LED module, manufacturing method thereof, and display screen

Abstract

The present application proposes an LED module, a preparation method thereof, and a display screen, wherein the LED module includes a light-emitting panel, an encapsulation colloid layer, and an optical coating. The encapsulation colloid layer is arranged on the front of the light-emitting panel, and the optical coating is arranged on the encapsulation colloid layer. The refractive index of the optical coating is smaller than the refractive index of the encapsulation colloid layer. The refractive index of the encapsulation colloid layer decreases successively from the light-emitting panel to the optical coating, thereby reducing the refractive index difference between the encapsulation structure on the surface of the light-emitting panel and the air interface, thereby increasing the light output efficiency of the panel.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and in particular relates to an LED module, a preparation method thereof, and a display screen. Background Art

[0002] LED displays feature high brightness, vivid colors, high luminous efficiency, high contrast, short response time, a wide operating temperature range, and low energy consumption. They are widely used in stage display equipment, advertising display equipment, data visualization display equipment, and commercial display equipment. Structurally, LED displays are first composed of several independent LED lamps connected by PCB circuits to form an LED display panel. Multiple display panels are then spliced ​​into independent cabinets. Finally, multiple independent cabinets are spliced ​​into the final complete screen. This special structure gives LED displays the significant advantages of flexible application in a variety of scenarios and high display integrity. Micro LED displays using COB and MIP packaging technologies are emerging in the industry. In terms of process, Micro LED displays first bond chip-level LED pixel particles to the PCB board, and then directly package the entire panel. Compared with traditional SMD LED displays, Micro LED displays have a shorter process chain and are easier to achieve ultra-fine pitch.

[0003] However, due to the unavoidable chip skew during the Micro LED panel die bonding process, the light emission angles of the LED chips in each pixel vary, resulting in screen artifacts and pitting. The industry's common solution is to add a high proportion of diffuser to the panel encapsulation adhesive to achieve a uniform light effect. However, while the diffuser scatters the light emitted by the chip, it also reflects external light, causing the panel to appear whitish and severely reducing the display contrast. Secondly, because the refractive index of the epoxy resin used for light-emitting panel encapsulation is mostly between 1.55 and 1.65, while the refractive index of air is close to 1, with a refractive index difference of 0.55-0.65, a considerable proportion of the chip light is fully reflected at the epoxy-air interface, reducing the panel's light extraction efficiency. Summary of the Invention

[0004] The purpose of this application is to provide an LED module and a preparation method thereof, and a display screen, aiming to solve the problem of low light extraction efficiency of the LED packaging structure in the related art.

[0005] A first aspect of an embodiment of the present application provides an LED module, comprising:

[0006] Luminous panels;

[0007] an encapsulation colloid layer, disposed on the front surface of the light-emitting panel;

[0008] an optical coating, the optical coating being disposed on the encapsulating colloid layer, and having a refractive index smaller than that of the encapsulating colloid layer; light emitted by the light-emitting panel when lit is refracted through the encapsulating colloid layer and the optical coating;

[0009] The refractive index of the encapsulation colloid layer decreases gradually from the light emitting panel to the optical coating.

[0010] In some embodiments, the encapsulating colloid layer comprises:

[0011] a first colloid layer formed on the front surface of the light-emitting panel and configured to refract light emitted by the light-emitting panel;

[0012] a second colloid layer formed between the first colloid layer and the optical coating layer, and configured to refract the light emitted from the first colloid layer and output the light to the optical coating layer;

[0013] The refractive index of the first colloid layer is greater than the refractive index of the second colloid layer.

[0014] In some embodiments, the light emitting panel includes a plurality of micro light emitting diode chips, and the first colloid layer is further filled between adjacent micro light emitting diode chips; and / or

[0015] The thickness of the first colloid layer is 1.2-1.5 times the thickness of the micro-LED chip; and / or

[0016] The thickness of the second colloid layer is 0.5-1 times the thickness of the first colloid layer; and / or

[0017] The encapsulating colloid in the first colloid layer is at least one of epoxy resin, polyurethane resin and acrylic resin; and / or

[0018] The refractive index of the encapsulated colloid in the first colloid layer is 1.5-1.7; and / or

[0019] The encapsulating colloid in the second colloid layer is an organic silicone resin; and / or

[0020] The refractive index of the encapsulating colloid in the second colloid layer is 1.4-1.5.

