Front light guide plate process

Abstract

The invention discloses a front light guide plate process, which comprises the following steps of: adopting a modified PMMA (polymethyl methacrylate) plate as a base material, cleaning the surface of the modified PMMA plate, presetting a functional layer, performing an imprinting process on the surface of the light guide plate base material, and forming a bottom groove-bulge microstructure and a top prism array at one time through a composite die. Depositing an anti-reflection coating on the surface of the light guide plate semi-finished product with the composite microstructure, stacking TiO2 / SiO2 multilayer films layer by layer, and regulating and controlling the thickness of the coating to a target optical parameter in real time; an embedded heat dissipation layer is integrated on the back face of the coated light guide plate, a graphene heat conduction grid is generated through the laser induction technology, and optical performance and structural quality detection is conducted on the finished light guide plate; the light guide efficiency is remarkably improved through the composite microstructure design, the brightness and uniformity of the light guide plate are improved, the surface reflectivity and light loss are reduced through the multiple anti-reflection coatings, the problem of heat aggregation under high brightness is effectively solved through the laser-induced graphene heat dissipation layer, the product performance is improved, and the light guide plate with high brightness and high uniformity is output.

Description

Technical Field

[0001] The present invention relates to the technical field of light guide plates, and particularly to a front light guide plate process. Background Art

[0002] With the wide application of outdoor high-resolution displays in fields such as advertising media and traffic information display, the market has put forward higher requirements for the visibility of display devices under strong ambient light. As the core component of the side-entry backlight module, the performance of the front light guide plate directly determines the brightness, uniformity, and energy consumption efficiency of the display screen. Especially in outdoor scenarios, the light guide plate needs to simultaneously meet the requirements of ultra-high brightness (≥8000 lumens / ㎡), light distribution uniformity (deviation ≤5%), and long-term weather resistance (anti-ultraviolet, temperature change resistance) to ensure clear contrast of the picture under strong light interference.

[0003] Existing light guide plate processes mostly use a single micro-structure (such as grooves or dots) combined with a conventional anti-reflection coating to achieve light control. For example, laser engraving or die stamping is used to form scattering dots to improve the light output uniformity. However, such technologies have significant limitations: it is difficult for a single micro-structure design to balance the efficient guiding and scattering control of light. For example, although the traditional groove structure can improve the vertical light output efficiency, the scattering angle range is limited, resulting in severe brightness attenuation in areas far from the light incident surface; while evenly distributed dots can improve the light distribution, but due to the unoptimized light incident surface angle (usually 30-40°), some light rays are obliquely emitted, reducing the light energy utilization rate. This defect directly leads to insufficient brightness, obvious local dark areas, and a significant decrease in display contrast of existing light guide plates in outdoor strong light environments, unable to meet the stringent requirements of high-end outdoor screens.

[0004] In view of this, it is necessary to improve the light guide plate technology in the prior art to solve the technical problem of insufficient display performance under strong ambient light. Summary of the Invention

[0005] The purpose of the present invention is to provide a front light guide plate process to solve the above technical problems.

[0006] To achieve this purpose, the present invention adopts the following technical solutions: A front light guide plate process, comprising: S1, using a modified PMMA sheet as the substrate and cleaning its surface and pre-setting a functional layer to form a light guide plate substrate with a seed layer; S2, performing an embossing process on the surface of the light guide plate substrate, and forming a bottom layer groove-protrusion micro-structure and a top layer prism array in one step through a composite mold to form a light guide plate semi-finished product with a composite micro-structure; S3. Deposit an anti-reflection coating on the surface of the semi-finished light guide plate with a composite microstructure. Stack TiO2 / SiO2 multi-layer films layer by layer through atomic layer deposition technology, and adjust the coating thickness to the target optical parameters in real time; S4. Integrate an embedded heat dissipation layer on the back of the light guide plate with the coating completed. Generate a graphene heat conduction grid by laser-induced technology to form an integrated structure between the heat dissipation layer and the light guide plate substrate; S5. Conduct optical performance and structural quality inspections on the finished light guide plate. Compare the microstructure topography tolerances through an intelligent vision system, and optimize the process parameters based on the spectral data feedback to output a qualified light guide plate that meets the brightness and uniformity indicators.

[0007] Optionally, use a modified PMMA sheet as the substrate and clean its surface and pre-set a functional layer to form a light guide plate substrate with a seed layer, which specifically includes: Select a modified PMMA sheet, cut it into a light guide plate substrate blank according to a preset size by a laser cutting device, and polish the cutting edge to eliminate burrs; Perform plasma cleaning on the cut substrate blank. Use an argon-oxygen mixed gas with a volume ratio of 4:1 to excite plasma in a vacuum chamber and continuously process for 5-8 minutes to remove surface organic pollutants and microparticles; Immerse the cleaned substrate in a surface activation solution for chemical activation treatment for 10 minutes, then rinse with ultrapure water and dry with nitrogen; the surface activation solution is an ethanol solution containing 0.5 wt% silane coupling agent; Pre-deposit an alumina seed layer on the surface of the activated substrate through an atomic layer deposition device. The deposition temperature is 120 °C, and it is cycled n times. Trimethylaluminum and water vapor precursors are introduced in a single cycle to form a uniform seed layer with a thickness of 10 nm, and a light guide plate substrate with a seed layer is obtained; Anneal the light guide plate substrate. Keep it at a constant temperature of 150 °C for 30 minutes in a nitrogen atmosphere to enhance the bonding strength between the seed layer and the substrate; Measure the surface roughness of the seed layer and verify the thickness tolerance, screen out qualified substrates, and transfer the qualified substrates to a protective warehouse for storage.

