Vehicle-mounted high-color-gamut QD-LED backlight display module

Abstract

The invention relates to the technical field of semiconductor display, in particular to a vehicle-mounted high-color-gamut QD-LED backlight display module which further comprises a high-color-gamut QD-LED lamp bead which serves as a lateral light source and is arranged on at least one side edge of a light guide plate. The high-color-gamut QD-LED lamp bead comprises a circuit board and a plurality of LED lamp beads welded on the circuit board, and the LED lamp beads are patch devices packaged by composite luminescent materials of green quantum dots and KSF fluorescent powder. The circuit board and the LED lamp beads on the circuit board are integrally packaged by a silica gel packaging layer, and the silica gel packaging layer is connected with the light guide plate through a light guide protection layer, so that the high-color-gamut QD-LED lamp beads and the light guide plate are integrated. Through multi-dimensional collaborative innovation, the problems of reliability, light quality, mechanical durability and the like are comprehensively solved, a vehicle-mounted display backlight solution which is ultrahigh in color gamut, high in brightness, high in uniformity, high in reliability and long in service life is created, and high commercial value and market prospects are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor display, in particular to a high color gamut QD-LED backlight display module for vehicle. BACKGROUND

[0002] Quantum dots are semiconductor nanocrystals with a size in the nanometer range (typically between 1-10 nanometers), which are unique in that they are significantly dominated by quantum size effect and quantum confinement effect. When the physical size of quantum dots is smaller than the exciton Bohr radius, the movement of carriers (electrons and holes) is limited in three-dimensional space, resulting in the energy level structure changing from continuous energy band to discrete quantum energy level. This quantum effect makes the optical (such as absorption spectrum and emission spectrum) and electrical properties (such as conductivity and carrier mobility) of quantum dots highly adjustable with slight changes in their size. In terms of light-emitting performance, quantum dots have the advantage of extremely high color purity, with a half-width of photoluminescence or electroluminescence spectrum as narrow as 20-30 nanometers, and extremely strong monochromaticity, which can accurately emit red, green and blue high-purity primary color light.

[0003] This feature enables quantum dots to cover a wider color range than traditional light-emitting materials, achieving more vivid and realistic color display. In the vehicle display application field with extremely high reliability requirements, in order to ensure that the quantum dot light-emitting device (QD-LED light bar) works stably and reliably in the harsh vehicle-grade environment (such as long-term high temperature and high humidity, temperature cycling, mechanical vibration), it is necessary to apply a dense protective glue for encapsulation again on the basis of the original QD-LED light bar encapsulation structure. This secondary encapsulation glue mainly plays the role of enhancing the water vapor (H2O) and oxygen (O2) barrier protection, effectively delaying the degradation of quantum dot materials caused by environmental erosion factors, thereby significantly improving the long-term environmental resistance and service life of high color gamut quantum dot light bar products, and ultimately meeting the stringent vehicle reliability standard requirements. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application discloses a high color gamut QD-LED backlight display module for vehicle, which solves the above problems.

[0005] The present application is implemented by the following technical solutions:

[0006] The present application provides a high color gamut QD-LED backlight display module for vehicle, comprising a back plate, a reflective sheet arranged on the back plate, a light guide plate arranged on the reflective sheet, and an optical film piece group arranged in the light emitting direction of the light guide plate in sequence,

[0007] The backlight display module further comprises a high color gamut QD-LED lamp bead arranged at least one side edge of the light guide plate as a side-in type light source;

[0008] The high color gamut QD-LED lamp bead comprises a circuit board and a plurality of LED lamp beads welded on the circuit board;

[0009] The LED lamp bead is a patch device packaged with a composite light-emitting material of green quantum dots and KSF fluorescent powder;

[0010] The circuit board and the LED lamp beads thereon are entirely encapsulated by a layer of silica gel encapsulation layer;

[0011] The silica gel encapsulation layer is connected with the light guide plate through a light guide protection layer, and an optical microstructure is arranged at the connection between the light guide protection layer and the light guide plate.

