Low-reflection film, display substrate and preparation method therefor, and display device

Abstract

A low-reflection film, a display substrate and a preparation method therefor, and a display device. The low-reflection film comprises a first metal layer, a first inorganic layer, a second metal layer and a second inorganic layer. The first inorganic layer is located on one side of the first metal layer, and the refractive index of the first inorganic layer is less than that of the first metal layer. The second metal layer is located on the side of the first inorganic layer away from the first metal layer, and the refractive index of the second metal layer is greater than that of the first inorganic layer. The second inorganic layer is located on the side of the second metal layer away from the first inorganic layer, and the refractive index of the second inorganic layer is less than that of the second metal layer.

Description

Low-reflection film, display substrate, preparation method thereof, and display device

[0001] This application claims priority to Chinese patent application No. 202310625409.1, filed on May 29, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to the field of display technology, and in particular to a low-reflection film, a display substrate and a preparation method thereof, and a display device. Background Art

[0003] Organic light-emitting diodes (OLEDs) offer numerous advantages, including self-luminescence, high brightness, high contrast, fast response, wide viewing angle, simple structure, and flexible display. Submillimeter light-emitting diodes (Mini LEDs) and micro LEDs offer superior performance, including lower power consumption, faster response, longer lifespan, higher color saturation, and higher contrast.

[0004] Summary of the Invention

[0005] In one aspect, a low-reflection film is provided. The low-reflection film includes a first metal layer, a first inorganic layer, a second metal layer, and a second inorganic layer. The first inorganic layer is located on one side of the first metal layer; the refractive index of the first inorganic layer is lower than that of the first metal layer. The second metal layer is located on a side of the first inorganic layer away from the first metal layer; the refractive index of the second metal layer is higher than that of the first inorganic layer. The second inorganic layer is located on a side of the second metal layer away from the first inorganic layer; the refractive index of the second inorganic layer is lower than that of the second metal layer.

[0006] In some embodiments, in a direction perpendicular to the first metal layer, a size of the first metal layer is larger than a size of the first inorganic layer.

[0007] In some embodiments, in a direction perpendicular to the first metal layer, a size of the first metal layer is larger than a size of the second metal layer.

[0008] In some embodiments, in a direction perpendicular to the first metal layer, a size of the first metal layer is larger than a size of the second inorganic layer.

[0009] In some embodiments, in a direction perpendicular to the first metal layer, a ratio of a size of the first metal layer to a size of the first inorganic layer is greater than or equal to 2.5 and less than or equal to 3.5.

[0010] In some embodiments, in a direction perpendicular to the first metal layer, a ratio of a size of the first metal layer to a size of the second metal layer is greater than or equal to 11.5 and less than or equal to 17.5.

[0011] In some embodiments, in a direction perpendicular to the first metal layer, a ratio of a size of the first metal layer to a size of the second inorganic layer is greater than or equal to 2 and less than or equal to 3.

[0012] In some embodiments, in a direction perpendicular to the first metal layer, a size of the first inorganic layer is larger than a size of the second metal layer.

[0013] In some embodiments, in a direction perpendicular to the first metal layer, a size of the second inorganic layer is larger than a size of the second metal layer.

[0014] In some embodiments, in a direction perpendicular to the first metal layer, a ratio of a size of the first inorganic layer to a size of the second metal layer is greater than or equal to 4 and less than or equal to 6.5.

[0015] In some embodiments, in a direction perpendicular to the first metal layer, a ratio of a size of the second inorganic layer to a size of the second metal layer is greater than or equal to 4.5 and less than or equal to 7.

[0016] In some embodiments, in a direction perpendicular to the first metal layer, a size of the low-reflection film is greater than or equal to 1800 Å and less than or equal to 2500 Å.

[0017] In some embodiments, the low-reflection film includes N metal layers and multiple inorganic layers, the refractive index of the metal layer is greater than the refractive index of the inorganic layer. The N metal layers and the multiple inorganic layers are alternately stacked in sequence; wherein N is a positive integer greater than or equal to three.

[0018] On the other hand, a display substrate is provided. The display substrate includes at least one display side. The display substrate also includes a base substrate, a plurality of metal traces, a light-emitting unit, and a low-reflection film as described in any of the above embodiments. The base substrate defines a light-emitting area and a non-light-emitting area other than the light-emitting area. The plurality of metal traces are located on one side of the base substrate and are arranged in the non-light-emitting area. The light-emitting unit is located on a side of the plurality of metal traces away from the base substrate and is arranged in the light-emitting area. The low-reflection film is located on at least one side of the plurality of metal traces close to the display side and is arranged in the non-light-emitting area.

[0019] In some embodiments, the display substrate is a top emission type display substrate or a bottom emission type display substrate, wherein the low reflection film is located on a side of the light emitting unit away from the base substrate.

[0020] In some embodiments, the display substrate is a dual-side emission type display substrate. The low-reflection film includes a first low-reflection film and / or a second low-reflection film. The first low-reflection film is located between the base substrate and the plurality of metal traces; and / or the second low-reflection film is located on a side of the light-emitting unit away from the base substrate.

[0021] In another aspect, a method for manufacturing a display substrate is provided. The method includes forming a base substrate, wherein the base substrate defines a light-emitting region and a non-light-emitting region other than the light-emitting region. A plurality of metal traces are formed on one side of the base substrate, wherein the plurality of metal traces are disposed in the non-light-emitting region. A light-emitting unit is formed on a side of the plurality of metal traces away from the base substrate, wherein the light-emitting unit is disposed in the light-emitting region.

[0022] The method further includes: after forming the light-emitting unit, forming a low-reflection film on a side of the light-emitting unit away from the base substrate; and / or, before forming the plurality of metal traces, forming a low-reflection film on a side of the base substrate. The low-reflection film is disposed in the non-light-emitting area; the low-reflection film comprises a first metal layer, a first inorganic layer, a second metal layer, and a second inorganic layer. The first inorganic layer is located on one side of the first metal layer, and the refractive index of the first inorganic layer is less than the refractive index of the first metal layer. The second metal layer is located on a side of the first inorganic layer away from the first metal layer, and the refractive index of the second metal layer is greater than the refractive index of the first inorganic layer. The second inorganic layer is located on a side of the second metal layer away from the first inorganic layer, and the refractive index of the second inorganic layer is less than the refractive index of the second metal layer.

