Full-color mini / micro LED display screen

Abstract

The utility model provides a full-color mini / micro LED display screen. The full-color mini / micro LED display screen comprises a substrate, a light-emitting chip array, a fluorescent powder film layer and a quantum dot packaging film layer, wherein the light-emitting chip array comprises a plurality of light-emitting chips, the plurality of light-emitting chips are uniformly distributed on the substrate, the fluorescent powder film layer is arranged above the light-emitting chip array, and the quantum dot packaging film layer is arranged above the fluorescent powder film layer. By adopting the technical scheme of the utility model, the mini / micro LED full-color display can be realized, the influence of higher junction temperature of the light-emitting chip on the stability of the quantum dots is avoided, the quality of the LED display screen is improved, the driving complexity can be reduced, the production yield is improved, and the cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of LED packaging technology, specifically to a full-color mini / micro LED display screen. Background Technology

[0002] Current Mini / Micro LEDs are achieved using LED arrays, where each pixel is much smaller than that of a traditional LED. Their applications are wide-ranging, including smartwatch / phone displays, tablets, laptops, monitors, televisions, and near-eye displays such as AR / VR (Augmented Reality / Virtual Reality). However, Mini / Micro LEDs face challenges in mass transfer and production yield, and the increased complexity of driving mechanisms leads to high production costs.

[0003] The current feasible approach is to integrate a single blue mini / micro LED with a quantum dot (QD) color conversion layer, thereby simplifying the manufacturing process, improving yield, simplifying driving, and reducing production costs. However, current mini / micro LED display products operate at chip junction temperatures of 80-120℃, which significantly impacts the lifespan and color conversion efficiency of the quantum dot color conversion layer. This leads to a rapid decline in the overall stability of the quantum dot color conversion layer, affecting its overall lifespan.

[0004] Another approach is to use a blue LED with red and green phosphors to form white light, and then use a color filter to form a color display. However, the red phosphors used in this method are mostly nitrides (such as Sr2Si5N8:Eu2+), which usually need to be prepared under high temperature and high pressure, resulting in high cost, and their quantum efficiency and stability are not ideal. Utility Model Content

[0005] To better address the aforementioned issues, this invention provides a full-color mini / micro LED display screen, which enables full-color display of mini / micro LEDs and avoids the impact of high junction temperature of the light-emitting chip on the stability of quantum dots, thereby improving the quality of the LED display screen.

[0006] To achieve the above objectives, an embodiment of this utility model provides a full-color mini / micro LED display screen, including a substrate, a light-emitting chip array, a phosphor film layer, and a quantum dot encapsulation film layer; wherein, the light-emitting chip array includes multiple light-emitting chips, which are evenly distributed on the substrate, the phosphor film layer is disposed above the light-emitting chip array, and the quantum dot encapsulation film layer is disposed above the phosphor film layer.

[0007] Optionally, the light-emitting chip is a blue LED chip, the phosphor film layer contains green phosphor, and the quantum dot encapsulation film layer includes LED encapsulating adhesive containing red quantum dots.

[0008] Optionally, the light-emitting chip is an ultraviolet LED chip, the phosphor film layer contains blue phosphor, and the quantum dot encapsulation film layer includes LED encapsulating adhesive containing red and green quantum dots.

[0009] Optionally, multiple light-emitting chips are arranged on the substrate in a row or column, spaced apart from each other.

[0010] Optionally, it also includes a filler that fills the gaps between the multiple light-emitting chips on the substrate.

[0011] Optionally, it also includes a filter layer disposed above the quantum dot encapsulation layer.

[0012] The full-color mini / micro LED display screen of this utility model consists of a light-emitting structure formed by sequentially arranging a light-emitting chip array, a phosphor film layer, a quantum dot encapsulation film layer, and a filter layer. By adjusting the color and amount of the light-emitting chip, phosphor, and quantum dot materials, a white light source containing red, green, and blue can be formed, which can be used for healthy lighting. With the help of a filter, a full-color display with high color reproduction can be achieved.

[0013] Furthermore, by isolating the light-emitting chip from the quantum dot encapsulation film through a phosphor layer, the phosphor layer can block the heat generated by the light-emitting chip, which can significantly reduce the impact of the light-emitting chip's operating temperature on the quantum dot, improve the stability of the quantum dot, thereby increasing the lifespan and color conversion efficiency of the quantum dot film, solving the problem of decreased overall reliability of the quantum dot film due to high junction temperature of the light-emitting chip, and improving the quality of the LED display screen.

[0014] Furthermore, the light-emitting structure of this full-color mini / micro LED display simplifies the problem of mass transfer of three-primary-color LED chips, improves production yield, and reduces costs; it can also use same-color light-emitting chips, which can significantly reduce driving complexity; and it can also avoid the problems of poor efficiency and high cost caused by phosphors prepared under high temperature and high pressure conditions. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1This is a structural schematic diagram of a full-color mini / micro LED display screen according to an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram illustrating the manufacturing process of a full-color mini / micro LED display screen according to an embodiment of this utility model.