[0012] Further, the optical microstructure is a V-shaped groove structure arranged continuously or at intervals, and the opening of the V-shaped groove is directed towards the light guide plate, for reflecting the light rays emitted at a large angle into the light guide plate.

[0013] Further, the optical microstructure is a microlens array structure, and the microlens array comprises one of convex lenses, Fresnel lenses or free-form surface lenses, for at least one of collimating, converging or diffusing the emitted light rays.

[0014] Further, the reflectivity of the light guide protection layer is less than or equal to the reflectivity of the light guide plate.

[0015] Further, the light guide protection layer is integrally formed with the silica gel encapsulation layer through a nano-imprinting process or a photoresist template transfer process.

[0016] Further, the silica gel encapsulation layer is embedded with a nano-barrier layer.

[0017] The nano-barrier layer is a multi-layer nano-layered structure formed by alternately stacking metal oxides and non-metal oxides.

[0018] Further, the nano-barrier layer is a structure formed by alternately stacking Al2O3 layers and SiO2 layers, with a single layer thickness of 20-40 nm and a total number of layers of 1-5 layers.

[0019] Further, the surface of the reflective sheet is provided with a photonic crystal structure layer.

[0020] The photonic crystal structure layer is configured to have a reflectivity of greater than 99% for light rays in the visible light band, and a transmittance of greater than 90% for light rays in the infrared band.

[0021] Further, the period of the photonic crystal structure layer is 280-320 nm.

[0022] Further, the backlight display module is manufactured by including the following steps:

[0023] Provide the circuit board and solder the LED beads onto it;

[0024] A silicone encapsulation layer is formed on the circuit board and its LEDs using dispensing or molding processes.

[0025] Before or during the curing process of the silicone encapsulation layer, the optical microstructure is formed by imprinting a mold with a preset pattern onto its light-emitting surface.

[0026] The beneficial effects of this invention are as follows:

[0027] This invention, through multi-dimensional collaborative innovation and system-level design in materials, structure, optics, and thermals, does not simply solve a single problem, but comprehensively overcomes a series of technical challenges such as reliability, light quality, and mechanical durability faced by the application of high color gamut QD-LED technology in automotive displays. It successfully creates an automotive display backlight solution that combines ultra-high color gamut, high brightness, high uniformity, high reliability, and long lifespan, and has extremely high commercial application value and market prospects. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the backlight module architecture of the present invention;

[0030] Figure 2 This is a structural diagram of the silicone encapsulation layer and buffer microstructure layer of the present invention;

[0031] The labels in the diagram represent:

[0032] 1. High color gamut QD-LED lamp beads; 2. Backplate; 3. Reflector; 4. Light guide plate; 5. Lower diffuser; 6. Lower light-enhancing prism; 7. Upper light-enhancing prism; 8. Upper diffuser; 9. Silicone encapsulation layer; 10. Light guide protection layer. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] like Figure 1 and 2 As shown, the present invention provides a high color gamut QD-LED backlight display module for automotive applications. Its basic architecture includes a backplate, a reflective sheet, a light guide plate, and an optical film assembly arranged sequentially from bottom to top (with reference to the light emission direction). The optical film assembly typically includes a lower diffuser, a lower brightness enhancement prism sheet, an upper brightness enhancement prism sheet, and an upper diffuser. They work together to achieve light homogenization, convergence, and diffusion, ultimately forming a surface light source.

[0035] The integration of high color gamut QD-LED lamp beads in this embodiment is as follows:

[0036] One of the core features of this invention is the use of high color gamut QD-LED chips as a side-lit light source. These chips are positioned on at least one side of the light guide plate (single-sided, double-sided, or quad-sided light incidence can be configured according to display size and brightness requirements). As shown in the figure, the high color gamut QD-LED chip includes a circuit board (such as an FPC or PCB) and multiple LED chips soldered onto it using SMT technology.

