Vehicle-mounted screen integrated assembling and processing method based on capacitive touch control

Abstract

The invention discloses a vehicle-mounted screen integrated assembling and processing method based on capacitive touch control, and belongs to the field of vehicle-mounted display and touch control device manufacturing. S2, preparing a touch electrode layer; s3, coating an insulating layer; s4, forming an optical adjustment layer; s5, integrally forming a display function layer; s6, integrating an electromagnetic shielding layer; s7, packaging and lead connection; s8, carrying out segmented function detection; s9, carrying out reliability strengthening treatment; and S10, performing final quality control and packaging. An integrated structure is adopted, an independent touch module protection cover plate and an optical adhesive for attachment are not needed, the material cost is remarkably reduced, through the gradient refractive index design, the interface reflectivity between the touch electrodes and the display layer is greatly reduced, the overall light transmittance and the display contrast ratio are remarkably improved, and the display quality is improved. The method can also support manufacturing of vehicle-mounted touch screens with different sizes and different forms.

Description

Technical Field

[0001] This invention relates to the field of automotive display and touch device manufacturing technology, specifically to an integrated assembly and processing method for automotive screens based on capacitive touch. Background Technology

[0002] As the automotive industry transforms towards intelligent and electric vehicles, in-vehicle display systems have evolved from simple information output terminals into core control units integrating display, touch, and interaction. The requirements for functional integration, performance stability, and environmental adaptability continue to increase. Capacitive touch technology, with its advantages of high sensitivity, multi-point touch, no mechanical wear, and fast response, has become the mainstream solution for in-vehicle touch interaction.

[0003] However, the manufacturing of existing automotive capacitive touchscreens still mainly relies on a split-type process. This model originated from the technological migration of consumer electronics touchscreens, and it has exposed many technical bottlenecks when adapting to automotive scenarios, making it difficult to meet the high-performance requirements of smart cars.

[0004] The split-type process requires the touch module and display module to be processed on two separate production lines, and then transported to the bonding production line for secondary assembly through multiple logistics transfers. This not only extends the production cycle, but also increases inventory management costs and material loss risks.

[0005] Secondly, during the bonding process, micron-level flatness deviations between the touch module and the display module, as well as environmental particulate matter contamination, can easily lead to optical defects such as bubbles and Newton's rings after bonding, affecting the display effect. The traditional connection method between the touch electrode and the driver IC is prone to changes in contact resistance or even open circuits under the wide temperature range cycling and vibration environment of the vehicle, resulting in touch delay and accidental touches.

[0006] Meanwhile, existing processes require functional testing only after all assembly is complete. If defects such as touch dead zones or dark lines are detected, the entire module needs to be disassembled. This not only makes it impossible to recycle most of the disposable parts, but may also cause secondary damage to the substrate, increasing rework time and costs.

[0007] In summary, existing separate manufacturing processes can no longer meet the requirements of smart cars for "high integration, high reliability, low cost, and lightweight" in-vehicle touch screens. Developing a new processing method that integrates touch and display manufacturing, simplifies processes, and improves performance has become a key direction for the in-vehicle display industry to break through technological bottlenecks. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides an integrated assembly and processing method for vehicle screens based on capacitive touch control, which solves the problems mentioned in the background section.

[0009] To achieve the above objectives, the present invention provides the following technical solution: an integrated assembly and processing method for vehicle-mounted screens based on capacitive touch control, comprising the following specific steps:

[0010] S1. A borosilicate glass substrate is selected as the base; a three-stage cleaning process is first adopted:

[0011] The alkaline cleaning stage uses a 5%–8% potassium hydroxide solution (temperature 50–60℃, ultrasonic power 300–400W, cleaning time 5–8min) to remove surface oil and organic contaminants;

[0012] During the acid cleaning stage, a 3%–5% hydrofluoric acid solution (temperature 25–30℃, soaking time 2–3 min) is used to remove the surface oxide layer and minor scratches;

[0013] The ultrapure water rinsing stage uses 18.2 MΩ·cm ultrapure water (temperature 40-45℃, ultrasonic power 200-300W, rinsing time 8-10min).

[0014] After cleaning, the product is dried with hot air (temperature 80-90℃, wind speed 1-2m / s) and sterilized with ultraviolet light (wavelength 254nm, irradiation intensity 10-15mW / cm²). 2 The substrates are processed (3-5 minutes); finally, laser flatness detection (accuracy ±0.1μm) is used to screen substrates with flatness error ≤1μm for later use.