[0023] In some embodiments, forming a low-reflection film on a side of the light-emitting unit away from the base substrate includes: forming a first low-reflection base film on the side of the light-emitting unit away from the base substrate by sequentially forming a first metal layer, a first inorganic layer, a second metal layer, and a second inorganic layer stacked in layers; and removing the first low-reflection base film in the light-emitting area using a dry etching process, while retaining the first low-reflection base film in the non-light-emitting area as the low-reflection film.

[0024] In some embodiments, forming a low-reflection film on one side of the base substrate includes: forming a second low-reflection base film on one side of the base substrate by sequentially forming a stacked second inorganic layer, a second metal layer, a first inorganic layer, and a first metal layer; and removing the second low-reflection base film in the light-emitting area using a dry etching process, while retaining the second low-reflection base film in the non-light-emitting area as the low-reflection film.

[0025] In another aspect, a display device is provided. The display device includes a circuit board and a display substrate according to any of the above embodiments. The display substrate is located on one side of the circuit board and is coupled to the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of the present disclosure.

[0027] FIG1 is a structural diagram of a display device according to some embodiments;

[0028] FIG2 is a perspective view of a display substrate according to some embodiments;

[0029] FIG3 is a cross-sectional view of a display substrate along line AA′ in FIG2 in some embodiments;

[0030] 4 and 5 are diagrams showing the arrangement structures of sub-pixels in a display substrate according to some embodiments;

[0031] FIG6 is a structural diagram of a low-reflection film according to some embodiments;

[0032] FIG7 is a cross-sectional view of a display substrate along line AA′ in FIG2 in some other embodiments;

[0033] FIG8 is a cross-sectional view of a display substrate along line AA′ in FIG2 in still other embodiments;

[0034] FIG9 is a diagram comparing the display effects of a display device according to some embodiments with those of other display devices;

[0035] FIG10 is a comparison diagram of the reflectivity of incident light of low-reflection films having different thicknesses of the first inorganic layer according to some embodiments;

[0036] 11 and 12 are comparative diagrams showing fluctuation ranges of reflectivity of incident light for low-reflection films of different thicknesses according to some embodiments;

[0037] FIG13 is a comparison diagram of the reflectivity of incident light of low-reflection films having different thicknesses of the second inorganic layer according to some embodiments;

[0038] 14 to 18 are flow charts of methods for preparing a display substrate according to some embodiments. DETAILED DESCRIPTION

[0039] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0040] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0041] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0042] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. The term "connected" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. The term "coupled" indicates, for example, that two or more components are in direct physical or electrical contact. The term "coupled" or "communicatively coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0043] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0044] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0045] As used herein, the term "if" is optionally interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined that" or "if [stated condition or event] is detected" are optionally interpreted to mean "upon determining" or "in response to determining" or "upon detecting [stated condition or event]" or "in response to detecting [stated condition or event]," depending on the context.

[0046] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0047] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0048] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0049] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0050] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0051] Currently, display substrates include a light-emitting area, where light-emitting devices are distributed, and a non-light-emitting area. A black matrix organic film layer is provided in the non-light-emitting area. This shields the metal traces within the display substrate, reducing or even eliminating reflections from the metal traces on ambient light entering the display device, ensuring uniform light emission and a seamless black display effect.

[0052] However, the inventors of this disclosure discovered through research that the black matrix organic film layer has a poor light-shielding effect. It absorbs less incident light that would otherwise be directed at the metal traces, resulting in more light reflected from the metal traces. This results in a poor, uniformly black display effect in the display device. Furthermore, after the black matrix organic film layer is formed, during the laser etching of the metal traces located on the side of the display substrate, the black matrix organic film layer near the metal traces is easily damaged by the high temperature, reducing the manufacturing yield of the display device.

[0053] Based on this, embodiments of the present disclosure provide a low-reflection film, a display substrate, a method for manufacturing the same, and a display device to overcome the above-mentioned problems, which are described below.

[0054] FIG. 1 is a structural diagram of a display device according to some embodiments.

[0055] 1 , some embodiments of the present disclosure provide a display device 1000. The display device 1000 can be used to display static images or dynamic images. Exemplarily, the display device 1000 can be an OLED display device, a Mini LED display device, or a Micro LED display device, etc. For example, the display device 1000 can be a small or medium-sized display device such as a tablet computer, a smart phone, a head-mounted display, a car navigation unit, a camera, an in-vehicle center information display (CID), a watch-type display device or other wearable device, a personal digital assistant (PDA), a portable multimedia player (PMP), and a game console, as well as medium and large electronic devices such as televisions, external billboards, monitors, home appliances including display screens, personal computers, and laptop computers. The above electronic devices can represent simple examples of application of the display device 1000, so those skilled in the art can recognize that the display device 1000 can also be other electronic devices without departing from the spirit and scope of the present disclosure.

[0056] As shown in FIG1 , a display device 1000 may include a display substrate 100 and a circuit board 200, wherein the display substrate 100 is coupled to the circuit board 200. The circuit board 200 may be located on the backlight side of the display substrate 100 (i.e., the side opposite to the display side of the display substrate 100). For example, the circuit board 200 may be a flexible printed circuit board (FPC) or a printed circuit board 200. The circuit board 200 may provide a light-emitting data signal, and the display substrate 100 emits light based on the light-emitting data signal provided by the circuit board 200.

[0057] Figure 2 is a perspective view of a display substrate according to some embodiments. Figure 3 is a cross-sectional view of a display substrate along line AA' in Figure 2 according to some embodiments.

[0058] Referring to Figures 2 and 3, some embodiments of the present disclosure provide a display substrate 100. The display substrate 100 is a display component capable of emitting display light. The display substrate 100 can emit monochromatic light (light of a single color) or colored light. The display substrate 100 can be applied to the above-mentioned display device 1000. For example, the display substrate 100 can be an OLED display substrate, a Mini LED display substrate, or a Micro LED display substrate, etc., which is not limited here.

[0059] In some embodiments, as shown in FIG. 3 , the display substrate 100 may include a base substrate 10 , a plurality of metal traces 20 , a light emitting unit 30 , and a low-reflection film 40 .

[0060] The display substrate 100 also includes at least one display side, which can be understood as the side where the display light can be seen by the human eye. In some examples, the display substrate 100 may include one display side. For example, the display substrate 100 may be a top-emitting display substrate 100, where both the light-emitting side and the display side of the top-emitting display substrate 100 are the sides of the light-emitting unit 30 away from the base substrate 10. For another example, the display substrate 100 may be a bottom-emitting display substrate 100, where the light-emitting side of the bottom-emitting display substrate 100 is the side of the light-emitting unit 30 close to the base substrate 10, and the display side of the bottom-emitting display substrate 100 is the side of the light-emitting unit 30 away from the base substrate 10. In other examples, the display substrate 100 may be a dual-emitting display substrate 100, where the display substrate 100 includes two display sides. The two display sides of a dual-emitting display substrate 100 are the side of the light-emitting unit 30 away from the base substrate 10 and the side of the light-emitting unit 30 close to the base substrate 10, respectively.