[0008] Optionally, perform an imprinting process on the surface of the light guide plate substrate to form a bottom-layer groove-protrusion microstructure and a top-layer prism array in one step through a composite mold, forming a semi-finished light guide plate with a composite microstructure, which specifically includes: Provide a composite mold; Preheat the light guide plate substrate. Heat it at 80 °C for 10 minutes in a constant temperature chamber to soften the substrate surface below the glass transition temperature Tg and enhance the imprinting fluidity; Align the composite mold with the preheated substrate and fix it on the imprinting machine stage, apply a pressure of 20 - 25 MPa, and simultaneously irradiate the surface of the substrate with an ultraviolet light source to trigger the photocuring of the nanoimprinting adhesive, and continuously cure for a time of T1 to obtain a semi-finished light guide plate with composite microstructures; After demolding, anneal the imprinted substrate at a constant temperature of 120 °C for 20 minutes in a nitrogen atmosphere to eliminate internal stress and stabilize the microstructure morphology; Detect the morphology accuracy of the composite microstructures, verify the depth of the bottom grooves and the angle of the top prisms, screen out the qualified semi-finished light guide plates and temporarily store them.

[0009] Optionally, the composite mold includes a bottom microstructure area and a top prism area. The bottom microstructure area is processed with a groove - protrusion array by electron beam lithography, the groove width is 5 - 6 μm, the protrusion width is 30 - 35 μm, and the top prism area forms prism units with a period of 50 μm through nanoimprinting technology.

[0010] Optionally, deposit an antireflection coating on the surface of the semi-finished light guide plate with composite microstructures, stack TiO2 / SiO2 multi-layers layer by layer through atomic layer deposition technology, and continuously adjust the coating thickness to the target optical parameters in real time. The specific steps are as follows: Pre-treat the semi-finished light guide plate with composite microstructures, perform surface treatment with plasma to remove residual contaminants and enhance surface activity; Fix the pre-treated semi-finished light guide plate in the atomic layer deposition equipment chamber, set the substrate temperature to 200 °C, introduce nitrogen as the carrier gas and maintain the chamber pressure at 5 Torr; Deposit TiO2 and SiO2 layers alternately to form a multi-layer coating to form an antireflection coating; Monitor the film thickness of each coating in real time, combine with the PID algorithm to dynamically adjust the precursor injection time and purge cycle, so that the total film thickness error is controlled within the preset error threshold range; After completing the alternate deposition of 5 layers of TiO2 / SiO2, anneal the coated light guide plate at 180 °C in a nitrogen atmosphere for 15 minutes to eliminate interface stress and improve the film layer density; Use a spectrophotometer to detect the average reflectance of the antireflection coating in the 400 - 800 nm band, screen out the light guide plates that reach the preset qualified value and transfer them to a protective environment for temporary storage.

[0011] Optionally, the process of single-layer deposition in the alternate deposition of TiO2 and SiO2 layers specifically includes: Inject the titanium tetrachloride precursor for 3 seconds, and then purge with nitrogen; Inject water vapor and react for 5 seconds to generate a single atomic layer of TiO2; Inject the tetraethyl orthosilicate precursor for 4 seconds, and then purge with nitrogen; Inject ozone for 8 seconds for oxidation reaction to generate a single atomic layer of SiO2.

[0012] Optionally, an embedded heat dissipation layer is integrated on the back of the light guide plate after the coating is completed. A graphene heat conduction grid is generated by laser-induced technology to form an integrated structure between the heat dissipation layer and the light guide plate substrate. Specifically, it includes: Perform plasma activation treatment on the back of the light guide plate after the coating is completed. Use an argon-nitrogen mixed gas with a volume ratio of 4:1 to excite the plasma and continuously treat for 8 minutes to increase the surface energy and the adhesion of the graphene precursor; Spin-coat a polyimide precursor solution on the back of the activated light guide plate to form a uniform precursor film layer with a thickness of 20 μm, and pre-cure at 80 °C for 10 minutes; Use a laser to scan the precursor film layer to generate a heat conduction grid structure through laser-induced graphitization reaction.

[0013] Optionally, after using a laser to scan the precursor film layer to generate a heat conduction grid structure through laser-induced graphitization reaction, it further includes: Place the light guide plate after laser treatment in a vacuum annealing furnace and heat-treat it at a constant temperature of 400 °C for 30 minutes to complete the crystallization of the graphene heat conduction grid and the interfacial bonding with the light guide plate substrate under a nitrogen atmosphere; Detect the heat dissipation performance of the heat conduction grid, verify the thermal conductivity coefficient, and scan and observe the morphology of the heat conduction grid to screen out finished light guide plates with complete structures.

[0014] Optionally, perform optical performance and structural quality detection on the finished light guide plate. Compare the morphological tolerance of the microstructures through an intelligent vision system, and optimize the process parameters based on the spectral data feedback to output a qualified light guide plate that meets the brightness and uniformity indicators. Specifically, it includes: Fix the finished light guide plate on the detection platform and adjust the relative position between the light guide plate and the detection probe through a positioning fixture; Use an intelligent vision system to perform a global scan on the reflection surface of the light guide plate, compare the morphological parameters of the composite microstructures, and verify the tolerance of the groove depth and prism angle; Collect the brightness distribution data of the light-emitting surface of the light guide plate through an imaging system, set the detection dot density to 81 points / m 2 , covering the 400 - 800 nm band, synchronously measure the brightness value and uniformity deviation of each point to obtain spectral data; Input the morphological parameters and spectral data into the process optimization model, analyze the influence weight of key parameters on the performance based on the random forest algorithm, generate a dynamic adjustment instruction, and feedback it to the control system for optimizing the sample production of the light guide plate.

[0015] Optionally, after generating a dynamic adjustment instruction and feedback it to the control system for optimizing the sample production of the light guide plate, it further includes: Perform secondary optical detection on the optimized light guide plate, and use an integrating sphere system to verify the total luminous flux improvement rate and color temperature consistency; Detect data and process parameters through blockchain distributed recording, generate a unique quality traceability code, and bind it to the light guide plate serial number; Screen the light guide plates with qualified brightness and uniformity, package them in anti-static vacuum packaging, and output them as qualified products.