[0021] In some embodiments, diffusion particles are provided in the first colloid layer and the second colloid layer, the particle size of the diffusion particles is less than 10 μm, and the proportion of the diffusion particles is 2%-10%; and / or

[0022] The proportion of the diffusion particles in the first colloid layer is less than 1%, and the refractive index of the diffusion particles in the first colloid layer is greater than 1.9; and / or

[0023] The proportion of the diffusion particles in the second colloid layer is 1%-3%, and the refractive index of the diffusion particles in the second colloid layer is less than 1.7.

[0024] In some embodiments, the optical coating has a refractive index of 1.3-1.4; and / or

[0025] The thickness of the optical coating is 2-10 μm; and / or

[0026] The optical coating comprises magnesium fluoride and a fluorinated polymer.

[0027] In some embodiments, diffusion particles are provided in the encapsulation colloid layer, and the diffusion particles in the encapsulation colloid layer are distributed gradually in a direction from the light-emitting panel to the optical coating.

[0028] In some embodiments, the encapsulating colloid layer includes a plurality of encapsulating colloid regions stacked in sequence, and a proportion of diffusion particles in the plurality of encapsulating colloid regions gradually decreases in a direction from the light emitting panel toward the optical coating.

[0029] In some embodiments, the proportions of the diffusion particles in the plurality of encapsulation colloid regions are arranged in an arithmetic progression in a direction from the light emitting panel to the optical coating; and / or

[0030] The diffusion particles in the plurality of encapsulating colloid regions are charged, and the charge of the diffusion particles in the plurality of encapsulating colloid regions gradually increases in a direction from the light emitting panel to the optical coating; and / or

[0031] The diffusion particles in the plurality of encapsulated colloid regions are charged, and the charges of the diffusion particles in the plurality of encapsulated colloid regions are arranged in an arithmetic progression in a direction from the light emitting panel to the optical coating.

[0032] A second aspect of the present application further provides a method for preparing an LED module, the method comprising:

[0033] Adding diffusion particles with different charge amounts into the encapsulation glue, mixing and dispersing them, and then dispensing them on the light-emitting panel;

[0034] Using a mold to shape the packaging glue;

[0035] Applying an electric field on both sides of the light-emitting panel, wherein the direction of the electric field is from close to the light-emitting panel to away from the light-emitting panel;

[0036] After applying the electric field for a preset time, the packaging glue is cured and the mold is removed.

[0037] A third aspect of the embodiments of the present application further provides a display screen, comprising the LED module as described in any of the above embodiments; or comprising the LED module prepared by the preparation method as described in the above embodiments.

[0038] The beneficial effects of the embodiments of the present application compared with the prior art are as follows: the LED module includes a light-emitting panel, an encapsulation colloid layer, and an optical coating; the encapsulation colloid layer is arranged on the front of the light-emitting panel, and the optical coating is arranged on the encapsulation colloid layer, and the refractive index of the optical coating is smaller than the refractive index of the encapsulation colloid layer; the refractive index of the encapsulation colloid layer decreases successively from the light-emitting panel to the optical coating, thereby reducing the refractive index difference between the encapsulation structure on the surface of the light-emitting panel and the air interface, and increasing the light output efficiency of the panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0040] Figure 1 Schematic diagram of the structure of the LED module provided in the embodiment of the present application Figure 1 ;

[0041] Figure 2 Schematic diagram of the structure of the LED module provided in the embodiment of the present application Figure 2 ;

[0042] Figure 3 Schematic diagram of the structure of the LED module provided in the embodiment of the present application Figure 3 ;

[0043] Figure 4 Schematic diagram of the structure of the LED module provided in the embodiment of the present application Figure 4 ;

[0044] Figure 5 A schematic diagram of a method for preparing an LED module provided in an embodiment of the present application;

[0045] Figure 6 A schematic structural diagram of a light-emitting panel provided in an embodiment of the present application;

[0046] Figure 7 A schematic structural diagram of a light-emitting panel provided in an embodiment of the present application;

[0047] Figure 8 A schematic diagram of the structure of the packaging adhesive after shaping provided in an embodiment of the present application;

[0048] Figure 9A schematic diagram of the structure after an electric field is applied to the packaging glue provided in an embodiment of the present application;

