Display module

Abstract

The application provides a display module, and belongs to the technical field of display devices. The display module comprises a substrate, a plurality of pixel units, each pixel unit comprising at least one light-emitting chip mounted on the substrate, a packaging structure comprising a transition layer, a light-adjusting layer and a diffusion layer arranged in sequence on the light-emitting chip, wherein the difference between the refractive index of the transition layer and the refractive index of the light-emitting surface of the light-emitting chip is not more than 0.05, the refractive index of the light-adjusting layer is less than the refractive index of the transition layer, and the refractive index of the diffusion layer is less than the refractive index of the light-adjusting layer; wherein the light-adjusting layer comprises a plurality of light-collecting units, and the light-collecting units are arranged in one-to-one correspondence with the pixel units. The refractive index of the transition layer is close to that of the light-emitting surface of the light-emitting chip, the critical angle of total reflection at the contact surface between the light-emitting chip and the packaging structure is improved, and more light rays enter the packaging structure; the light-adjusting layer is provided with a light-collecting unit for focusing light rays for each pixel unit, so that the light rays propagate downward at a smaller incident angle, and the light-emitting efficiency is improved.

Description

Technical Field

[0001] This application belongs to the field of display device technology, and more specifically, relates to a display module. Background Technology

[0002] The core principle of LED direct-view technology is to precisely control the on / off state and color changes of a large number of LED beads to directly present image and video information, bringing users an intuitive and stunning visual experience. Light output efficiency is a key indicator for measuring the performance of LED direct-view products, directly affecting the screen's brightness and display effect. A higher light output efficiency allows more light to pass through the encapsulation layer, thereby increasing screen brightness and making the picture clearer and brighter.

[0003] Currently, the most common methods to improve light extraction efficiency are to optimize the materials and processes of the packaging structure to enhance its light transmittance. However, due to limitations in material and processing technology, a significant amount of light is still absorbed and scattered during transmission within the packaging structure, hindering further improvements in light extraction efficiency. Utility Model Content

[0004] The purpose of this application is to provide a display module to solve the technical problem that the light output efficiency of display modules in the prior art is limited by the development of materials and processing technology and cannot be further improved.

[0005] To achieve the above objectives, the technical solution adopted in this application is: to provide a display module, comprising:

[0006] substrate;

[0007] Multiple pixel units, each pixel unit including at least one light-emitting chip, the light-emitting chip being mounted on the substrate;

[0008] The encapsulation structure includes a transition layer, a dimming layer, and a diffusion layer sequentially disposed on the light-emitting chip. The difference between the refractive index of the transition layer and the refractive index of the light-emitting surface of the light-emitting chip does not exceed 0.05. The refractive index of the dimming layer is less than that of the transition layer, and the refractive index of the diffusion layer is less than that of the dimming layer. The dimming layer includes a plurality of light-concentrating units, and the light-concentrating units are disposed in a one-to-one correspondence with the pixel units.

[0009] Optionally, the light-concentrating unit has a convex-transparent structure.

[0010] Optionally, the area between the convex surfaces of two adjacent through-hole structures forms a recess without a flat top.

[0011] Optionally, the thickness of the adhesive layer at the thinnest point of the convex permeable structure is not less than 15 μm.

[0012] Optionally, the dimming layer further includes a connecting portion that connects to the light-concentrating unit, the connecting portion being disposed in an area outside the pixel unit on the substrate.

[0013] Optionally, the encapsulation structure further includes a surface layer, which is laid on the diffusion layer, and the side of the surface layer that is in contact with air is a roughened surface.

[0014] Optionally, the surface layer is an AG release film.

[0015] Optionally, the thickness of the transition layer is 4µm-6µm; and / or, the difference between the refractive index of the transition layer and the refractive index of the light-emitting surface of the light-emitting chip does not exceed 0.02.

[0016] Optionally, the transition layer is a layered structure formed by vapor deposition of silicon dioxide polymer on the surfaces of the light-emitting chip and the PCB substrate.

