High-thermal-conductivity light-transmitting composite material light guide plate and heat dissipation type high-brightness display module

Abstract

The invention discloses a high-heat-conductivity light-transmitting composite material light guide plate and a heat dissipation type high-brightness display module. The light guide plate is formed by compounding surface modified nano hexagonal boron nitride with the volume fraction of 10%-20% and polymethyl methacrylate, the light transmittance is larger than or equal to 90%, the heat conductivity coefficient is larger than or equal to 2.0 W / (m.K), a heat conduction micro-channel is arranged in the light guide plate, and a light guide micro-structure is integrated on the surface of the light guide plate; the display module comprises an aluminum alloy frame and the light guide plate, a micro-channel heat dissipation structure is integrally formed on the aluminum alloy frame through 3D printing, and heat of the LED lamp strip is efficiently dissipated sequentially through the heat conduction micro-channel of the light guide plate and the micro-channel heat dissipation structure of the frame. Through collaborative innovation of materials and structures, the light guide plate has high light transmittance and high thermal conductivity, a low-thermal-resistance heat dissipation path is constructed, the LED heat dissipation efficiency is remarkably improved, the junction temperature is reduced by 20 DEG C or above, high brightness, long service life and lightening and thinning of a display module are achieved, and the light guide plate is suitable for the field of vehicle-mounted, industrial control and high-end consumer electronics.

Description

Technical Field

[0001] This invention relates to the field of display module technology, and in particular to a high thermal conductivity and light transmittance composite material light guide plate and a heat dissipation type high brightness display module provided with the light guide plate. Background Technology

[0002] With the development of display technology, users have increasingly higher requirements for screen brightness, especially in automotive displays, industrial control displays, and high-end consumer electronics. For example, outdoor high-brightness screens and HDR displays require clear visibility even in strong light environments, necessitating the use of higher-power LEDs for backlighting. However, high-power driving inevitably leads to greater heat generation. In traditional display module structures, light guide plates often use PMMA or PC materials, which have extremely low thermal conductivity (approximately 0.2 W / (m·K), making them ineffective at conducting the heat generated by the LEDs. Furthermore, the backlight frame is often made of ordinary plastic materials with poor thermal conductivity. The heat generated by the LED light board cannot be quickly dissipated, easily accumulating near the LEDs, leading to severe LED light decay, accelerated aging of the liquid crystal material, and ultimately shortening the lifespan of the display module. Existing light guide plate materials cannot simultaneously achieve both light transmission and thermal conductivity. For instance, aluminum substrates have good thermal conductivity but are opaque; PMMA or PC plastic substrates have good light transmission but extremely poor thermal conductivity, failing to meet the heat dissipation requirements of high-brightness modules. To address heat dissipation issues, existing technologies typically require additional heat sinks, heat pipes, or fans, leading to bulky structures, increased costs, and a lack of alignment with the trend towards thinner and lighter designs. Currently, the industry lacks an integrated composite material for creating a light guide plate that can efficiently guide light and conduct heat effectively, as well as a heat dissipation optimization structure for high-brightness display modules incorporating this light guide plate. Summary of the Invention

[0003] In view of this, this technical solution aims to solve the technical pain points of existing TFT display modules, such as the separation of light guiding and heat dissipation functions, high thermal resistance, short lifespan, and low luminous efficiency. It proposes a high thermal conductivity and light transmittance composite material light guide plate, as well as a heat dissipation type high brightness display module with the light guide plate and heat dissipation structure, so that the light guide plate of the module can simultaneously carry out light guiding and heat dissipation, and meet the requirements of high brightness, good heat dissipation performance, and thinness of the module.