[0015] S2. Fabrication of the touch electrode layer: A transparent conductive layer is deposited on the pretreated substrate surface using magnetron sputtering. The sputtering target is a composite target of indium tin oxide (ITO) and zinc oxide (ZnO) (mass ratio 9:1). The sputtering environment is a mixture of argon and oxygen (argon flow rate 20–25 sccm, oxygen flow rate 1–2 sccm), with a vacuum degree of 5 × 10⁻⁶. -4 ~8×10 -4 Pa, substrate temperature 150–180℃, sputtering power 200–250W, deposition thickness 80–100nm, ensuring sheet resistance ≤15Ω / □ and transmittance ≥90%; subsequently, femtosecond laser etching (wavelength 1064nm, pulse width 50–100fs, repetition frequency 1–2kHz, energy density 1–2J / cm²) is performed. 2A predetermined pattern of touch electrode array is formed on the conductive layer, including driving electrodes (linewidth 50-80 μm, spacing 200-300 μm along the X-axis) and sensing electrodes (linewidth 50-80 μm, spacing 200-300 μm along the Y-axis). After etching, the etching residue is removed by plasma cleaning (argon atmosphere, power 100-150 W, time 3-5 min). Then, the uniformity of electrode sheet resistance (deviation ≤5%) is detected by four-point probe method, and the flatness of electrode edge (edge ​​roughness ≤0.5 μm) is observed by microscope.

[0016] S3. Insulation Layer Coating: An insulating material is coated onto the surface of the touch electrode layer using a spin-coating process. Polyimide (PI) resin (solid content 30%–40%, viscosity 500–800 cps) is selected, with a coating speed of 3000–4000 rpm and a coating time of 30–60 s, forming a wet film thickness of 1–2 μm. Subsequently, segmented curing is performed: first, pre-curing at 80–100℃ for 30–60 min (to remove solvent), and then high-temperature curing at 200–220℃ for 120–180 min (cross-linking molding), resulting in a final insulation layer thickness of 800–1200 nm. After curing, the breakdown voltage (≥100V / μm), dielectric constant (≤3.5 at 1kHz), and surface roughness (≤0.1μm) of the insulation layer are tested to ensure that the electrical insulation performance and surface smoothness meet the standards.

[0017] S4. Formation of the optical adjustment layer: An optical adjustment layer is prepared on the surface of the insulating layer to eliminate interface reflection between the touch electrode and the display layer. A composite system of high refractive index resin (refractive index 1.6-1.7) and low refractive index nanoparticles (silica, particle size 20-50nm, refractive index 1.45-1.5) is selected and formed by slit coating process (coating speed 5-10mm / s, wet film thickness 2-3μm). After coating, it is cured by baking at 120-150℃ for 60-90min, and the final thickness of the optical adjustment layer is 1.5-2.5μm. The refractive index distribution of this layer is detected by ellipsometer (gradually changing along the thickness direction, from 1.6 on the insulating layer side to 1.5 on the display layer side) to ensure that the interface reflectivity is ≤0.5% (visible light band 400-700nm). At the same time, the overall transmittance is detected by spectrometer (≥91%) to avoid optical loss.

[0018] S5. The display functional layer is integrally formed, and the complete display functional layer is directly prepared on the surface of the optical adjustment layer without the need for post-lamination. Specifically, it includes:

[0019] (1) TFT array fabrication: Low-temperature polycrystalline silicon (LTPO) process was used to deposit an amorphous silicon layer (thickness 50-80 nm) on the surface of the optical adjustment layer by chemical vapor deposition (CVD), followed by laser annealing (wavelength 308 nm, energy density 300-400 mJ / cm²).2 The process involves converting the material into polycrystalline silicon; then, through photolithography and etching, an active layer (channel width 10–20 μm), a gate (molybdenum metal, thickness 100–150 nm), and source / drain electrodes (aluminum metal, thickness 200–250 nm) are formed to complete the fabrication of the TFT array.

[0020] (2) Fabrication of pixel electrode and common electrode: Indium tin oxide (ITO) layer (thickness 60-80nm) is deposited by magnetron sputtering, and pixel electrode (connected to TFT source and drain, area corresponding to pixel size) and common electrode (located above pixel electrode and isolated by insulating layer) are formed by photolithography etching.