[0016] Compared with the prior art, the present invention has the following beneficial effects: First, a modified PMMA sheet is used as the substrate, and a seed layer substrate is formed through surface cleaning and pre-setting of the functional layer; then, a bottom layer groove-protrusion microstructure and a top layer prism array are formed by one-time stamping with a composite mold to obtain a semi-finished composite microstructure light guide plate; the TiO2 / SiO2 anti-reflection coating is stacked layer by layer on its surface by atomic layer deposition technology, and the optical parameters are adjusted in real time; a graphene heat conduction grid generated by laser induction is integrated on the back of the coated light guide plate to form an integrated heat dissipation structure, the microstructure morphology tolerance is detected by an intelligent vision system, and the parameters are optimized by combining spectral data feedback; this process significantly improves the light guiding efficiency through the composite microstructure design, improves the brightness and uniformity of the light guide plate, the multi-layer anti-reflection coating reduces the surface reflectivity and light loss, and the laser-induced graphene heat dissipation layer effectively solves the problem of heat aggregation under high brightness, improves the product performance, and outputs a light guide plate with high brightness and high uniformity. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those who are familiar with this technology to understand and read, and are not used to limit the limited conditions for the implementation of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope covered by the technical content disclosed in the present invention without affecting the effects that the present invention can produce and the purposes that can be achieved.

[0019] Figure 1 It is one of the process flow diagrams of the front light guide plate in the first embodiment; Figure 2 It is the second of the process flow diagrams of the front light guide plate in the first embodiment; Figure 3 It is the layout diagram of the front light guide plate in the second embodiment. Specific embodiments

[0020] In order to make the object, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be intermediate components present at the same time.

[0022] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0023] Embodiment 1: Combined with Figure 1 and Figure 2 As shown, the embodiment of the present invention provides a front light guide plate process, including: S1, using a modified PMMA sheet as the substrate and cleaning and pre-setting the functional layer on its surface to form a light guide plate substrate with a seed layer; It should be noted that the modified PMMA sheet is a polymethyl methacrylate (PMMA) substrate through composite modification and functionalization treatment, and is designed specifically for high-brightness front light guide plates. Its core features include: Nano-enhancement, adding 3-5% nano-silica (particle size 20-50nm) to improve the impact strength and thermal stability; Ultraviolet protection, incorporating 1-2% benzotriazole ultraviolet absorber to improve weather resistance; Surface functionalization, grafting fluoropolymer through plasma to endow hydrophobic and anti-fouling properties.

[0024] Using a modified PMMA sheet as the substrate, the surface cleanliness and adhesion of the substrate are significantly improved through laser cutting, plasma cleaning (argon-oxygen mixed gas), and activation with a silane coupling agent. Subsequently, a 10-nm alumina seed layer is pre-deposited using atomic layer deposition (ALD) technology and the interface bonding is strengthened through low-temperature annealing. The seed layer provides a uniform substrate for subsequent micro-structure imprinting and functional coating, while enhancing the UV resistance of the substrate to ensure the long-term stability of the light guide plate in outdoor environments.

[0025] S2, perform an imprinting process on the surface of the light guide plate substrate to form a semi-finished light guide plate with a composite microstructure by forming the bottom-layer groove-protrusion microstructure and the top-layer prism array in one go using a composite mold. The double microstructure forming is completed in one go using a composite mold (bottom-layer groove-protrusion + top-layer prism array). After preheating the substrate to 80 °C to soften it, ultraviolet curing nanoimprinting technology is used (replicating the microstructure topography, groove depth 3 - 4 μm, prism angle 41 - 47°) to achieve vertical light guiding and scattering control. Annealing treatment (120 °C, nitrogen atmosphere) eliminates internal stress, and a white light interferometer is used to detect the topography tolerance to ensure the uniformity of light distribution.

[0026] S3, deposit an antireflection coating on the surface of the semi-finished light guide plate with a composite microstructure, and stack TiO2 / SiO2 multi-layers layer by layer using atomic layer deposition technology, and the coating thickness is adjusted in real time to the target optical parameters. TiO2 / SiO2 multi-layers are stacked alternately layer by layer using atomic layer deposition technology. The film thickness is monitored in real time using an in-situ ellipsometer, and the precursor injection time and reaction cycle are dynamically adjusted in combination with a PID algorithm. Low-temperature annealing eliminates interface defects, and a spectrophotometer verifies that the average reflectance of the coating in the 400 - 800 nm band is ≤ 0.5%, effectively reducing light loss and enhancing the brightness of the light guide plate.

[0027] S4, integrate an embedded heat dissipation layer on the back of the light guide plate with the coating completed, and use laser-induced technology to generate a graphene heat conduction grid to form an integrated structure between the heat dissipation layer and the light guide plate substrate. A polyimide precursor is spin-coated on the back of the light guide plate, and a graphene heat conduction grid with a period of 50 μm (line width 3 μm, thermal conductivity ≥ 1500 W / mK) is generated by laser induction. Vacuum annealing strengthens the interface bonding, and an infrared thermal imager verifies the heat dissipation performance to ensure uniform temperature distribution under high-brightness conditions and solve the problem of heat accumulation on outdoor screens.

[0028] S5, perform optical performance and structural quality inspections on the finished light guide plate, compare the microstructure topography tolerance through an intelligent vision system, and optimize the process parameters based on the spectral data feedback to output a qualified light guide plate that meets the brightness and uniformity indicators.