[0004] In a first aspect, the present invention provides a light guide plate of a high thermal conductivity and light transmittance composite material, wherein the light guide plate is composed of a high thermal conductivity ceramic material and an optical polymer material; the high thermal conductivity ceramic material is surface-modified nano-sized hexagonal boron nitride, and the optical polymer material is polymethyl methacrylate; the volume fraction of the nano-sized hexagonal boron nitride is 10%-20%; the light transmittance of the light guide plate is ≥90%, and the in-plane thermal conductivity is ≥2.0 W / (m·K); a thermally conductive microchannel is provided in the lower layer of the light guide plate, the thermally conductive microchannel extending from the light incident surface of the light guide plate to the edge side; and a light guiding microstructure is integrated on the upper surface of the light guide plate substrate.

[0005] Furthermore, the light guide plate includes an upper layer, a middle layer, and a lower layer arranged sequentially from top to bottom. The upper layer is a light-emitting layer with a thickness of 0.3-0.7 mm, and the light-guiding microstructure is integrated on its surface. The middle layer is a transition layer with a thickness of 0.2-0.4 mm, used to separate the light-guiding microstructure from the heat-conducting microchannel. The lower layer is a heat dissipation layer with a thickness of 1.2-1.7 mm, and the heat-conducting microchannel is disposed inside it.

[0006] Preferably, the heat-conducting microchannels are circular hollow channels with a diameter of 0.1-1.0 mm and a spacing of 1-3 mm, arranged in a longitudinal parallel pattern.

[0007] A second aspect of the present invention provides a method for preparing a light guide plate of a high thermal conductivity and light transmittance composite material, comprising the following steps: S1: Place polymethyl methacrylate particles into a vacuum drying oven, set the temperature to 80℃, and dry for 4-8 hours; provide nano-sized hexagonal boron nitride powder, the particle size of which is 50-200nm and the layer thickness is 10-50nm; perform surface modification treatment on the nano-sized hexagonal boron nitride powder using a silane coupling agent, the modification conditions being: stirring at 80℃ for 2 hours, followed by washing and drying; place the modified hexagonal boron nitride powder into a vacuum drying oven, set the temperature to 80℃, and dry for 4-8 hours; after drying, grind and pass through a 200-300 mesh sieve to obtain modified hexagonal boron nitride nanopowder; S2: Add the modified hexagonal boron nitride nanopowder treated in step S1 and polymethyl methacrylate particles to a high-speed mixer at a volume ratio of 10%-20%:80%-90%, and mix at a speed of 1000-1500 rpm for 10-15 minutes; add the mixed material to a twin-screw extruder for melt blending, setting the temperature of the twin-screw extruder to 180-200℃ in zone one and gradually increasing to 220-240℃ in zones two to five, with a screw speed of 100-150 rpm and a residence time of 2-3 minutes; after melt blending, the material is extruded, cooled, and pelletized to obtain composite granules; S3: After drying the composite granules obtained in step S2, a light guide plate with the light-guiding microstructure and the heat-guiding microchannel is integrally formed by injection molding or photopolymerization 3D printing.

[0008] Furthermore, in step S3, the injection molding process includes: drying the composite granules at 80°C for 4-6 hours; using a high-precision injection molding machine, setting the barrel temperature to 220-240°C, the injection pressure to 80-100MPa, the injection speed to 60-100mm / s, the holding pressure to 70%-80% of the injection pressure, the holding time to 5-10 seconds, the mold temperature to 65-85°C, and the cooling time to 10-20 seconds; forming the heat-conducting microchannels through a mold core-pulling mechanism, with the core-pulling mechanism pulling out at a speed of 3-8mm / s during demolding to ensure that the inner wall of the channel is smooth and without collapse.

[0009] Further, in step S3, the photopolymerization 3D printing process includes: mixing surface-modified hexagonal boron nitride powder with liquid polymethyl methacrylate at a volume ratio of 10%-20%:80%-90%, stirring at high speed for 20-40 minutes, and ultrasonically dispersing for 40-80 minutes to obtain a photopolymerization liquid resin material with a solid content ≤30%; using an industrial-grade SLA photopolymerization printer, setting the laser wavelength to 405nm, laser power to 400-600mW, scanning speed to 1500-2500mm / s, and layer thickness to 15-30μm, and importing a preset model for printing; after printing, ultrasonically cleaning with anhydrous ethanol for 5-15 minutes to remove uncured resin, and then placing it in a UV curing chamber for post-curing at a wavelength of 365nm for 20-40 minutes to obtain the finished light guide plate.