[0061] The base substrate 10 defines a light-emitting area EA and a non-light-emitting area FA excluding the light-emitting area. Multiple metal traces 20 are located on one side of the base substrate 10, and the light-emitting unit 30 is located on the side of the multiple metal traces 20 away from the base substrate 10. A low-reflection film 40 can be located on at least one side of the multiple metal traces 20. It can be understood that the low-reflection film 40 can be located on one side of the multiple metal traces 20, or the low-reflection film 40 can be located on both sides of the multiple metal traces 20. The low-reflection film 40 and the multiple metal traces 20 are both located in the non-light-emitting area FA, which can reduce the obstruction of display light by the low-reflection film 40 and the multiple metal traces 20, thereby ensuring the light extraction efficiency of the display substrate 100.

[0062] In this way, the incident light from the ambient light entering the display device 1000 first enters the low-reflection film 40 and then strikes the plurality of metal traces 20 . The low-reflection film 40 can block and absorb most of the incident light that would otherwise strike the metal traces.

[0063] The following are detailed descriptions of the base substrate 10 , the plurality of metal traces 20 , the light emitting unit 30 and the low-reflection film 40 in the display substrate 100 .

[0064] 4 and 5 are diagrams respectively showing the arrangement structures of sub-pixels in a display substrate according to some embodiments.

[0065] 3 , the base substrate 10 may include a plurality of repeatedly arranged pixel unit areas PU. Each pixel unit area PU may include a plurality of light emitting areas EA and a plurality of non-light emitting areas FA.

[0066] In some examples, as shown in Figure 4, the multiple emission areas EA of each pixel unit area PU may include a first sub-pixel area P1, a second sub-pixel area P2, and a third sub-pixel area P3 that display different colors. For example, the first sub-pixel area P1 is configured to display blue light, the second sub-pixel area P2 is configured to display green light, and the third sub-pixel area P3 is configured to display red light.

[0067] The non-emission area FA may be located between the first sub-pixel area P1 and the second sub-pixel area P2 , between the second sub-pixel area P2 and the third sub-pixel area P3 , and between the third sub-pixel area P3 and the first sub-pixel area P1 .

[0068] In some examples, as shown in FIG5 , each pixel unit region PU may include a first sub-pixel region P1, two second sub-pixel regions P2, and a third sub-pixel region P3. The first sub-pixel region P1, the two second sub-pixel regions P2, and the third sub-pixel region P3 may be spaced apart and arranged repeatedly. In this case, the non-luminous area FA may also be located between the two second sub-pixel regions P2.

[0069] For example, in the Mini LED display substrate 100 , the base substrate 10 may be a glass substrate or a printed circuit board (PCB) substrate.

[0070] As shown in FIG3 , the display substrate 100 includes a plurality of pixel circuits located between the base substrate 10 and the light emitting unit 30 . The plurality of pixel circuits may include a plurality of metal traces 20 . The plurality of pixel circuits are coupled to the light emitting unit 30 .

[0071] For example, a pixel unit area PU may include a first pixel circuit, a second pixel circuit, and a third pixel circuit. For example, the first pixel circuit is located in the first sub-pixel area P1, the second pixel circuit is located in the second sub-pixel area P2, and the third pixel circuit is located in the third sub-pixel area P3. For another example, the thin film transistor of at least one of the first pixel circuit, the second pixel circuit, and the third pixel circuit may be located in the non-luminous area FA.

[0072] There are many structures of pixel circuits, which can be selected according to actual needs. Exemplarily, the pixel circuit may include: at least two transistors and at least one capacitor. For example, the pixel circuit may have a structure such as "2T1C", "6T1C", "7T1C", "6T2C" or "7T2C". Among them, "T" represents a thin film transistor, the number before "T" represents the number of thin film transistors, and "C" represents a storage capacitor. The number before "C" represents the number of storage capacitors. For example, the thin film transistor of the pixel circuit may be a thin film transistor including polycrystalline silicon or a thin film transistor including an oxide semiconductor.

[0073] 3 , the plurality of metal traces 20 may include a plurality of first metal traces 21 and a plurality of second metal traces 22 . The plurality of second metal traces 22 may be located on a side of the plurality of first metal traces 21 away from the substrate 10 .

[0074] A first insulating layer PVX1 may be provided between the base substrate 10 and the plurality of first metal traces 21. A second insulating layer PVX2, a first adhesive layer OC1, and a third insulating layer PVX3 are stacked sequentially on the surface of the plurality of first metal traces 21 near the plurality of second metal traces 22. The second insulating layer PVX2, the first adhesive layer OC1, and the third insulating layer PVX3 are located between the plurality of first metal traces 21 and the plurality of second metal traces 22. A first through-hole (not shown) may be provided in the second insulating layer PVX2, the first adhesive layer OC1, and the third insulating layer PVX3. The first through-hole is located in the overlapping region between the orthographic projection of the first metal trace 21 on the base substrate 10 and the orthographic projection of the second metal trace 22 on the base substrate 10. A first conductive member (not shown) is provided within the first through-hole. The first conductive member has its two ends coupled to the first metal trace 21 and the second metal trace 22, respectively. The first conductive member can achieve electrical connection between the first metal trace 21 and the second metal trace 22.

[0075] An insulating layer is also provided between the plurality of metal traces 20 and the light-emitting unit 30. For example, a fourth insulating layer PVX4 is provided between the plurality of second metal traces 22 and the light-emitting unit 30, and the fourth insulating layer PVX4 simultaneously covers the third insulating layer PVX3 and the plurality of second metal traces 22. A second adhesive layer OC2 is provided on the surface of the fourth insulating layer PVX4 away from the plurality of second metal traces 22. A second through hole (not shown) may be provided in the second adhesive layer OC2 and the fourth insulating layer PVX4. The second through hole is located in the overlapping area of ​​the orthographic projection of the second metal trace 22 on the base substrate 10 and the orthographic projection of the electrode of the light-emitting unit 30 on the base substrate 10. A second conductive member (not shown) is provided inside the second through hole. The two ends of the second conductive member are respectively coupled to the second metal trace 22 and the electrode of the light-emitting unit 30. The second conductive member can realize electrical connection between the plurality of metal traces 20 and the electrode of the light-emitting unit 30.