[0037] The LED beads are made of green quantum dots and KSF(K2SiF6:Mn) 4+ This is a surface-mount device encapsulated with a composite luminescent material of phosphor. This composite solution combines the advantages of high color purity of quantum dots and high stability of KSF phosphor, enabling the generation of highly saturated green light. This green light, together with the blue light emitted by the blue LED chip itself and the red light converted from red quantum dots, constitutes the three primary colors, thereby achieving an ultra-high color gamut of over 90% NTSC.

[0038] The core functions of the multi-layer encapsulation structure and light guide protective layer in this embodiment are as follows:

[0039] To ensure that the aforementioned quantum dot materials, which are extremely sensitive to water and oxygen, can work stably for a long time in harsh automotive environments (such as temperature cycling from -40°C to 105°C, high humidity, and vibration), this invention designs a multi-layer protection and optical coupling structure.

[0040] First, a silicone encapsulation layer is formed on the circuit board with soldered LED beads using a high-precision dispensing or molding process. The silicone material is preferably a high-transmittance, yellowing-resistant, and heat-aging-resistant organic silicone. Its main functions are: first, to physically isolate the LED beads and their internal quantum dot materials from the external environment, providing basic water and oxygen barriers; second, as a primary optical structure, to perform initial shaping of the light emitted by the LED.

[0041] Secondly, and this is the key innovation of the invention, lies in the provision of a light-guiding protective layer. This layer is formed directly on the light-emitting surface of the silicone encapsulation layer and serves as an interface medium connecting to the light-incident side of the light guide plate. Its core function is reflected in the following two dimensions:

[0042] Optical coupling and conduction (light guiding function): The material of the light guide protective layer is carefully selected, and its refractive index is designed to be between that of the silicone encapsulation layer and the light guide plate, forming a gradual refractive index transition zone. This significantly reduces Fresnel reflection loss caused by refractive index mismatch at multiple interfaces of "silicone encapsulation layer / air / light guide plate" after light is emitted from the LED. More preferably, the reflectivity of the light guide protective layer is controlled to be less than or equal to the reflectivity of the light guide plate. This characteristic ensures that the light emitted from the QD-LED LED can be coupled into the interior of the light guide plate with extremely high efficiency, without damage or with low damage, greatly improving light utilization and thus indirectly improving the overall brightness and color gamut performance of the module.

[0043] Mechanical Connection and Stress Buffering (Protective Function): The light guide protective layer simultaneously serves as a robust mechanical connection layer and a stress buffer layer. Due to its excellent adhesion to both the silicone encapsulation layer and the light guide plate, it firmly integrates the "light strip" and "light guide plate" components, which might otherwise have physical gaps, into a single structure. This integrated design effectively resists continuous vibrations and impacts generated during vehicle operation, preventing the connection between the light strip and the light guide plate from loosening. Simultaneously, the material of this layer possesses a certain elastic modulus, capable of absorbing and dispersing the internal stress caused by the different thermal expansion coefficients of the components (such as the metal backplate, plastic light guide plate, and silicone) during drastic temperature changes, preventing cracking or peeling at the interface and thus ensuring long-term reliability.

[0044] The integrated manufacturing of the light guide protective layer and optical microstructure in this embodiment is as follows:

[0045] Optical microstructures can be further integrated into the light-emitting surface of the light guide protective layer (i.e., the surface in contact with the light guide plate) or at the interface between the silicone encapsulation layer and the light guide protective layer to achieve more precise light control. The formation process of this microstructure is closely integrated with the molding process of the light guide protective layer.

[0046] In a preferred embodiment, the light-guiding protective layer is integrally formed with the silicone encapsulation layer using a nanoimprinting process or a photoresist template transfer process. Specifically, before the silicone encapsulation layer is fully cured after dispensing (in a semi-fluid or gel state), a mold (such as a nickel plate) with a preset negative microstructure pattern is used to imprint the surface. After imprinting, the light-guiding protective layer is formed by coating or other methods, or the material of the light-guiding protective layer is directly filled into the microstructure of the mold during the imprinting process. After ultraviolet (UV) curing or thermal curing, the mold is demolded, thereby integrally forming a high-precision optical microstructure at the interface.