[0029] The working principle of the present invention is as follows: using a modified PMMA sheet as the substrate, a seed layer substrate is formed through surface cleaning and pre-setting of the functional layer; then, a bottom layer groove-protrusion microstructure and a top layer prism array are formed by one-time stamping with a composite mold to obtain a semi-finished composite microstructure light guide plate; the TiO2 / SiO2 anti-reflection coating is stacked layer by layer on its surface using atomic layer deposition technology, and the optical parameters are adjusted in real time; a graphene heat conduction grid generated by laser induction is integrated on the back of the coated light guide plate to form an integrated heat dissipation structure, and the microstructure topography tolerance is detected by an intelligent vision system, and the parameters are optimized in combination with the spectral data feedback; this process significantly improves the light guiding efficiency through the composite microstructure design, increases the brightness and uniformity of the light guide plate, the multi-layer anti-reflection coating reduces the surface reflectivity and light loss, and the laser-induced graphene heat dissipation layer effectively solves the problem of heat accumulation under high brightness, improves the product performance, and outputs a high-brightness and high-uniformity light guide plate.

[0030] In this embodiment, specifically, step S1 specifically includes: S11, select a modified PMMA sheet, cut it into a light guide plate substrate blank according to a preset size by a laser cutting device, and polish the cutting edge to eliminate burrs; Select a modified PMMA sheet, cut it into a light guide plate substrate blank according to a preset size by a high-precision laser cutting device, ensuring that the geometric tolerance ≤ ±0.1 mm. Laser cutting can avoid edge cracks caused by mechanical stress. After cutting, chemical mechanical polishing (CMP) is performed on the edge to eliminate burrs (Ra ≤ 0.5 μm), prevent micro-particle residues from affecting the surface quality in subsequent processes, and at the same time improve the optical uniformity of the substrate edge.

[0031] S12, perform plasma cleaning on the cut substrate blank, use an argon-oxygen mixed gas with a volume ratio of 4:1 to excite plasma in a vacuum chamber, and continuously process for 5 - 8 minutes to remove surface organic pollutants and micro-particles; Use an argon-oxygen mixed gas (volume ratio 4:1) to excite plasma in a vacuum chamber. Argon ions physically bombard to remove surface adsorbed particles, and oxygen free radicals oxidize and decompose organic pollutants, removing surface pollutants and increasing surface energy, providing a highly active substrate for subsequent activation treatment.

[0032] S13, immerse the cleaned substrate in a surface activation solution for chemical activation treatment for 10 minutes, then rinse with ultrapure water and dry with nitrogen; the surface activation solution is an ethanol solution containing 0.5 wt% silane coupling agent; Immerse the cleaned substrate in an ethanol solution containing 0.5 wt% silane coupling agent. Silane molecules form a dense monolayer on the substrate surface through hydrolysis reaction, enhancing the chemical bonding with the seed layer. After soaking for 10 minutes, rinse with ultrapure water to remove unreacted reagents, and dry with nitrogen to avoid water mark residues, ensuring that the activation layer is uniform and defect-free.

[0033] S14. Pre - deposit an aluminum oxide seed layer on the activated substrate surface through an atomic layer deposition equipment at a deposition temperature of 120 °C for n cycles. In each single cycle, trimethylaluminum and water vapor precursors are introduced to form a uniform seed layer with a thickness of 10 nm, and obtain a light guide plate substrate with a seed layer. In the atomic layer deposition equipment, set the deposition temperature at 120 °C, the number of cycles n = 50 times. In each single cycle, trimethylaluminum is introduced for 0.1 s, purged with nitrogen for 5 s, water vapor is introduced for 0.1 s, and purged with nitrogen for 5 s, and aluminum oxide is grown layer by layer. The thickness of the seed layer is achieved through self - limiting reactions, with uniform coverage, providing an atomically flat interface for subsequent micro - structure imprinting and functional coatings.

[0034] S15. Anneal the light guide plate substrate at a constant temperature of 150 °C for 30 minutes in a nitrogen atmosphere to enhance the bonding strength between the seed layer and the substrate. Under a nitrogen - protected atmosphere, anneal at a constant temperature of 150 °C for 30 minutes to promote the formation of Si - O - Al covalent bonds between the seed layer and the PMMA substrate, enhancing the interfacial bonding strength. The annealing process simultaneously eliminates the microscopic stress introduced by ALD deposition, avoiding coating peeling or micro - structure deformation in subsequent processes.

[0035] S16. Detect the surface roughness of the seed layer and verify the thickness tolerance, screen out qualified substrates, and transfer the qualified substrates to a protective chamber for storage. The qualified substrates are transferred to an inert protective chamber with a humidity ≤ 5%RH to avoid surface oxidation or contamination, ensuring the cleanliness and stability of the substrates before imprinting.

[0036] In this embodiment, specifically, step S2 specifically includes: S21. Provide a composite mold; among them, the composite mold includes a bottom - layer micro - structure area and a top - layer prism area. The bottom - layer micro - structure area is processed with a groove - protrusion array through electron beam lithography, the groove width is 5 - 6 μm, the protrusion width is 30 - 35 μm, and the top - layer prism area forms prism units with a period of 50 μm through nano - imprinting technology.

[0037] Use electron beam lithography technology to process the bottom - layer micro - structure area with a groove width of 5 - 6 μm and a protrusion width of 30 - 35 μm, and form prism units with a top - layer period of 50 μm through nano - imprinting technology. The partition design of the composite mold (bottom - layer guiding + top - layer focusing) realizes perpendicular light emission and scattering control. The groove - protrusion structure optimizes the light path reflection efficiency, and the prism array compresses the scattering angle range to ensure brightness uniformity.

[0038] S22. Pre - heat the light guide plate substrate by heating it at 80 °C for 10 minutes in a constant - temperature chamber to soften the substrate surface below the glass transition temperature Tg and enhance the imprinting fluidity.

[0039] Heat the light guide plate substrate in a constant temperature chamber at 80 °C for 10 minutes, so that its surface temperature is close to the glass transition temperature of PMMA (Tg≈105 °C) but lower than the softening point (Tg - 5 °C), promoting local relaxation of molecular chain segments, reducing surface viscosity, and enhancing imprint fluidity. Preheating avoids overall deformation of the substrate and ensures the integrity rate of microstructure replication.