[0076] For example, the material of the first insulating layer PVX1, the material of the second insulating layer PVX2, the material of the third insulating layer PVX3, and the material of the fourth insulating layer PVX4 can all be silicon nitride. The material of the first insulating layer PVX1, the material of the second insulating layer PVX2, the material of the third insulating layer PVX3, and the material of the fourth insulating layer PVX4 can be the same or different.

[0077] For example, the material of the first adhesive layer OC1 and the material of the second adhesive layer OC2 may be optically transparent adhesive.

[0078] For example, the plurality of first metal traces 21 may include power signal lines and data signal lines, and the power signal lines and the data signal lines may be provided on the same layer. The plurality of second metal traces 22 may include a plurality of adapters.

[0079] Exemplarily, the material of the metal trace may include copper.

[0080] As shown in FIG3 , the light-emitting unit 30 may include multiple light-emitting devices. The multiple light-emitting devices may be coupled to multiple pixel circuits, respectively. For example, the multiple light-emitting devices may be coupled to multiple pixel circuits, respectively, in a one-to-one correspondence. For another example, at least two light-emitting devices may be coupled to one pixel circuit.

[0081] Exemplarily, the light emitting device may include OLED, Mini LED or Micro LED.

[0082] FIG. 6 is a structural diagram of a low-reflection film according to some embodiments.

[0083] 6 , the low-reflection film 40 may include multiple metal layers 413 and multiple inorganic layers 424 , which are alternately stacked. The refractive index of the metal layer 413 is greater than that of the inorganic layer 424 .

[0084] There are at least two metal layers 413 and at least two inorganic layers 424. The number of metal layers 413 and inorganic layers 424 can be the same or different.

[0085] Exemplarily, the material of the metal layer 413 may include at least one of molybdenum, copper, aluminum, silver, and alloys thereof.

[0086] For example, the inorganic layer 424 has a high light transmittance requirement and needs to be able to isolate the inorganic layer 424 from water and oxygen corrosion. The inorganic layer 424 may be made of silicon nitride, silicon dioxide, or silicon trioxide.

[0087] It should be noted that in the low-reflection film 40 of the dual-emission display device 1000, the multiple inorganic layers 424 are made of the same material. In other low-reflection films 40 of the display devices 1000, the multiple inorganic layers 424 can be made of the same or different materials. The multiple metal layers 413 in the low-reflection film 40 of the display device 1000 can be made of the same or different materials.

[0088] In some examples, as shown in FIG6 , the low-reflection film 40 may include two metal layers 413 and two inorganic layers 424. The two metal layers 413 include a first metal layer 41 and a second metal layer 43, respectively, and the two inorganic layers 424 include a first inorganic layer 42 and a second inorganic layer 44, respectively. The first inorganic layer 42 is located on one side of the first metal layer 41, the second metal layer 43 is located on a side of the first inorganic layer 42 away from the first metal layer 41, and the second inorganic layer 44 is located on a side of the second metal layer 43 away from the first inorganic layer 42. The refractive index of the first inorganic layer 42 is lower than that of the first metal layer 41, the refractive index of the second metal layer 43 is higher than that of the first inorganic layer 42, and the refractive index of the second inorganic layer 44 is lower than that of the second metal layer 43.

[0089] For example, the first metal layer 41 and the second metal layer 43 may both be made of metal molybdenum. For example, the refractive index of the first metal layer 41 and the refractive index of the second metal layer 43 may both be 2.3.

[0090] For example, the materials of the first inorganic layer 42 and the second inorganic layer 44 may both include silicon nitride. For example, the refractive index of the first inorganic layer 42 and the refractive index of the second inorganic layer 44 may both be 2.

[0091] In this way, the refractive index of the first metal layer 41, the refractive index of the first inorganic layer 42, the refractive index of the second metal layer 43, and the refractive index of the second inorganic layer 44 follow a high-low-high-low pattern. Incident light entering the low-reflection film 40 can be refracted or totally reflected at the interfaces between adjacent layers among the second inorganic layer 44, the second metal layer 43, the first inorganic layer 42, and the first metal layer 41. Therefore, incident light entering the low-reflection film 40 can undergo multiple refractions or total reflections within the low-reflection film 40. On the one hand, the multiple refractions or total reflections can consume the energy of the incident light, thereby increasing the amount of incident light absorbed and blocked by the low-reflection film 40, reducing the reflectivity of the low-reflection film 40 to the incident light, and improving the light-shielding effect of the low-reflection film 40. On the other hand, coherent light will be generated during the process of multiple refractions or total reflection, and destructive interference is likely to occur between the two columns of coherent light respectively at the peak and the trough, which can further increase the amount of incident light absorbed and blocked by the low-reflection film 40, further reduce the reflectivity of the low-reflection film 40 to the incident light, and thus further improve the light-shielding effect of the low-reflection film 40.

[0092] In some examples, the low-reflection film 40 may include N metal layers 413 and multiple inorganic layers 424, which are alternately stacked in sequence. N is a positive integer greater than or equal to three, for example, three, four, five, or six.

[0093] For example, the low-reflection film 40 may include three metal layers 413 and three inorganic layers 424, wherein the three metal layers 413 and the three inorganic layers 424 are alternately stacked. For another example, the low-reflection film 40 may include three metal layers 413 and four inorganic layers 424, wherein the three metal layers 413 and three of the inorganic layers 424 are alternately stacked, and the other inorganic layer 424 is located on a side of the three inorganic layers 424 away from the metal layer 413.

[0094] In this way, incident light entering the low-reflection film 40 can be refracted or totally reflected at the interfaces between adjacent layers in the N metal layers 413 and the multiple inorganic layers 424. Therefore, the incident light entering the low-reflection film 40 can undergo multiple refractions or total reflections in the low-reflection film 40. The low-reflection film 40 can consume more energy of the incident light, and destructive interference is more likely to occur during the multiple refractions or total reflections. This can significantly increase the amount of incident light absorbed and blocked by the low-reflection film 40, reduce the reflectivity of the low-reflection film 40 to the incident light, and thus significantly improve the light-shielding effect of the low-reflection film 40.

[0095] In some embodiments, as shown in Figure 6, in the direction perpendicular to the first metal layer 41, the size L of the low-reflection film 40 is greater than or equal to 1800A and less than or equal to 2500A. For example, L can be 1800A, 1850A, 1876.5A, 1895A, 1900A, 1950A, 2000A, 2050A, 2100A, 2200A, 2350A, 2400A, 2450A or 2500A.