[0017] Optionally, the difference in refractive index between the transition layer and the dimming layer does not exceed 0.2, and / or the difference in refractive index between the diffusion layer and the dimming layer does not exceed 0.3.

[0018] The beneficial effects of the display module provided in this application are as follows: Compared with the prior art, the packaging structure in this application includes a transition layer, a dimming layer, and a diffusion layer. The refractive indices of the transition layer, the dimming layer, and the diffusion layer decrease sequentially. The refractive index of the transition layer is no more than 0.05 different from the refractive index of the light-emitting surface of the light-emitting chip, and the two are relatively close, thereby increasing the critical angle of total internal reflection at the contact surface between the light-emitting chip and the packaging structure, allowing more light emitted by the LED to enter the packaging structure. The dimming layer arranges a focusing unit for each pixel unit to focus the light, so that the light propagates to the packaging structure and the air contact surface at a smaller incident angle, thereby reducing the total internal reflection effect at the packaging structure and the air contact surface. By reducing the two total internal reflection effects, light loss is reduced and the light extraction efficiency is improved. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, 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 application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the substrate and the light-emitting chip after assembly, as provided in the embodiments of this application;

[0021] Figure 2 A schematic diagram of the structure of the substrate and light-emitting chip after a transition layer is provided in the embodiments of this application;

[0022] Figure 3 A schematic diagram of the structure of the substrate and light-emitting chip provided in the embodiments of this application after a transition layer and a dimming layer have been provided;

[0023] Figure 4 for Figure 3 The top view of the structure shown;

[0024] Figure 5 This is one of the structural schematic diagrams of the display module provided in the embodiments of this application;

[0025] Figure 6 for Figure 5 The image shown is an enlarged view of the display module at point A.

[0026] Figure 7 This is a second schematic diagram of the structure of the display module provided in the embodiments of this application;

[0027] Figure 8 for Figure 7 The image shown is an enlarged view of the display module at point B.

[0028] Figure 9 This is one of the structural schematic diagrams of the display module provided in the embodiments of this application;

[0029] Figure 10 for Figure 9 The image shown is an enlarged view of the display module at point C.

[0030] The following are the labeling elements in the figure:

[0031] 10. Substrate; 20. Light-emitting chip; 21. Pixel unit; 30. Packaging structure; 31. Transition layer; 311. Transition unit; 312. Adhesive-free area; 32. Dimming layer; 321. Concentrating unit; 322. Connector; 33. Diffusion layer; 34. Surface layer. Detailed Implementation

[0032] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0033] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0034] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0035] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0036] When light travels from a denser medium to a less dense medium, total internal reflection occurs at the interface between the two media, causing light loss. In a display module, the light-emitting chip has an external encapsulation structure, and total internal reflection may occur at the contact interface between the chip and the encapsulation structure, as well as at the interface between the encapsulation structure and air. Specifically, the light emitted from the chip may experience a first total internal reflection when entering the encapsulation structure. Then, after passing through the encapsulation structure and exiting into the air, a second total internal reflection may occur. These two total internal reflections inevitably reduce the amount of light transmitted from the chip into the air, thus reducing the light extraction efficiency. To address this, this application provides a display module that improves the light extraction efficiency by reducing the total internal reflection effects at the contact interface between the chip and the encapsulation structure, and at the interface between the encapsulation structure and air.

[0037] This application provides a display module, such as... Figure 5 As shown, it includes a substrate 10, multiple pixel units 21, and a packaging structure 30. Each pixel unit 21 includes at least one light-emitting chip 20, which is mounted on the substrate 10. The packaging structure 30 includes a transition layer 31, a dimming layer 32, and a diffusion layer 33 sequentially disposed. The difference between the refractive index of the transition layer 31 and the refractive index of the light-emitting surface of the light-emitting chip 20 does not exceed 0.05; the refractive index of the dimming layer 32 is less than that of the transition layer 31; and the refractive index of the diffusion layer 33 is less than that of the dimming layer 32. (See reference...) Figure 3 and Figure 4 The dimming layer 32 includes multiple light-concentrating units 321, and the light-concentrating units 321 are configured in a one-to-one correspondence with the pixel units 21.