[0049] Figure 10 This is a schematic structural diagram of forming an optical coating on the encapsulation colloid layer after removing the mold provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0051] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0052] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0054] Due to the unavoidable chip skew problem during the Micro LED panel die bonding process, the light emission angle of the LED chip in each pixel varies, resulting in screen artifacts and pitting. The common solution in the industry is to add a high proportion of diffuser to the panel encapsulation adhesive to achieve a uniform light effect. However, while the diffuser scatters the light emitted by the chip, it also reflects external light, causing the panel to turn white and seriously reducing the display contrast. Secondly, because the refractive index of the epoxy resin used for light-emitting panel encapsulation is mostly between 1.55 and 1.65, while the refractive index of air is close to 1, the refractive index difference reaches 0.55-0.65. A considerable proportion of the chip light is totally reflected at the epoxy-air interface, reducing the panel's light extraction efficiency.

[0055] In order to solve the above technical problems, the present application embodiment proposes an LED module, see Figure 1 As shown, the LED module in this embodiment includes: a light-emitting panel 400, an encapsulant layer 200, and an optical coating 100. The encapsulant layer 200 and the optical coating 100 are stacked and arranged on the front surface of the light-emitting panel 400. The optical coating 100 is arranged on the encapsulant layer 200, and the refractive index of the optical coating 100 is lower than the refractive index of the encapsulant layer 200. When the light-emitting panel 400 is turned on, the light is refracted by the encapsulant layer 200 and the optical coating 100 and then emitted into the air. The refractive index of the encapsulant layer 200 decreases in the direction from the light-emitting panel 400 to the optical coating 100.

[0056] In this embodiment, the light-emitting panel 400 can be driven by a driving circuit to illuminate, and emit light when illuminated. The encapsulation colloid layer 200 and the optical coating 100 refract the light emitted by the light-emitting panel 400. The encapsulation colloid layer 200 is divided into multiple layers. By setting the refractive index of the multiple layers of the encapsulation colloid layer 200 to decrease in sequence from the light-emitting panel 400 to the optical coating 100, the refractive index difference between the encapsulation structure on the surface of the light-emitting panel 400 and the air interface is reduced. This reduces the total internal reflection of the light emitted from the light-emitting panel 400 at the interface between the encapsulation colloid layer 200 and the optical coating 100, as well as between the optical coating 100 and the air, thereby increasing the light extraction efficiency of the LED module.

[0057] In some embodiments, the refractive index of the optical coating 100 is less than the refractive index of the encapsulation colloid layer 200, and the refractive index of the optical coating 100 is greater than the refractive index of the air. This allows the light emitted by the light-emitting panel 400 when it is turned on to be refracted step by step through the encapsulation colloid layer 200 and the optical coating 100 and then emitted into the air, thereby reducing the refractive index difference between the packaging structure on the surface of the light-emitting panel 400 and the air interface, and improving the light extraction efficiency of the light-emitting panel 400.

[0058] In some embodiments, the difference between the refractive index of the optical coating 100 and the refractive index of air is less than 30% of the optical coating 100. In this way, the refractive index of the optical coating 100 and the air can be kept within a smaller range, thereby reducing the occurrence of total internal reflection at the interface between the optical coating 100 and the air, and improving the light extraction efficiency of the LED module.

[0059] In some embodiments, see Figure 1As shown, the light-emitting panel includes a driver board 420, solder resist ink 410, a driver chip 430, and a micro-LED chip 450. The micro-LED chip 450 is fixed to the front of the driver board 420 via solder pads 440. The solder resist ink 410 is disposed on the front of the driver board 420 and is located between adjacent solder pads 440. This protects the driver board 420 and prevents components on the front of the driver board 420 from bridging interconnections, thereby avoiding problems such as short circuits in the wiring on the front of the driver board 420. The driver chip 430 is disposed on the back of the driver board 420. The driver chip 430 and its peripheral components constitute a driver circuit for driving the light-emitting panel 400 to illuminate. Specifically, the driver circuit can be connected to corresponding solder pads on the front of the driver board 420 via wiring within the driver board 420, providing a driving signal to the corresponding micro-LED chip 450 on the front of the light-emitting panel 400. The encapsulation colloid layer 200 completely covers the micro-LED chip 450.