[0040] S23, Align the composite mold with the preheated substrate and fix it on the imprinting machine stage, apply a pressure of 20 - 25 MPa, and at the same time irradiate the surface of the substrate with an ultraviolet light source to trigger the photocuring of the nanoimprinting adhesive, and continuously cure for T1 time to obtain a semi-finished light guide plate with a composite microstructure; After the composite mold is aligned with the substrate, apply a pressure of 20 - 25 MPa to fill the mold cavity with the nanoimprinting adhesive, and simultaneously irradiate with an ultraviolet light source for 15 seconds to trigger the photocuring reaction. The synergistic effect of pressure - photocuring precisely replicates the microstructure morphology and ensures the consistency of light efficiency.

[0041] S24, After demolding, anneal the imprinted substrate, keep it at a constant temperature of 120 °C for 20 minutes in a nitrogen atmosphere to eliminate internal stress and stabilize the microstructure morphology; After demolding, the semi-finished light guide plate is annealed at 120 °C for 20 minutes in a nitrogen atmosphere to promote the rearrangement of polymer chain segments, release the residual stress of imprinting, and control the shrinkage rate of the microstructure morphology within 0.1%. After annealing, the surface hardness is increased from 60 to 75, and the scratch resistance is enhanced to avoid structural damage in subsequent processes.

[0042] S25, Detect the morphology accuracy of the composite microstructure, verify the depth of the bottom groove and the angle of the top prism, screen out qualified semi-finished light guide plates and temporarily store them.

[0043] Use a white light interferometer to detect the groove depth and prism angle, and automatically eliminate products with out-of-tolerance morphology by combining with the AI image algorithm. Qualified semi-finished products are temporarily stored in a constant humidity warehouse to avoid microstructure deformation caused by environmental stress.

[0044] In this embodiment, specifically, step S3 specifically includes the following steps: S31, Pretreat the semi-finished light guide plate with a composite microstructure, perform surface treatment with plasma to remove residual contaminants and enhance surface activity; Perform argon plasma bombardment treatment on the semi-finished light guide plate with a composite microstructure. Through high-energy ion physical bombardment and free radical chemical reactions, completely remove the residual nanoimprinting adhesive, organic contaminants and microparticles on the surface, and at the same time increase the surface hydroxyl density, significantly enhancing the adhesion and uniformity of the atomic layer deposition coating.

[0045] S32. Fix the preprocessed semi-finished light guide plate in the atomic layer deposition equipment chamber, set the substrate temperature to 200 °C, introduce nitrogen as the carrier gas, and maintain the chamber pressure at 5 Torr; Fix the preprocessed semi-finished light guide plate in the ALD equipment chamber, set the substrate temperature to 200 °C, introduce high-purity nitrogen as the carrier gas, and maintain the chamber pressure at 5 Torr. These temperature and pressure conditions can optimize the precursor adsorption kinetics, avoid microstructure deformation caused by thermal stress, and at the same time ensure that the reaction gas fully diffuses to the aspect ratio region of the microstructure (such as inside the groove).

[0046] S33. Alternately deposit TiO2 and SiO2 layers to form a multi-layer coating, forming an anti-reflection coating; specifically, the process of single-layer deposition in the alternate deposition of TiO2 and SiO2 layers specifically includes: Inject the titanium tetrachloride precursor for 3 seconds, and then purge with nitrogen; TiCl4 molecules chemically adsorb on the substrate surface to form a monolayer coverage; nitrogen purging removes unreacted TiCl4 and by-products (HCl) to avoid gas-phase nucleation.

[0047] Inject water vapor and react for 5 seconds to generate a single atomic layer of TiO2; H2O reacts with the adsorbed TiCl4 to generate a single atomic layer of TiO2 (reaction formula: TiCl4 + 2H2O → TiO2 + 4HCl↑); remove the residual H2O and HCl to complete the deposition of a single layer of TiO2.

[0048] Similarly, the deposition process of the SiO2 layer is to inject the tetraethoxysilane precursor for 4 seconds, and then purge with nitrogen; inject ozone and oxidize for 8 seconds to generate a single atomic layer of SiO2.

[0049] S34. Monitor the film thickness of each coating in real time, and dynamically adjust the precursor injection time and purge cycle in combination with the PID algorithm to control the total film thickness error within the preset error threshold range; By monitoring the film thickness of each layer in real time, dynamically adjust the precursor injection time and purge cycle in combination with the proportional-integral-derivative (PID) algorithm. For example, if the detected TiO2 layer thickness deviation is +0.3 nm, then automatically shorten the TiCl4 injection time in the next cycle to 2.8 seconds to ensure that the total film thickness (after 5-layer alternate deposition) error ≤ ±2 nm, reaching the target optical parameters (refractive index gradient 1.8 - 2.2).

[0050] S35. After completing 5-layer alternate deposition of TiO2 / SiO2, anneal the coated light guide plate, keep it at 180 °C in a nitrogen atmosphere for 15 minutes to eliminate the interfacial stress and improve the film layer density; Anneal at 180 °C in a nitrogen atmosphere for 15 minutes to promote atomic-level interdiffusion at the TiO2 / SiO2 interface, eliminate the interlayer stress, and at the same time seal the micropore defects to improve the film layer density.

[0051] S36, Use a spectrophotometer to detect the average reflectance of the anti-reflection coating in the 400 - 800 nm band, screen the light guide plates that reach the preset qualified value, and transfer them to a temporary storage in a protective environment.

[0052] Use a spectrophotometer to detect the average reflectance in the 400 - 800 nm band, and set the qualified threshold to ≤0.5%. Automatically mark and reject the products with excessive reflectance (such as >0.55%), and transfer the qualified light guide plates to a nitrogen-filled protection chamber to avoid moisture absorption or oxidation of the coating.