[0010] A third aspect of the present invention provides a heat-dissipating high-brightness display module, comprising a metal frame, a TFT display screen, a brightness enhancement film assembly, a reflective film, LED strips, and a light guide plate made of the aforementioned high thermal conductivity and light transmittance composite material. The metal frame is integrally formed using an additive manufacturing process and includes a bottom wall and side walls surrounding the bottom wall. The bottom wall and the side walls together form a mounting cavity. A microchannel heat dissipation structure is provided inside the metal frame. The LED strips are disposed on the inner surface of the side walls of the metal frame, and the light guide plate is disposed in the mounting cavity, with its light-incident surface in close contact with the light-emitting side of the LED strips. The heat generated by the LED strips is conducted and dissipated sequentially through the thermally conductive microchannels of the light guide plate and the microchannel heat dissipation structure of the metal frame.

[0011] The TFT display screen, the brightness enhancement film assembly, the light guide plate, and the reflective film are stacked sequentially from top to bottom within the mounting cavity; the brightness enhancement film assembly includes a double brightness enhancement film, an upper prism film, a lower prism film, and a diffusion film stacked sequentially from top to bottom.

[0012] Furthermore, the number of LED light strips is one, two, or four, respectively arranged on one side, opposite sides, or all four sides of the sidewall; the LED light strips are fixed to the inner surface of the sidewall of the metal frame by thermally conductive double-sided adhesive, and the LED light strips are made of aluminum substrate or ceramic substrate.

[0013] Furthermore, the microchannel heat dissipation structure of the metal frame includes microchannels disposed inside the bottom wall and / or the side wall, and heat dissipation fins disposed on the outer surface of the side wall.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This solution uses a specific ratio and modified high thermal conductivity hexagonal boron nitride to composite with polymethyl methacrylate (PMMA) optical material to form a light guide plate, and integrates thermally conductive microchannels inside, so that the light guide plate has both high light transmittance and high thermal conductivity. The light transmittance of the light guide plate is ≥90%, and the in-plane thermal conductivity is ≥2.0 W / (m·K), which solves the problem that traditional light guide plates cannot simultaneously achieve "light transmission and thermal conductivity".

[0015] 2. This solution integrates heat dissipation into the light guide plate and the metal frame itself. By combining the heat dissipation properties of the light guide plate itself and the heat dissipation microchannels of the light guide plate, as well as the microchannel heat dissipation structure inside the bottom wall and / or side wall of the metal frame, it solves the problem of heat dissipation for high-brightness display modules while simultaneously addressing the need for high-density, high-power output LED panels, or multiple LED panels. The display module does not require additional heat sinks or fans, simplifying the module structure, facilitating thinner and lighter designs, reducing assembly steps, and lowering manufacturing costs.

[0016] 3. The display module designed using this technical solution has a lower LED lamp board junction temperature of more than 20°C, a more uniform temperature distribution in the TFT display liquid crystal layer, effectively suppresses LED light decay and liquid crystal material aging, and can extend its service life to more than twice that of traditional display modules. Attached Figure Description

[0017] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this disclosure together with the specification and serve to explain the principles of this disclosure.

[0018] Figure 1 This is an exploded view of the overall structure of the display module disclosed in this invention.

[0019] Figure 2 This is a perspective view of the overall assembly structure of the display module disclosed in this invention.

[0020] Figure 3 for Figure 1 A magnified schematic diagram of the structure at point A of the light guide plate.

[0021] Figure 4 for Figure 1 Enlarged schematic diagram of the structure at point B of the metal frame.

[0022] Figure 5 This is a front view of the overall structure of the display module disclosed in this invention.

[0023] Figure 6 for Figure 5 XX cross-sectional view in the image.

[0024] Figure 7 for Figure 6 A magnified schematic diagram of the structure at point C.

