A front light guide plate process

Abstract

The application discloses a front light guide plate process, comprising the following steps: using modified PMMA plate as a base material and cleaning the surface and pre-setting a functional layer, performing an embossing process on the surface of the light guide plate base material, one-time forming a bottom layer groove-protrusion microstructure and a top layer prism array through a composite mold, 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 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, generating a graphene heat conduction grid by using a laser induction technology, and detecting the optical performance and structural quality of the finished light guide plate; the light guiding efficiency is significantly improved through the composite microstructure design, the brightness and uniformity of the light guide plate are improved, the multilayer anti-reflection coating reduces the surface reflectivity and reduces light loss, the laser-induced graphene heat dissipation layer effectively solves the heat accumulation problem under high brightness, improves the product performance, and outputs a high-brightness and high-uniformity light guide plate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light guide plates, in particular to a front light guide plate process. BACKGROUND

[0002] With the wide application of outdoor high-resolution display screens in the fields of advertising media, traffic information display, etc., the market has put forward higher requirements for the visibility of display devices under strong environmental light. As the core component of the side-in backlight module, the performance of the front light guide plate directly determines the brightness, uniformity and energy efficiency of the display screen. Especially in open-air scenes, the light guide plate needs to meet the requirements of ultra-high brightness (≥ 8000 lumens / m2), light distribution uniformity (deviation ≤ 5%) and long-term weather resistance (anti-ultraviolet, temperature resistance) at the same time, in order to guarantee the clear contrast of the picture under strong light interference.

[0003] The existing light guide plate process mostly uses a single microstructure (such as a groove or a dot) combined with a conventional anti-reflection coating to achieve light regulation, for example, by laser engraving or mold imprinting to form scattering dots to improve light uniformity. However, such technology has significant limitations: a single microstructure design cannot balance the efficient guidance and scattering control of light. For example, although the traditional groove structure can improve the vertical light efficiency, the scattering angle range is limited, resulting in serious brightness decay in the area far from the light entrance surface; while the uniformly distributed dots can improve the light distribution, but due to the unoptimized light-incident angle (usually 30-40°), part of the light is emitted obliquely, reducing the light energy utilization rate. This defect directly leads to insufficient brightness, obvious local dark area and greatly reduced display contrast of the existing light guide plate under strong outdoor light, which cannot meet the stringent requirements of high-end outdoor screens.

[0004] Therefore, 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 environmental light. SUMMARY

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

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] A front light guide plate process, comprising:

[0008] S1, using a modified PMMA plate as a substrate and cleaning and prepositioning a functional layer on the surface thereof to form a light guide plate substrate with a seed layer;

[0009] S2, performing an imprinting process on the surface of the light guide plate substrate to form a light guide plate semi-finished product with a composite microstructure by one-time molding of a bottom groove-protrusion microstructure and a top prism array through a composite mold;

[0010] S3, depositing an anti-reflection coating on the surface of the light guide plate semi-finished product with a composite microstructure, depositing TiO2 / SiO2 multilayer films layer by layer through atomic layer deposition technology, and real-time regulating the coating thickness to the target optical parameters;

[0011] S4, integrating an embedded heat dissipation layer on the back of the light guide plate with the completed coating, generating a graphene heat conduction grid using laser induction technology, and forming an integrated structure of the heat dissipation layer and the light guide plate substrate;

[0012] S5, detecting the optical performance and structural quality of the finished light guide plate, comparing the microstructure morphology tolerance through an intelligent vision system, and optimizing the process parameters based on spectral data feedback, and outputting qualified light guide plates that meet the brightness and uniformity indicators.

[0013] Optionally, the modified PMMA plate is used as the substrate, and the surface is cleaned and the functional layer is pre-set to form a light guide plate substrate with a seed layer, which specifically includes:

[0014] Selecting a modified PMMA plate, cutting it into a light guide plate substrate blank according to the predetermined size through a laser cutting device, and polishing the cutting edge to remove burrs;

[0015] Plasma cleaning the cut substrate blank, exciting plasma in a vacuum chamber using a mixture of argon-oxygen gas with a volume ratio of 4:1, and continuously treating for 5-8 minutes to remove surface organic contaminants and microparticles;

[0016] Chemically activating the cleaned substrate by immersing it in a surface activation solution for 10 minutes, then rinsing it with ultrapure water and drying it with nitrogen; the surface activation solution is an ethanol solution containing 0.5wt% silane coupling agent;

[0017] Pre-depositing an aluminum oxide seed layer on the surface of the activated substrate through an atomic layer deposition device, with a deposition temperature of 120°C, n cycles, and a single cycle of tri-methyl aluminum and water vapor precursors, forming a uniform seed layer with a thickness of 10nm, obtaining a light guide plate substrate with a seed layer;

[0018] Annealing the light guide plate substrate at 150°C for 30 minutes in a nitrogen atmosphere to enhance the bonding strength of the seed layer and the substrate;

[0019] Detecting the surface roughness of the seed layer and verifying the thickness tolerance to select qualified substrates, and transferring the qualified substrates to a protection bin for storage.

[0020] Optionally, the light guide plate substrate surface is subjected to an embossing process, which forms a light guide plate semi-finished product with a composite microstructure by one-time molding of a bottom layer of groove-protrusion microstructure and a top layer of prism array through a composite mold, specifically including:

[0021] A composite mold is provided;

[0022] The light guide plate substrate is preheated at 80°C for 10 minutes in a constant temperature chamber to soften the surface of the substrate below the glass transition temperature Tg, enhancing the embossing fluidity;

[0023] The composite mold is aligned with the preheated substrate and fixed on the embossing machine platform, a pressure of 20-25 MPa is applied, and the substrate surface is irradiated with an ultraviolet light source to trigger the nanoembossing glue photocuring, and the curing time T1 is obtained. The light guide plate semi-finished product with a composite microstructure is obtained;

[0024] After demolding, the embossed substrate is annealed at 120°C for 20 minutes in a nitrogen atmosphere to eliminate internal stress and stabilize the microstructure morphology;

[0025] The morphology precision of the composite microstructure is detected, the bottom groove depth and the top prism angle are verified, and the qualified light guide plate semi-finished product is screened and temporarily stored.

