated. The nitrogen injection system is equipped with a ring array nozzle with a nozzle diameter of 0.8 mm, a spacing of 15 mm, and a distance of 20 ± 0.5 mm from the steel plate surface. The initial spraying stage uses -30℃ liquid nitrogen vaporized gas with a pressure of 0.25MPa and a flow rate of 120L / min. It covers the entire steel plate at a 45° angle and forcibly reduces the steel plate temperature from 180℃ to 80℃±1℃ within 60 seconds. The cooling rate is strictly controlled at 1.5℃ / s. Temperature monitoring is achieved through real-time feedback from 12 PT100 platinum resistance thermometers embedded in the steel plate. The temperature measurement point is located at the boundary between the stepped area and the non-stepped area, with a data sampling frequency of 10Hz. When the detected temperature difference in the area is greater than 2℃, the flow rate of the corresponding nozzle is automatically adjusted, with a flow rate adjustment accuracy of ±0.5L / min. During the natural cooling stage, the assembly is moved into a constant temperature inert environment chamber, which is filled with 99.999% high-purity nitrogen and has an oxygen content of <10ppm. The temperature is uniformly reduced from 80℃ to 40℃, with a cooling gradient of 0.67℃ / min. An airflow field with a laminar flow velocity of 0.2m / s is set in the chamber to eliminate heat accumulation. During the cooling process, the shape change of the stack is recorded every 5 minutes. The laser displacement sensor has a measurement accuracy of 0.1μm. When the warpage of the PET hinge area is detected to be >0.05mm, the auxiliary flattening mechanism is triggered. The pressure head applies a local pressure of 5N / cm² for 30 seconds for correction. When the temperature drops to 40℃±0.5℃, vacuum demolding is initiated. The demolding force increases linearly to the maximum value of 50N and is held for 3 seconds. The separation speed is 0.1mm / s. Immediately after demolding, the finished product is placed in a 23℃ / 50%RH constant humidity chamber for 24 hours to equilibrate. After demolding, the laminated steel sheet enters the surface regeneration process. First, dry ice blasting is used to remove residual polymer, followed by sandblasting. The steel sheet temperature must be cooled to below 25°C before the regeneration cycle can begin.

6. The PET hinge positioned passport page high temperature lamination method of claim 5, wherein: The surface regeneration treatment is carried out in a dedicated sandblasting chamber. The sandblasting medium is 120-mesh white corundum abrasive with a Mohs hardness of 9.0 and a particle size distribution of 150~180μm. The abrasive moisture content is strictly controlled below 0.3%. Before sandblasting, the laminated steel plate is fixed on the magnetic platform, the platform temperature is maintained at 25±1℃, the spray gun is tilted at a 30° angle to the steel plate surface, the moving speed is 0.5m / s, the working distance is 100±5mm, the compressed air pressure is 0.3MPa±0.01MPa, and the flow rate is 60L / min. The sandblasting process is carried out in three stages: the first stage is parallel sweeping along the long axis of the steel plate, the second stage is vertical sweeping with a 90° rotation, and the third stage is diagonal sweeping at 45°. Each sweep is spaced 10 seconds apart to allow for dust settling, and the total abrasive consumption is 400g / m². Plasma cleaning is performed in a vacuum reaction chamber. After the chamber is evacuated to a vacuum level of 5×10⁻³Pa, argon gas is introduced with a purity of 99.999%, a flow rate of 20 sccm, and a working pressure of 10Pa. The RF power supply is 300W±5W, the excitation frequency is 13.56MHz, the processing time is 30 minutes, the electrode spacing is 50mm, and the steel plate temperature is controlled below 40℃ during the processing by a water cooling system. The nano-zirconia coating was applied by sol-gel spraying. The precursor solution was zirconium oxychloride ethanol solution with 3% yttrium nitrate stabilizer added. The atomization pressure was 0.15 MPa and the spray gun moving speed was 1 m / s. The coating is applied in two layers: after the first layer is sprayed, it is preheated at 120℃ for 60 seconds to form a porous substrate; after the second layer is sprayed, it is cured at 150℃ for 30 minutes. The final coating thickness is 1.0~1.2μm, and the thickness uniformity deviation is ≤±0.05μm. The recycled steel plates must pass three tests: white light interferometer to measure the roughness Ra value of the step area, contact angle tester to verify that the surface energy is >72mN / m, and XRD to detect that the tetragonal zirconium oxide content is >85%; Each batch of recycled steel sheets must undergo process verification testing. Take three steel sheets and laminate five standard samples on each sheet. The proportion of samples with straightness exceeding 0.15mm in the PET hinge area must not exceed 1 / 1000.