[0038] The light-emitting chip 20 is an LED chip or a light-emitting diode, etc. During product design, the LED chip or light-emitting diode is selected as the light-emitting chip 20 based on the application scenario, cost budget, and performance requirements. The pixel unit 21 is a light-emitting area that can be controlled individually. For a monochrome display module, the pixel unit 21 corresponds to one light-emitting chip 20; for a full-color display module, the pixel unit 21 consists of multiple light-emitting chips 20. Taking RGB three-color display as an example, one pixel unit 21 includes three light-emitting chips 20 for red, green, and blue.

[0039] The display module's encapsulation structure 30 includes at least three layers: a transition layer 31, a dimming layer 32, and a diffusion layer 33. (See attached image for details.) Figure 1 Multiple light-emitting chips 20 are mounted on the substrate 10. Then... Figure 1 The structure shown has a transition layer 31 formed on its surface through deposition or other processing techniques. The transition layer 31 is bonded to the light-emitting surface of the light-emitting chip 20, guiding the light emitted by the chip into the packaging structure 30. (See reference...) Figure 3 and Figure 5 The dimming layer 32 is located between the transition layer 31 and the diffusion layer 33, with the diffusion layer 33 located on the light-emitting side of the encapsulation structure 30. The refractive indices of the transition layer 31, the dimming layer 32, and the diffusion layer 33 decrease sequentially, thereby forming an encapsulation structure 30 with a gradient change in refractive index.

[0040] The refractive index of the transition layer 31 differs from that of the light-emitting surface of the light-emitting chip 20 by no more than 0.05, making the refractive index of the transition layer 31 similar to that of the light-emitting surface of the light-emitting chip 20. This increases the critical angle for total internal reflection at the interface between the light-emitting chip 20 and the packaging structure 30, thereby preventing reflection when light enters the packaging structure 30 and ensuring that most light can enter the interior of the packaging structure 30. For example, if the light-emitting chip 20 is a flip-chip structure with a light-emitting surface made of sapphire (Al2O3) and a refractive index of 1.8, then the transition layer 31 can be made of SiO2 polymer or other high-refractive-index materials with a refractive index of 1.75, 1.85, or 1.78, 1.8, 1.82, or any value between 1.75 and 1.85.

[0041] The light-concentrating unit 321 optimizes the light output characteristics of a single pixel unit 21, reduces light loss within the encapsulation structure 30, and allows more light to escape from the encapsulation structure 30. One light-concentrating unit 321 corresponds to one pixel unit 21. See also... Figure 3 and Figure 4During encapsulation, adhesive is applied to each pixel unit 21 in a dispensing manner, ensuring that each pixel unit 21 is completely encapsulated independently and completely. Thus, after the dimming layer 32 is dispensed, multiple light-focusing units 321 are formed for the multiple pixel units 21 formed by the light-emitting chip 20. The multiple light-focusing units 321 are arranged in an array according to the array pattern of the multiple pixel units 21.

[0042] Optionally, the adhesive for the dimming layer 32 is a composite adhesive made primarily of epoxy resin and incorporating TiO2 nanoparticles. The incorporation of TiO2 nanoparticles helps to adjust the optical properties of the composite adhesive, such as its refractive index, creating a gradient with the refractive index of the transition layer 31. The overall viscosity of the composite adhesive is between 2000 mPa·s and 3000 mPa·s, ensuring that the adhesive can be precisely spread and maintain the desired shape after dispensing, avoiding excessive dispersion or the formation of undesirable morphologies, which is beneficial for the formation of the focusing unit 321.

[0043] The refractive index of the diffusion layer 33 is less than that of the dimming layer 32. For example, the refractive index of the dimming layer 32 is 1.7, and the refractive index of the diffusion layer 33 is 1.5. Optionally, the diffusion layer 33 is made of epoxy resin doped with a diffusing agent, which fills the dimming layer 32 and forms a light-emitting plane outside the dimming layer 32.