[0025] Figure 8 for Figure 5 YY cross-sectional view.

[0026] Figure 9 for Figure 8 A magnified schematic diagram of the structure at point D.

[0027] Figure 10 For Figure 9 A schematic diagram showing the upper, middle, and lower layers of the indicator light guide plate.

[0028] Explanation of reference numerals in the attached figures: 1. Metal frame; 101. Bottom wall; 1011. Second micro-through hole; 102. Side wall; 1021. First micro-through hole; 1022. Heat dissipation fins; 2. Reflective film; 3. Light guide plate; 301. Light guide microstructure; 302. Thermally conductive microchannel; 4. Brightness enhancement film assembly; 5. TFT display screen; 6. LED light board; 7. Thermally conductive double-sided adhesive; 8. Fixing front frame; 01. Upper layer; 02. Middle layer; 03. Lower layer. Detailed Implementation

[0029] The technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this disclosure. Example 1

[0030] This embodiment discloses a light guide plate made of a high thermal conductivity and light transmittance composite material. The light guide plate 3 is composed of a high thermal conductivity ceramic material and an optical polymer material. The high thermal conductivity ceramic material is surface-modified nano-sized hexagonal boron nitride, and the optical polymer material is polymethyl methacrylate. The volume fraction of the nano-sized hexagonal boron nitride is 10%-20%. The light transmittance of the light guide plate 3 is ≥90%, and the in-plane thermal conductivity is ≥2.0 W / (m·K). A thermally conductive microchannel 302 is provided inside the lower layer 03 of the light guide plate 3, and the thermally conductive microchannel 302 extends from the light incident surface of the light guide plate 3 to the edge side. A light guide microstructure 301 is integrated on the surface of the upper layer 01 of the substrate of the light guide plate 3.

[0031] Please refer to Figure 5 , Figures 8 to 10 In this embodiment, the light guide plate 3 includes an upper layer 01, a middle layer 02, and a lower layer 03 arranged sequentially from top to bottom. The upper layer 01 is a light-emitting layer with a thickness of 0.3-0.7 mm, and its surface is integrated with the light-guiding microstructure 301. The middle layer 02 is a transition layer with a thickness of 0.2-0.4 mm, used to separate the light-guiding microstructure 301 from the heat-conducting microchannel 302. The lower layer 03 is a heat-dissipating layer with a thickness of 1.2-1.7 mm, and its interior contains the heat-conducting microchannel 302. Preferably, the heat-conducting microchannel 302 is a circular hollow channel with a diameter of 0.1-1.0 mm and a spacing of 1-3 mm, arranged longitudinally in parallel.

[0032] Preferably, the light guide microstructure 301 adopts a V-shaped groove, and the V-shaped groove parameters are: apex angle 60°, depth 58μm, and spacing 0.15mm. Figure 3 (as shown); or a microlens array, with microlens protrusions of 50μm in diameter, used for light homogenization and emission. A 1mm diameter thermal conductive microchannel 302 can be realized through a mold core-pulling mechanism. For a more closely spaced thermal conductive microchannel 302, such as a multilayer thermal conductive microchannel 302 with a diameter of 0.1-0.5mm, it can be realized through 3D printing. Example 2

[0033] This embodiment discloses a method for preparing a light guide plate of high thermal conductivity and light transmittance composite material.

[0034] 1. Raw material preparation and pretreatment The matrix material is optical grade polymethyl methacrylate (PMMA), specifically VH5 produced by Nantong Mitsubishi Rayon, with a light transmittance of 93%. The PMMA particles are vacuum dried at 80°C for 6 hours.

[0035] The filler material is nano-sized hexagonal boron nitride (h-BN) with a particle size of 50-200 nm and a layer thickness of 10-50 nm. Surface modification is performed using the silane coupling agent KH570: stirring at 80℃ for 2 hours, washing with ethanol, and then drying. The modified h-BN powder is dried at 80℃ for 6 hours, ground, and then sieved through a 300-mesh sieve for later use.