[0060] In some embodiments, the encapsulating colloid layer 200 includes a plurality of colloid layers stacked in sequence, and the refractive indices of the plurality of colloid layers decrease in sequence from the light emitting panel 400 to the optical coating 100 .

[0061] In this embodiment, by disposing multiple colloid layers with gradually decreasing refractive indices in the direction from the light-emitting panel 400 toward the optical coating 100, the light emitted from the light-emitting panel 400 can be gradually reduced between the multiple colloid layers, thereby avoiding a sudden drop in the refractive index at the interface between the light-emitting panel 400 and the encapsulating colloid layer 200, and reducing the probability of total internal reflection within the encapsulating colloid layer 200. In this embodiment, the multiple colloid layers with gradually decreasing refractive indices effectively reduce the refractive index difference between the optical coating 100 and air, reducing total internal reflection of the light emitted from the light-emitting panel 400 at the interfaces between the colloid layers and the optical coating 100, as well as between the optical coatings 100, thereby increasing the light extraction efficiency of the LED module.

[0062] In some embodiments, combined Figure 2 As shown, the encapsulation colloid layer 200 includes: a first colloid layer 210 and a second colloid layer 220. The first colloid layer 210 is formed on the front of the light-emitting panel 400, and the first colloid layer 210 is used to refract the light emitted by the light-emitting panel 400; the second colloid layer 220 is formed between the first colloid layer 210 and the optical coating 100, and the second colloid layer 220 is used to refract the light emitted by the first colloid layer 210 and output it to the optical coating 100; the refractive index of the first colloid layer 210 is greater than the refractive index of the second colloid layer 220.

[0063] In this embodiment, the first colloid layer 210 is formed on the front of the light-emitting panel 400 and completely covers the micro-LED chip 450 in the light-emitting panel 400. The second colloid layer 220 is formed between the first colloid layer 210 and the optical coating 100. The refractive index of the first colloid layer 210 is greater than the refractive index of the second colloid layer 220, and the refractive index of the second colloid layer 220 is greater than the refractive index of the optical coating 100. The second colloid layer 220 buffers the refractive index difference between the first colloid layer 210 and the optical coating 100, thereby avoiding the problem of total reflection caused by the excessive refractive index difference between the two interfaces of the encapsulated colloid layer 200.

[0064] In some embodiments, the interface between the first colloid layer 210 and the second colloid layer 220 may be wavy.

[0065] In some embodiments, combined Figure 1 As shown, the main structure of the micro LED chip 450 is a cube or a cuboid, has five-side light emitting characteristics, and is welded on the front surface of the driving board 420.

[0066] In some embodiments, the light emitting panel 400 includes a plurality of micro LED chips 450 , and the first colloid layer 210 is further filled between adjacent micro LED chips 450 .

[0067] In this embodiment, the first colloid layer 210 wraps the micro-LED chip 450. The light emitted from the five sides of the micro-LED chip 450 is refracted by the first colloid layer 210 and enters the second colloid layer 220. Then, the light is emitted through the second colloid layer 220 and the optical coating 100. This can improve the light extraction efficiency of the LED module.

[0068] In some embodiments, the thickness of the first colloid layer 210 is 1.2-1.5 times the thickness of the micro LED chip 450 .

[0069] In some embodiments, the thickness of the second colloid layer 220 is 0.5-1 times the thickness of the first colloid layer 210 .

[0070] In some embodiments, the encapsulating colloid in the first colloid layer 210 is at least one of epoxy resin, polyurethane resin, and acrylic resin.

[0071] In some embodiments, the first colloid layer 210 can be made of a colorless transparent material with a refractive index between 1.5 and 1.7, such as epoxy resin, polyurethane resin, or acrylic resin. The thickness of the first colloid layer 210 is 1.2 to 1.5 times the thickness of the micro LED chip 450 .

[0072] In some embodiments, the refractive index of the encapsulating colloid in the first colloid layer 210 is 1.5-1.7.

[0073] In some embodiments, the encapsulating colloid in the second colloid layer 220 is silicone resin.

[0074] In some embodiments, the refractive index of the encapsulating colloid in the second colloid layer 220 is 1.4-1.5.

[0075] In some embodiments, combined Figure 3 As shown, diffusion particles are provided in the first colloid layer 210 and the second colloid layer 220 .