[0018] Figure label:

[0019] 1. Substrate; 2. Light-emitting chip; 3. Filler; 4. Phosphor film; 5. Quantum dot encapsulation film; 6. Filter layer; 7. Quantum dot. Detailed Implementation

[0020] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the implementations of the base model disclosed below.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] like Figure 1 As shown, the full-color mini / micro LED display screen of this utility model embodiment includes a substrate 1, a light-emitting chip array, a phosphor film layer 4, and a quantum dot encapsulation film layer 5; wherein, the light-emitting chip array includes multiple light-emitting chips 2, which are evenly distributed on the substrate 1, the phosphor film layer 4 is disposed above the light-emitting chip array, and the quantum dot encapsulation film layer 5 is disposed above the phosphor film layer 4 and spaced at a certain distance from the phosphor film layer 4.

[0023] In this embodiment of the full-color mini / micro LED display, substrate 1 is located at the bottom layer. On substrate 1, an array of light-emitting chips, a phosphor film layer 4, and a quantum dot encapsulation film layer 5 are arranged sequentially. The light emitted by the light-emitting chip 2 causes the phosphor to emit light, and the light shining on the quantum dot encapsulation film layer 5 excites the quantum dots 7 to emit light, forming a light-emitting structure of light-emitting chip-phosphor-quantum dot. Based on this structure, different colors of light-emitting chips 2, phosphors, and quantum dots 7 can be configured to ultimately form different colors of illumination, achieving a full-color mini / micro LED display with high color reproducibility. This structure can greatly simplify the problem of mass transfer of three-primary-color LED chips, improve production yield, and reduce costs; since the same color light-emitting chip 2 can be used on substrate 1, the driving complexity can be greatly simplified. Meanwhile, this structure uses a phosphor film layer 4 to isolate the light-emitting chip 2 from the quantum dots, which can isolate the heat generated by the light-emitting chip 2, significantly reduce the impact of the operating temperature of the light-emitting chip 2 on the quantum dots, improve the stability of the quantum dots, and ensure the lifespan and color conversion efficiency of the quantum dot film. This solves the problem of the overall reliability (lifespan and color conversion efficiency) of the quantum dot film caused by the high junction temperature of the light-emitting chip, and improves the quality of the LED display screen.

[0024] In one optional embodiment, the light-emitting chip 2 is a blue LED chip, the phosphor film layer 4 contains green phosphor, and the quantum dot encapsulation film layer 5 includes LED encapsulating adhesive containing red quantum dots. The light-emitting chip 2 emits blue light, the phosphor emits light to form a blue-green mixed light, and the red quantum dots are excited to emit red light to form a white light source containing red, green, and blue. The green phosphor may include materials such as aluminates or silicates, which absorb blue light and emit green light with a wavelength of 510-540 nm.

[0025] In another optional embodiment, the light-emitting chip 2 is an ultraviolet LED chip, the phosphor film layer 4 contains blue phosphor, and the quantum dot encapsulation film layer 5 includes LED encapsulating adhesive containing red and green quantum dots. The light-emitting chip 2 emits ultraviolet light, the phosphor emits light to form blue light, and the red and green quantum dots are excited to emit red light, forming a white light source containing red, green, and blue.

[0026] This embodiment of the full-color mini / micro LED display screen is a lighting fixture structure for LED lighting. It can be adjusted using various colors of phosphors and other nano-luminescent materials to form a better white light source for healthy lighting. To achieve color display, the full-color mini / micro LED display screen may also include a filter layer 6. The filter layer 6 is disposed above the quantum dot encapsulation layer and is formed by sequentially arranging the light-emitting chip array, phosphor film layer 4, quantum dot encapsulation film layer 5, and filter layer 6. The filter layer 6 is located at the end and filters the white light source containing red, green, and blue colors to achieve color display.

[0027] like Figure 2 As shown, taking the structure of substrate-blue light-emitting chip-green phosphor film-red quantum dot encapsulation film-filter layer as an example, the fabrication process of this full-color mini / micro LED display screen may include:

[0028] In the light-emitting chip transfer step, multiple blue light-emitting chips 2 are soldered onto a substrate 1 to form an array. The substrate 1 can be made of a PCB substrate, glass, sapphire, etc. The light-emitting chips 2 of the array can be transferred onto the substrate 1 by soldering, with the light-emitting side facing upwards. The multiple light-emitting chips 2 are spaced apart from each other and arranged in rows and columns to form an array.

[0029] Planarization step: Filler 3 is used to fill the gaps between the light-emitting chips 2 and on the outer side of the light-emitting chips 2 (at the edge of the substrate 1). The height of the filler 3 is consistent with the height of the light-emitting chips 2. This planarization and fixing process is performed on the light-emitting chip array, and the filler 3 and the light-emitting chips 2 form a planarization layer. Here, the filler 3 can be made of a material with a certain thermal conductivity to assist in chip heat dissipation; it can be transparent or opaque, preferably a black material, which can cover the problem of inconsistent colors between the metal lines and the substrate. For example, the filler 3 can be made of epoxy resin or silicone, and can be cured by light or heat curing.