[0044] The display module provided in this application embodiment includes a packaging structure 30 comprising a transition layer 31, a dimming layer 32, and a diffusion layer 33. The refractive indices of the transition layer 31, the dimming layer 32, and the diffusion layer 33 decrease sequentially. The refractive index of the transition layer 31 differs from that of the light-emitting surface of the light-emitting chip 20 by no more than 0.05, which is relatively close. This increases the critical angle of total internal reflection at the contact surface between the light-emitting chip 20 and the packaging structure 30, allowing more light emitted by the LED to enter the packaging structure 30. The dimming layer 32 provides a focusing unit 321 for each pixel unit 21 to focus the light, allowing the light to propagate to the packaging structure 30 and the air contact surface at a smaller incident angle. This reduces the total internal reflection effect at the packaging structure 30 and the air contact surface, thereby increasing the light extraction efficiency.

[0045] In some optional embodiments, the light-concentrating unit 321 is in the shape of a reflective cup. Multiple light-emitting chips 20 constituting the same pixel unit 21 use the reflective cup-shaped light-concentrating unit 321 to concentrate light, reduce the angle at which light is incident on the packaging structure 30 and the air contact surface, that is, reduce the incident angle at the packaging structure 30 and the air contact surface, thereby reducing the incident angle at the packaging structure 30 and the air contact surface and reducing the total internal reflection effect of light at the packaging structure 30 and the air contact surface.

[0046] In some alternative embodiments, see [link to relevant documentation] Figure 3 and Figure 4The light-concentrating unit 321 is a convex-lens structure. The light-emitting surface of the convex-lens structure is convex and transparent, and its optical performance is similar to that of a convex lens, capable of converging incident light rays. Optionally, the light-emitting surface of the convex-lens structure can be spherical or aspherical. When light propagates within the encapsulation structure 30, it is converged by the convex-lens structure, reducing the incident angle of the light rays after passing through the convex-lens structure.

[0047] Optionally, the convex-lens structures have the same convex surface shape to facilitate encapsulation and ensure uniform light emission throughout the display module. Alternatively, the multiple convex-lens structures can be divided into multiple regions, with the convex-lens structures within each region having the same convex surface shape, while the convex-lens structures in different regions have different convex surface shapes. This application does not specifically limit the possibilities in this regard.

[0048] The display module provided in this application embodiment has a convex-transparent structure for the light-concentrating unit 321. The convex-transparent structure enables light to propagate to the diffusion layer 33 at a smaller incident angle, thereby reducing the incident angle of light from the inside to the outside of the encapsulation structure 30, reducing the total internal reflection effect of light at the air contact surface of the encapsulation structure 30, and thus improving the light extraction efficiency.

[0049] For details, please refer to Figure 4 The region between the convex surfaces of two adjacent convex-permeable structures forms a recessed area without a flat top. That is, when fabricating two adjacent convex-permeable structures, the adhesive applied by the two dots does not flow to form a single plane. For example, the convex-permeable structure is spherical and wraps around the pixel unit 21. Alternatively, the convex-permeable structure includes a cylindrical segment and a spherical segment disposed on top of the cylindrical segment. The cylindrical segment surrounds a pixel unit 21, and the spherical segment allows light to be focused by the spherical surface of the spherical segment before entering the diffusion layer 33.