[0053] In this embodiment, specifically, step S4 specifically includes: S41, Perform plasma activation treatment on the back of the light guide plate with the coating completed. Use a mixed gas of argon - nitrogen with a volume ratio of 4:1 to excite plasma, and continuously treat for 8 minutes to increase the surface energy and the adhesion of the graphene precursor. It should be noted that nitrogen radicals (N+) introduce amino (-NH2) functional groups through chemical bonding to increase the surface energy. Continuously treat for 8 minutes to increase the adhesion of the graphene precursor (polyimide) to ≥2.5 N / cm, providing a highly active substrate for subsequent laser-induced graphitization.

[0054] S42, Spin-coat the polyimide precursor solution on the back of the activated light guide plate to form a uniform precursor film layer with a thickness of 20 μm, and pre-cure at 80°C for 10 minutes. Use the spin-coating process to form a 20-μm-thick polyimide precursor film layer on the back of the light guide plate. Pre-curing (80°C, 10 minutes) promotes the volatilization of the solvent. At this stage, the glass transition temperature (Tg) of the film layer is 150°C, ensuring controllable local thermal stress during subsequent laser processing and avoiding warping of the substrate.

[0055] S43, Use a laser to scan the precursor film layer, set the scanning pitch to 10 μm and the power density to 5 GW / cm², and generate a thermal conduction grid structure through the laser-induced graphitization reaction. The line width of the micron-scale grid structure is 3 μm, and the period is 50 μm.

[0056] Carbonize the polyimide through the multi-photon absorption effect to generate a three-dimensional graphene grid. Optimize the laser parameters to ensure the line width and period, the density of the thermal conduction path, and the thermal conductivity; at the same time, avoid thermal damage to the substrate.

[0057] S44, Place the laser-treated light guide plate in a vacuum annealing furnace and perform a constant-temperature treatment at 400°C for 30 minutes to complete the crystallization of the graphene thermal conduction grid and the interfacial bonding with the light guide plate substrate under a nitrogen atmosphere. Place the laser-treated light guide plate in a vacuum annealing furnace, and perform isothermal treatment at 400 °C for 30 minutes. Under a nitrogen atmosphere, promote the increase in the proportion of the graphene hybrid structure, reduce the sheet resistance of graphene, and achieve the synergy of efficient heat conduction and electrical insulation.

[0058] S45. Detect the heat dissipation performance of the heat conduction grid, verify the thermal conductivity coefficient, and scan and observe the morphology of the heat conduction grid to screen the finished light guide plates with complete structures.

[0059] Verification of thermal conductivity performance: Use an infrared thermal imager to measure the temperature rise curve of the light guide plate under a heat flux density of 5 W / cm², and verify that the thermal conductivity coefficient ≥ 1500 W / m·K (steady-state temperature difference ΔT ≤ 3 °C); Analysis of morphological integrity: Observe the porosity and line width consistency of the graphene grid with a scanning electron microscope; Screening criteria: Automatically eliminate the light guide plates with unqualified thermal conductivity coefficients (< 1450 W / m·K) or excessive porosities (> 3%). Transfer the qualified products to the clean warehouse for temporary storage to ensure stability before entering quality inspection.

[0060] In this embodiment, specifically, step S5 specifically includes: S51. Fix the finished light guide plate on the detection platform, and adjust the relative positions of the light guide plate and the detection probe through the positioning fixture; Fix the finished light guide plate on a six-degree-of-freedom detection platform, and adjust the relative positions of the light guide plate and the optical sensor and the vision probe through the air-floating positioning fixture to reduce the perpendicularity error between the normal of the light-emitting surface and the detection optical path and eliminate the optical detection deviation caused by installation tilt.

[0061] S52. Use an intelligent vision system to perform a global scan on the reflective surface of the light guide plate, compare the morphological parameters of the composite microstructure, and verify the tolerances of the groove depth and prism angle; Use an intelligent vision system (resolution 5 μm, frame rate 200 fps) to perform a global scan on the reflective surface of the light guide plate, extract the morphological features of the groove depth (3 - 4 μm ± 0.2 μm) and prism angle (41 - 47° ± 0.5°) based on the convolutional neural network algorithm, and compare with the CAD design model in real time through three-dimensional point cloud reconstruction, automatically mark the out-of-tolerance areas, and calculate the morphological qualification rate.

[0062] S53. Collect the brightness distribution data of the light-emitting surface of the light guide plate through the imaging system, set the detection dot matrix density to 81 points / m 2 , covering the 400 - 800 nm band, synchronously measure the brightness values and uniformity deviations of each point to obtain spectral data; Through a high-resolution imaging spectrometer at 81 points / m 2Collect density-based luminance data, and synchronously measure the luminance value and uniformity deviation at each detection point. After the data is denoised by Kalman filtering, a heat map is generated to quantitatively display the luminance gradient and identify local dark areas or bright spots.

[0063] S54. Input the topography parameters and spectral data into the process optimization model. Analyze the influence weights of key parameters on performance based on the random forest algorithm, generate dynamic adjustment instructions, and feedback them to the control system for optimizing the sample production of the light guide plate. Input the topography tolerance data (groove depth, prism angle) and spectral luminance data into the random forest model, and analyze the influence weights (feature importance ranking) of parameters such as imprinting pressure, ALD deposition layer number (5 layers), and laser power on luminance and uniformity. The model outputs dynamic adjustment instructions and real-time feedbacks them to the production equipment to optimize the performance of the next batch of light guide plates.

[0064] S55. Conduct secondary optical detection on the optimized light guide plate, and use an integrating sphere system to verify the total luminous flux improvement rate and color temperature consistency. Use an integrating sphere system to measure the total luminous flux and color temperature consistency of the optimized light guide plate. The luminous flux improvement rate is obtained by comparing the data of the initial batch (e.g., from 7600 lm to 8200 lm, improvement rate ≈ 8%), and the color temperature uniformity is quantified by the standard deviation of the color coordinates (x, y) (σ ≤ 0.001) to ensure no color deviation in the display screen.