[0021] (3) Preparation of the color filter layer: Using a photoresist coloring process, red (R), green (G), and blue (B) photoresist (thickness 1.5-2 μm) are sequentially coated, and exposed through a mask (wavelength 365 nm, energy 100-150 mJ / cm). 2 ), and develop to form color filter units, ensuring color gamut coverage ≥ NTSC 95%;

[0022] (4) Liquid crystal injection and sealing: A sealant (UV-curable type, linewidth 50-80 μm) is coated on the surface of the color filter layer. Liquid crystal (nematic liquid crystal, response time ≤10 ms) is injected using the drop-casting method. Then it is bonded to the opposing substrate (which has also undergone pretreatment and electrode preparation). Finally, it is UV cured (wavelength 365 nm, energy 2000-3000 mJ / cm). 2 )seal;

[0023] After each step is completed, the TFT switching characteristics (conduction current ≥1μA, shutdown current ≤1pA), pixel voltage uniformity (deviation ≤5%), and liquid crystal alignment consistency (pretilt angle deviation ≤1°) are tested respectively.

[0024] S6. Electromagnetic shielding layer integration: Electromagnetic shielding layers are fabricated on the outer side of the substrate opposite the display functional layer (non-display surface) and the inner side of the substrate of the touch electrode layer (non-touch surface), forming a "double shielding" structure.

[0025] The inner shielding layer is formed by magnetron sputtering of a copper-nickel alloy layer (copper-nickel mass ratio 9:1, thickness 100-150nm), and a grid pattern (linewidth 20-30μm, grid spacing 500-800μm) is formed by photolithography etching to ensure a light transmittance of ≥85%.

[0026] The outer shielding layer is formed by screen printing conductive silver paste (screen mesh number 300-400 mesh, printing thickness 5-10μm) to form a grid pattern (arranged in a staggered manner with the inner grid, line width 30-40μm, grid spacing 500-800μm), and then cured by baking at 120-150℃ for 30-60 minutes.

[0027] After the shielding layer is prepared, a vector network analyzer is used to test the electromagnetic shielding effectiveness (≥40dB in the 10kHz~6GHz frequency band) to ensure that it meets the vehicle EMC standard; at the same time, the grid conductivity is tested (node ​​contact resistance ≤100mΩ) to avoid shielding failure.

[0028] S7. Package and lead connection, as detailed below:

[0029] (1) The module encapsulation uses a glass cover plate (made of the same material as the substrate glass, with a thickness of 0.5-0.7 mm) and is bonded to the shielding layer on the outside of the display functional layer with UV-curable adhesive (refractive index 1.5-1.6, thickness 50-100 μm) to form an overall protective structure; after bonding, it is UV-cured (wavelength 365 nm, energy 1500-2000 mJ / cm). 2 (Time 30-60s), ensuring the overall thickness after encapsulation is ≤5mm;

[0030] (2) The lead wires are connected to the electrode lead-out area (width 2-3mm) reserved at the edge of the substrate. The touch electrode lead wires are directly connected to the FPC of the driver IC by laser micro-welding process (wavelength 1064nm, pulse energy 1-2mJ, welding time 10-20μs), replacing the traditional ACF hot-press bonding. Before welding, flux (low residue type, melting point 80-100℃) is applied to the connection area. After welding, the flux residue is removed by ultrasonic cleaning (power 100-150W, time 2-3min).

[0031] After encapsulation and connection are completed, the sealing performance is tested (using a helium mass spectrometer leak detector, leak rate ≤1×10⁻⁶). -8 Pa·m 3 / s), lead contact resistance (≤30mΩ) and FPC pull-out force (≥5N);

[0032] S8. Segmented Functional Testing: The integrated module undergoes segmented testing to avoid rework later.

[0033] Display performance testing involves measuring brightness (≥500 cd / m²) using a display tester. 2 Contrast ratio (≥1000:1), color gamut (≥NTSC95%), response time (≤10ms), and uniformity (brightness deviation ≤5%).

[0034] Touch performance testing was conducted using a touch tester to measure touch sensitivity (trigger force ≤50g), touch accuracy (deviation ≤0.1mm), multi-touch (supports simultaneous operation of 10 points), and response time (≤5ms).

[0035] EMC performance testing was conducted in a shielded anechoic chamber according to CISPR 25 Class 5 standards, testing radiated emissions (≤40dBμV / m@30~1000MHz) and immunity (≥200V / m@80~1000MHz).

[0036] The defective products are marked with their defects and can be repaired directly in the current process (e.g., touch dead zones can be repaired by laser fine-tuning of the electrode pattern) without the need for complete disassembly.