[0026] 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, and the protrusion width is 30-35 μm. The top prism area forms a prism unit with a period of 50 μm by nanoembossing technology.

[0027] Optionally, an antireflection coating is deposited on the surface of the light guide plate semi-finished product with a composite microstructure, a TiO2 / SiO2 multilayer film is stacked layer by layer by atomic layer deposition technology, and the coating thickness is real-time controlled to the target optical parameters, specifically including the following steps:

[0028] The light guide plate semi-finished product with a composite microstructure is pretreated, and the surface is treated by plasma to remove residual contaminants and enhance surface activity;

[0029] 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 gas is introduced as the carrier gas, and the chamber pressure is maintained at 5 Torr;

[0030] Alternately depositing TiO2 and SiO2 layers forms a multilayer coating, forming an antireflection coating;

[0031] Real-time monitoring of the film thickness of each coating, combined with PID algorithm dynamic adjustment of precursor injection time and purge cycle, so that the total film thickness error is controlled within the preset error threshold range;

[0032] After completing the 5-layer TiO2 / SiO2 alternate deposition, the coated light guide plate is annealed at 180°C in a nitrogen atmosphere for 15 minutes to eliminate interface stress and improve film layer density;

[0033] The average reflectivity of the anti-reflective coating in the 400-800 nm waveband is detected by a spectrophotometer, and the light guide plate reaching the preset qualified value is screened and transferred to a protective environment for temporary storage.

[0034] Optionally, the process of depositing a single layer in the TiO2 and SiO2 layer alternately comprises:

[0035] Titanium tetrachloride precursor is injected for 3 seconds, followed by nitrogen blowing;

[0036] Water vapor reaction is injected for 5 seconds to form a TiO2 monolayer;

[0037] The tetraethoxysilane precursor is injected for 4 seconds, followed by nitrogen blowing;

[0038] Ozone oxidation reaction is injected for 8 seconds to form a SiO2 monolayer.

[0039] Optionally, the embedded heat dissipation layer on the back of the light guide plate with completed coating is integrated 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, which specifically comprises:

[0040] The back of the light guide plate with completed coating is subjected to plasma activation treatment, and a mixed gas of argon and nitrogen with a volume ratio of 4:1 is used to excite plasma, and the treatment is continued for 8 minutes to improve the surface energy and the adhesion of the graphene precursor;

[0041] A polyimide precursor solution is spin-coated on the back of the activated light guide plate to form a uniform precursor film layer with a thickness of 20 μm, and is pre-cured at 80°C for 10 minutes;

[0042] The precursor film layer is scanned by laser to generate a heat conduction grid structure through laser-induced graphene reaction.

[0043] Optionally, the precursor film layer is scanned by laser to generate a heat conduction grid structure through laser-induced graphene reaction, and then further comprises:

[0044] The light guide plate after laser treatment is placed in a vacuum annealing furnace and treated at 400°C for 30 minutes to complete the crystallization of the graphene heat conduction grid and the interface bonding between the light guide plate substrate;

[0045] The heat dissipation performance of the heat conduction grid is detected to verify the thermal conductivity and scan the morphology of the heat conduction grid, and the finished product light guide plate with complete structure is selected.

[0046] Optionally, the optical performance and structural quality of the finished product light guide plate are detected, the microstructure morphology tolerance is compared by an intelligent vision system, and the process parameters are optimized based on spectral data feedback, and the qualified light guide plate meeting the brightness and uniformity indicators is output, which specifically comprises:

[0047] The finished light guide plate is fixed on a detection platform, and the relative position of the light guide plate and the detection probe is adjusted through a positioning clamp;

[0048] An intelligent vision system is used to scan the entire domain of the light guide plate reflection surface, and the topographic parameters of the composite microstructure are compared to verify the tolerance of the groove depth and the prism angle;

[0049] The imaging system is used to collect the luminance distribution data of the light guide plate light emitting surface, and the detection point array density is set to 81 points / m 2 , covering the 400-800nm waveband, and the luminance value and uniformity deviation of each point are measured synchronously to obtain spectral data;

[0050] The topographic parameters and spectral data are input into a process optimization model, the influence weight of the key parameters on the performance is analyzed based on a random forest algorithm, dynamic adjustment instructions are generated and fed back to the control system for sample production optimization of the light guide plate.

[0051] Optionally, the generation of dynamic adjustment instructions and feedback to the control system for sample production optimization of the light guide plate is followed by:

[0052] The optimized light guide plate is subjected to secondary optical detection, and an integrating sphere system is used to verify the total luminous flux improvement rate and color temperature consistency;

[0053] The detection data and process parameters are recorded in a distributed manner through a blockchain, a unique quality traceability code is generated, and is bound to the serial number of the light guide plate;

[0054] The light guide plate that meets the standards of brightness and uniformity is packaged in an anti-static vacuum package and output as a qualified product.