[0096] Compared to the black matrix organic film layer, the dimension L (ie, thickness) of the low-reflection film 40 is smaller, which is beneficial for reducing the overall thickness of the display substrate 100 .

[0097] In some embodiments, as shown in FIG. 6 , in a direction perpendicular to the first metal layer 41 , a size L1 of the first metal layer 41 is greater than a size L2 of the first inorganic layer 42 .

[0098] In this way, the optical path of the incident light entering the first metal layer 41 after being refracted at the interface between the first inorganic layer 42 and the first metal layer 41 can be extended, the energy of the incident light can be consumed, and the reflectivity of the low-reflection film 40 to the incident light can be reduced, thereby improving the shading effect of the low-reflection film 40.

[0099] In some examples, in a direction perpendicular to the first metal layer 41, the ratio of the size L1 of the first metal layer 41 to the size L2 of the first inorganic layer 42 is greater than or equal to 2.5 and less than or equal to 3.5. For example, the ratio of L1 to L2 can be 2.5, 2.66, 2.7, 2.8, 2.9, 3.0, 3.12, 3.2, 3.35, 3.4 or 3.5.

[0100] In this way, the optical path of the incident light entering the first metal layer 41 after being refracted at the interface between the first inorganic layer 42 and the first metal layer 41 can be reasonably extended, the energy of the incident light can be consumed more, and the reflectivity of the low-reflection film 40 to the incident light can be greatly reduced, thereby further improving the shading effect of the low-reflection film 40.

[0101] In some embodiments, as shown in FIG. 6 , in a direction perpendicular to the first metal layer 41 , a dimension L1 of the first metal layer 41 is greater than a dimension L3 of the second metal layer 43 .

[0102] In this way, since the transmittance of the metal layer is lower than that of the inorganic layer, the size of the second metal layer 43 is smaller, the energy consumed by the incident light during refraction or total reflection at the interface between the second inorganic layer 44 and the second metal layer 43, and at the interface between the second metal layer 43 and the first inorganic layer 42 can be relatively stable. Therefore, on the basis of ensuring the shading effect of the low-reflection film 40, the fluctuation range of the reflectivity of the low-reflection film 40 to the incident light is smaller, thereby making the stability and uniformity of the shading effect of the low-reflection film 40 higher.

[0103] In some examples, in a direction perpendicular to the first metal layer 41, the ratio of the dimension L1 of the first metal layer 41 to the dimension L3 of the second metal layer 43 is greater than or equal to 11.5 and less than or equal to 17.5. For example, the ratio of L1 to L3 can be 11.5, 12.2, 12.5, 13.1, 13.5, 14.2, 14.5, 15.2, 15.5, 15.8, 16.2, 16.5, 16.9 or 17.5.

[0104] By reasonably limiting the ratio of the size L1 of the first metal layer 41 to the size L3 of the second metal layer 43, the energy consumed by the incident light during refraction or total reflection at the interface between the first inorganic layer 42 and the second metal layer 43, and at the interface between the second inorganic layer 44 and the second metal layer 43 can be made more stable. This allows the fluctuation range of the reflectivity of the low-reflection film 40 to the incident light to be as small as possible while ensuring the shading effect of the low-reflection film 40, thereby greatly improving the stability and uniformity of the shading effect of the low-reflection film 40.

[0105] In some embodiments, as shown in FIG. 6 , in a direction perpendicular to the first metal layer 41 , a dimension L1 of the first metal layer 41 is greater than a dimension L4 of the second inorganic layer 44 .

[0106] In this way, the size of the second inorganic layer 44 is smaller, which can make the incident light easily refracted or totally reflected at the interface between the second inorganic layer 44 and the second inorganic layer 44 and the second metal layer 43, thereby consuming the energy of the incident light, reducing the reflectivity of the low-reflection film 40 to the incident light, and improving the shading effect of the low-reflection film 40.

[0107] In some examples, in a direction perpendicular to the first metal layer 41, the ratio of the size L1 of the first metal layer 41 to the size L4 of the second inorganic layer 44 is greater than or equal to 2 and less than or equal to 3. For example, the ratio of L1 to L4 can be 2, 2.1, 2.3, 2.35, 2.36, 2.4, 2.5, 2.6, 2.7, 2.8, 2.85, 2.9 or 3.

[0108] By reasonably limiting the ratio of the size L1 of the first metal layer 41 to the size L4 of the second inorganic layer 44, the incident light can be more easily refracted or totally reflected at the interface between the second inorganic layer 44 and the second metal layer 43, thereby consuming more energy of the incident light, greatly reducing the reflectivity of the low-reflection film 40 to the incident light, and greatly improving the shading effect of the low-reflection film 40.

[0109] In some embodiments, as shown in FIG. 6 , in a direction perpendicular to the first metal layer 41 , a dimension L2 of the first inorganic layer 42 is greater than a dimension L3 of the second metal layer 43 .

[0110] In this way, the incident light can be easily refracted or totally reflected at the interface between the second inorganic layer 44 and the second metal layer 43, and at the interface between the second metal layer 43 and the first inorganic layer 42, thereby consuming the energy of the incident light and improving the light-shielding effect of the low-reflection film 40. In addition, since the second metal layer 43 is relatively small in size, the energy consumed by the incident light during the process of refraction or total reflection at the interface between the second inorganic layer 44 and the second metal layer 43, and at the interface between the second metal layer 43 and the first inorganic layer 42 can be relatively stable. Therefore, on the basis of improving the light-shielding effect of the low-reflection film 40, the fluctuation range of the reflectivity of the low-reflection film 40 to the incident light is reduced, thereby making the light-shielding effect of the low-reflection film 40 more stable and uniform.

[0111] In some examples, in a direction perpendicular to the first metal layer 41, the ratio of the size L2 of the first inorganic layer 42 to the size L3 of the second metal layer 43 is greater than or equal to 4 and less than or equal to 6.5. For example, the ratio of L2 to L3 can be 4, 4.2, 4.5, 4.9, 5, 5.2, 5.5, 5.8, 6, 6.3 or 6.5.

[0112] By reasonably limiting the ratio of the size L2 of the first inorganic layer 42 to the size L3 of the second metal layer 43, incident light can be more easily refracted or totally reflected at the interface between the second inorganic layer 44 and the second metal layer 43, and at the interface between the second metal layer 43 and the first inorganic layer 42, thereby consuming more energy of the incident light and significantly improving the light-shielding effect of the low-reflection film 40. Furthermore, the energy consumed during the refraction or total reflection of incident light at the interface between the second inorganic layer 44 and the second metal layer 43, and at the interface between the second metal layer 43 and the first inorganic layer 42 can be made more stable. Thus, while significantly improving the light-shielding effect of the low-reflection film 40, the fluctuation range of the reflectivity of the low-reflection film 40 to incident light can be minimized, thereby further enhancing the stability and uniformity of the light-shielding effect of the low-reflection film 40.