[0047] The specific morphology of the optical microstructure can be selected according to the optical target:

[0048] Implementation Scheme 1: The optical microstructure is a V-shaped groove structure arranged continuously or at intervals. The opening of the V-shaped groove faces the light guide plate. When some of the large-angle light emitted by the LED is incident on the inclined surface of the V-shaped groove, total internal reflection or specular reflection will occur, thereby changing the direction of light propagation, redirecting it and capturing it inside the light guide plate, reducing side light leakage, improving the utilization rate of the light source and the uniformity of the light incident side of the light guide plate.

[0049] Implementation Scheme 2: The optical microstructure is a microlens array structure. This array may include one of a convex lens, a Fresnel lens, or a freeform lens. The microlens array can collimate (reduce the light emission angle), converge (increase center brightness), or moderately diffuse (eliminate bright spots in the LED) the Lambertian distribution light emitted by the LED, thereby pre-processing the light before it enters the light guide plate, contributing to a higher uniformity and higher brightness light emission effect.

[0050] Enhanced barrier and reflection structure

[0051] To further improve the overall module, especially the long-term environmental reliability of the quantum dot material, this invention also introduces an enhanced barrier and reflection structure.

[0052] In this embodiment, a nano-barrier layer is embedded within the silicone encapsulation layer. This barrier layer is not a uniformly dispersed filler, but rather a multi-layered nanostructure formed by alternating stacking of metal oxides (such as Al2O3) and non-metal oxides (such as SiO2) using processes such as atomic layer deposition (ALD) or plasma-enhanced chemical vapor deposition (PECVD). Water and oxygen molecules experience extremely tortuous paths when penetrating this "maze-like" multi-layered structure, thus being significantly slowed down. In a specific embodiment, the nano-barrier layer is a structure formed by alternating stacking of Al2O3 and SiO2 layers, with a single layer thickness controlled at 20-40 nm and a total number of 1-5 layers. This structure can achieve water and oxygen barrier capabilities equivalent to millimeter-level high-quality barrier adhesives (WVTR < 10) within a micrometer-thick silicone layer. -5 g / m 2 / day).

[0053] In this embodiment, a photonic crystal reflector has a photonic crystal structure layer on its surface. This structure layer is a nanophotonic crystal with a specific period (preferably 280-320nm). Its band structure is designed to produce a photonic bandgap effect for visible light (380nm-780nm), achieving an extremely high reflectivity of over 99%. This reflects almost all unscattered visible light back into the light guide plate, greatly improving luminous efficiency. Simultaneously, this structure has high transmittance (over 90%) for infrared light (especially above 800nm), allowing heat generated by the LED chips to pass through the reflector as infrared radiation, be absorbed by the rear panel, and dissipate, achieving photothermal separation management and effectively reducing the module's operating temperature.

[0054] The manufacturing process of this embodiment is briefly described as follows:

[0055] The manufacturing method of this backlight display module mainly includes the following steps:

[0056] 1. Providing and soldering: Providing a circuit board and soldering LED beads encapsulated with green quantum dots and KSF phosphor onto it.

[0057] 2. Forming a silicone encapsulation layer: A silicone encapsulation layer is formed on the circuit board and the LED beads thereon using a dispensing or molding process.

[0058] 3. Imprinting of optical microstructures: Before the silicone encapsulation layer cures (pre-curing stage) or during the curing process (such as mid-stage of thermosetting), the desired optical microstructure is formed by imprinting a mold with a preset pattern (such as a V-groove or microlens) onto its light-emitting surface. This step can be performed in conjunction with the coating of the light-guiding protective layer.

[0059] IV. Integration of other components: Subsequently, the light strip assembly with the light guide protective layer is assembled in sequence with the light guide plate, reflector, optical film group and back plate to complete the preparation of the entire backlight module.