[0055] Compared with the prior art, the present application has the following beneficial effects: first, a modified PMMA plate is used as a substrate, and a seed layer substrate is formed after surface cleaning and functional layer prepositioning; then, a composite mold is used to imprint a one-time forming bottom groove-protruding microstructure and a top prism array to obtain a composite microstructure light guide plate semi-finished product; an atomic layer deposition technique is used to stack TiO2 / SiO2 anti-reflection coating on the surface layer by layer, and the optical parameters are real-time controlled; a graphene heat dissipation grid generated by laser induction is integrated on the back of the coating light guide plate to form an integrated heat dissipation structure; the microstructure topographic tolerance is detected by an intelligent vision system, and the optimization parameters are fed back in combination with the spectral data; the present process significantly improves the light guiding efficiency through the composite microstructure design, improves the brightness and uniformity of the light guide plate, reduces the surface reflectivity through the multi-layer anti-reflection coating, reduces the light loss, effectively solves the heat accumulation problem under high brightness through the laser-induced graphene heat dissipation layer, improves the product performance, and outputs a high-brightness and high-uniformity light guide plate. BRIEF DESCRIPTION OF DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0057] The structures, proportions, sizes, etc. shown in the drawings of the present specification are only used to cooperate with the content disclosed in the present specification, to be understood and read by those skilled in the art, and are not used to limit the conditions that the present application can be implemented, so they do not have technical significance. Any modification of structure, change of proportion relationship or adjustment of size, without affecting the effects and purposes that the present application can produce, should still fall within the scope of the technical content disclosed by the present application.

[0058] Figure 1 Figure 1 is a schematic diagram of the process flow of the front light guide plate of the present embodiment one;

[0059] Figure 2 Figure 2 is another schematic diagram of the process flow of the front light guide plate of the present embodiment one;

[0060] Figure 3 Figure 3 is a schematic diagram of the layout of the front light guide plate of the present embodiment two. DETAILED DESCRIPTION

[0061] In order to make the purposes, features and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely in the following, combined with the drawings in the embodiments of the present application. Obviously, the following described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0062] In the description of the present application, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation of the present application. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there can be a component disposed therebetween.

[0063] The technical solutions of the present application will be further described in the following by specific embodiments, combined with the drawings.

[0064] Embodiment one:

[0065] In combination Figure 1 And Figure 2 As shown in the drawings, the embodiment of the application provides a front light guide plate process, comprising:

[0066] S1, using a modified PMMA plate as a substrate and cleaning the surface and pre-setting a functional layer to form a light guide plate substrate with a seed layer;

[0067] It should be noted that the modified PMMA plate is a kind of polymethyl methacrylate (PMMA) substrate which is processed by composite modification and functionalization, and is designed for high-brightness front light guide plates. Its core features include:

[0068] Nano-enhanced, adding 3-5% nano-silicon dioxide (particle size 20-50nm) to improve impact strength and thermal stability;

[0069] UV protection, incorporating 1-2% benzotriazole UV absorber to improve weather resistance;

[0070] Surface functionalization, plasma grafting of fluorine-containing polymers to impart hydrophobic and anti-fouling properties.

[0071] Using the modified PMMA plate as the substrate, the substrate cleanliness and adhesion are significantly improved by laser cutting, plasma cleaning (argon-oxygen mixed gas) and silane coupling agent surface activation; then 10nm aluminum oxide seed layer is pre-deposited by atomic layer deposition (ALD) technology, and the interface bonding is strengthened by low temperature annealing. The seed layer provides a uniform substrate for subsequent microstructure imprinting and functional coating, while enhancing the substrate's UV resistance and ensuring the long-term stability of the light guide plate in outdoor environments.

[0072] S2, performing an imprinting process on the surface of the light guide plate substrate to form a light guide plate semi-finished product with a composite microstructure by one-time molding of a bottom groove-protrusion microstructure and a top prism array through a composite mold;

[0073] The double microstructure molding is completed by the composite mold (bottom groove-protrusion + top prism array) in one time. After preheating the substrate to 80°C to soften, the ultraviolet curing nano-imprinting technology is used to replicate the microstructure morphology, with groove depth of 3-4μm and prism angle of 41-47°, to realize light vertical guiding and scattering control. Annealing treatment (120°C, nitrogen atmosphere) is used to eliminate internal stress, and white light interferometer is used to detect the morphology tolerance to ensure light distribution uniformity.

[0074] S3, depositing an anti-reflection coating on the surface of the light guide plate semi-finished product with a composite microstructure, and using atomic layer deposition technology to stack TiO2 / SiO2 multilayer films layer by layer, and real-time control the coating thickness to the target optical parameters;

[0075] TiO2 / SiO2 multilayer films are alternately stacked layer by layer by using atomic layer deposition technology, the film thickness is monitored in real time by an in-situ ellipsometer, and the precursor injection time and reaction period are dynamically adjusted by combining a PID algorithm. Low-temperature annealing eliminates interface defects, and a spectrophotometer verifies that the average reflectivity of the coating is ≤0.5% in the 400-800 nm waveband, effectively reducing light loss and improving the brightness of the light guide plate.

[0076] S4, after the coating of the light guide plate back surface is integrated with the embedded heat dissipation layer, a laser-induced technology is used to generate a graphene heat conduction grid, so that the heat dissipation layer and the light guide plate substrate form an integrated structure;

[0077] The polyimide precursor is spin-coated on the back surface 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 outdoor screen heat accumulation.

[0078] S5, the optical performance and structural quality of the finished light guide plate are detected, the microstructure morphology tolerance is compared by an intelligent vision system, and the process parameters are optimized based on spectral data feedback, and the qualified light guide plate meeting the brightness and uniformity indicators is output.