[0076] In some embodiments, the particle size of the diffusion particles in the first colloid layer 210 and the second colloid layer 220 is less than 10 μm, and the ratio of the diffusion particles in the first colloid layer 210 and the second colloid layer 220 is 2%-10%.

[0077] In this embodiment, diffusion particles are added to the first colloidal layer 210 and the second colloidal layer 220. The proportion of the diffusion particles in the first colloidal layer 210 and the second colloidal layer 220 is 2%-10%. The diffusion particles in the first colloidal layer 210 and the second colloidal layer 220 can be diffusion powders with a particle size of less than 10 μm, such as SiO2, TiO2, ZnO, and Al2O3.

[0078] In some embodiments, the second colloid layer 220 is a second layer of encapsulation colloid prepared closely to the first colloid layer 210 . The second colloid layer 220 can be made of a colorless transparent material such as silicone resin with a refractive index between 1.4 and 1.5. The thickness of the second colloid layer 220 is 0.5 to 1 times the thickness of the first colloid layer 210 .

[0079] In some embodiments, diffusion particles are added to the second colloid layer 220 at a ratio of 2%-10%. The diffusion particles in the second colloid layer 220 can be diffusion powders with a particle size of less than 10 μm, such as SiO 2 , TiO 2 , ZnO, and Al 2 O 3 .

[0080] In some embodiments, the refractive index of the optical coating 100 is 1.3-1.4.

[0081] In some embodiments, the optical coating 100 has a thickness of 2-10 μm.

[0082] In some embodiments, optical coating 100 includes magnesium fluoride.

[0083] In some embodiments, optical coating 100 includes a fluorinated polymer.

[0084] In some embodiments, optical coating 100 may be composed of a mixture of magnesium fluoride and a fluorinated polymer.

[0085] In this embodiment, the optical coating 100 is prepared in close contact with the second colloid layer 220. The optical coating 100 can be made of a colorless and transparent material with a refractive index between 1.3 and 1.4, such as magnesium fluoride and fluorinated polymer. The coating thickness is 2-10 μm. The refractive index of the encapsulation colloid layer 200 decreases in sequence from the light-emitting panel 400 to the optical coating 100, and the refractive index of the optical coating 100 is less than the refractive index of the encapsulation colloid layer 200, which effectively reduces the refractive index difference between the encapsulation colloid layer 200 and the air, reduces the total reflection of the light emitted by the light-emitting panel at the interface between the encapsulation colloid layer and the air, and increases the light output efficiency of the LED module.

[0086] In some embodiments, the proportion of the diffusion particles in the first colloidal layer 210 is less than 1%, and the refractive index of the diffusion particles in the first colloidal layer 210 is greater than 1.9.

[0087] In this embodiment, the first colloid layer 210 is the bottom layer of the encapsulation colloid of the light-emitting panel. The first colloid layer 210 can be made of colorless and transparent materials such as epoxy resin, polyurethane resin, acrylic resin, and silicone resin. The thickness of the first colloid layer 210 is 1.2-1.5 times that of the micro-LED chip 450.

[0088] In some embodiments, diffusion particles are added to the first colloidal layer 210 , and the proportion of the diffusion particles is less than 1%. The diffusion particles in the first colloidal layer 210 can be made of diffusion powders such as TiO 2 and ZnO with a refractive index greater than 1.9 and a particle size less than 10 μm.

[0089] In some embodiments, the proportion of the diffusion particles in the second colloid layer 220 is 1%-3%, and the refractive index of the diffusion particles in the second colloid layer 220 is less than 1.7.

[0090] In this embodiment, the second colloid layer 220 is a second layer of encapsulation colloid prepared in close contact with the first colloid layer 210. The second colloid layer 220 can be made of colorless and transparent materials such as epoxy resin, polyurethane resin, acrylic resin, and silicone resin. The thickness of the second colloid layer 220 is 0.5-1 times the thickness of the first colloid layer 210.

[0091] In some embodiments, diffusion particles are added to the second colloidal layer 220, and the proportion of the diffusion particles in the second colloidal layer 220 is 1%-3%. The diffusion particles in the second colloidal layer 220 can be made of diffusion powders such as Al2O3 and SiO2 with a refractive index of less than 1.7 and a particle size of less than 10um.