[0113] In some embodiments, as shown in FIG. 6 , in a direction perpendicular to the first metal layer 41 , a dimension L4 of the second inorganic layer 44 is greater than a dimension L3 of the second metal layer 43 .

[0114] Since the second metal layer 43 is relatively small in size, the energy consumed by the incident light during refraction or total reflection at the interface between the second inorganic layer 44 and the second metal layer 43, and at the interface between the second metal layer 43 and the first inorganic layer 42 can be relatively stable. Therefore, on the basis of ensuring the shading effect of the low-reflection film 40, the fluctuation range of the reflectivity of the low-reflection film 40 to the incident light is smaller, thereby improving the stability and uniformity of the shading effect of the low-reflection film 40.

[0115] In some examples, in a direction perpendicular to the first metal layer 41, the ratio of the size L4 of the second inorganic layer 44 to the size L3 of the second metal layer 43 is greater than or equal to 4.5 and less than or equal to 7. For example, the ratio of L4 to L3 can be 4.5, 4.8, 5, 5.4, 5.54, 5.6, 5.8, 6, 6.2, 6.4, 6.8, 6.9 or 7.

[0116] By reasonably limiting the ratio of the size L4 of the second inorganic layer 44 to the size L3 of the second metal layer 43, the energy consumed by the incident light during refraction or total reflection at the interface between the second inorganic layer 44 and the second metal layer 43, and at the interface between the second metal layer 43 and the first inorganic layer 42 can be made more stable. This allows the fluctuation range of the reflectivity of the low-reflection film 40 to the incident light to be smaller while ensuring the shading effect of the low-reflection film 40, thereby greatly improving the stability and uniformity of the shading effect of the low-reflection film 40.

[0117] In some examples, as shown in FIG6 , in a direction perpendicular to the first metal layer 41 , a dimension L1 of the first metal layer 41 is greater than or equal to 1000A and less than or equal to 1100A. For example, L1 may be 1000A, 1020A, 1050A, 1080A, or 1100A.

[0118] In some examples, as shown in Figure 6, in the direction perpendicular to the first metal layer 41, the size L2 of the first inorganic layer 42 is greater than or equal to 350A and less than or equal to 395A. For example, L2 can be 350A, 360A, 376A, 380A, 390A or 395A.

[0119] In some examples, as shown in FIG6 , in a direction perpendicular to the first metal layer 41 , a dimension L3 of the second metal layer 43 is greater than or equal to 65A and less than or equal to 85A. For example, L3 may be 65A, 68A, 70A, 76.5A, 80A, or 85A.

[0120] In some examples, as shown in Figure 6, in the direction perpendicular to the first metal layer 41, the size L4 of the second inorganic layer 44 is greater than or equal to 400A and less than or equal to 450A. For example, L4 can be 400A, 405A, 410A, 420A, 424A, 435A, 440A, 445A or 450A.

[0121] In which, when the wavelength of the incident light is greater than or equal to 400nm and less than or equal to 700nm (for example, 400nm, 420nm, 480nm, 500nm, 550nm, 600nm, 650nm or 700nm), the reflectivity of the low-reflection film 40 to the incident light is greater than or equal to 2.5% and less than or equal to 4% (for example, 2.5%, 2.6%, 2.8%, 3%, 3.25%, 3.65%, 3.85% or 4%), and the difference between the maximum and minimum values ​​of the reflectivity of the low-reflection film 40 to the incident light is greater than or equal to 0.5% and less than or equal to 1.5% (for example, 0.5%, 0.6%, 0.8%, 0.85%, 1%, 1.05%, 1.15%, 1.25%, 1.38% or 1.5%).

[0122] By reasonably limiting the size L1 of the first metal layer 41, the size L2 of the first inorganic layer 42, the size L3 of the second metal layer 43, and the size L4 of the second inorganic layer 44, the number of times incident light entering the low-reflection film 40 is refracted or totally reflected at the interfaces between adjacent layers among the second inorganic layer 44, the second metal layer 43, the first inorganic layer 42, and the first metal layer 41 can be increased, thereby extending the optical path of the incident light in the low-reflection film 40. Furthermore, destructive interference is more likely to occur during multiple refractions or total reflections, thereby consuming more energy from the incident light, reducing the reflectivity of the low-reflection film 40 to the incident light, and improving the light-shielding effect of the low-reflection film 40. Furthermore, while maintaining the light-shielding effect of the low-reflection film 40, the fluctuation range of the reflectivity of the low-reflection film 40 to the incident light is reduced, thereby improving the stability and uniformity of the light-shielding effect of the low-reflection film 40.

[0123] Fig. 7 is a cross-sectional view of a display substrate along line AA' in Fig. 2 in some other embodiments. Fig. 8 is a cross-sectional view of a display substrate along line AA' in Fig. 2 in some other embodiments.

[0124] In some embodiments, as shown in Figures 3, 7 and 8, the low-reflection film 40 can be located on at least one side of the multiple metal traces 20 close to the display side. It can be understood that one layer of low-reflection film 40 can be located on one side of the multiple metal traces 20 close to at least one display side, or two layers of low-reflection film 40 can be located on each side of the multiple metal traces 20 close to the two display sides.

[0125] On the one hand, because both the metal layer and the inorganic layer in the low-reflection film 40 have excellent thermal stability and high hardness, after the low-reflection film 40 is formed, the laser etching of the metal leads located on the side of the display substrate 100 will not damage the low-reflection film 40, thereby improving the manufacturing yield of the display substrate 100 and the display device 1000. On the other hand, due to the excellent light-shielding effect of the low-reflection film 40, the low-reflection film 40 can absorb a large amount of incident light that would otherwise be directed toward the metal traces 20, resulting in less incident light being reflected from the metal traces 20. This reduces the reflectivity of the metal traces 20 in the display substrate 100 to incident light and improves the "one-piece black" display effect of the display substrate 100 and the display device 1000. Furthermore, due to the high stability and uniformity of the light-shielding effect of the low-reflection film 40, the reflectivity of the metal traces 20 in the display substrate 100 to incident light fluctuates within a smaller range, further improving the "one-piece black" display effect of the display substrate 100 and the display device 1000.