7. The PET hinge registered passport page high temperature lamination method of claim 6, wherein: The finished product inspection adopts a dual-laser profilometer synchronous scanning system. The main laser is a helium-neon laser with a wavelength of 632.8nm and a line scanning frequency of 10kHz. The auxiliary laser is a 405nm blue laser with a dot density of 500 dots / mm². Before scanning, a reference marking tape with a bandwidth of 0.5 mm and containing chrome lines spaced 10 μm apart was pasted on the PET hinge area as an optical positioning reference. The marking tape was peeled off non-destructively with ethanol after the inspection. The main laser continuously scans along the long side of the hinge, with the scanning path 0.3mm ± 0.02mm from the edge. 200 contour points are collected every millimeter. The system fits a straight line using the least squares method and calculates the deviation value. When the straightness deviation is > 0.2mm, the system automatically sprays red UV marking paint on the defect area. A secondary laser synchronously scans the chip packaging area to detect the coplanarity of the copper wires and the chip. A yellow marker is triggered when the coplanarity exceeds the tolerance by more than 5μm. Peel strength tests were conducted on samples marked as qualified, using a custom pneumatic clamp to hold the exposed end of the PET hinge. The clamping area was 10×20mm, the pneumatic pressure was 0.6MPa, the peel angle was 180°, and the tensile speed was 100mm / min. During testing, the force-displacement curve is recorded in real time. When the peel strength first reaches 8 N / cm², the displacement value L1 is recorded. When the strength decreases by 20%, the displacement value L2 is recorded. If L2-L1>0.5mm, the interface is judged to be in failure. All test data are uploaded to the MES system. Products that fail to meet the straightness standard are directly crushed and recycled with a particle size ≤0.5mm. Products that fail the peel strength standard but meet the straightness standard enter the rework process: first, the adhesive layer is softened with 120℃ hot air at a speed of 5m / s for 30 seconds, then the residual adhesive is removed with a precision scraper with a blade radius of 50μm. After removal, the epoxy film is recoated. Returned products need to undergo secondary lamination. The lamination parameters are adjusted to: temperature 170℃, pressure 150N / cm², and time 15 minutes. After secondary lamination, the peel strength meets the standard rate >99.2%. The final qualified products are sealed in nitrogen gas with an oxygen content of less than 100 ppm. They are also accompanied by a laser-etched process traceability code containing the steel plate batch number, lamination timeline, and test data hash value.

8. The PET hinge registered passport page high temperature lamination method of claim 7, wherein: Zoned pressure control is achieved through a piezoelectric ceramic actuator array, which consists of 576 independent drive units, each unit measuring 10×10mm. Each unit integrates a pressure sensor and a temperature compensation module. The total thickness of the array is 1.8mm, and it is embedded in the surface of the laminator hot plate. The pressure zoning strategy is based on the precise division of the laminated steel plate step position: the unit corresponding to the PET hinge bonding area is defined as the high pressure zone, with a width of 20±0.1mm; the non-hinge area is the reference pressure zone; the boundary between the high pressure zone and the reference zone is located by laser projection, with a positioning accuracy of ±0.05mm; When lamination starts, all units are subjected to a base pressure of 180 N / cm²; when the temperature reaches 120℃ in the pre-melting stage, the high-pressure zone units increase the pressure to 200 N / cm² at a rate of 5 N / cm² per second, while the base zone remains unchanged at 180 N / cm². Dynamic pressure adjustment and pressure-sensitive color-changing signal linkage: When the area of ​​the red region in the dynamic compensation zone is greater than 30%, the system automatically reduces the pressure of the corresponding coordinate point unit by 5 N / cm², and returns to the set value in three steps within 10 seconds, with each return being 1.67 N / cm². The actuator control adopts an adaptive pulse drive mode: the piezoelectric ceramic drive voltage is adjustable from 0 to 150V, the voltage resolution is 2mV, and the pressure output linearity error is ≤0.3%; the high-pressure zone unit applies a 220N / cm² pulse pressure for 50ms every 15 seconds to overcome the material flow resistance; The temperature compensation module monitors the unit temperature rise in real time. When the local temperature exceeds 185℃, it automatically reduces the driving voltage by 0.5V / N / cm² to prevent thermal depolarization of the piezoelectric ceramic. Five minutes before the end of lamination, the pressure equalization program is initiated: the high-pressure zone decreases to 185 N / cm² at a rate of 0.8 N / cm² per second, and the reference zone decreases to 175 N / cm² simultaneously, so that the internal stress gradient of the material is released gradually. Pressure data is recorded throughout the entire cycle, with a sampling frequency of 100Hz. The generated pressure-position-time three-dimensional map is used for process traceability. The actuator array needs to be calibrated for its piezoelectric constant every 50 hours of operation, with a calibration accuracy of ±0.5%.

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