A process for coating a car light-adjusting glass

Abstract

The application relates to the technical field of glass manufacturing, in particular to a car light-adjusting glass coating process, which sequentially carries out alkali cleaning, deionized water rinsing, drying and plasma activation treatment on a glass substrate; if the glass substrate is a curved glass, the glass needs to be first subjected to hot bending or cold bending forming after pretreatment, and then enters the subsequent steps; if the glass substrate is an ultrathin plane glass, the glass directly enters the subsequent steps after pretreatment. The application optimizes a functional layer by adopting a composite doping system, breaks the performance bottleneck of a single component through synergistic effect of multiple elements, greatly improves the light transmission adjustment range and ion migration efficiency of the coated glass, simultaneously enhances the stability of the film layer structure, and avoids problems such as precipitation and embrittlement.

Description

Technical Field

[0001] This invention relates to the field of glass manufacturing technology, and more specifically to a coating process for automotive dimming glass. Background Technology

[0002] In the glass manufacturing industry, coating technology is being used more and more widely, especially in high-end applications such as automotive sunroofs, where stringent requirements are placed on the comprehensive performance of coated glass. High-quality coated glass must have excellent light transmission adjustment capabilities, fast response speed, and long service life. At the same time, it must meet the requirements of weather resistance and mechanical strength in complex environments, resist the corrosion of extreme environments such as high and low temperatures and humid heat, and have good film adhesion and electrical conductivity stability.

[0003] However, existing coating processes suffer from numerous shortcomings that urgently need to be addressed, severely limiting their application and promotion in high-end fields. In terms of composition design, functional layers often employ single-component systems, lacking effective elemental doping optimization. This results in limited dimming range, insufficient ion migration efficiency, difficulty in achieving performance breakthroughs, and a susceptibility to problems such as precipitation and film embrittlement. Regarding process parameter design, parameters at each stage are set in isolation, failing to consider the synergistic compatibility between composition and process. This leads to numerous interfacial defects and weak adhesion in the film, directly impacting the overall performance of the product.

[0004] The conductive connection method is relatively simple, relying solely on ordinary conductive adhesive for bonding without any reinforcement measures. This results in poor conductive channels, insufficient connection stability, and a tendency for poor contact during long-term use. Some processes omit necessary protective layer structures, making the film layer weak in resistance to oxidation and moisture erosion, prone to bulging, cracking, or even detachment in extreme environments. The encapsulation process uses traditional methods, lacking specialized materials and precise temperature and pressure control, resulting in poor component sealing, insufficient mechanical strength, and inability to adapt to complex automotive and outdoor usage scenarios.

[0005] Furthermore, existing processes have poor adaptability to glass substrates, making it difficult to meet the coating requirements of both curved and ultra-thin flat glass. The underlying film structure design is also limited, failing to adapt flexibly to different application scenarios, further restricting the process's applicability. Additionally, some process parameters are set too narrowly, making it difficult to meet the diverse needs of industrial mass production, resulting in low production efficiency and high costs. Summary of the Invention

[0006] The primary objective of this invention is to provide a coating process for automotive dimming glass.

[0007] A further objective of this invention is to provide a coating process for automotive dimming glass, comprising the following steps: (1) Pretreatment of glass substrate: The glass substrate is sequentially cleaned with alkaline solution, rinsed with deionized water, dried and activated by plasma. If the glass substrate is curved glass, it needs to be hot-bent or cold-bent after pretreatment before proceeding to the next step. If it is ultra-thin flat glass, it can proceed directly to the next step after pretreatment. (2) Bottom layer deposition: The bottom layer is deposited using APCVD equipment. The bottom layer can be one of the following two schemes: Scheme 1 is to continuously deposit an FTO layer and a TiO2 layer; Scheme 2 is to continuously deposit a SiO2 barrier layer, an FTO layer, a TiO2 layer and a WO3 layer. (3) Laser scribing and masking: The above APCVD deposited film layer is etched using a nanosecond laser or a picosecond laser to form a stepped structure to prevent electrode conduction. At the same time, the other side of the above APCVD deposited film layer is etched to expose part of the FTO layer, and the exposed FTO area is masked. (4) Functional layer deposition: The electrochromic layer, ion conduction layer, storage layer, lithium metal layer, second resistive layer and second conductive layer are sequentially deposited in a vacuum environment using PVD process. After deposition, the mask is removed. (5) Connecting the conductive layer: The first conductive FTO layer and the second conductive layer are electrically connected and cured by using conductive tape and conductive adhesive in combination with silver paste. (6) Protective layer deposition: A silicon nitride protective layer is deposited using PVD or PECVD processes; (7) Lamination encapsulation: The coated glass and the matching glass are bonded together using a special film, and the encapsulation is completed under the set temperature, pressure and vacuum conditions.