[0037] S9. Reliability Enhancement Process: For modules that pass the inspection, reliability enhancement for the automotive environment is performed, as detailed below:

[0038] High and low temperature cycling test: 500 cycles between -40℃ (held for 2 hours) and 85℃ (held for 2 hours), with a temperature change rate ≤10℃ / min;

[0039] Damp heat aging test: placed at 85℃ and 85%RH for 1000 hours;

[0040] Vibration test: Vibrate for 200 hours at 10g acceleration (root mean square) within the 10-2000Hz frequency band (66.7 hours each for the X, Y, and Z axes).

[0041] After reliability testing, display performance, touch performance, and electrical parameters are retested to ensure that performance degradation is ≤10%.

[0042] S10. Final quality control and packaging: 10% of products that pass the reliability test are randomly selected for full performance retesting (including display, touch, EMC, and mechanical strength) to ensure a batch pass rate ≥99%; surface scratches (depth ≤0.1μm, length ≤1mm) and bubbles (diameter ≤0.1mm) are detected using a visual inspection system (20 million pixels resolution); antistatic foam (surface resistance 10... 6 ~10 9 The product is packaged in an aluminum foil bag (with shielding effectiveness ≥30dB) and each product is placed independently to avoid electrostatic damage or mechanical impact during transportation.

[0043] This invention provides an integrated assembly and processing method for automotive screens based on capacitive touch control, which has the following beneficial effects:

[0044] This integrated assembly and processing method for automotive screens based on capacitive touch integrates the traditional separate processing method into continuous processing on a single production line, which greatly shortens the production cycle, significantly reduces the number of material transfers, and reduces the risk of glass substrate breakage. At the same time, the integrated structure eliminates the need for separate touch module protective covers and bonding optical adhesives, significantly reducing material costs and effectively controlling the overall manufacturing cost.

[0045] Secondly, the optical adjustment layer, through gradient refractive index design, significantly reduces the interface reflectivity between the touch electrode and the display layer, thereby significantly improving the overall light transmittance and display contrast. Furthermore, the integrated manufacturing process avoids flatness deviation and particulate contamination during bonding, greatly reducing the occurrence rate of optical defects such as bubbles and Newton's rings. This significantly improves the uniformity of the display and visual comfort, fully meeting the display requirements under different lighting conditions in automotive scenarios.

[0046] Meanwhile, the laser micro-welding lead connection method avoids the problems of temperature stress and uneven particle distribution in ACF hot-press bonding, and the contact resistance remains stable over a long period of time, with no significant changes after high and low temperature cycling and vibration tests; while the dual electromagnetic shielding layer design effectively improves electromagnetic shielding performance, and the radiated emission and immunity fully comply with automotive EMC standards, significantly improving the signal-to-noise ratio of touch signals and greatly reducing touch drift and false touch rate.

[0047] This method supports the manufacturing of in-vehicle touch screens of different sizes and shapes. By adjusting the touch electrode pattern and display pixel size, product models can be quickly switched, significantly shortening production line changeover time. Furthermore, the materials and processes of the optical adjustment layer and electromagnetic shielding layer can be flexibly adjusted according to customer needs, adapting to the development trend of multi-screen interaction and personalized customization in smart cars. In addition, this method significantly reduces the cleanliness requirements of the production environment, reducing the construction and operation costs of cleanrooms. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the process flow of the invention. Detailed Implementation

[0049] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0050] Example 1: An integrated assembly and processing method for a vehicle-mounted screen based on capacitive touch control, the steps of which are as follows:

[0051] S1. Substrate pretreatment: Select substrate with a thickness of 0.6 mm, light transmittance of 93%, and coefficient of thermal expansion of 3.2 × 10⁻⁶. -6 For borosilicate glass substrates at / ℃, perform the following sequentially:

[0052] Alkaline cleaning uses a 6% potassium hydroxide solution at 55℃, with an ultrasonic power of 350W, for 6 minutes to remove surface oil and organic contaminants; acidic cleaning uses a 4% hydrofluoric acid solution at 28℃, for 2.5 minutes to remove the surface oxide layer and minor scratches; ultrapure water rinsing uses 18.2 MΩ·cm ultrapure water at 42℃, with an ultrasonic power of 250W, for 9 minutes; after hot air drying (temperature 85℃, air velocity 1.5m / s), it is sterilized with ultraviolet light at a wavelength of 254nm and an intensity of 12mW / cm² for 4 minutes.