[0060] In summary, this invention, through multi-dimensional collaborative innovation in materials (quantum dot composite phosphor, nano barrier layer, photonic crystal), structure (light guide protective layer, integrated connection, microstructure), and process (nanoimaging integrated molding), systematically solves the core challenges of high color gamut QD-LED technology in automotive applications, such as reliability, light quality, and mechanical durability, and successfully provides a high-performance backlight solution that meets automotive-grade requirements.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high color gamut QD-LED backlight display module for vehicle, comprising a back plate, a reflective sheet arranged on the back plate, a light guide plate arranged on the reflective sheet, and an optical film set arranged in the light guide plate in sequence, characterized in that: the backlight display module further comprises a high color gamut QD-LED lamp bead arranged as a side-in type light source at at least one side of the light guide plate; the high color gamut QD-LED lamp bead comprises a circuit board and a plurality of LED lamp beads welded on the circuit board; the LED lamp bead is a patch device packaged with a composite light emitting material of green quantum dots and KSF fluorescent powder; the circuit board and the LED lamp beads thereon are integrally encapsulated by a layer of silica gel encapsulation layer; the silica gel encapsulation layer is connected with the light guide plate through a light guide protection layer, and an optical microstructure is arranged at the connection between the light guide protection layer and the light guide plate; the optical microstructure is a V-shaped groove structure arranged continuously or at intervals, and the opening of the V-shaped groove is directed towards the light guide plate for reflecting the light rays emitted at a large angle into the light guide plate; the optical microstructure is a microlens array structure, and the microlens array comprises one of convex lenses, Fresnel lenses or free-form surface lenses for at least one of collimation, convergence or diffusion of the emitted light rays; the reflectivity of the light guide protection layer is less than or equal to the reflectivity of the light guide plate; the light guide protection layer is integrally formed with the silica gel encapsulation layer through a nano-imprinting process or a photoresist template transfer process; the silica gel encapsulation layer is embedded with a nano-barrier layer; the nano-barrier layer is a multi-layer nano-layered structure formed by alternately stacking metal oxides and non-metal oxides; the nano-barrier layer is a structure formed by alternately stacking Al2O3 layers and SiO2 layers, the thickness of a single layer is 20-40 nm, and the total number of layers is 1-5 layers; the surface of the reflective sheet is provided with a photonic crystal structure layer; the photonic crystal structure layer is configured to have a reflectivity of greater than 99% for light rays in the visible light band and a transmittance of greater than 90% for light rays in the infrared band; the period of the photonic crystal structure layer is 280-320 nm; and the backlight display module is manufactured by the following steps: providing a circuit board and welding LED lamp beads thereon; forming a silica gel encapsulation layer on the circuit board and the lamp beads by a dispensing process or a molding process; and pressing and forming the optical microstructure on the light emitting surface of the silica gel encapsulation layer by a mold with a preset pattern before or during curing of the silica gel encapsulation layer. ​ ​ ​ ​ ​ 2.The high color gamut QD-LED backlight display module for vehicle according to claim 1, characterized in that, ​ 3.The high color gamut QD-LED backlight display module for vehicle according to claim 1, characterized in that, ​ 4.The high color gamut QD-LED backlight display module for vehicle according to claim 1, characterized in that, ​ 5.The high color gamut QD-LED backlight display module for vehicle according to claim 4, characterized in that, ​ 6.The high color gamut QD-LED backlight display module for vehicle according to claim 1, characterized in that, ​ ​ 7.The high color gamut QD-LED backlight display module for vehicle according to claim 6, characterized in that, ​ 8.The high color gamut QD-LED backlight display module for vehicle according to claim 1, characterized in that, ​ ​ 9.The high color gamut QD-LED backlight display module for vehicle according to claim 8, characterized in that, ​ 10.The high color gamut QD-LED backlight display module for vehicle according to claim 1, characterized in that, ​ ​ ​ ​

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