[0126] In some examples, as shown in FIG. 3 , the display substrate 100 is a top emission type display substrate 100 or a bottom emission type display substrate 100 , and the low reflection film 40 may be located on a side of the light emitting unit 30 away from the base substrate 10 .

[0127] The low-reflection film 40 can block and absorb the incident light that would otherwise be directed toward the metal trace 20, so that less incident light can be reflected from the metal trace 20, thereby reducing the reflectivity of the metal trace 20 in the top-emitting display substrate 100 or the bottom-emitting display substrate 100 to the incident light, and improving the integral black display effect of the top-emitting display substrate 100 or the bottom-emitting display substrate 100.

[0128] For example, the display substrate 100 may further include a color filter. The color filter may be located on a side of the light-emitting unit 30 away from the base substrate 10. The color filter is disposed in the light-emitting area EA, and the low-reflection film 40 is disposed in the non-light-emitting area FA. The distance between the color filter and the base substrate 10 may be the same as or different from the distance between the low-reflection film 40 and the base substrate 10.

[0129] For example, the display substrate 100 may further include a touch layer. The touch layer may be located on a side of the light emitting unit 30 away from the base substrate 10 . The low-reflection film 40 is located on a side of the touch layer away from the light emitting unit 30 .

[0130] The low-reflection film 40 can block and absorb the incident light that would otherwise be directed toward the touch layer, as well as the incident light that passes through the touch layer and the light-emitting unit 30 and enters the metal trace 20, so that less incident light can be reflected from the touch layer and the metal trace 20, thereby reducing the reflectivity of the touch layer and the metal trace 20 in the display substrate 100 to the incident light, thereby improving the display effect of the display substrate 100.

[0131] In some examples, as shown in Figures 3, 7, and 8, the display substrate 100 is a dual-emission display substrate 100, and the low-reflection film 40 may include a first low-reflection film 401 or a second low-reflection film 402. For example, as shown in Figure 7, the first low-reflection film 401 may be located between the base substrate 10 and the plurality of metal traces 20. For another example, when the display substrate 100 in Figure 3 is a dual-emission display substrate 100, the second low-reflection film 402 may be located on the side of the light-emitting unit 30 away from the base substrate 10.

[0132] The low-reflection film 40 can block and absorb the incident light that would originally be emitted from one display side to the metal trace 20, so that less incident light can be reflected from the metal trace 20, thereby reducing the reflectivity of the incident light emitted from one display side to the metal trace 20 in the double-sided emission display substrate 100, and improving the display effect of one display side being completely black in the double-sided emission display substrate 100.

[0133] In some examples, as shown in FIG8 , the display substrate 100 is a double-sided emission type display substrate 100, and the low-reflection film 40 may include a first low-reflection film 401 and a second low-reflection film 402. The first low-reflection film 401 is located between the base substrate 10 and the plurality of metal traces 20. The second low-reflection film 402 is located on a side of the light-emitting unit 30 away from the base substrate 10.

[0134] The low-reflection film 40 can block and absorb the incident light that would originally be emitted from the two display sides to the metal traces 20, so that less incident light can be reflected from the metal traces 20, thereby reducing the reflectivity of the incident light from the two display sides to the metal traces 20 in the double-sided emission display substrate 100, and improving the overall black display effect of the double-sided emission display substrate 100.

[0135] FIG. 9 is a diagram comparing display effects of a display device according to some embodiments with display effects of other display devices.

[0136] As shown in FIG9 , in a non-luminous region where no light-emitting devices are arranged, display device 2001 includes, in order, a glass substrate 1, a first insulating layer 2, a second insulating layer 3, a first adhesive layer 4, a third insulating layer 5, a second adhesive layer 6, and a fourth insulating layer 7, along a direction perpendicular to the display device. Display device 2001 does not include a low-reflection film layer. Compared to display device 2001, display device 2002 includes a black matrix (BM) organic film layer 8 between the second adhesive layer 6 and the fourth insulating layer 7. The overall black display effect of display device 2002 is superior to that of display device 2001. Display device 2003 includes amorphous silicon (a-Si) 9 between the glass substrate 1 and the first insulating layer 2. The overall black display effect of display device 2002 is superior to that of display device 2003. Compared with display device 2002, display device 2004 uses amorphous silicon (a-Si) 9 to replace the first insulating layer 2, and uses a flat layer PLN to replace the first glue layer 4. The overall thickness of display device 2004 is thinner, and the display effect of display device 2002 in black is better than that of display device 2004 in black.

[0137] As shown in FIG9 , compared to display device 2001, display device 1000 provided in the embodiment of the present disclosure includes a low-reflection film 40 disposed between second adhesive layer 6 and fourth insulating layer 7. Low-reflection film 40 includes a first metal layer 41, a first inorganic layer 42, a second metal layer 43, and a second inorganic layer 44. Compared to display devices 2001, 2002, 2003, and 2004, display device 1000 exhibits the best display effect with its all-black display.

[0138] Figure 10 is a graph comparing the reflectivity of incident light for low-reflection films with different first inorganic layer thicknesses according to some embodiments. Figures 11 and 12 are graphs comparing the fluctuation range of the reflectivity of incident light for low-reflection films with different thicknesses according to some embodiments. Figure 13 is a graph comparing the reflectivity of incident light for low-reflection films with different second inorganic layer thicknesses according to some embodiments.

[0139] Schemes 1 through 11 respectively include low-reflection films 40 having different thicknesses L1 of the first metal layer 41, L2 of the first inorganic layer 42, L3 of the second metal layer 43, and / or L4 of the second inorganic layer 44. The maximum and minimum values, as well as the fluctuation ranges, of the reflectivity of the low-reflection films 40 for incident light in Schemes 1 through 11 are shown in Table 1 below:

[0140] Table 1

[0141] In Table 1, "Max" represents the maximum value of the reflectivity of the low-reflection film 40 to the incident light; "Min" represents the minimum value of the reflectivity of the low-reflection film 40 to the incident light; and "Fluctuation" represents the difference between the maximum value of the reflectivity of the low-reflection film 40 to the incident light and the minimum value of the reflectivity of the low-reflection film 40 to the incident light, that is, the fluctuation range of the reflectivity of the low-reflection film 40 to the incident light.

[0142] 10 and the data in Table 1, it can be seen that the thickness L2 of the first inorganic layer 42 is positively correlated with the reflectivity of the low-reflection film 40 to the incident light, that is, the greater the thickness L2 of the first inorganic layer 42, the greater the reflectivity of the corresponding low-reflection film 40 to the incident light.