[0008] Preferably, in the functional layer deposition, the electrochromic layer is a composite layer of WO3 and Mo and Ti, the ion conduction layer is a composite layer of WO3 and Li, the storage layer is a composite layer of NiWO3 and Ta, and the second conductive layer is an ITO layer.

[0009] Preferably, the electrochromic layer also contains Nb, the ion-conducting layer also contains SiO2, and the storage layer also contains V.

[0010] Preferably, the storage layer also contains W.

[0011] Preferably, in the glass substrate pretreatment, the plasma activation power is 200 watts to 12000 watts, and the activation time is 30 seconds to 600 seconds.

[0012] Preferably, in the bottom layer deposition, the deposition temperature is 550 degrees Celsius to 620 degrees Celsius, the reaction pressure is standard atmospheric pressure, and the deposition rate is 10 nanometers per minute to 2000 nanometers per minute.

[0013] Preferably, in the laser scribing and masking process, the mask is a polyimide film or a metal mask plate, the mask accuracy is no more than ±3 mm, the etching depth is 100 nanometers to 1500 nanometers, and the line width is 50 micrometers to 5000 micrometers.

[0014] Preferably, in the conductive layer connection, the conductive strip is a copper conductive strip or a silver alloy conductive strip, the curing temperature is 100 degrees Celsius to 200 degrees Celsius, and the curing time is 20 minutes to 90 minutes.

[0015] Preferably, the deposition temperature for the protective layer is between 100 degrees Celsius and 300 degrees Celsius.

[0016] Preferably, in the laminated encapsulation, the special film is a PVB film, an SGP film, or an EVA film, the lamination temperature is 110 degrees Celsius to 190 degrees Celsius, the vacuum pressure is 1 Pa to 100 Pa, the bonding pressure is -10 MPa to -100 MPa, and the heat preservation and pressure holding time is 20 minutes to 120 minutes.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention optimizes the functional layer using a composite doping system. Through the synergistic effect of multiple elements, it breaks through the performance bottleneck of a single component, significantly improving the light transmittance adjustment range and ion migration efficiency of the coated glass. At the same time, it enhances the stability of the film structure and avoids problems such as precipitation and embrittlement. In terms of process design, the parameters of each step are precisely matched to achieve synergistic linkage between pretreatment, deposition, scribing and other processes, reducing defects inside the film and at the interface, improving charge transport and storage efficiency, and laying a solid foundation for product performance.

[0018] 2. This invention optimizes the underlying film structure and provides two underlying deposition schemes, which can be flexibly selected according to product performance requirements. The newly added SiO2 barrier layer can effectively prevent ion diffusion and further improve film stability. At the same time, it takes into account the coating requirements of curved glass and ultra-thin flat glass, expands the application range of the process, and is suitable for the preparation of different types of high-end glass products such as automotive sunroofs.

[0019] 3. This invention combines highly conductive materials with robust bonding technology. Through the synergistic effect of conductive strips, conductive adhesives, and silver-containing pastes, it not only ensures the smoothness of the conductive channels but also enhances the mechanical stability and weather resistance of the connection parts, effectively extending the product's service life. The added protective layer is deposited using an adapted process, which significantly improves the film's resistance to oxidation and water vapor erosion, strengthening the product's adaptability to extreme environments.

[0020] 4. The packaging process of this invention uses special films and optimizes temperature and pressure parameters, while introducing a vacuum environment, which greatly improves the sealing performance and mechanical strength of the components, enabling them to resist impact and corrosion from complex environments.

[0021] In addition, the range of each process parameter has been optimized and expanded to meet the diverse needs of industrial mass production, reduce the precision requirements of equipment and the scrap rate, improve production efficiency and reduce production costs. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1:

[0024] Glass substrate pretreatment: A 1.5 mm thick ultrathin planar float glass substrate is selected. It is first ultrasonically cleaned with 8 parts by weight of sodium hydroxide solution for 15 minutes, then rinsed with deionized water 3 times, dried with hot air at 80 degrees Celsius for 20 minutes, and finally activated with 200 watts plasma for 60 seconds. Within the plasma activation parameter range preset in this invention, the surface activity of the substrate is improved to enhance the adhesion of subsequent film layers, laying the foundation for the entire process.