[0036] 2. Preparation of composite granules The treated hexagonal boron nitride powder (h-BN) and polymethyl methacrylate (PMMA) granules were added to a high-speed mixer at a volume ratio of 15%:85% and mixed at 1200 rpm for 12 minutes. The mixture was then melt-blended in a twin-screw extruder. The extruder temperatures were set as follows: zone 1 190℃, zone 2 210℃, zone 3 230℃, zone 4 235℃, and zone 5 235℃; the screw speed was 120 rpm; and the residence time was 2.5 minutes. After extrusion, the mixture was water-cooled and pelletized to obtain composite granules with a diameter of 2 mm and a length of 3 mm. The granules were then vacuum-dried at 80℃ for 8 hours.

[0037] 3. Light guide plate forming The composite granules are injection molded using a high-precision injection molding machine. Injection parameters: barrel temperature 230℃, injection pressure 90MPa, injection speed 80mm / s, holding pressure 60MPa, holding time 8 seconds, mold temperature 75℃, cooling time 15 seconds.

[0038] The mold is designed with V-shaped grooves (60° apex angle, 58μm depth, 0.15mm spacing) for forming the light-guiding microstructure 301, and a core-pulling mechanism for forming longitudinal parallel heat-conducting microchannels 302 with a diameter of 1mm and a spacing of 2mm. During demolding, the core-pulling mechanism pulls out at a speed of 5mm / s to ensure the smoothness of the inner wall of the channel.

[0039] The final light guide plate 3 has a total substrate thickness of 2.5 mm, with the upper layer 01 (light-emitting layer) being 0.5 mm thick, the middle layer 02 (transition layer) being 0.3 mm thick, and the lower layer 03 (heat dissipation layer) being 1.7 mm thick. Testing showed that the light guide plate 3 has a light transmittance of 90.1% and an in-plane thermal conductivity of 2.30 W / (m·K).

[0040] In this embodiment, photopolymerization 3D printing can also be used to replace injection molding. The photopolymerization 3D printing process includes: mixing surface-modified hexagonal boron nitride powder (h-BN) with liquid polymethyl methacrylate (PMMA) at a volume ratio of 15%:85%, stirring at high speed for 30 minutes, and ultrasonically dispersing for 60 minutes to obtain a photopolymerization liquid resin material with a solid content ≤30%; using an industrial-grade SLA photopolymerization printer, setting the laser wavelength to 405nm, laser power to 500mW, scanning speed to 12000mm / s, and layer thickness to 20μm, and importing a preset model for printing; after printing, ultrasonically cleaning with anhydrous ethanol for 10 minutes to remove uncured resin, and then placing it in a UV curing chamber for post-curing at a wavelength of 365nm for 30 minutes to obtain the finished light guide plate 3.

[0041] Table 1 below details the experimental data on the transmittance and in-plane thermal conductivity of the light guide plate 3 made of pure PMMA material and light guide plates 3 made with different h-BN and PMMA ratios. The light guide plate 3 prepared by mixing hexagonal boron nitride powder and polymethyl methacrylate particles at a volume ratio of 15%:85% obtained from the experimental data has a measured transmittance of 90.1% and an in-plane thermal conductivity of 2.30 W / (m·K), which meets the requirements of ≥90% transmittance and ≥2.0 W / (m·K) for the light guide plate 3 in this scheme.