[0053] Laser flatness inspection was used to select substrates with a flatness error of 0.8μm for future use;

[0054] S2. Fabrication of the touch electrode layer: Magnetron sputtering was performed using an ITO-ZnO composite target (mass ratio 9:1), with an argon flow rate of 22 sccm, an oxygen flow rate of 1.5 sccm, and a vacuum degree of 6 × 10⁻⁶. -4 Pa, substrate temperature 160℃, power 220W, conductive layer with a deposition thickness of 90nm, sheet resistance of 12Ω / □, and transmittance of 91%;

[0055] Femtosecond laser etching, wavelength 1064nm, pulse width 70fs, frequency 1.5kHz, energy density 1.5J / cm². 2 An X-axis driving electrode (60 μm linewidth, 250 μm spacing) and a Y-axis sensing electrode (60 μm linewidth, 250 μm spacing) were formed; plasma cleaning was performed under an argon atmosphere at a power of 120 W for 4 min, and the sheet resistance uniformity deviation of the detection electrode was 4% and the edge roughness was 0.4 μm.

[0056] S3. Insulation layer coating: Polyimide resin with 35% solid content and 650 cps viscosity is used to form a wet film through a spin-coating process (3500 rpm, 45 s). Pre-curing is carried out at 90℃ for 45 min. High-temperature curing is carried out at 210℃ for 150 min, with a final insulation layer thickness of 1000 nm. The test results are: breakdown voltage 110 V / μm, dielectric constant 3.3 (1 kHz), and surface roughness 0.09 μm.

[0057] S4. Formation of the optical adjustment layer: A composite system of high refractive index resin (1.65) and silica nanoparticles (35nm in diameter, 1.48 refractive index) was selected and formed by slit coating (7mm / s speed, 2.5μm wet film thickness). Baking and curing were performed at 135℃ for 75min, resulting in a final optical adjustment layer thickness of 2.0μm. The refractive index gradually decreased from 1.6 to 1.5 along the thickness direction. The interfacial reflectance was 0.3% (visible light band 400-700nm), and the overall transmittance was 92%.

[0058] S5. The display functional layer is integrated into the TFT array, which adopts LTPO process, CVD deposition of a 65nm amorphous silicon layer, and laser annealing (wavelength 308nm, energy density 350mJ / cm²). 2 The active layer has a channel width of 15 μm, a gate electrode (molybdenum, 120 nm thick), and source / drain electrodes (aluminum, 220 nm thick), with a detection on-state current of 1.2 μA. The pixel / common electrode uses a magnetron sputtered ITO layer (70 nm thick), with a detection pixel voltage deviation of 4%. The R / G / B photoresist thickness of the color filter layer is 1.8 μm, and the mask exposure is performed (wavelength 365 nm, energy 120 mJ / cm²). 2 The color gamut was detected at NTSC 96%; nematic liquid crystal in liquid crystal filling (response time 9ms); UV-cured adhesive (energy 2500mJ / cm³). 2 The pretilt angle deviation of the liquid crystal was detected to be 0.8°.

[0059] S6. Electromagnetic shielding layer integration: The inner shielding layer uses a magnetron sputtered copper-nickel alloy layer (120nm thick) with an etched grid (25μm linewidth, 650μm spacing) and 86% light transmittance; the outer shielding layer uses a 350-mesh conductive silver paste screen printing (35μm linewidth, 650μm spacing, offset from the inner layer) and is cured by baking at 135℃ for 45 minutes; the testing uses a shielding effectiveness of 42dB (10kHz-6GHz) and a node contact resistance of 80mΩ.

[0060] S7. In the encapsulation and lead connection process, the encapsulation uses a 0.6mm borosilicate glass cover plate, UV-curable adhesive (refractive index 1.55, thickness 80μm), and UV curing (wavelength 365nm, energy 1800mJ / cm²). 2 The overall thickness is 4.8 mm; the lead connection uses laser micro-welding (wavelength 1064 nm, pulse energy 1.5 mJ, time 15 μs), low-residue flux, and ultrasonic cleaning (120 W, 2.5 min); the test uses a package leak rate of 8 × 10⁻⁶. -9 Pa·m³ / s, lead contact resistance 25mΩ, FPC pull-out force 6N;

[0061] S8, segmented function test, display performance is 530cd / m² brightness. 2 The contrast ratio is 1100:1, the response time is 9ms, and the brightness uniformity deviation is 4%. The touch performance is a trigger force of 45g, an accuracy deviation of 0.09mm, 10-point touch, and a response time of 4ms. The EMC performance parameters are radiated emission of 38dBμV / m (30-1000MHz) and immunity of 210V / m (80-1000MHz). There are no defective products.