[0025] Substrate deposition scheme 1: During the tin bath transport process, start the APCVD equipment, set the deposition temperature to 550 degrees Celsius, within the deposition temperature range preset by this invention, the reaction pressure is standard atmospheric pressure, and the deposition rate is 10 nanometers per minute. Within the deposition rate range preset by this invention, first deposit an FTO layer to a thickness of 100 nanometers, then deposit a TiO2 layer to a thickness of 50 nanometers. The two film layers are deposited continuously to avoid interface contamination and ensure the conductivity and resistance matching of the substrate.

[0026] 100-micron linewidth laser scribing and masking: Nanosecond laser etching is used to etch to a depth of 250 nanometers. Within the preset etching depth range of this invention, the linewidth is 100 micrometers. Within the preset linewidth range of this invention, a stepped shape is etched to accurately expose part of the FTO layer. Subsequently, a polyimide film is used to mask the exposed FTO area with a masking accuracy of ±3 mm, which meets the preset masking accuracy requirements of this invention, preventing short circuits in the conductive layer during subsequent functional layer deposition and ensuring circuit stability.

[0027] Functional layer deposition: The glass substrate is moved into the PVD vacuum chamber and evacuated to 1×10⁻⁶. -3At a deposition rate of 5 nm per minute, a composite electrochromic layer of WO3 and Mo, Ti with a thickness of 150 nm, a composite ion-conducting layer of WO3 and Li with a thickness of 80 nm, a composite storage layer of NiWO3 and Ta with a thickness of 100 nm, a lithium metal layer with a thickness of 20 nm, a second NiWO3 resistive layer with a thickness of 40 nm, and a second ITO conductive layer with a thickness of 100 nm were deposited sequentially. After deposition, the mask was precisely removed to ensure the compatibility between the functional layer and the underlying layer.

[0028] Conductive layer connection: A copper conductive strip with a thickness of 100 micrometers is used, bonded with conductive adhesive and laid with silver-containing paste to achieve electrical connection between the first conductive layer FTO and the second conductive layer ITO. It is cured at 120 degrees Celsius for 60 minutes to ensure that the conductive channel is unobstructed and the connection is firm within the curing parameters preset in this invention.

[0029] Protective layer deposition: A silicon nitride protective layer with a thickness of 50 nanometers is deposited using PVD process at a deposition temperature of 200 degrees Celsius. Within the preset protective layer deposition temperature range of this invention, the film layer's resistance to oxidation and water vapor erosion is improved, thus extending the product's service life.

[0030] Laminated encapsulation: A 1.14 mm thick PVB film is used to bond the coated glass to the matching flat tempered glass. The lamination temperature is set to 150 degrees Celsius, the vacuum pressure to 50 Pa, the bonding pressure to -50 MPa, and the heat and pressure are maintained for 60 minutes to complete the encapsulation, ensuring the component's sealing performance and mechanical strength.

[0031] Example 2:

[0032] The glass substrate pretreatment, bottom layer deposition, laser scribing and masking, conductive layer connection, protective layer deposition and encapsulation steps are completely consistent with those in Example 1, maintaining stable process parameters and avoiding interference with performance from non-component factors.

[0033] Functional layer deposition: The PVD process parameters such as vacuum degree and deposition rate are the same as in Example 1. Only the composition system is optimized to achieve a performance breakthrough. A composite electrochromic layer with a thickness of 150 nm is deposited sequentially with WO3 and Mo, Ti plus 1 part by weight of Nb. The optimized electrochromic layer composition design of this invention uses Mo, Ti and Nb to synergistically improve the ion migration rate and enhance the stability of the film structure, solving the problem of easy precipitation of single dopants. A composite ion conduction layer with a thickness of 80 nm is deposited with WO3 and Li plus 1 part by weight of SiO2. The optimized ion conduction layer composition design of this invention uses Li and SiO2 to synergistically enhance the film density and improve the ion conduction efficiency. A composite storage layer with a thickness of 100 nm is deposited with NiWO3 and Ta plus 1 part by weight of V. The optimized storage layer composition design of this invention uses Ta and V to synergistically improve the charge storage capacity and cycle stability. The thickness of the remaining functional layers is the same as in Example 1, achieving precise matching of composition and process.