[0079] The working principle of the present application is as follows: a modified PMMA plate is used as a substrate, and a seed layer substrate is formed by surface cleaning and functional layer prepositioning; then a composite mold is used to imprint a one-time forming bottom groove-protrusion microstructure and a top prism array to obtain a composite microstructure light guide plate semi-finished product; atomic layer deposition technology is used to stack TiO2 / SiO2 anti-reflection coating layer by layer on the surface, and the optical parameters are adjusted in real time; a laser-induced graphene heat conduction grid is integrated on the back surface of the coating light guide plate to form an integrated heat dissipation structure, and the microstructure morphology tolerance is detected by an intelligent vision system, and the parameters are optimized based on spectral data feedback; the present process significantly improves the light guiding efficiency by composite microstructure design, improves the brightness and uniformity of the light guide plate, reduces the surface reflectivity by multi-layer anti-reflection coating, reduces the light loss, and effectively solves the problem of heat accumulation under high brightness by laser-induced graphene heat dissipation layer, improves the product performance, and outputs a high-brightness and high-uniformity light guide plate.

[0080] In the present embodiment, it is specifically explained that step S1 specifically comprises:

[0081] S11, a modified PMMA plate is selected, cut into a light guide plate substrate blank according to a predetermined size by a laser cutting device, and the cutting edge is polished to eliminate burrs;

[0082] The modified PMMA plate material is cut into a light guide plate base material blank according to a preset size by a high-precision laser cutting equipment, so as to ensure that the geometric tolerance is less than or equal to ±0.1 mm. The laser cutting can avoid edge cracks caused by mechanical stress. After cutting, the edge is subjected to chemical mechanical polishing (CMP) to eliminate burrs (Ra≤0.5 μm) and prevent micro-particle residues from affecting the surface quality in subsequent processes, while improving the optical uniformity of the edge of the base material.

[0083] In S12, the cut base material blank is subjected to plasma cleaning. Argon-oxygen mixed gas with a volume ratio of 4:1 is used to excite plasma in a vacuum chamber for 5-8 minutes to remove surface organic contaminants and micro-particles.

[0084] The argon-oxygen mixed gas (volume ratio of 4:1) is used to excite plasma in a vacuum chamber. The argon ions physically bombard to remove surface adsorbed particles, and the oxygen radicals oxidize and decompose organic contaminants, so that the surface contaminants are removed and the surface energy is improved, providing a high-activity substrate for subsequent activation treatment.

[0085] In S13, the cleaned base material is immersed in a surface activation solution for chemical activation treatment for 10 minutes, and then washed with ultrapure water and dried with nitrogen; the surface activation solution is an ethanol solution containing 0.5wt% silane coupling agent.

[0086] The cleaned base material is immersed in an ethanol solution containing 0.5wt% silane coupling agent. The silane molecules form a dense monolayer on the surface of the base material through hydrolysis reaction, enhancing the chemical bonding with the seed layer. After soaking for 10 minutes, the unreacted reagents are removed by washing with ultrapure water, and nitrogen is used for drying to avoid water mark residues, ensuring that the activated layer is uniform and defect-free.

[0087] In S14, an aluminum oxide seed layer is pre-deposited on the surface of the activated base material by an atomic layer deposition equipment. The deposition temperature is 120℃, the cycle number n is 50, and the three-methyl aluminum and water vapor precursors are introduced in each cycle to form a uniform seed layer with a thickness of 10 nm, obtaining a light guide plate base material with a seed layer.

[0088] In the atomic layer deposition equipment, the deposition temperature is set to 120℃, the cycle number n is 50, and the three-methyl aluminum is introduced for 0.1s, nitrogen is purged for 5s, water vapor is introduced for 0.1s, and nitrogen is purged for 5s in each cycle to grow aluminum oxide layer by layer. The self-limiting reaction realizes the thickness of the seed layer, covers uniformly, and provides an atomic-level flat interface for subsequent microstructure imprinting and functional coating.

[0089] In S15, the light guide plate base material is subjected to annealing treatment at 150℃ for 30 minutes in a nitrogen atmosphere to enhance the bonding strength of the seed layer and the base material.

[0090] The seed layer and the PMMA substrate are annealed at 150°C for 30 minutes under a nitrogen atmosphere to form Si-O-Al covalent bonds between the seed layer and the PMMA substrate, thereby improving the interface bonding strength. The annealing process simultaneously eliminates the microscopic stress introduced by ALD deposition, thereby avoiding coating peeling or microstructure deformation in subsequent processes.

[0091] In S16, the surface roughness of the seed layer is detected, and the thickness tolerance is verified, and the qualified substrate is screened out. The qualified substrate is transferred to a protective bin for storage. The qualified substrate is transferred to an inert protective bin with a humidity of less than or equal to 5% RH to avoid surface oxidation or contamination, and to ensure the cleanliness and stability of the substrate before entering the embossing.

[0092] In this embodiment, it is specified that step S2 specifically includes:

[0093] In S21, a composite mold is provided; wherein the composite mold includes a bottom microstructure area and a top prism area, the bottom microstructure area is processed by electron beam lithography to form a groove-protrusion array, the groove width is 5-6 μm, and the protrusion width is 30-35 μm, and the top prism area is formed by nano-imprinting technology to form a prism unit with a period of 50 μm.

[0094] The bottom microstructure area is processed by electron beam lithography technology, the groove width is 5-6 μm, and the protrusion width is 30-35 μm, and the top prism unit with a period of 50 μm is formed by nano-imprinting technology. The composite mold is designed in a partitioned manner (bottom guiding + top focusing) to realize light vertical emission and scattering control, the groove-protrusion structure optimizes the light path reflection efficiency, the prism array compresses the scattering angle range, and the brightness uniformity is ensured.

[0095] In S22, the light guide plate substrate is preheated in a constant temperature chamber at 80°C for 10 minutes to soften the surface of the substrate below the glass transition temperature Tg, thereby enhancing the embossing fluidity.