[0042] Table 1: Serial Number h-BN volume fraction h-BN surface modification state 2mm thick sample with high light transmittance In-plane thermal conductivity (25℃) Molding process adaptability Matching with the core indicators of this technology 1 0% (Pure PMMA) - 92.0% 0.20 W / (m·K) Excellent, capable of precision injection molding microstructures Benchmark comparison 2 8% Unmodified 87.3% 0.65 W / (m·K) Good, slight reunion Mismatch; both light transmittance and thermal conductivity fail to meet standards. 3 8% KH570 Modification 91.7% 0.72 W / (m·K) Excellent, capable of precision injection molding microstructures Mismatch; thermal conductivity not ≥2.0 W / (m·K) 4 12% KH570 Modification 90.8% 1.85 W / (m·K) Excellent, capable of precision injection molding microstructures It has reached the critical threshold and is close to meeting the core indicators of this application. 5 15% KH570 Modification 90.1% 2.30 W / (m·K) Excellent, capable of precision injection molding V-cut / microlens microstructures To meet the requirements of this application, the light transmittance is ≥90% and the thermal conductivity is ≥2.0 W / (m·K). 6 20% KH570 Modification 89.1% 3.10 W / (m·K) Good, injection molding process needs optimization. Heat output significantly exceeds standards; light transmittance is slightly below 90%. 7 25% KH570 Modification 85.3% 4.20 W / (m·K) Poor melt flowability, unable to form precise microstructures. Mismatch; light transmittance and formability both fail to meet standards. Example 3 Please refer to Figures 1 to 10 This embodiment discloses a display module equipped with the light guide plate obtained in the above embodiment. This display module meets the requirement of high brightness. To achieve high brightness, the LED light panel 6 of the display module uses high-density LEDs, or LEDs are arranged on opposite sides, or LED light panels 6 are arranged on all four sides, thereby improving brightness and meeting the high brightness requirement. Since meeting the high brightness requirement may lead to excessive heat generation in the LED light panel 6, its heat conduction and heat dissipation structure needs further optimization, thus providing the technical solution of this embodiment.

[0043] In this embodiment, a heat-dissipating high-brightness display module includes a metal frame 1, a TFT display screen 5, a brightness enhancement film assembly 4, a reflective film 2, LED strips, and a light guide plate 3 made of the aforementioned high thermal conductivity and light transmittance composite material. The metal frame 1 is integrally formed using additive manufacturing technology and includes a bottom wall 101 and side walls 102 surrounding the bottom wall 101. The bottom wall 101 and the side walls 102 together form a mounting cavity. A microchannel heat dissipation structure is provided inside the metal frame 1. The LED strips are disposed on the inner surface of the side walls 102 of the metal frame 1, and the light guide plate 3 is disposed in the mounting cavity, with its light-incident surface in close contact with the light-emitting side of the LED strips. The heat generated by the LED strips is conducted and dissipated sequentially through the thermally conductive microchannels 302 of the light guide plate 3 and the microchannel heat dissipation structure of the metal frame 1.

[0044] Please refer to Figure 1 , Figure 2 The TFT display screen 5, the brightness enhancement film assembly 4, the light guide plate 3, and the reflective film 2 are stacked sequentially from top to bottom within the mounting cavity. A fixing front frame 8 is provided at the upper edge of the uppermost TFT display screen 5 and is bonded and fixed to the step formed by the cavity opening. Preferably, the brightness enhancement film assembly 4 includes a double brightness enhancement film, an upper prism film, a lower prism film, and a diffusion film stacked sequentially from top to bottom.

[0045] In this embodiment, the number of LED light strips is one, two, or four, respectively disposed on one side, opposite sides, or all four sides of the sidewall 102; the LED light strips are fixed to the inner surface of the sidewall 102 of the metal frame 1 by thermally conductive double-sided adhesive 7, and the LED light strips are made of aluminum substrate or ceramic substrate. When one set of LED light panels 6 is used, a high-density LED light panel 6 with multiple rows of LEDs is employed; when two or four sets are used, the LED density of the LED light panels 6 can be adaptively reduced.

[0046] Preferably, the microchannel heat dissipation structure of the metal frame 1 includes microchannels disposed inside the bottom wall 101 and / or the side wall 102, and heat dissipation fins 1022 disposed on the outer surface of the side wall 102. The microchannels can be formed by first micro-holes 1021 penetrating both sides of the solid side wall 102 of the metal frame 1. The first micro-holes 1021 can be arranged in multiple layers, and several neatly arranged hollow positions with openings facing outwards are provided on the solid side wall 102 between the multiple layers of first micro-holes 1021. The connecting pieces between adjacent hollow positions are the heat dissipation fins 1022. Figure 4 As shown), a plurality of second micro-holes 1011 penetrate from one side to the other side of the bottom wall 101 of the metal frame 1, and the plurality of second micro-holes 1011 are arranged at intervals on the entire bottom wall 101 plate surface.