[0034] Example 3:

[0035] Glass substrate pretreatment: A curved float glass substrate with a thickness of 2.0 mm is selected. It is first ultrasonically cleaned with 8 parts by weight of sodium hydroxide solution for 15 minutes, then rinsed with deionized water 3 times, dried with hot air at 80 degrees Celsius for 20 minutes, and activated with 8000 watt plasma for 300 seconds to improve the surface activity and roughness of the substrate within the plasma activation parameter range preset in this invention. Then, it is hot-bent to fit the curved surface requirements of the automotive sunroof. The remaining steps are the same as in Example 1.

[0036] Substrate deposition scheme two: Start the APCVD equipment, set the deposition temperature to 600 degrees Celsius, within the deposition temperature range preset by this invention, the reaction pressure is standard atmospheric pressure, the deposition rate is 1000 nanometers per minute, and within the deposition rate range preset by this invention, continuously deposit a SiO2 barrier layer with a thickness of 80 nanometers, an FTO layer with a thickness of 120 nanometers, a TiO2 layer with a thickness of 60 nanometers, and a WO3 layer with a thickness of 40 nanometers. The four film layers are continuously deposited. The SiO2 barrier layer prevents ion diffusion, and the WO3 layer enhances the compatibility between the substrate and the functional layer, ensuring the conductivity and structural stability of the substrate.

[0037] 2000-micron linewidth laser scribing and masking: Picosecond laser etching is used to etch at a depth of 800 nanometers. Within the preset etching depth range of this invention, the linewidth is 2000 micrometers. Within the preset linewidth range of this invention, a stepped shape is etched to accurately expose part of the FTO layer. Subsequently, a metal mask is used to mask the exposed FTO area with a masking accuracy of ±2 mm, which meets the preset masking accuracy requirements of this invention, prevents short circuits in the conductive layer during subsequent functional layer deposition, and ensures circuit stability.

[0038] Functional layer deposition: PVD vacuum level increased to 5×10- 4 The deposition rate was increased to 500 nanometers per minute. Within the deposition rate range preset in this invention, the thickness of the electrochromic layer was adjusted to 180 nanometers, the thickness of the ion conduction layer was adjusted to 100 nanometers, and the thickness of the storage layer was adjusted to 120 nanometers. One part by weight of W was added to the storage layer. The optimized storage layer composition design of this invention reduced internal defects of the composite component functional layer by adjusting parameters, thereby improving ion migration and charge storage efficiency. The remaining components were the same as in Example 2.

[0039] Conductive layer connection: A 100-micron thick silver alloy conductive strip is used, bonded with conductive adhesive and laid with silver-containing paste to achieve electrical connection between the first conductive layer FTO and the second conductive layer ITO. It is cured at 180 degrees Celsius for 30 minutes to ensure that the conductive channel is unobstructed and the connection is firm within the curing parameters preset in this invention.

[0040] Protective layer deposition: A silicon nitride protective layer with a thickness of 50 nanometers is deposited using the PECVD process at a deposition temperature of 250 degrees Celsius. Within the preset protective layer deposition temperature range of this invention, the density and adhesion of the protective layer are improved, further enhancing its resistance to environmental erosion.

[0041] Laminated encapsulation: 1.5 mm thick SGP film is used to bond the coated curved glass with the matching curved tempered glass. The lamination temperature is set to 170 degrees Celsius, the vacuum pressure to 80 Pa, the bonding pressure to -80 MPa, and the heat and pressure are maintained for 90 minutes. This adapts to the thickened functional layer and curved structure to ensure tight encapsulation and avoid the generation of interlayer bubbles.

[0042] Example 4:

[0043] The glass substrate pretreatment, bottom layer deposition, laser scribing and masking, functional layer deposition, and protective layer deposition steps are completely consistent with those in Example 3, maintaining the synergistic advantages of composition and process, and ensuring the continuity of performance improvement.

[0044] Conductive layer connection: Abandoning the conventional connection method of Example 3, a composite connection scheme of silver alloy conductive tape with 95 parts by weight of silver and low-temperature curing silver paste is adopted. First, the silver alloy conductive tape is used to bond and position to ensure conductivity. Then, the conductive channel is filled with silver paste to enhance mechanical stability. The conductivity is optimized by laying silver paste. The curing temperature of silver paste is 100 degrees Celsius and the curing time is 90 minutes. Within the curing parameter range preset by this invention, high conductivity, connection reliability and temperature resistance are taken into account.

[0045] Laminated encapsulation: 2.0 mm thick EVA film is used instead of SGP film. EVA film has higher weather resistance and bonding strength. The lamination temperature is adjusted to 190 degrees Celsius, the vacuum pressure is 100 Pa, the bonding pressure is -100 MPa, and the heat and pressure are maintained for 120 minutes. While adapting to composite connection methods, it further improves the overall mechanical strength and sealing of the component, meeting the needs of automotive outdoor impact protection.