[0096] In the constant temperature chamber, the light guide plate substrate is heated at 80°C for 10 minutes, so that the surface temperature is close to the glass transition temperature (Tg≈105°C) of PMMA but lower than the softening point (Tg-5°C), which promotes the local relaxation of molecular chains, reduces the surface viscosity, and improves the embossing fluidity. Preheating avoids deformation of the entire substrate, while ensuring the integrity of the microstructure replication.

[0097] In S23, the composite mold is aligned with the preheated substrate and fixed on the embossing machine stage, a pressure of 20-25 MPa is applied, and at the same time, the surface of the substrate is irradiated with a ultraviolet light source to trigger the photocuring of the nano-imprinting glue, and the curing time T1 is continued to obtain a light guide plate semi-finished product with a composite microstructure.

[0098] After the composite mold is aligned with the substrate, a pressure of 20-25 MPa is applied to fill the mold cavity with nanoimprint glue, and a UV light source is irradiated at the same time for 15 seconds to trigger the light curing reaction. The pressure-light curing synergy precisely replicates the microstructure morphology, ensuring consistent light efficiency.

[0099] S24, after demolding, the imprinted substrate is annealed at 120°C for 20 minutes in a nitrogen atmosphere to eliminate internal stress and stabilize the microstructure morphology;

[0100] After demolding, the light guide plate semi-finished product is annealed at 120°C for 20 minutes in a nitrogen atmosphere to promote polymer chain rearrangement and release residual stress from imprinting, with a microstructure morphology shrinkage rate controlled within 0.1%. After annealing, the surface hardness increases from 60 to 75, and the scratch resistance is enhanced to prevent structure damage in subsequent processes.

[0101] S25, detect the morphology precision of the composite microstructure, verify the groove depth of the bottom layer and the prism angle of the top layer, select qualified light guide plate semi-finished products and store them temporarily.

[0102] The groove depth and prism angle are detected by a white light interferometer, and AI image algorithms are used to automatically reject products with poor morphology. Qualified semi-finished products are temporarily stored in a constant humidity bin to prevent environmental stress from causing microstructure deformation.

[0103] In this embodiment, step S3 specifically includes the following steps:

[0104] S31, pretreat the light guide plate semi-finished product with a composite microstructure, use plasma for surface treatment to remove residual contaminants and enhance surface activity;

[0105] The light guide plate semi-finished product with a composite microstructure is treated by argon plasma bombardment. Through high-energy ion physical bombardment and free radical chemical reaction, surface residual nanoimprint glue, organic contaminants, and micro-particles are completely removed, and the surface hydroxyl density is increased, significantly enhancing the adhesion and uniformity of the atomic layer deposition coating.

[0106] S32, fix the pretreated light guide plate semi-finished product in the atomic layer deposition equipment chamber, set the substrate temperature to 200°C, introduce nitrogen gas as the carrier gas and maintain the chamber pressure at 5 Torr;

[0107] Fix the pretreated light guide plate semi-finished product in the ALD equipment chamber, set the substrate temperature to 200°C, introduce high-purity nitrogen gas as the carrier gas, and maintain the chamber pressure at 5 Torr. This temperature and pressure condition optimizes the precursor adsorption kinetics, avoids thermal stress-induced microstructure deformation, and ensures that the reaction gas diffuses sufficiently to the microstructure aspect ratio area (such as the inside of the groove).

[0108] S33, forming a multilayer coating by alternately depositing TiO2 and SiO2 layers to form an anti-reflective coating; specifically, the process of alternately depositing TiO2 and SiO2 layers includes:

[0109] Injecting titanium tetrachloride precursor for 3 seconds, followed by nitrogen blowing; TiCl4 molecules are chemisorbed on the substrate surface to form a monolayer coverage; nitrogen blowing removes unreacted TiCl4 and byproducts (HCl) to avoid gas phase nucleation.

[0110] Injecting water vapor for 5 seconds to generate a TiO2 monolayer; H2O reacts with adsorbed TiCl4 to generate a TiO2 monolayer (reaction: TiCl4 + 2H2O → TiO2 + 4HCl↑); residual H2O and HCl are removed to complete the deposition of a monolayer of TiO2.

[0111] Similarly, the deposition process of the SiO2 layer is as follows: injecting tetraethoxysilane precursor for 4 seconds, followed by nitrogen blowing; injecting ozone for oxidation reaction for 8 seconds to generate a SiO2 monolayer.

[0112] S34, real-time monitoring of the film thickness of each coating, combined with PID algorithm to dynamically adjust the precursor injection time and blowing period, so that the total film thickness error is controlled within the preset error threshold range;

[0113] By real-time monitoring of the film thickness of each layer, combined with proportional-integral-derivative (PID) algorithm to dynamically adjust the precursor injection time and blowing period. For example, if the TiO2 layer thickness deviation is +0.3 nm, the TiCl4 injection time is automatically shortened to 2.8 seconds in the next cycle to ensure that the total film thickness (after 5 layers of alternating deposition) error is ≤±2 nm, reaching the target optical parameters (refractive index gradient 1.8-2.2).

[0114] S35, after completing 5 layers of TiO2 / SiO2 alternating deposition, annealing the coated light guide plate in a nitrogen atmosphere at 180°C for 15 minutes to eliminate interface stress and improve film layer density;

[0115] Annealing at 180°C for 15 minutes in a nitrogen atmosphere promotes atomic-level interdiffusion at the TiO2 / SiO2 interface, eliminates interlayer stress, and simultaneously seals micropore defects, improving film layer density.

[0116] S36, using a spectrophotometer to detect the average reflectivity of the anti-reflective coating in the 400-800 nm wavelength range, selecting light guide plates that meet the preset qualified value and transferring them to a protected environment for temporary storage.