[0047] By integrating the heat dissipation function into the light guide plate 3 and the metal frame 1, and combining the heat conduction performance of the light guide plate 3 itself with the heat conduction microchannel 302 of the light guide plate 3 and the microchannel heat dissipation structure inside the bottom wall 101 and / or side wall 102 of the metal frame 1, the problem of heat dissipation of high-density, high-power output LED lamp boards 6 or multiple sets of LED lamp boards 6 is solved while meeting the high brightness of the display module. The display module does not need to add heat sinks or fans, which simplifies the module structure, facilitates thin and light design, reduces assembly steps, and lowers manufacturing costs.

[0048] The parts not described in detail in this technical solution specification are obvious to those skilled in the art and can be supplemented and improved based on existing technical knowledge. At the same time, those skilled in the art should understand that the above embodiments are merely preferred embodiments of the present invention. For those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A light guide plate made of high thermal conductivity and light transmittance composite material, characterized in that, The light guide plate is composed of a high thermal conductivity ceramic material and an optical polymer material. The high thermal conductivity ceramic material is surface-modified nano-sized hexagonal boron nitride, and the optical polymer material is polymethyl methacrylate. The volume fraction of the nano-sized hexagonal boron nitride is 10%-20%. The light guide plate has a light transmittance ≥90% and an in-plane thermal conductivity ≥2.0 W / (m·K). The lower layer of the light guide plate has a thermally conductive microchannel extending from the light incident surface of the light guide plate to the edge side. The upper surface of the light guide plate substrate has a light-guiding microstructure integrated thereon.

2. The high thermal conductivity and light transmittance composite material light guide plate according to claim 1, characterized in that, The light guide plate includes an upper layer, a middle layer, and a lower layer arranged sequentially from top to bottom; The upper layer is a light-emitting layer with a thickness of 0.3-0.7 mm, and the light-guiding microstructure is integrated on its surface; The middle layer is a transition layer with a thickness of 0.2-0.4 mm, used to separate the light-guiding microstructure from the heat-guiding microchannel; The lower layer is a heat dissipation layer with a thickness of 1.2-1.7mm, and the heat-conducting microchannels are arranged inside it.

3. The high thermal conductivity and light transmittance composite material light guide plate according to claim 1, characterized in that, The heat-conducting microchannels are circular hollow channels with a diameter of 0.1-1.0 mm and a spacing of 1-3 mm, arranged in a longitudinal parallel pattern.

4. A method for preparing a high thermal conductivity and light transmittance composite material light guide plate as described in any one of claims 1-3, characterized in that, Includes the following steps: S1: Place polymethyl methacrylate particles into a vacuum drying oven, set the temperature to 80℃, and dry for 4-8 hours; provide nano-sized hexagonal boron nitride powder, the particle size of which is 50-200nm and the layer thickness is 10-50nm; perform surface modification treatment on the nano-sized hexagonal boron nitride powder using a silane coupling agent, the modification conditions being: stirring at 80℃ for 2 hours, followed by washing and drying; place the modified hexagonal boron nitride powder into a vacuum drying oven, set the temperature to 80℃, and dry for 4-8 hours; after drying, grind and pass through a 200-300 mesh sieve to obtain modified hexagonal boron nitride nanopowder; S2: Add the modified hexagonal boron nitride nanopowder treated in step S1 and polymethyl methacrylate particles to a high-speed mixer at a volume ratio of 10%-20%:80%-90%, and mix at a speed of 1000-1500 rpm for 10-15 minutes; add the mixed material to a twin-screw extruder for melt blending, setting the temperature of the twin-screw extruder to 180-200℃ in zone one and gradually increasing to 220-240℃ in zones two to five, with a screw speed of 100-150 rpm and a residence time of 2-3 minutes; after melt blending, the material is extruded, cooled, and pelletized to obtain composite granules; S3: After drying the composite granules obtained in step S2, a light guide plate with the light-guiding microstructure and the heat-guiding microchannel is integrally formed by injection molding or photopolymerization 3D printing.