[0050] Ideally, the convex surfaces of two adjacent convex-through structures should be tangent. However, during the dispensing process, the adhesive has fluidity, making it difficult to achieve perfect tangency. Therefore, during dispensing, the overall viscosity of the adhesive in the light-adjusting layer 32 is controlled between 2000 MPa·s and 3000 MPa·s, and the dispensing amount is controlled to ensure that the convex surface of each convex-through structure meets the design standards as much as possible, and to ensure that the convex surfaces of two adjacent convex-through structures are essentially tangent after the adhesive has cured. Figure 4 As shown, each pixel unit 21 includes three light-emitting chips 20, and a convex-lens structure is provided for this pixel unit 21. The convex-lens structure is hemispherical. (See reference...) Figure 4Multiple pixel units 21 are arranged in a square array, with the central convex-lens structure being substantially tangent to the four surrounding convex-lens structures. In some embodiments, the enclosure region S0 formed by the outer tangency of the multiple convex-lens structures also has an adhesive, thereby allowing the multiple convex-lens structures to be connected into a complete layered structure by means of the adhesive in the enclosure region S0. In this embodiment, the dimming layer 32 is a continuous adhesive structure covering each pixel unit 21 and the area outside the pixel unit 21. In other embodiments, the enclosure region S0 formed by the outer tangency of the multiple convex-lens structures is not provided with an adhesive, so that the multiple convex-lens structures are connected only by means of tangency. That is, in this embodiment, the dimming layer 32 is an adhesive structure with holes, covering at least each pixel unit 21.

[0051] In some specific embodiments, the thickness of the adhesive layer at the thinnest point of the convex-lens structure is not less than 15 μm. For example, the thickness of the thinnest point of the convex-lens structure is 15 μm, 16 μm, or 20 μm, etc. The light-emitting surface of the convex-lens structure is convex, and the distance from its convex surface to the light-emitting chip 20 varies at different points. The adhesive layer thickness at the thinnest point of the convex-lens structure is not less than 15 μm, so that the distance between the light-emitting surface of the convex-lens structure and the light-emitting chip 20 is greater than 15 μm.

[0052] In some embodiments, the dimming layer 32 is a continuous and complete adhesive layer. Specifically, the dimming layer 32 further includes a connection portion 322 connecting the light-concentrating unit 321, and the connection portion 322 is disposed in the area outside the pixel unit 21 on the substrate 10.

[0053] Among them, see Figure 3 and Figure 5 The side of the connecting portion 322 facing the diffusion layer 33 is planar. When the transition layer 31 has a connected and complete layered structure, the side of the connecting portion 322 facing the transition layer 31 is planar, thus ensuring that the colloid thickness is uniform throughout the connecting portion 322. (See also...) Figure 7 and Figure 8 When the transition layer 31 covers the light-emitting surface of the light-emitting chip 20 and has a glue-free area 312, the connecting portion 322 fills the glue-free area 312.

[0054] The adhesive layer thickness of the connecting portion 322 is no greater than the height of the light-emitting chip 20, and the focusing surface of the focusing unit 321 is in contact with the surface of the connecting portion 322. The adhesive layer thickness of the connecting portion 322 is no greater than the height of the light-emitting chip 20, allowing some light emitted from the side of the light-emitting chip 20 to act on the focusing surface of the focusing unit 321 and converge, thus helping to improve the light extraction efficiency.

[0055] The display module provided in this application embodiment provides a light-concentrating unit 321 for multiple pixel units 21, and the light-concentrating units 321 are connected by a connecting part 322, so that the dimming layer 32 forms an array-type colloidal structure, which not only ensures the packaging independence of individual pixel units 21, but also achieves the consistency of the overall structure.

[0056] In some other embodiments, the dimming layer 32 is a non-connected colloidal structure. For example, the light-concentrating unit 321 covers only a single pixel unit 21, and there are uncoated areas between the light-concentrating units 321.

[0057] In some optional embodiments of this application, see [reference]. Figure 5 , Figure 7 and Figure 9 The encapsulation structure 30 also includes a surface layer 34, which is deposited on the diffusion layer 33. The side of the surface layer 34 that is in contact with air is a roughened surface. The roughened surface can increase light scattering, increase the chance of light leaving the encapsulation structure 30 at an angle less than the critical angle, thereby reducing the second total internal reflection effect and improving the light extraction efficiency.

[0058] Optionally, the surface layer 34 is an anti-glare (AG) release film. By attaching the AG release film to the surface of the diffusion layer 33, the light-emitting surface of the encapsulation structure 30 is roughened. One side of the AG release film is coated with a release agent, allowing it to adhere to the diffusion layer 33 and peel off without damaging it, thus protecting the diffusion layer 33. The roughened surface of the AG release film or the addition of scattering particles causes diffuse reflection of light on its surface, increasing the chance of light leaving the encapsulation structure 30 at an angle less than the critical angle.