[0062] S9. Reliability enhancement treatment: high and low temperature cycling: -40℃ to 85℃ (2h) for 500 cycles, temperature change rate 8℃ / min; damp heat aging: placed at 85℃ and 85%RH for 1000h; vibration test parameters: 10-2000Hz frequency band, 10g acceleration vibration for 200h; detection parameter: performance degradation of 8% (brightness reduced to 498cd / m²). 2 Touch response time increased to 4.3ms).

[0063] S10. Final quality control and packaging: 10% full performance retest: 99.5% pass rate; Appearance inspection: no scratches (depth ≤ 0.1μm), no bubbles (diameter ≤ 0.1mm); Packaging uses anti-static foam (surface resistance ≤ 10). 7 Ω) + aluminum foil bag (shielding effectiveness 32dB), placed separately.

[0064] Example 2: Adaptation for small-sized automotive screens (7 inches) processing; key parameters and performance steps are as follows:

[0065] 1. Substrate pretreatment: Borosilicate glass substrate: thickness 0.5mm, light transmittance 92%; Cleaning parameters: 5% KOH (50℃, 300W, 5min) → 3% HF (25℃, 2min) → 18.2MΩ·cm ultrapure water (40℃, 200W, 8min); Ultraviolet sterilization: 10mW / cm 2 3 min; flatness error 0.7 μm;

[0066] 2. Fabrication of the touch electrode layer, magnetron sputtering: argon 20 sccm, oxygen 1 sccm, vacuum degree 5×10 -4 Pa, substrate 150℃, power 200W, conductive layer thickness 80nm (sheet resistance 14Ω / □, transmittance 90%); femtosecond laser: pulse width 50fs, frequency 1kHz, energy density 1J / cm²; plasma cleaning 100W, 3min (sheet resistance deviation 5%, roughness 0.5μm).

[0067] 3. Insulating layer and optical adjustment layer: Insulating layer: PI solid content 30%, rotation speed 3000 rpm, pre-curing 80℃ (30 min), high temperature 200℃ (120 min), thickness 800 nm (breakdown voltage 105 V / μm); Optical adjustment layer: high refractive index resin 1.6, slit coating 5 mm / s, baking 120℃ (60 min), thickness 1.5 μm (reflectivity 0.4%, transmittance 91%).

[0068] 4. Core performance test results: Display performance: brightness 500cd / m², contrast ratio 1050:1, color gamut 95% NTSC, response time 10ms; Touch performance: trigger force 50g, accuracy deviation 0.1mm, response time 5ms.

[0069] Comparative example (traditional split-type process): The traditional split-type processing method is used, and the steps and performance are as follows:

[0070] 1. Processing Steps: Display Module Fabrication: Ordinary soda-lime glass substrate → TFT array → pixel electrode → color filter layer → liquid crystal injection → glass cover encapsulation (independent production line, cycle 24h); Touch Module Fabrication: Independent borosilicate glass substrate → ITO sputtering → etching → PI insulating layer → protective cover (OCA adhesive bonding, independent production line, cycle 16h); Module Bonding: Bonding the display module and touch module with OCA optical adhesive (100μm thickness) (bonding production line, cycle 8h); Lead Connection: Connecting the FPC using ACF hot-press bonding (temperature 180℃, pressure 5MPa).

[0071] 2. Key Parameters and Performance Material Costs: An additional set of touch module protective cover (cost +25%) and OCA adhesive (cost +8%) increases the total material cost by 33% compared to Example 1; Optical Performance: Due to the addition of two interfaces (display-OCA, OCA-touch), the interface reflectivity is 1.8%, the overall transmittance is 88%, the contrast ratio is 800:1, and the brightness is 450 cd / m². 2 Reliability: The contact resistance of the ACF hot-pressed connection increased to 50mΩ after high and low temperature cycling (27mΩ in Example 1), and the performance degraded by 15% after damp heat aging (8% in Example 1); Production efficiency: Total cycle time was 48h (22h in Example 1), and the bubble occurrence rate in the bonding process was 5% (no bubbles in Example 1); EMC performance: With only a single-sided shielding layer, the shielding effectiveness was 32dB (42dB in Example 1), and the radiated emission was 45dBμV / m (exceeding the CISPR25 Class 5 standard).