[0117] The average reflectivity in the 400-800 nm band is detected by a spectrophotometer, and the qualified threshold is set to be ≤0.5%. The products with reflectivity exceeding the standard (e.g., >0.55%) are automatically marked and removed, and the qualified light guide plates are transferred to a nitrogen-filled protective bin to avoid coating moisture absorption or oxidation.

[0118] In the present embodiment, it is specifically explained that step S4 specifically comprises:

[0119] S41, the back surface of the light guide plate with coating is subjected to plasma activation treatment, argon-nitrogen mixed gas with a volume ratio of 4:1 is used to excite plasma, and the treatment is continuously performed for 8 minutes to improve the surface energy and the adhesion of graphene precursor;

[0120] It should be noted that the nitrogen radical (N+) introduces an amino (-NH2) functional group through chemical bonding to improve the surface energy. The continuous treatment for 8 minutes improves the adhesion of the graphene precursor (polyimide) to ≥2.5 N / cm, providing a high-activity substrate for subsequent laser-induced graphitization.

[0121] S42, spin-coating polyimide precursor solution on the activated back surface of the light guide plate to form a uniform precursor film layer with a thickness of 20 μm, and pre-curing at 80°C for 10 minutes;

[0122] A 20 μm thick polyimide precursor film layer is formed on the back surface of the light guide plate by spin coating process, and pre-curing (80°C, 10 minutes) promotes solvent evaporation. The glass transition temperature (Tg) of the film layer at this stage is 150°C, which ensures that the local thermal stress is controllable during subsequent laser processing, avoiding substrate warping.

[0123] S43, scanning the precursor film layer with laser, setting the scanning interval to 10 μm and the power density to 5 GW / cm², and generating a heat-conducting grid structure through laser-induced graphitization reaction. The line width of the micron-level grid structure is 3 μm, and the period is 50 μm.

[0124] The polyimide is carbonized to form a three-dimensional graphene grid through multi-photon absorption effect, and the laser parameters are optimized to ensure the line width and period, the density of heat-conducting path, and the thermal conductivity; at the same time, the thermal damage to the substrate is avoided.

[0125] S44, placing the light guide plate after laser treatment in a vacuum annealing furnace, and treating at 400°C for 30 minutes to complete the crystallization of the graphene heat-conducting grid and the interface bonding of the light guide plate substrate in a nitrogen atmosphere;

[0126] Placing the light guide plate after laser treatment in a vacuum annealing furnace, and treating at 400°C for 30 minutes to promote the increase of the proportion of graphene hybrid structure in a nitrogen atmosphere, reduce the resistance of the graphene layer, and realize the synergy of efficient heat conduction and electrical insulation.

[0127] S45, detect the heat dissipation performance of the heat-conducting grid, verify the thermal conductivity and scan and observe the morphology of the heat-conducting grid, and screen the finished light guide plate with complete structure.

[0128] Thermal conductivity verification: The temperature rise curve of the light guide plate at a heat flux density of 5W / cm² was measured by infrared thermal imager, verifying that the thermal conductivity is ≥1500W / m·K (steady-state temperature difference ΔT≤3℃).

[0129] Morphological integrity analysis and scanning electron microscopy were used to observe the porosity and linewidth consistency of the graphene mesh.

[0130] The screening criteria are as follows: light guide plates with substandard thermal conductivity (<1450W / m·K) or excessive porosity (>3%) are automatically rejected. Qualified products are transferred to a cleanroom for temporary storage to ensure stability before entering the quality inspection.

[0131] In this embodiment, step S5 specifically includes:

[0132] S51, Fix the finished light guide plate to the testing platform, and adjust the relative position of the light guide plate and the testing probe by using the positioning fixture;

[0133] The finished light guide plate is fixed on a six-degree-of-freedom detection platform. The relative position of the light guide plate, optical sensor, and vision probe is adjusted by an air-floating positioning fixture to reduce the perpendicularity error between the normal of the light-emitting surface and the detection light path, and to eliminate optical detection deviation caused by installation tilt.

[0134] S52 uses an intelligent vision system to perform a full-area scan of the light guide plate's reflective surface, compares the morphological parameters of the composite microstructure, and verifies the tolerances of the groove depth and prism angle.

[0135] A smart vision system (5μm resolution, 200fps) is used to perform a full-area scan of the reflective surface of the light guide plate. Based on the convolutional neural network algorithm, the morphological features of the groove depth (3-4μm±0.2μm) and prism angle (41-47°±0.5°) are extracted. The 3D point cloud reconstruction is compared with the CAD design model in real time, and the out-of-tolerance areas are automatically marked and the morphological pass rate is calculated.

[0136] S53 collects brightness distribution data of the light-emitting surface of the light guide plate through the imaging system, and sets the detection dot matrix density to 81 points / m. 2 It covers the 400-800nm ​​wavelength band, and simultaneously measures the brightness value and uniformity deviation at each point to obtain spectral data;

[0137] Using a high-resolution imaging spectrometer at 81 points / m 2 Density-based brightness data is collected, and the brightness value and uniformity deviation are measured simultaneously at each detection point. After noise reduction using a Kalman filter, the data is used to generate a heatmap, which quantifies and displays the brightness gradient to identify local dark areas or bright spots.

[0138] S54, input the topography parameters and the spectrum data into a process optimization model, analyze the influence weight of the key parameters on the performance based on a random forest algorithm, generate dynamic adjustment instructions and feedback to a control system for sample production optimization of the light guide plate;

[0139] Input the topography tolerance data (groove depth, prism angle) and the spectrum brightness data into a random forest model, analyze the influence weight (feature importance ranking) of the imprinting pressure, ALD deposition layer number (5 layers), laser power and other parameters on the brightness and uniformity. The model outputs dynamic adjustment instructions, which are fed back to the production equipment in real time to optimize the performance of the next batch of light guide plates.