[0046] Example 5:

[0047] Glass substrate pretreatment: A high-end curved glass substrate with a thickness of 2.5 mm is selected. The plasma activation power is increased to 12,000 watts and the activation time is extended to 600 seconds. The plasma activation parameters preset in this invention maximize the surface activity and roughness of the substrate, ensuring a firm bond between each film layer and the substrate. Subsequently, cold bending is performed to adapt to complex curved surface requirements.

[0048] Substrate deposition scheme two: The APCVD deposition temperature is adjusted to 620 degrees Celsius. The deposition temperature and reaction pressure preset in this invention are standard atmospheric pressure. The deposition rate is increased to 2000 nanometers per minute. The preset deposition rate of this invention continuously deposits a SiO2 barrier layer with a thickness of 100 nanometers, an FTO layer with a thickness of 150 nanometers, a TiO2 layer with a thickness of 70 nanometers, and a WO3 layer with a thickness of 50 nanometers, balancing the conductivity, resistance matching and film density of the substrate.

[0049] Laser scribing and masking: Picosecond laser etching is used with an etching depth of 1500 nanometers. The preset etching depth and line width of this invention are 5000 micrometers. A metal mask is used with a masking accuracy of ±3 millimeters. The preset masking accuracy of this invention further improves the accuracy of conductive layer exposure, avoids short circuit risks, and ensures circuit stability.

[0050] Functional layer deposition: PVD vacuum degree 3×10 -4 At a deposition rate of 2000 nm per minute, within the preset deposition rate range of this invention, a composite electrochromic layer of WO3 and Mo, Ti plus 2 parts by weight of Nb with a thickness of 200 nm, a composite ion-conducting layer of WO3 and Li plus 1 part by weight of SiO2 with a thickness of 90 nm, and a composite storage layer of NiWO3 and Ta plus 2 parts by weight of V plus 1 part by weight of W with a thickness of 150 nm are deposited sequentially. Using the optimized functional layer composition of this invention, a lithium metal layer with a thickness of 30 nm, a NiWO second resistive layer with a thickness of 50 nm, and an ITO second conductive layer with a thickness of 120 nm are designed. Multi-element synergistic doping and parameter optimization maximize the improvement of electrochromic performance, ion conduction efficiency, and cycle stability.

[0051] Conductive layer connection: A silver alloy conductive strip with a thickness of 120 micrometers and a silver content of 98 parts by weight is used. It is bonded with a high thermal conductivity and conductive adhesive, and then laid with a silver-containing paste. It is cured at 130 degrees Celsius for 70 minutes. Within the curing parameters preset in this invention, high conductivity, mechanical stability and weather resistance are taken into account.

[0052] Protective layer deposition: A silicon nitride protective layer with a thickness of 60 nanometers is deposited using CVD process at a deposition temperature of 300 degrees Celsius, which improves the density and adhesion of the protective layer and further enhances its resistance to environmental corrosion.

[0053] Laminated encapsulation: 2.0 mm thick EVA film is used, with a lamination temperature of 110 degrees Celsius, a vacuum pressure of 1 Pa, a bonding pressure of -10 MPa, and a heat and pressure holding time of 20 minutes. This adapts to the optimized film characteristics of the entire system, ensuring the best overall performance of the module while improving production efficiency.

[0054] Comparative Example 1: The steps are basically the same as in Example 1, except that the functional layer adopts a single-component system commonly used in existing technologies, the electrochromic layer is pure WO3, the ion conduction layer is pure WO3, the storage layer is pure NiWO3, without any doped elements, and the remaining process parameters are the same as in Example 1, simulating the core defect of the single component in existing technologies.

[0055] Comparative Example 2: The steps are basically the same as in Example 1, using isolated process parameters designed with existing technology: APCVD deposition temperature 550 degrees Celsius, reaction pressure at standard atmospheric pressure, and deposition rate 2000 nanometers per minute; PVD deposition vacuum degree 5 × 10⁻⁶. -3 Pa, deposition rate 2000 nm per minute, without considering the synergistic matching of process parameters, to simulate the limitations of existing technology process design.

[0056] Comparative Example 3: The steps are basically the same as in Example 1. A simple conductive connection method commonly used in the prior art is adopted. Only ordinary conductive adhesive is used to directly bond the first conductive layer and the second conductive layer. No metal conductive strip or silver-containing paste is used. The remaining parameters are the same as in Example 1, simulating the defect of insufficient reliability of conductive connection in the prior art.