[0059] In some optional embodiments, the difference between the refractive index of the transition layer 31 and the refractive index of the light-emitting surface of the light-emitting chip 20 does not exceed 0.02, making the refractive indices of the transition layer 31 and the light-emitting surface of the light-emitting chip 20 more similar, thereby minimizing reflection and light loss at the bonding interface. For example, if the light-emitting surface of the light-emitting chip 20 is sapphire, and the light emitted from the active region inside the light-emitting chip 20 enters the packaging structure 30 through the sapphire, then the refractive index of the transition layer 31 is any value between 1.78 and 1.82, such as 1.78, 1.82, or 1.8, 1.81.

[0060] The thickness of the transition layer 31 is 4µm-6µm. If the transition layer 31 is too thick, it will increase the optical path and affect heat dissipation; if it is too thin, it will not effectively cover the light-emitting chip 20 and the substrate 10. For example, the thickness of the transition layer 31 can be any value between 4µm and 6µm, such as 4µm, 6µm, 4.5µm, or 5µm. Specifically, the transition layer 31 is made of SiO2 polymer. During encapsulation, the die-bonded substrate 10 is placed in a vapor deposition chamber, and the SiO2 polymer is deposited on the substrate 10 using physical or chemical vapor deposition to completely encapsulate the light-emitting chip 20, with a deposition thickness of 5µm.

[0061] In some alternative embodiments, see Figure 5 and Figure 6 The transition layer 31 is a continuous layered structure laid flat on the surfaces of the substrate 10 and the light-emitting chip 20, with uniform thickness throughout. Specifically, an colloid is laid between two adjacent light-emitting chips 20, that is, the transition layer 31 is uniformly laid on... Figure 1 The structure shown completely covers the entire structure surface.

[0062] In some alternative embodiments, the transition layer 31 is a discontinuous layered structure laid flat on the surfaces of the substrate 10 and the light-emitting chip 20. For details, see [link to relevant documentation]. Figure 8 and Figure 10 The transition layer 31 includes multiple transition units 311, each corresponding to one of the multiple light-emitting chips 20. At least some of the transition units 311 have adhesive-free regions 312 between them.

[0063] For example, any two adjacent transition units 311 of each transition unit 311 have a glue-free area 312. Alternatively, the transition units 311 corresponding to multiple light-emitting chips 20 constituting the same pixel unit 21 are connected as one unit, and the transition units 311 corresponding to light-emitting chips 20 located in different pixel units 21 have a glue-free area 312. The shape of the transition unit 311 can be square or circular, etc.

[0064] Specifically, during encapsulation, Figure 1 The structure shown is placed in a vapor deposition chamber, and with the aid of a mask or other techniques, a transition layer 31 with a glue-free region 312 is deposited only in specific areas. (See also...) Figure 8 and Figure 10 Each transition unit 311 covers the surface of the light-emitting chip 20 and the substrate 10 surrounding the light-emitting chip 20.

[0065] In some alternative embodiments, such as Figure 7 and Figure 8 As shown, the dimming layer 32 fills the adhesive-free area 312 with a colloid. Specifically, in Figure 1After depositing the transition layer 31 on the structure shown, a continuous and complete dimming layer 32 is formed by dispensing adhesive onto each pixel unit. It is understood that the adhesive in the dimming layer 32 may only fill a portion of the adhesive-free area 312, and the adhesive in the diffusion layer 33 will ultimately completely fill the adhesive-free area 312. In some alternative embodiments, such as... Figure 9 and Figure 10 As shown, the glue-free region 312 can be filled with a different colloid than the transition unit 311, and this colloid has a lower refractive index than the colloid in the transition unit 311. For example, in Figure 1 After the transition unit 311 is deposited on the structure shown, another type of colloid is deposited in the glue-free region 312. The thickness of this colloid layer is the same as the thickness of the transition unit 311. Therefore, the transition unit 311 and the glue-free region 312 use colloids of different materials, reducing the consumption of high-refractive-index colloids and thus reducing material costs.