[0140] S55, perform secondary optical detection on the optimized light guide plate, and verify the total luminous flux improvement rate and color temperature consistency using an integrating sphere system;

[0141] The total luminous flux and color temperature consistency of the optimized light guide plate are measured using an integrating sphere system. The luminous flux improvement rate is compared with the initial batch data (such as from 7600 lm to 8200 lm, with an improvement rate of about 8%), and the color temperature uniformity is quantified by the standard deviation (σ≤0.001) of the color coordinates (x, y), to ensure that the display picture is free of color deviation.

[0142] S56, record the detection data and process parameters in a distributed manner through a blockchain, generate a unique quality traceability code, and bind it to the light guide plate serial number;

[0143] Based on the blockchain, a distributed quality database is constructed, and the detection data (topography tolerance, brightness, color temperature) and process parameters (pressure, temperature, laser power) are encrypted and chained to generate a unique hash value as a 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 the specific process node for after-sales fault).

[0144] S57, screen the light guide plates that meet the brightness and uniformity standards, vacuum package them in anti-static aluminum plastic composite film, and output them as qualified products.

[0145] Screen the light guide plates that meet the brightness and uniformity standards, vacuum package them in anti-static aluminum plastic composite film, and output them as qualified products.

[0146] Example two:

[0147] In combination with Figure 3 The application also provides a front light guide plate, which is prepared by using the front light guide plate of example one. The front light guide plate specifically comprises:

[0148] Substrate layer 10 (modified PMMA plate, thickness 3mm), lower end surface of substrate layer 10 (back surface): form groove-protrusion microstructure 20 (groove width 5-6μm, protrusion width 30-35μm, depth 3-4μm) by embossing process, for optimizing light reflection path, improving vertical light extraction efficiency.

[0149] Upper end surface of substrate layer 10 (light emitting surface): form prism array 30 (period 50μm, inclination angle 41-47°) by the same embossing process, for focusing scattered light, controlling light emitting angle.

[0150] Seed layer is aluminum oxide material, located on the upper end surface of substrate layer 10 (contact with prism array 30), enhance the bonding strength of substrate and anti-reflection coating 40.

[0151] Anti-reflection coating 40, covers the upper end surface of substrate layer 10 prism array 30 surface, reduces reflectivity, improves light energy utilization.

[0152] Embedded heat dissipation layer 50 (graphene heat conduction grid, line width 3μm, period 50μm), located on the lower end surface of substrate layer 10 (same side with groove-protrusion microstructure 20), generated by laser induction technology, coexist with groove-protrusion structure in the same surface, but do not interfere with each other.

[0153] The above-described and the above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part 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 each embodiment of the present application.

Claims

1. A front light guide plate process, characterized in that, include: A light guide plate substrate with a seed layer is formed by using modified PMMA sheet as the substrate and cleaning its surface and pre-applying functional layers. An embossing process is performed on the surface of the light guide plate substrate to form a bottom groove-protrusion microstructure and a top prism array in one step using a composite mold, thus forming a light guide plate semi-finished product with a composite microstructure. An anti-reflective coating is deposited on the surface of a light guide plate semi-finished product with a composite microstructure. TiO2 / SiO2 multilayer films are stacked layer by layer using atomic layer deposition technology, and the coating thickness is adjusted in real time to the target optical parameters. An embedded heat dissipation layer is integrated on the back of the coated light guide plate, and a graphene thermally conductive grid is generated using laser-induced technology, so that the heat dissipation layer and the light guide plate substrate form an integrated structure. The finished light guide plate is subjected to optical performance and structural quality testing. The microstructure morphology tolerance is compared by an intelligent vision system, and the process parameters are optimized based on spectral data feedback to output a qualified light guide plate that meets the brightness and uniformity index. Specifically, the method of integrating an embedded heat dissipation layer on the back of the coated light guide plate, and using laser-induced technology to generate a graphene thermally conductive mesh, so that the heat dissipation layer and the light guide plate substrate form an integrated structure, includes: The back of the coated light guide plate is subjected to plasma activation treatment. The plasma is excited by an argon-nitrogen mixed gas with a volume ratio of 4:1 and the treatment is continued for 8 minutes to improve the surface energy and the adhesion of the graphene precursor. A polyimide precursor solution was spin-coated onto the back of the activated light guide plate to form a uniform precursor film with a thickness of 20 μm, and then pre-cured at 80°C for 10 minutes. Laser scanning was used to scan the precursor film layer, and a thermally conductive mesh structure was generated by laser-induced grapheneization reaction; The laser-treated light guide plate was placed in a vacuum annealing furnace and treated at a constant temperature of 400℃ for 30 minutes to complete the crystallization of the graphene thermally conductive mesh and the interface bonding with the light guide plate substrate under a nitrogen atmosphere. The heat dissipation performance of the heat-conducting mesh was tested, the thermal conductivity was verified, and the morphology of the heat-conducting mesh was scanned and observed to screen out finished light guide plates with complete structures.