[0057] Comparative Example 4: The steps are basically the same as in Example 1, except that the protective layer is omitted in some existing technologies and no silicon nitride protective layer is deposited. The remaining parameters are the same as in Example 1, simulating the poor environmental resistance of existing technologies.

[0058] Comparative Example 5: The steps are basically the same as in Example 1. The conventional encapsulation method of existing technology is adopted, and ordinary glass glue is used for sealing. No special film or vacuum heat preservation and pressure preservation process is used. The remaining parameters are the same as in Example 1, simulating the defects of insufficient mechanical strength and sealing performance of existing technology.

[0059] Comparative Example 6: By combining the core technologies of the three existing technologies mentioned above, the electrochromic layer is made of pure WO3, the storage layer is made of pure NiWO3, and a simple conductive adhesive is used for connection. The protective layer is omitted, and ordinary PVB film is used for conventional lamination and encapsulation. The remaining process parameters are set within a reasonable range to simulate the performance limit of the simple combination of existing technologies.

[0060] Performance testing: Test items and methods: (1) Transmittance adjustment range: The transmittance difference between the colored and faded states of the coated glass at a wavelength of 550 nm was measured using a UV-Vis spectrophotometer to reflect the light-adjusting capability of the coated glass. The test equipment was a UV-3600, the test environment temperature was 25 degrees Celsius and the humidity was 50%RH. Each sample was tested 3 times and the average value was taken as the final result.

[0061] (2) Response time: An electrochromic performance tester was used to record the coloring time from the faded state to the colored state and the fading time from the colored state to the faded state of the coated glass. The test voltage was ±3V, which reflects the dimming response speed of the coated glass. The test equipment model was EC-1000, the test environment temperature was 25 degrees Celsius and the humidity was 50%RH. Each sample was tested 5 times, and the average value was taken after removing the maximum and minimum values.

[0062] (3) Cyclic stability: The coated glass was subjected to a color fading cycle test at ±3V voltage. The number of cycles when the transmittance remained at the initial value of 80% was recorded to reflect the service life of the coated glass. The test equipment was EC-2000, the test environment temperature was 25 degrees Celsius, the humidity was 50%RH, and the cycle frequency was 1 time per minute.

[0063] (4) Adhesion: The 100-grid test was used. 3M tape was applied to the coated glass with a grid spacing of 1 mm. After peeling, the film was observed to peel off, and the results were rated from 0 to 5. Rating 0 indicates no peeling, and rating 5 indicates complete peeling. This reflects the adhesion of the coated glass film. The testing equipment was a BG-100. Before testing, the sample surface was cleaned to remove dust and oil. Three different areas were tested for each sample, and the worst rating was taken as the final result.

[0064] (5) Environmental resistance: The coated glass was subjected to high and low temperature cycling tests, with conditions ranging from -40°C to 85°C. Each temperature point was maintained for 2 hours, and the transmittance change rate was tested after 50 cycles. The damp heat aging test conditions were 85°C and 85% RH. After 500 hours, the transmittance change rate and film integrity were tested to reflect the coated glass's ability to withstand extreme environments. The testing equipment models were GDW-1000 and SH-800, respectively. After the test, it was observed whether the film layer showed phenomena such as bulging, cracking, or peeling.

[0065] (6) Mechanical strength: The drop ball impact test was adopted. A 1 kg steel ball was dropped freely from a height of 1 meter to impact the coated glass. The glass was observed to see if it cracked or if the coating was peeled off, reflecting the actual safety of the coated glass in use. The test equipment model was LQ-500. During the test, the sample was fixed horizontally and the steel ball was dropped vertically. Each sample was tested at 3 different positions and the test results were recorded.

[0066] The test results are shown in Table 1 below: Table 1:

[0067] The results are analyzed as follows: Example 5, as the optimal solution for the entire system, achieves peak performance in all aspects: transmittance adjustment range reaches 70.1%, coloring time is the shortest, fading time is the shortest, cycle stability is up to 25,000 times, adhesion is the best grade 0, transmittance change rate is as low as 1.2% and 1.8% under high and low temperature cycles and damp heat aging, respectively, and mechanical strength is undamaged, fully meeting the stringent requirements of high-end glass such as automotive sunroofs.