[0066] The display module provided in this application, by setting a transition unit 311 with a glue-free area 312, can reduce optical crosstalk between adjacent units on the one hand, and reduce the amount of high refractive index adhesive used in the transition layer 31 on the other hand, thereby reducing costs.

[0067] The refractive index difference between the transition layer 31 and the dimming layer 32 does not exceed 0.2, optimizing the transmission efficiency of light within the encapsulation structure 30, more effectively guiding and controlling the light path, and improving the light extraction efficiency of the encapsulation structure 30. For example, the refractive index difference between the transition layer 31 and the dimming layer 32 is 0.2 or a value less than 0.2, such as 0.1 or 0.15. In some specific embodiments, the refractive index of the transition layer 31 is 1.8, then the refractive index of the dimming layer 32 is 1.6 or any value greater than 1.6 and less than 1.8, such as 1.65 or 1.7. For example, the refractive index of the dimming layer 32 is 1.7, forming a gradient refractive index transition design.

[0068] The difference in refractive index between the diffusion layer 33 and the dimming layer 32 does not exceed 0.3. For example, the difference in refractive index between the diffusion layer 33 and the dimming layer 32 is 0.3 or a value less than 0.3, such as 0.2 or 0.25. In some specific embodiments, if the refractive index of the dimming layer 32 is 1.7, then the refractive index of the diffusion layer 33 is 1.5, 1.4, etc.

[0069] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A display module, characterized in that: include: PCB substrate(10); Multiple pixel units (21), each pixel unit (21) includes at least one light-emitting chip (20), the light-emitting chip (20) being mounted on the PCB substrate (10); The encapsulation structure (30) includes a transition layer (31), a dimming layer (32), and a diffusion layer (33) sequentially disposed on the light-emitting chip (20). The difference between the refractive index of the transition layer (31) and the refractive index of the light-emitting surface of the light-emitting chip (20) is no more than 0.

05. The refractive index of the dimming layer (32) is less than that of the transition layer (31), and the refractive index of the diffusion layer (33) is less than that of the dimming layer (32). The dimming layer (32) includes a plurality of light-concentrating units (321), and the light-concentrating units (321) are disposed in a one-to-one correspondence with the pixel units (21).

2. The display module as described in claim 1, characterized in that: The light-concentrating unit (321) has a convex-transparent structure.

3. The display module as described in claim 2, characterized in that: The area between the convex surfaces of two adjacent convex through-hole structures forms a recess without a flat top.

4. The display module as described in claim 2, characterized in that: The thickness of the adhesive layer at the thinnest point of the convex-perforated structure is not less than 15 μm.

5. The display module as described in claim 1, characterized in that: The dimming layer (32) further includes a connecting portion (322) that connects to the light-concentrating unit (321), and the connecting portion (322) is disposed in the area outside the pixel unit (21) on the substrate (10).

6. The display module as described in claim 1, characterized in that: The encapsulation structure (30) also includes a surface layer (34), which is laid on the diffusion layer (33), and the side of the surface layer (34) that is in contact with air is a roughened surface.

7. The display module as described in claim 6, characterized in that: The surface layer (34) is an AG release film.

8. The display module as described in claim 1, characterized in that: The thickness of the transition layer (31) is 4 μm-6 μm; and / or the difference between the refractive index of the transition layer (31) and the refractive index of the light-emitting surface of the light-emitting chip (20) does not exceed 0.

02.

9. The display module as described in claim 1 or 8, characterized in that: The transition layer (31) is a layered structure formed by vapor deposition of silicon dioxide polymer on the surfaces of the light-emitting chip (20) and the PCB substrate (10).

10. The display module as described in claim 1, characterized in that: The difference in refractive index between the transition layer (31) and the dimming layer (32) shall not exceed 0.2, and / or the difference in refractive index between the diffusion layer (33) and the dimming layer (32) shall not exceed 0.3.

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