[0092] In some embodiments, the refractive index and concentration of the diffusion particles in the first colloidal layer 210 and the second colloidal layer 220 are different. The refractive index of the diffusion particles in the first colloidal layer 210 is higher, and the proportion of the diffusion particles in the first colloidal layer is lower. The refractive index of the diffusion particles in the second colloidal layer 220 is lower and the proportion is moderate. While achieving the uniform light effect, it effectively reduces the problem of the black screen and whitening of the panel and reduced contrast caused by the excessive proportion of a single diffusion powder.

[0093] In some embodiments, the refractive indices of the first colloid layer 210, the second colloid layer 220, and the optical coating 100 decrease from bottom to top, effectively reducing the refractive index difference between the packaging layer and the air, reducing the total reflection of the chip light at the interface between the packaging layer and the air, and increasing the light extraction efficiency of the LED module.

[0094] In some embodiments, combined Figure 4 As shown, diffusion particles are provided in the encapsulation colloid layer 200 , and the diffusion particles in the encapsulation colloid layer 200 are distributed gradually in a direction from the light emitting panel 400 to the optical coating 100 .

[0095] In this embodiment, different amounts of charge can be applied to the diffusion particles in the encapsulation colloid layer 200, and then the position of the diffusion particles in the encapsulation colloid layer 200 can be set by an electric field, so that the diffusion particles in the encapsulation colloid layer 200 are gradually distributed in the direction from the light-emitting panel 400 to the optical coating 100, thereby achieving the effect of the refractive index of the encapsulation colloid layer 200 gradually decreasing in the direction from the light-emitting panel 400 to the optical coating 100.

[0096] In some embodiments, the encapsulant layer 200 includes a plurality of encapsulant regions stacked sequentially, and the proportion of the diffusion particles in the plurality of encapsulant regions gradually decreases in a direction from the light emitting panel 400 to the optical coating 100 .

[0097] In this embodiment, the encapsulation colloid layer 200 is the bottom layer of the light emitting panel 400 . The encapsulation colloid layer 200 can be made of colorless and transparent materials such as epoxy resin, polyurethane resin, acrylic resin, and silicone resin.

[0098] In some embodiments, the thickness of the encapsulation colloid layer 200 is 1.2-1.5 times the thickness of the micro LED chip 450 .

[0099] In some embodiments, diffusion particles are added to the encapsulation colloid layer 200, with a total proportion of 5-10%. The diffusion particles in the encapsulation colloid layer 200 can be modified SiO2, TiO2, ZnO, Al2O3, etc., which have controllable charge and particle size below 10um.

[0100] In some embodiments, the optical coating 100 is prepared closely to the encapsulation colloid layer. The optical coating 100 can be made of colorless and transparent materials with a refractive index between 1.3 and 1.4, such as magnesium fluoride and fluorinated polymer. The thickness of the optical coating 100 is 2-10 μm.

[0101] In some embodiments, as Figure 4 As shown, there are requirements for the proportional distribution of the diffusion particles in the encapsulation colloid layer 200 in each thickness interval. The proportion of the diffusion particles in the encapsulation colloid layer 200 in each thickness interval of the encapsulation colloid layer 200 and the corresponding charge of the diffusion particles are different. According to the different forces they are subjected to in the electric field, the diffusion particles with different charges will move to different intervals of the encapsulation glue in the encapsulation colloid layer 200 during the encapsulation process, forming a structure with a gradually varying distribution of the diffusion agent ratio in the encapsulation glue of the encapsulation colloid layer 200. The distribution trend is that the diffusion agent ratio is the highest near the bottom of the encapsulation colloid layer and the lowest at the top. The ratio gradually decreases as the thickness of the encapsulation colloid increases, and the arrangement is gradually arranged from bottom to top.

[0102] In some embodiments, the encapsulant layer 200 includes a plurality of encapsulant regions stacked sequentially, and the proportion of the diffusion particles in the plurality of encapsulant regions gradually decreases in a direction from the light emitting panel 400 to the optical coating 100 .

[0103] In some embodiments, the proportions of the diffusion particles in the plurality of encapsulation colloid regions are arranged in an arithmetic progression in a direction from the light emitting panel 400 to the optical coating 100 .