[0072] Performance Comparison Table of Examples and Comparative Examples

[0073] index Example 1 Example 2 Comparative example (traditional process) Material costs (relative value) 100% 105% 133% Production cycle (h) 22 24 48 Overall light transmittance (%) 92 91 88 Contrast ratio (:1) 1100 1050 800 Touch response time (ms) 4 5 6 Reliability degradation (%) 8 9 15 Electromagnetic shielding effectiveness (dB) 42 40 32 Bubble occurrence rate (%) 0 0 5

[0074] As shown in the table above, the integrated processing method of the present invention is significantly superior to the traditional split process in terms of cost, efficiency, optical performance, reliability and EMC compatibility, and is fully adapted to the high-performance requirements of automotive scenarios.

[0075] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for integrated assembly and processing of vehicle-mounted screens based on capacitive touch control, characterized in that, The specific steps include the following: S1. Substrate pretreatment: Borosilicate glass substrates are selected and sequentially cleaned with alkaline solution, acidic solution, and ultrapure water, then dried with hot air and sterilized with ultraviolet light. Finally, substrates with a flatness error ≤1μm are screened by laser flatness detection. S2. Preparation of touch electrode layer: The conductive layer is deposited by magnetron sputtering, and the touch electrode array is formed by femtosecond laser etching. After etching, the electrode is cleaned by plasma and the electrode performance is tested. S3. Insulation layer coating: Polyimide resin is coated using a spin-coating process, and the insulation layer is formed by pre-curing and high-temperature curing, and the electrical insulation performance is tested. S4. Optical adjustment layer formation: A high refractive index resin-low refractive index nanoparticle composite system is coated by slit coating, and the optical performance is tested after baking and curing. S5. The integrated display functional layer is formed by sequentially completing the TFT array fabrication, pixel electrode and common electrode fabrication, color filter layer fabrication, liquid crystal injection and encapsulation, and the display functional parameters are tested after each step. S6. Electromagnetic shielding layer integration: Electromagnetic shielding layers are prepared on the outer side of the substrate facing the display functional layer and the inner side of the substrate facing the touch electrode layer, respectively, and the shielding effectiveness and conductivity are tested. S7. Encapsulation and lead connection: Glass cover plate and UV curing adhesive are used for encapsulation. Laser micro-welding is used to connect the control electrode and FPC. The sealing performance and connection reliability of the encapsulation are tested. S8. Segmented function test: Test display performance, touch performance, and EMC performance. Defective products are repaired in the current process. S9. Reliability enhancement treatment, including high and low temperature cycling, damp heat aging, and vibration testing, ensuring performance degradation ≤10% after testing; S10. Final quality control and packaging: full performance retesting is conducted proportionally, and anti-static materials are used for packaging after detecting appearance defects.

2. The method according to claim 1, characterized in that, In step S1, the borosilicate glass substrate has a thickness of 0.5–0.7 mm, a light transmittance ≥92%, and a coefficient of thermal expansion of 3.2 × 10⁻⁶. -6 / ℃; Alkaline cleaning uses 5%–8% potassium hydroxide solution, temperature 50–60℃, ultrasonic power 300–400W, time 5–8min; Acidic cleaning uses 3%–5% hydrofluoric acid solution, temperature 25–30℃, time 2–3min; Ultrapure water rinsing uses 18.2MΩ·cm ultrapure water, temperature 40–45℃, ultrasonic power 200–300W, time 8–10min; Ultraviolet sterilization wavelength 254nm, intensity 10–15mW / cm 2 Time: 3-5 minutes.

3. The method according to claim 1, characterized in that, In step S2, magnetron sputtering uses an ITO-ZnO composite target, with an argon flow rate of 20–25 sccm, an oxygen flow rate of 1–2 sccm, and a vacuum level of 5 × 10⁻⁶. -4 ~8×10 -4 Pa, substrate temperature 150~180℃, power 200~250W, conductive layer thickness 80~100nm, sheet resistance ≤15Ω / □, transmittance ≥90%; femtosecond laser etching wavelength 1064nm, pulse width 50~100fs, frequency 1~2kHz, energy density 1~2J / cm²; touch electrode array includes driving electrodes along the X-axis and sensing electrodes along the Y-axis; plasma cleaning is performed in an argon atmosphere, power 100~150W, time 3~5min, detection electrode sheet resistance uniformity deviation ≤5%, edge roughness ≤0.5μm.