5. The method for preparing the high thermal conductivity and light transmittance composite material light guide plate according to claim 4, characterized in that, In step S3, the injection molding process includes: drying the composite granules at 80°C for 4-6 hours; using a high-precision injection molding machine, setting the barrel temperature to 220-240°C, the injection pressure to 80-100MPa, the injection speed to 60-100mm / s, the holding pressure to 70%-80% of the injection pressure, the holding time to 5-10 seconds, the mold temperature to 65-85°C, and the cooling time to 10-20 seconds; forming the heat-conducting microchannels through a mold core-pulling mechanism, and pulling out the core at a speed of 3-8mm / s during demolding to ensure that the inner wall of the channel is smooth and without collapse.

6. The method for preparing the high thermal conductivity and light transmittance composite material light guide plate according to claim 4, characterized in that, In step S3, the photopolymerization 3D printing process includes: mixing surface-modified hexagonal boron nitride powder with liquid polymethyl methacrylate at a volume ratio of 10%-20%:80%-90%, stirring at high speed for 20-40 minutes, and ultrasonically dispersing for 40-80 minutes to obtain a photopolymerization liquid resin material with a solid content ≤30%; using an industrial-grade SLA photopolymerization printer, setting the laser wavelength to 405nm, laser power to 400-600mW, scanning speed to 1500-2500mm / s, and layer thickness to 15-30μm, and importing a preset model for printing; after printing, ultrasonically cleaning with anhydrous ethanol for 5-15 minutes to remove uncured resin, and then placing it in a UV curing chamber for post-curing at a wavelength of 365nm for 20-40 minutes to obtain the finished light guide plate.

7. A heat-dissipating high-brightness display module, characterized in that, include: The metal frame is integrally formed using additive manufacturing technology. It includes a bottom wall and side walls surrounding the bottom wall. The bottom wall and the side walls together form a mounting cavity. The interior of the metal frame is provided with a microchannel heat dissipation structure. The metal frame is made of one or more combinations of aluminum alloy, copper alloy, magnesium alloy or titanium alloy. LED light strips are disposed on the inner surface of the side wall of the metal frame; And the high thermal conductivity and light transmittance composite material light guide plate as described in any one of claims 1-3; The light guide plate is disposed in the mounting cavity, and its light-incident surface is in close contact with the light-emitting side of the LED light strip; the heat generated by the LED light strip is conducted and dissipated in sequence through the heat-conducting microchannel of the light guide plate and the microchannel heat dissipation structure of the metal frame.

8. The heat-dissipating high-brightness display module according to claim 7, characterized in that, The number of LED light strips is one, two, or four, respectively set on one side, opposite sides, or all four sides of the sidewall; the LED light strips are fixed to the inner surface of the sidewall of the metal frame by thermally conductive double-sided adhesive, and the LED light strips are made of aluminum substrate or ceramic substrate.

9. The heat-dissipating high-brightness display module according to claim 7, characterized in that, The microchannel heat dissipation structure of the metal frame includes microchannels disposed inside the bottom wall and / or the side wall, and heat dissipation fins disposed on the outer surface of the side wall.

10. The heat-dissipating high-brightness display module according to claim 7, characterized in that, It also includes a TFT display screen, a brightness enhancement film assembly, and a reflective film, wherein the TFT display screen, the brightness enhancement film assembly, the light guide plate, and the reflective film are stacked sequentially from top to bottom in the mounting cavity; the brightness enhancement film assembly includes a double brightness enhancement film, an upper prism film, a lower prism film, and a diffusion film stacked sequentially from top to bottom.

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