[0104] In some embodiments, the diffusion particles in the multiple encapsulated colloid areas carry an electric charge, and the electric charge of the diffusion particles in the multiple encapsulated colloid areas gradually increases in the direction from the light-emitting panel 400 to the optical coating 100. By placing the light-emitting panel 400 in a magnetic field, the diffusion particles in the multiple encapsulated colloid areas can be adjusted so that the proportion of the diffusion particles in the multiple encapsulated colloid areas gradually decreases in the direction from the light-emitting panel 400 to the optical coating 100, thereby achieving the purpose of gradually decreasing the refractive index of the encapsulated colloid layer 200 in the direction from the light-emitting panel 400 to the optical coating 100.

[0105] In some embodiments, the diffusion particles in the plurality of encapsulated colloid regions carry electric charges, and the electric charges of the diffusion particles in the plurality of encapsulated colloid regions are arranged in an arithmetic progression in a direction from the light emitting panel to the optical coating.

[0106] In some embodiments, the encapsulation colloid layer 200 includes a plurality of encapsulation colloid regions. The charge amounts of the diffusion particles in the plurality of encapsulation colloid regions are specifically shown in Table 1.

[0107] Table 1:

[0108] Thickness range Diffuser ratio The charge of the particle Interval 1 7-10％ 1 Coulomb Interval 2 4-7％ 2 Coulombs Interval Three 1-4％ 3 Coulombs … … …

[0109] In this embodiment, the diffusion particles in the encapsulation colloid layer 200 are gradually distributed in the direction from the light-emitting panel 400 to the optical coating 100, so that the refractive index of the encapsulation colloid layer 200 and the optical coating 100 decreases from bottom to top, effectively reducing the refractive index difference between the encapsulation layer and the air, reducing the total reflection of the chip light at the interface between the encapsulation layer and the air, and increasing the light output efficiency of the display panel.

[0110] The present application also provides a method for preparing an LED module. Figure 5 As shown, the preparation method in this embodiment includes steps S100 to S400.

[0111] In step S100 , diffusion particles with different charge amounts are added into packaging glue for mixing and dispersion, and then dispensed onto the light-emitting panel.

[0112] In this embodiment, if Figure 6 As shown, the micro LED chip 450 is welded on the driving board 420 to form the light emitting panel 400. The diffusion particles with different charge amounts are added to the packaging glue for mixing and dispersion. The charge amounts of the diffusion particles are shown in Table 1. The packaging glue 230 is dispensed on the light emitting panel 400. Figure 7 As shown, at this time, the diffusion particles are evenly distributed in the packaging glue 230 .

[0113] In step S200 , the packaging adhesive is shaped using a mold.

[0114] In this embodiment, combined with Figure 8 As shown, the encapsulation glue is shaped using a mold 300 . The shape of the mold 300 can be designed according to the application requirements of the LED module. A sealed cavity is formed between the mold 300 and the driving board 420 . The encapsulation glue 230 in the sealed cavity has fluidity.

[0115] In step S300 , an electric field is applied to both sides of the light emitting panel 400 , and the direction of the electric field is from close to the light emitting panel 400 to away from the light emitting panel 400 .

[0116] In this embodiment, the light emitting panel 400 is placed in a uniform electric field, and the electric field covers the entire light emitting panel 400 . The upper plate 310 is negatively charged, and the lower plate 320 is positively charged.

[0117] In step S400 , the encapsulant is cured after applying an electric field for a preset time to obtain an encapsulant layer, and an optical coating 100 is formed on the encapsulant layer 200 after removing the mold.

[0118] In this embodiment, the diffused particles with different charges migrate to a predetermined thickness range of the encapsulating adhesive within the mold cavity (as shown in Table 1) based on the electric field forces they experience. The encapsulating adhesive is then cured by heating the mold cavity. The panel is then demolded, yielding a finished encapsulating adhesive layer. An optical coating is then applied using a coating or magnetron sputtering process, completing the light panel package.

[0119] An embodiment of the present application further provides a display screen comprising the LED module as described in any of the above embodiments.

[0120] The beneficial effects of the embodiments of the present application compared with the prior art are as follows: the LED module includes a light-emitting panel, an encapsulation colloid layer, and an optical coating; the encapsulation colloid layer is arranged on the front of the light-emitting panel, and the optical coating is arranged on the encapsulation colloid layer, and the refractive index of the optical coating is smaller than the refractive index of the encapsulation colloid layer; the refractive index of the encapsulation colloid layer decreases successively from the light-emitting panel to the optical coating, thereby reducing the refractive index difference between the encapsulation structure on the surface of the light-emitting panel and the air interface, and increasing the light output efficiency of the panel.