[0065] S56. Record the detection data and process parameters through blockchain distributed recording, generate a unique quality traceability code, and bind it to the light guide plate serial number. Build a distributed quality database based on blockchain, encrypt and upload the detection data (topography tolerance, luminance, color temperature) and process parameters (pressure, temperature, laser power) to the chain, and generate a unique hash value as the quality traceability code. The traceability code is bound to the light guide plate serial number through laser marking, supporting full life cycle traceability (such as locating after-sales faults to specific process nodes).

[0066] S57. Screen the light guide plates with qualified luminance and uniformity, package them in anti-static vacuum packaging, and output them as qualified products.

[0067] Screen the light guide plates with qualified luminance and uniformity, vacuum package them with anti-static aluminum-plastic composite film, and classify and mark the unqualified products and return them to the corresponding process nodes (such as returning the products with excessive topography to S2 imprinting, and returning the products with coating defects to S3 deposition), realizing closed-loop production and zero-waste manufacturing.

[0068] Embodiment 2: Combined with Figure 3 As shown, the present invention also provides a front light guide plate, which is made by using the front light guide plate in Embodiment 1. The front light guide plate specifically includes: Substrate layer 10 (modified PMMA sheet, thickness 3 mm), lower end face (back face) of substrate layer 10: A groove-protrusion microstructure 20 is formed by an imprinting process (groove width 5 - 6 μm, protrusion width 30 - 35 μm, depth 3 - 4 μm), which is used to optimize the light reflection path and improve the vertical light extraction efficiency.

[0069] Upper end face (light-emitting surface) of substrate layer 10: A prism array 30 is formed by the same imprinting process (period 50 μm, tilt angle 41 - 47°), which is used to focus scattered light and control the light-emitting angle.

[0070] The seed layer is made of alumina and is located on the upper end face of substrate layer 10 (in contact with prism array 30), which enhances the bonding strength between the substrate and the anti-reflection coating 40.

[0071] Anti-reflection coating 40 covers the surface of prism array 30 on the upper end face of substrate layer 10, which reduces the reflectivity and improves the light energy utilization rate.

[0072] Embedded heat dissipation layer 50 (graphene heat conduction grid, line width 3 μm, period 50 μm) is located on the lower end face of substrate layer 10 (on the same side as the groove-protrusion microstructure 20), which is generated by laser-induced technology and coexists on the same surface as the groove-protrusion structure without interference.

[0073] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A front light guide plate process, characterized in that, Including: Using a modified PMMA sheet as the substrate, cleaning its surface and pre - depositing a functional layer to form a light - guide plate substrate with a seed layer; Performing an imprinting process on the surface of the light - guide plate substrate, forming a bottom - layer groove - protrusion microstructure and a top - layer prism array in one - step through a composite mold to form a semi - finished light - guide plate with a composite microstructure; Depositing an anti - reflection coating on the surface of the semi - finished light - guide plate with a composite microstructure, stacking TiO2 / SiO2 multi - layer films layer by layer through atomic layer deposition technology, and real - time regulating the coating thickness to target optical parameters; Integrating an embedded heat - dissipation layer on the back of the light - guide plate with the coating completed, using laser - induced technology to generate a graphene heat - conduction grid, so that the heat - dissipation layer and the light - guide plate substrate form an integrated structure; Performing optical performance and structural quality inspections on the finished light - guide plate, comparing the microstructure topography tolerance through an intelligent vision system, and optimizing process parameters based on spectral data feedback to output a qualified light - guide plate that meets brightness and uniformity indicators.

2. The front light guide plate process according to claim 1, wherein The step of using a modified PMMA sheet as the substrate, cleaning its surface and pre - depositing a functional layer to form a light - guide plate substrate with a seed layer specifically includes: Selecting a modified PMMA sheet, cutting it into a light - guide plate substrate blank according to a preset size by a laser cutting device, and polishing the cutting edge to eliminate burrs; Performing plasma cleaning on the cut substrate blank, using an argon - oxygen mixed gas with a volume ratio of 4:1 to excite plasma in a vacuum chamber, and continuously processing for 5 - 8 minutes to remove surface organic pollutants and microparticles; Immersing the cleaned substrate in a surface activation solution for chemical activation treatment for 10 minutes, then rinsing with ultrapure water and drying with nitrogen; the surface activation solution is an ethanol solution containing 0.5wt% silane coupling agent; Pre - depositing an alumina seed layer on the activated substrate surface through an atomic layer deposition device, with a deposition temperature of 120℃, circulating n times, introducing trimethylaluminum and water vapor precursors in a single cycle, forming a uniform seed layer with a thickness of 10nm, and obtaining a light - guide plate substrate with a seed layer; Performing annealing treatment on the light - guide plate substrate, maintaining a constant temperature of 150℃ for 30 minutes in a nitrogen atmosphere to enhance the bonding strength between the seed layer and the substrate; Detecting the surface roughness of the seed layer and verifying the thickness tolerance, screening out qualified substrates, and transferring the qualified substrates to a protective storage bin.

3. The front light guide plate process according to claim 1, characterized in that, The step of performing an imprinting process on the surface of the light - guide plate substrate, forming a bottom - layer groove - protrusion microstructure and a top - layer prism array in one - step through a composite mold to form a semi - finished light - guide plate with a composite microstructure specifically includes: Providing a composite mold; Performing pre - heating treatment on the light - guide plate substrate, heating it at 80℃ for 10 minutes in a constant - temperature chamber to soften the substrate surface below the glass transition temperature Tg and enhance the imprinting fluidity; Aligning the composite mold with the pre - heated substrate and fixing it on the imprinting machine stage, applying a pressure of 20 - 25MPa, and simultaneously irradiating the substrate surface with an ultraviolet light source to trigger the photocuring of the nano - imprinting adhesive, and continuously curing for T1 time to obtain a semi - finished light - guide plate with a composite microstructure; After demolding, the imprinted substrate is annealed at a constant temperature of 120 °C for 20 minutes in a nitrogen atmosphere to eliminate internal stress and stabilize the microstructure morphology; The morphology accuracy of the composite microstructure is detected, the depth of the bottom groove and the angle of the top prism are verified, and the qualified light guide plate semi-finished products are screened and temporarily stored.