[0068] In contrast, each comparative example exhibits significant performance shortcomings due to single or multiple technical defects. Comparative example 6 shows the worst performance, with all indicators at the lowest level, confirming that the simple superposition of existing technologies cannot solve the problem of overall system performance optimization. The performance shortcomings of comparative examples 4, 5, and 2 are particularly prominent, further demonstrating that the targeted improvements proposed by this invention to address the defects of existing technologies have irreplaceable technical value.

[0069] (1) The transmittance adjustment range directly reflects the dimming capability of the coated glass, and the response time reflects the dimming efficiency. Both are closely related to the synergy between the functional layer composition and process parameters. The transmittance adjustment range of Examples 1-5 is 55.2%-70.1%, the coloring time is 4.2-8.3 seconds, and the fading time is 3.1-6.5 seconds, which are significantly better than the comparative examples. Among them, Example 2, compared with Example 1, has a 13.8% increase in transmittance adjustment range and a 26.5% and 26.2% reduction in coloring / fading time due to the addition of Nb, SiO2, and V doping to the functional layer, which confirms the optimization effect of the multi-element composite doping system on the performance of the functional layer. Examples 3-5 further improve the performance through the optimization of the bottom film layer and the adjustment of process parameters, indicating that the synergistic matching of the bottom structure and process parameters can further break through the performance bottleneck.

[0070] Comparative Example 1 has a transmittance adjustment range of only 42.6% and a response time as long as 12.5 / 9.8 seconds, clearly demonstrating that a single-component system cannot achieve a performance breakthrough and is prone to insufficient ion migration efficiency. Comparative Example 6 has multiple defects such as single component, simple connection, and no protective layer, resulting in the lowest transmittance adjustment range and the longest response time, further highlighting the necessity of multi-dimensional synergistic improvement in this invention.

[0071] (2) Cyclic stability directly determines the service life of coated glass and is closely related to the stability of the functional layer, the adhesion of the film layer, and the performance of the protective layer. The cyclic stability of Examples 1-5 is 10,000-25,000 cycles, which is much higher than that of the comparative examples. Among them, Example 5 is 150% higher than Example 1 and 733.3% higher than Comparative Example 6. The cyclic stability of Example 2 is 50% higher than that of Example 1, thanks to the optimization of the functional layer composite doping, which reduces the problems of film precipitation and embrittlement. Examples 3-4 further improve the cyclic stability through the upgrade of the protective layer process and the optimization of conductive connection, which shows that the synergistic improvement of each link can significantly extend the service life of the product.

[0072] Comparative Example 4 showed the lowest cycle stability, far lower than other groups, and the membrane layer peeled off over a large area after damp heat aging, confirming the key protective role of the protective layer in membrane stability. Comparative Example 6 showed the lowest cycle stability, and due to the superposition of multiple defects, the membrane structure was easily damaged, making it impossible to achieve long-term stable use, which is highly consistent with the short service life of existing technologies.

[0073] (3) Adhesion reflects the bonding strength between the film layer and the substrate, and between each film layer, and is closely related to the glass substrate pretreatment and the underlayer deposition process. The adhesion of Examples 2-5 is all grade 0, while that of Example 1 is grade 1, both of which are better than the comparative examples. Examples 3-5 have optimized plasma activation parameters and underlayer film structure, ensuring a strong film bonding. Example 1 has slightly lower adhesion than the other examples due to its lower activation power, which confirms the influence of substrate pretreatment parameters on adhesion.

[0074] Comparative Example 2 showed an adhesion level of 3, while Comparative Examples 4 and 6 showed a level of 4. This indicates that incompatible process parameters and a lack of a protective layer can lead to increased interfacial defects and weak adhesion of the film, making it prone to peeling. This is consistent with the shortcomings of film adhesion in existing technologies.

[0075] (4) Environmental resistance reflects the adaptability of coated glass to extreme environments and is closely related to the protective layer and encapsulation process. The high and low temperature cycling transmittance change rate of Examples 1-5 was 1.2%-3.2%, and the damp heat aging transmittance change rate was 1.8%-4.5%, both of which were much lower than the comparative examples, and there were no phenomena of film bulging, cracking, or peeling. Examples 3-5 adopted PECVD / CVD process to deposit protective layer and vacuum lamination with special film, which significantly improved environmental resistance. Among them, Example 5 had the best environmental resistance, which confirmed the technical effect of the optimized protective layer and encapsulation process.