4. The method according to claim 1, characterized in that, In steps S3 and S4, the polyimide resin has a solid content of 30%–40% and a viscosity of 500–800 cps. The spin-coating speed is 3000–4000 rpm, the time is 30–60 s, the pre-curing temperature is 80–100℃, the time is 30–60 min, the high-temperature curing temperature is 200–220℃, the time is 120–180 min, the insulation layer thickness is 800–1200 nm, the degree of crosslinking is ≥90%, the breakdown voltage is ≥100 V / μm, and the dielectric constant is ≤3. 5 (1kHz), surface roughness ≤0.1μm; in the composite system, the high refractive index resin has a refractive index of 1.6 to 1.7, the low refractive index nanoparticles are silicon dioxide, the slit coating speed is 5 to 10 mm / s, the wet film thickness is 2 to 3 μm, the baking temperature is 120 to 150℃ and the time is 60 to 90 min, the optical adjustment layer thickness is 1.5 to 2.5 μm and the refractive index gradually changes from 1.6 on the insulating layer side to 1.5 on the display layer side along the thickness direction, the reflectivity of the detection interface is ≤0.5%, and the overall transmittance is ≥91%.

5. The method according to claim 1, characterized in that, In step S5, the TFT array is produced using the LTPO process, with CVD deposition of a 50–80 nm amorphous silicon layer and laser annealing at a wavelength of 308 nm and an energy density of 300–400 mJ / cm². 2 The active layer channel width is 10–20 μm, the gate is made of molybdenum, and the source and drain electrodes are made of aluminum; the ITO layer thickness of the pixel electrode and the common electrode is 60–80 nm; the R / G / B photoresist thickness of the color filter layer is 1.5–2 μm, and the mask exposure wavelength is 365 nm with an energy of 100–150 mJ / cm². 2 Color gamut ≥ NTSC 95%; liquid crystal is nematic liquid crystal; sealant is UV-curable type, UV curing energy 2000~3000mJ / cm² 2 After each step, the TFT conduction current is tested to be ≥1μA, the pixel voltage deviation is ≤5%, and the liquid crystal pretilt angle deviation is ≤1°.

6. The method according to claim 1, characterized in that, In steps S6 and S7, the inner electromagnetic shielding layer is a 100-150nm copper-nickel alloy layer with an etched grid line width of 20-30μm, a spacing of 500-800μm, and a transmittance ≥85%. The outer electromagnetic shielding layer is screen-printed with conductive silver paste using a 300-400 mesh screen, with a grid line width of 30-40μm, a spacing of 500-800μm, and staggered from the inner layer. It is cured by baking at 120-150℃ for 30-60 minutes, and the shielding effectiveness is tested to be ≥40dB and the node contact resistance ≤100mΩ. The glass cover is made of the same material as the substrate glass, with a UV-curable adhesive refractive index of 1.5-1.6, a thickness of 50-100μm, a curing shrinkage rate ≤1%, and a UV curing wavelength of 365nm and an energy of 1500-2000mJ / cm². 2 The laser micro-welding process involves a time of 30–60 seconds, resulting in an overall thickness ≤5 mm after encapsulation. The laser micro-welding wavelength is 1064 nm, with a pulse energy of 1–2 mJ and a time of 10–20 μs. The flux used is low-residue. Ultrasonic cleaning power is 100–150 W, and the time is 2–3 minutes. The leak rate during encapsulation is detected to be ≤1 × 10⁻⁶. -8 Pa·m 3 / s, lead contact resistance ≤30mΩ, FPC pull-out force ≥5N.

7. The method according to claim 1, characterized in that, In steps S8 and S9, the display performance testing index is a brightness of ≥500 cd / m². 2 Contrast ratio ≥1000:1, color gamut ≥95% NTSC, response time ≤10ms, brightness uniformity deviation ≤5%; touch performance test indicators are trigger force ≤50g, accuracy deviation ≤0.1mm, support for 10-point simultaneous touch, response time ≤5ms; EMC performance complies with CISPR25 Class 5 standard, radiated emission ≤40dBμV / m@30~1000MHz, immunity ≥200V / m@80~1000MHz; high and low temperature cycling temperature range -40℃~85℃, damp heat aging is placed at 85℃ and 85%RH environment for 1000h, vibration test is in the 10~2000Hz frequency band, and the performance degradation after the test is ≤10%.

8. The method according to claim 1, characterized in that, In step S10, the full performance retest ratio is 10%, and the appearance defect detection standards are scratch depth ≤0.1μm and bubble diameter ≤0.1mm; the packaging uses a surface resistivity of 10. 6 ~10 9 The product is placed independently in an Ω-sized antistatic foam and an aluminum foil bag with a shielding effectiveness of ≥30dB.

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