[0030] Phosphor film preparation steps: Green phosphor can be added to an organic polymer material with poor thermal properties (such as polypropylene block polymer materials) and cured to form a phosphor film. Preferably, to increase photoluminescence efficiency and adjust the blue-green light ratio, nanoparticles, such as silicon oxide and titanium oxide, are uniformly mixed into the phosphor. It should be noted that the thickness of the phosphor film 4 can be adjusted according to the requirements of blue-green light ratio, brightness, etc., and the composition and film thickness can be adjusted accordingly; a typical thickness is 1 micrometer. The prepared phosphor film 4 is then adhered to the upper side of the planarization layer.

[0031] The quantum dot encapsulation film preparation steps are as follows: Synthesized nanoluminescent materials are mixed into polymers such as polyacrylic acid and epoxy resin to form a uniformly dispersed precursor material, which is then cured after film formation. The nanoluminescent materials are excited by blue and green light, emitting red light within the 620-630 nm wavelength range. To adjust the proportion of each color and the light emission direction, oxide nanomaterials are added. Therefore, the precursor solution for this encapsulation film contains polymers, quantum dots, and oxide nanomaterials. The nanoluminescent materials include quantum dots, nanorods, and nanosheets, and the material systems include, but are not limited to, mononuclear nanoluminescent materials such as CdSe, CdTe, CdS, ZnSe, ZnTe, ZnS, CuInS, CuInSeS, AgInS, AgInSeS, InP, CuZnSe, ZnMnSe, PbS, PbSe, Cd-based alloys, In-based alloys, Zn-based alloys, or perovskite materials. The oxide nanomaterials include, but are not limited to, silicon oxide, titanium oxide, and zirconium oxide. The thickness of the quantum dot encapsulation film 5 is adjustable, typically ranging from 2 to 3 micrometers. The prepared quantum dot encapsulation film 5 is then attached to the upper side of the phosphor film 4.

[0032] Fabrication steps of the filter layer: The filter layer 6 is a color group layer array of filters. The specific fabrication method can be as follows: First, spin-coating is used to form a color resist layer photoresist film of one color. Then, a photomask with a specific pattern is used for exposure and development to form a color resist layer pattern of that color. Then, the same method is repeated to form color resist layer patterns of the other two colors. The fabricated filter layer 6 is placed above the quantum dot encapsulation film layer 5 (at a certain distance from the quantum dot encapsulation film layer 5).

[0033] In practical applications, the substrate 1, light-emitting chip 2, phosphor, quantum dot material, etc., in the full-color mini / micro LED display of this embodiment can all be made using existing devices with corresponding functions, according to the actual display color requirements. Furthermore, other devices or components can be added to the full-color mini / micro LED display, or the actual installation positions of each device or component can be adjusted to achieve the actual application or other functions of the full-color mini / micro LED display. For example, it also includes an external lampshade or display bracket (transparent or non-transparent).

[0034] It should be noted that, depending on the implementation needs, the various components described in the embodiments of this utility model can be split into more components, or two or more components or parts of components can be combined into new components to achieve the purpose of the embodiments of this utility model.

[0035] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A full-color mini / micro LED display screen, characterized in that, The device includes a substrate, a light-emitting chip array, a phosphor film layer, and a quantum dot encapsulation film layer. The light-emitting chip array comprises multiple light-emitting chips evenly distributed on the substrate. The phosphor film layer is disposed above the light-emitting chip array, and the quantum dot encapsulation film layer is disposed above the phosphor film layer. On the substrate, the light-emitting chip array, phosphor film layer, and quantum dot encapsulation film layer are arranged sequentially. Light emitted by the light-emitting chips causes the phosphor to emit light, and light illuminating the quantum dot encapsulation film layer excites the quantum dots to emit light, forming a light-emitting chip-phosphor-quantum dot light-emitting structure. By configuring light-emitting chips, phosphors, and quantum dots of different colors, different colors of light can be generated. It also includes a filter layer, which is disposed above the quantum dot encapsulation layer. The filter layer is formed by sequentially arranging the light-emitting chip array, phosphor film layer, quantum dot encapsulation film layer and filter layer to form a light-emitting structure, which filters the white light source containing red, green and blue colors to achieve color display.

2. A full-color mini / micro LED display screen according to claim 1, characterized in that, The light-emitting chip is a blue LED chip, the phosphor film layer contains green phosphor, and the quantum dot encapsulation film layer includes LED encapsulating adhesive containing red quantum dots.

3. A full-color mini / micro LED display screen according to claim 1, characterized in that, The light-emitting chip is an ultraviolet LED chip, the phosphor film layer contains blue phosphor, and the quantum dot encapsulation film layer includes LED encapsulating adhesive containing red and green quantum dots.

4. A full-color mini / micro LED display screen according to claim 1, characterized in that... The plurality of light-emitting chips are arranged on the substrate in a row or column with spacing between them.

5. A full-color mini / micro LED display screen according to claim 4, characterized in that, It also includes fillers, which fill the gaps between multiple light-emitting chips on the substrate.

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