[0076] Comparative Example 4 exhibited the worst environmental resistance, with a transmittance change rate of 10.3% during high and low temperature cycling and 12.5% ​​during damp heat aging, resulting in large-area film peeling. Comparative Example 5 also showed relatively poor environmental resistance, with transmittance change rates of 6.2% and 8.5%, and slight cracking, indicating that traditional encapsulation methods cannot meet the requirements of complex outdoor environments. Comparative Example 6 exhibited the worst environmental resistance, further highlighting the severe impact of multiple defects on environmental resistance.

[0077] (5) Mechanical strength reflects the actual safety of coated glass in use and is closely related to the encapsulation process and the structure of the underlying film layer. Examples 1-5 showed no cracking or film peeling, demonstrating excellent mechanical strength and the ability to withstand outdoor impacts. Examples 4-5 further improved mechanical strength through upgraded encapsulation solutions, making them suitable for harsh outdoor use scenarios in automobiles.

[0078] Comparative Examples 2 and 5 showed minor cracks, while Comparative Example 6 showed cracks and large-area film peeling, indicating that isolated process parameters and traditional encapsulation methods can lead to poor component sealing and insufficient mechanical strength, failing to meet the safety requirements of high-end glass. Although Comparative Example 4 did not show cracks, the large-area film peeling still could not guarantee the safety of actual use.

[0079] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A coating process for automotive dimming glass, characterized in that, Includes the following steps: (1) Pretreatment of glass substrate: The glass substrate is sequentially cleaned with alkaline solution, rinsed with deionized water, dried and activated by plasma. If the glass substrate is curved glass, it needs to be hot-bent or cold-bent after pretreatment before proceeding to the next step. If it is ultra-thin flat glass, it can proceed directly to the next step after pretreatment. (2) Bottom layer deposition: The bottom layer is deposited using APCVD equipment. The bottom layer can be one of the following two schemes: Scheme 1 is to continuously deposit an FTO layer and a TiO2 layer; Scheme 2 is to continuously deposit a SiO2 barrier layer, an FTO layer, a TiO2 layer and a WO3 layer. (3) Laser scribing and masking: The above APCVD deposited film layer is etched using a nanosecond laser or a picosecond laser to form a stepped structure to prevent electrode conduction. At the same time, the other side of the above APCVD deposited film layer is etched to expose part of the FTO layer, and the exposed FTO area is masked. (4) Functional layer deposition: The electrochromic layer, ion conduction layer, storage layer, lithium metal layer, second resistive layer and second conductive layer are sequentially deposited in a vacuum environment using PVD process. After deposition, the mask is removed. (5) Connecting the conductive layer: The first conductive FTO layer and the second conductive layer are electrically connected and cured by using conductive tape and conductive adhesive in combination with silver paste. (6) Protective layer deposition: A silicon nitride protective layer is deposited using PVD or PECVD processes; (7) Lamination encapsulation: The coated glass and the matching glass are bonded together using a special film, and the encapsulation is completed under the set temperature, pressure and vacuum conditions. In the functional layer deposition, the electrochromic layer is a composite layer of WO3 with Mo, Ti and Nb, the ion conduction layer is a composite layer of WO3 with Li and SiO2, the storage layer is a composite layer of NiWO3 with Ta and V, and the second conductive layer is an ITO layer. In the conductive layer connection, the conductive strip is a copper conductive strip or a silver alloy conductive strip, the curing temperature is 100 degrees Celsius to 200 degrees Celsius, and the curing time is 20 minutes to 90 minutes; In the laminated encapsulation, the special film is PVB film, SGP film or EVA film, the lamination temperature is 110 degrees Celsius to 190 degrees Celsius, the vacuum pressure is 1 Pa to 100 Pa, and the heat and pressure holding time is 20 minutes to 120 minutes.

2. The automotive dimming glass coating process according to claim 1, characterized in that, In the glass substrate pretreatment, the plasma activation power is 200 watts to 12,000 watts, and the activation time is 30 seconds to 600 seconds.

3. The automotive dimming glass coating process according to claim 1, characterized in that, In the bottom layer deposition, the deposition temperature is 550°C to 620°C, the reaction pressure is standard atmospheric pressure, and the deposition rate is 10 nanometers per minute to 2000 nanometers per minute.

4. The automotive dimming glass coating process according to claim 1, characterized in that, In laser scribing and masking, the mask is made of polyimide film or metal mask plate, the mask accuracy is no more than ±3 mm, the etching depth is 100 nanometers to 1500 nanometers, and the line width is 50 micrometers to 5000 micrometers.

5. The automotive dimming glass coating process according to claim 1, characterized in that, The deposition temperature for the protective layer is between 100 and 300 degrees Celsius.

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