[0121] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for preparing an LED module, characterized in that: The preparation method comprises: Adding diffusion particles with different charge amounts into the encapsulation glue, mixing and dispersing them, and then dispensing them on the light-emitting panel; Using a mold to shape the packaging glue; Applying an electric field on both sides of the light-emitting panel, wherein the direction of the electric field is from close to the light-emitting panel to away from the light-emitting panel; After applying an electric field for a preset time, the encapsulant is cured to obtain an encapsulant layer, and after removing the mold, an optical coating is formed on the encapsulant layer, so that the diffusion particles in the encapsulant layer are gradually distributed in a direction from the light-emitting panel to the optical coating; The encapsulating colloid layer includes a plurality of encapsulating colloid regions stacked in sequence, and the proportion of diffusion particles in the plurality of encapsulating colloid regions gradually decreases in a direction from the light emitting panel to the optical coating.

2. The preparation method according to claim 1, wherein Also includes: forming an optical coating on the encapsulating colloid layer, wherein the refractive index of the optical coating is smaller than the refractive index of the encapsulating colloid layer; When the light emitting panel is turned on, the light emitted is refracted by the encapsulating colloid layer and the optical coating; The refractive index of the encapsulation colloid layer decreases gradually from the light emitting panel to the optical coating.

3. The preparation method according to claim 1, wherein The encapsulation colloid layer comprises: a first colloid layer formed on the front surface of the light-emitting panel and configured to refract light emitted by the light-emitting panel; a second colloid layer formed between the first colloid layer and the optical coating layer, and configured to refract the light emitted from the first colloid layer and output the light to the optical coating layer; The refractive index of the first colloid layer is greater than the refractive index of the second colloid layer.

4. The preparation method according to claim 3, wherein The light emitting panel includes a plurality of micro light emitting diode chips, and the first colloid layer is further filled between adjacent micro light emitting diode chips; and / or The thickness of the first colloid layer is 1.2-1.5 times the thickness of the micro-LED chip; and / or The thickness of the second colloid layer is 0.5-1 times the thickness of the first colloid layer; and / or The encapsulating colloid in the first colloid layer is at least one of epoxy resin, polyurethane resin and acrylic resin; and / or The refractive index of the encapsulated colloid in the first colloid layer is 1.5-1.7; and / or The encapsulating colloid in the second colloid layer is an organic silicone resin; and / or The refractive index of the encapsulating colloid in the second colloid layer is 1.4-1.

5.

5. The preparation method according to claim 3, wherein The first colloid layer and the second colloid layer are provided with diffusion particles, the particle size of the diffusion particles is less than 10 μm, and the proportion of the diffusion particles is 2%-10%; and / or The proportion of the diffusing particles in the first colloid layer is less than 1%, and the refractive index of the diffusing particles in the first colloid layer is greater than 1.9; and / or The proportion of the diffusion particles in the second colloid layer is 1%-3%, and the refractive index of the diffusion particles in the second colloid layer is less than 1.

7.

6. The preparation method according to claim 1, wherein The refractive index of the optical coating is 1.3-1.4; and / or The thickness of the optical coating is 2-10 μm; and / or The optical coating comprises magnesium fluoride and a fluorinated polymer.

7. The preparation method according to claim 6, wherein The proportions of the diffusion particles in the plurality of encapsulated colloid regions are arranged in an arithmetic progression in a direction from the light emitting panel to the optical coating; and / or The diffusion particles in the plurality of encapsulating colloid regions are charged, and the charge of the diffusion particles in the plurality of encapsulating colloid regions gradually increases in a direction from the light emitting panel to the optical coating; and / or The diffusion particles in the plurality of encapsulated colloid regions are charged, and the charges of the diffusion particles in the plurality of encapsulated colloid regions are arranged in an arithmetic progression in a direction from the light emitting panel to the optical coating.

8. An LED module, characterized in that: Prepared by the preparation method according to any one of claims 1 to 7.

9. A display screen, characterized in that: An LED module prepared by the preparation method according to any one of claims 1 to 7.

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