2. The front light guide plate process according to claim 1, characterized in that, The process of using modified PMMA sheet as a substrate, cleaning its surface, and pre-applying functional layers to form a light guide plate substrate with a seed layer specifically includes: Modified PMMA sheets are selected and cut into light guide plate substrate blanks according to preset dimensions using laser cutting equipment. The cut edges are then polished to eliminate burrs. The cut substrate blank is subjected to plasma cleaning. The plasma is excited in a vacuum chamber using an argon-oxygen mixture with a volume ratio of 4:1 and the treatment is continued for 5-8 minutes to remove surface organic contaminants and microparticles. The cleaned substrate is immersed in a surface activation solution for chemical activation treatment for 10 minutes, then rinsed with ultrapure water and dried with nitrogen; the surface activation solution is an ethanol solution containing 0.5 wt% silane coupling agent. An alumina seed layer is pre-deposited on the surface of an activated substrate using an atomic layer deposition device at a deposition temperature of 120°C. The deposition is repeated n times, with trimethylaluminum and water vapor precursor introduced in each cycle to form a uniform seed layer with a thickness of 10 nm, thus obtaining a light guide plate substrate with a seed layer. The light guide plate substrate is annealed and kept at 150°C for 30 minutes in a nitrogen atmosphere to enhance the bonding strength between the seed layer and the substrate. The surface roughness of the seed layer was tested and the thickness tolerance was verified. Qualified substrates were screened and transferred to a protective chamber for storage.

3. The front light guide plate process according to claim 1, characterized in that, An embossing process is performed on the surface of the light guide plate substrate to form a bottom groove-protrusion microstructure and a top prism array in one step using a composite mold, forming a semi-finished light guide plate with a composite microstructure, specifically including: Provide composite molds; The light guide plate substrate is preheated by heating it at 80°C for 10 minutes in a constant temperature chamber to soften the surface of the substrate to below the glass transition temperature Tg, thereby enhancing the flowability of the printing process. The composite mold is aligned with the preheated substrate and fixed on the imprinting machine stage. A pressure of 20-25MPa is applied, and the substrate surface is irradiated with ultraviolet light to trigger the photocuring of nanoimprinting adhesive. The curing time is T1 to obtain a light guide plate semi-finished product with composite microstructure. After demolding, the imprinted substrate is annealed at 120°C for 20 minutes in a nitrogen atmosphere to eliminate internal stress and stabilize the microstructure morphology. The morphological accuracy of the composite microstructure is tested, the depth of the bottom groove and the angle of the top prism are verified, and 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 region and a top prism region. The bottom microstructure region is formed by electron beam lithography to create a groove-protrusion array with a groove width of 5-6 μm and a protrusion width of 30-35 μm. The top prism region is formed by nanoimprint technology to create prism units with a period of 50 μm.

5. The front light guide plate process according to claim 1, characterized in that, The process of depositing an anti-reflective coating on the surface of a semi-finished light guide plate with a composite microstructure, and stacking TiO2 / SiO2 multilayer films layer by layer using atomic layer deposition technology, while controlling the coating thickness to the target optical parameters in real time, specifically includes the following steps: The semi-finished light guide plate with composite microstructure is pretreated by plasma surface treatment to remove residual contaminants and enhance surface activity. The pre-treated light guide plate semi-finished product was fixed in the chamber of the atomic layer deposition equipment, the substrate temperature was set to 200℃, nitrogen was introduced as the carrier gas and the chamber pressure was maintained at 5 Torr. Alternating deposition of TiO2 and SiO2 layers forms a multilayer coating, creating an anti-reflective coating; The film thickness of each coating is monitored in real time, and the precursor injection time and purging cycle are dynamically adjusted in combination with the PID algorithm to keep the total film thickness error within the preset error threshold range. After completing the alternating deposition of 5 layers of TiO2 / SiO2, the coated light guide plate was annealed and kept at 180℃ in a nitrogen atmosphere for 15 minutes to eliminate interfacial stress and improve the film density. The average reflectance of the anti-reflection coating in the 400-800nm ​​wavelength range was detected using a spectrophotometer. Light guide plates that meet the preset qualified values ​​were screened and transferred to a protective environment for temporary storage.

6. The front light guide plate process according to claim 5, characterized in that, The process of alternating deposition of TiO2 and SiO2 layers specifically includes: Inject titanium tetrachloride precursor for 3 seconds, then purge with nitrogen; Injecting water vapor and reacting for 5 seconds produces a TiO2 monolayer. Inject the tetraethoxysilane precursor for 4 seconds, then purge with nitrogen. Ozone was injected for an oxidation reaction for 8 seconds to generate a single layer of SiO2.

7. The front light guide plate process according to claim 1, characterized in that, The process of inspecting the optical performance and structural quality of the finished light guide plate, comparing microstructure morphology tolerances using 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, specifically includes: The finished light guide plate is fixed on the testing platform, and the relative position of the light guide plate and the testing probe is adjusted by the positioning fixture; A smart vision system was used to perform a full-area scan of the reflective surface of the light guide plate, and the morphological parameters of the composite microstructure were compared to verify the tolerances of the groove depth and prism angle. The brightness distribution data of the light-emitting surface of the light guide plate was collected by an imaging system, and the detection dot density was set to 81 dots / m. 2 It covers the 400-800nm ​​wavelength band, and simultaneously measures the brightness value and uniformity deviation at each point to obtain spectral data; The morphological parameters and spectral data are input into the process optimization model. The influence weight of key parameters on performance is analyzed based on the random forest algorithm. Dynamic adjustment instructions are generated and fed back to the control system to optimize the sample production of the light guide plate.

8. The front light guide plate process according to claim 7, characterized in that, The process of generating dynamic adjustment commands and feeding them back to the control system for optimizing the sample production of the light guide plate also includes: The optimized light guide plate was subjected to secondary optical testing, and the total luminous flux improvement rate and color temperature consistency were verified using an integrating sphere system. By using blockchain to record and process parameters in a distributed manner, a unique quality traceability code is generated and bound to the light guide plate serial number; Light guide plates that meet the brightness and uniformity standards are selected, packaged in anti-static vacuum packaging, and output as qualified products.

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