4. The front light guide plate process according to claim 3, characterized in that, The composite mold includes a bottom microstructure area and a top prism area. The bottom microstructure area is processed with a groove-protrusion array by electron beam lithography, the groove width is 5-6 μm, the protrusion width is 30-35 μm, and the top prism area forms prism units with a period of 50 μm through nanoimprint technology.

5. The front light guide plate process according to claim 1, characterized in that, An antireflection coating is deposited on the surface of the light guide plate semi-finished product with the composite microstructure. TiO2 / SiO2 multilayer films are stacked layer by layer through atomic layer deposition technology, and the coating thickness is adjusted in real time to the target optical parameters. The specific steps are as follows: The light guide plate semi-finished product with the composite microstructure is pretreated, and surface treatment is carried out with plasma to remove residual pollutants and enhance surface activity; The pretreated light guide plate semi-finished product is fixed in the chamber of the atomic layer deposition equipment, the substrate temperature is set to 200 °C, nitrogen is introduced as the carrier gas, and the chamber pressure is maintained at 5 Torr; TiO2 and SiO2 layers are alternately deposited to form a multilayer coating to form an antireflection coating; The film thickness of each coating is monitored in real time, and the precursor injection time and purge period are dynamically adjusted in combination with the PID algorithm to control the total film thickness error within the preset error threshold range; After 5 layers of TiO2 / SiO2 are alternately deposited, the coated light guide plate is annealed and kept warm for 15 minutes in a nitrogen atmosphere at 180 °C to eliminate interface stress and improve the film density; The average reflectance of the antireflection coating in the 400-800 nm band is detected by a spectrophotometer, and the light guide plates that reach the preset qualified value are screened and transferred to a protective environment for temporary storage.

6. The front light guide plate process according to claim 5, characterized in that, Among them, the process of single-layer deposition in the alternate deposition of TiO2 and SiO2 layers specifically includes: Inject the titanium tetrachloride precursor for 3 seconds, and then purge with nitrogen; Inject water vapor and react for 5 seconds to generate a single atomic layer of TiO2; Inject the tetraethyl orthosilicate precursor for 4 seconds, and then purge with nitrogen; Inject ozone and oxidize for 8 seconds to generate a single atomic layer of SiO2.

7. The front light guide plate process according to claim 1, wherein An embedded heat dissipation layer is integrated on the back of the coated light guide plate, and a graphene heat conduction grid is generated by laser-induced technology to form an integrated structure between the heat dissipation layer and the light guide plate substrate. The specific steps include: Perform plasma activation treatment on the back of the coated light guide plate, use an argon-nitrogen mixed gas with a volume ratio of 4:1 to excite plasma, and continuously treat for 8 minutes to increase the surface energy and the adhesion of the graphene precursor; Spin-coat the polyimide precursor solution on the back of the activated light guide plate to form a uniform precursor film layer with a thickness of 20 μm, and pre-cure at 80 °C for 10 minutes; Use a laser to scan the precursor film layer to generate a heat conduction grid structure through laser-induced graphitization reaction.

8. The front light guide plate process according to claim 7, characterized in that, After using a laser to scan the precursor film layer to generate a heat conduction grid structure through laser-induced graphitization reaction, it also includes: Place the laser-treated light guide plate in a vacuum annealing furnace and perform isothermal treatment at 400 °C for 30 minutes to complete the crystallization of the graphene heat conduction grid and the interfacial bonding with the light guide plate substrate under a nitrogen atmosphere; Detect the heat dissipation performance of the heat conduction grid, verify the thermal conductivity coefficient, scan and observe the morphology of the heat conduction grid, and screen the finished light guide plates with complete structures.

9. The front light guide plate process according to claim 1, wherein Perform optical performance and structural quality inspections on the finished light guide plates, compare the morphological tolerances of the microstructures through an intelligent vision system, and optimize the process parameters based on the spectral data feedback to output qualified light guide plates that meet the brightness and uniformity indicators. Specifically, it includes: Fix the finished light guide plate on the detection platform and adjust the relative positions of the light guide plate and the detection probe through a positioning fixture; Use an intelligent vision system to perform global scanning on the reflective surface of the light guide plate, compare the morphological parameters of the composite microstructure, and verify the tolerances of the groove depth and prism angle; Collect the luminance distribution data of the light-emitting surface of the light guide plate through the imaging system, set the detection dot matrix density to 81 points / m 2 , covering the 400-800nm band, synchronously measure the luminance value and uniformity deviation of each point to obtain spectral data; Input the morphological parameters and spectral data into the process optimization model, analyze the influence weights of key parameters on the performance based on the random forest algorithm, generate dynamic adjustment instructions, and feedback them to the control system for optimizing the sample production of the light guide plate.

10. The front light guide plate process according to claim 9, characterized in that, After generating the dynamic adjustment instructions and feedbacking them to the control system for optimizing the sample production of the light guide plate, it further includes: Perform secondary optical inspection on the optimized light guide plate, and use an integrating sphere system to verify the total luminous flux increase rate and color temperature consistency; Record the detection data and process parameters through blockchain distributed recording, generate a unique quality traceability code, and bind it to the light guide plate serial number; Screen the light guide plates with qualified brightness and uniformity, package them in anti-static vacuum packaging, and output them as qualified products.

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