[0143] 11 , 12 , and the data in Table 1, it can be seen that: there is no obvious correlation between the thickness L3 of the second metal layer 43 and the reflectivity of the low-reflection film 40 to the incident light; however, there is a positive correlation between the thickness L3 of the second metal layer 43 and the fluctuation range of the reflectivity of the low-reflection film 40 to the incident light; that is, the smaller the thickness L3 of the second metal layer 43, the smaller the fluctuation range of the reflectivity of the corresponding low-reflection film 40 to the incident light.

[0144] 13 and the data in Table 1, it can be seen that the thickness L4 of the second inorganic layer 44 is negatively correlated with the reflectivity of the low-reflection film 40 to the incident light, that is, the greater the thickness L4 of the second inorganic layer 44, the smaller the reflectivity of the corresponding low-reflection film 40 to the incident light.

[0145] In summary, in the low-reflection film 40, the display substrate 100 and the display device 1000 provided by the embodiments of the present disclosure, the refractive index of the first metal layer 41, the refractive index of the first inorganic layer 42, the refractive index of the second metal layer 43 and the refractive index of the second inorganic layer 44 sequentially present a high-low-high-low pattern. The incident light entering the low-reflection film 40 can be refracted or totally reflected at the interface between the adjacent layers in the second inorganic layer 44, the second metal layer 43, the first inorganic layer 42 and the first metal layer 41. Therefore, the incident light entering the low-reflection film 40 can undergo multiple refractions or total reflections in the low-reflection film 40; the energy of the incident light can be consumed in the process of multiple refractions or total reflections, and coherent light can also be generated in the process of multiple refractions or total reflections. Destructive interference is likely to occur between the two columns of coherent light at the peak and the trough respectively, which can further increase the incident light reflected by the low-reflection film 40. The amount of incident light absorbed and blocked reduces the reflectivity of the low-reflection film 40 to the incident light, so that the light-shielding effect of the low-reflection film 40 is better, and the stability and uniformity of the light-shielding effect of the low-reflection film 40 are higher; since the metal layer and the inorganic layer in the low-reflection film 40 both have better thermal stability and higher hardness, after the low-reflection film 40 is formed, the low-reflection film 40 will not be damaged during the laser etching of the metal leads located on the side of the display substrate 100, which can improve the production yield of the display substrate 100 and the display device 1000; the low-reflection film 40 can absorb a large amount of incident light that would originally be directed to the metal traces 20, so that less incident light can be reflected from the metal traces 20, thereby reducing the reflectivity of the metal traces 20 in the display substrate 100 to the incident light, and improving the integrated black display effect of the display substrate 100 and the display device 1000.

[0146] 14 to 18 are flow charts of methods for preparing a display substrate according to some embodiments.

[0147] As shown in FIG. 14 , the embodiment of the present disclosure further provides a method for preparing a display substrate 100 , which may include steps S100 to S300 .

[0148] Step S100: forming a base substrate 10. The base substrate 10 defines a light emitting area EA and a non-light emitting area FA other than the light emitting area. The structural features of the base substrate 10 have been described in detail above and will not be repeated here.

[0149] The substrate 10 may be a rigid substrate or a flexible substrate. For example, the substrate 10 may be made of polyethylene terephthalate (PET), polyimide (PI), cycloolefin polymer (COP), or the like.

[0150] For example, in the Mini LED display substrate 100 , the base substrate 10 may be a glass substrate or a printed circuit board (PCB) substrate.

[0151] Step S200: forming a plurality of metal traces 20 on one side of the base substrate 10. The plurality of metal traces 20 are disposed in the non-light emitting area FA.

[0152] As shown in Figure 3, the display substrate 100 includes a plurality of pixel circuits located on a base substrate 10. The plurality of pixel circuits may include a plurality of metal traces 20. The structural features of the pixel circuits have been described in detail above and will not be repeated here.

[0153] The plurality of metal traces 20 may include a plurality of first metal traces 21 and a plurality of second metal traces 22. The plurality of second metal traces 22 may be located on a side of the plurality of first metal traces 21 away from the substrate 10.

[0154] Step S200 may include: forming a first insulating layer PVX1 on one side of the base substrate 10 through a deposition process. Then, forming a full-layer first metal material layer through a deposition process on the surface of the first insulating layer PVX1 facing away from the base substrate 10. Then, removing the first metal material layer within the luminous area EA through an etching process, retaining the first metal material layer with a corresponding pattern within the non-luminous area FA, thereby forming a plurality of first metal traces 21. Then, forming a second insulating layer PVX2 through a deposition process on the surface of the first insulating layer PVX1 and the plurality of first metal traces 21 facing away from the base substrate 10. Then, forming a first adhesive layer OC1 through a coating, exposure, and development process on the surface of the second insulating layer PVX2 facing away from the base substrate 10. Then, forming a third insulating layer PVX3 through a deposition process on the surface of the first adhesive layer OC1 facing away from the base substrate 10. Then, forming first through-holes (not shown) partially exposing the first metal traces 21 through a dry etching process in the second insulating layer PVX2, the first adhesive layer OC1, and the third insulating layer PVX3. Next, a second metal layer is formed by a deposition process on the surface of the third insulating layer PVX3 away from the base substrate 10. An etching process is then used to remove the second metal layer within the light-emitting area EA, while retaining the second metal layer with the corresponding pattern within the non-light-emitting area FA, thereby forming a plurality of second metal traces 22.

[0155] The first through-hole is located in the overlapping region of the orthographic projection of the first metal trace 21 on the substrate 10 and the orthographic projection of the second metal trace 22 on the substrate 10. After the first through-hole is formed, a first conductive member (not shown) is further formed inside the first through-hole, so that the two ends of the first conductive member are respectively coupled to the first metal trace 21 and the second metal trace 22, and the first conductive member can realize the electrical connection between the first metal trace 21 and the second metal trace 22.

[0156] After step S200, the process further includes forming a fourth insulating layer PVX4 by a deposition process on a surface of the plurality of second metal traces 22 and the third insulating layer PVX3 away from the plurality of first metal traces 21, the fourth insulating layer PVX4 covering both the plurality of second metal traces 22 and the third insulating layer PVX3. Subsequently, forming a second adhesive layer OC2 by coating, exposing, and developing processes on a surface of the fourth insulating layer PVX4 away from the plurality of second metal traces 22.

[0157] Exemplarily, the material of the metal trace may include copper.

[0158] For example, the plurality of first metal traces 21 may include power signal lines and data signal lines, and the power signal lines and the data signal lines may be provided on the same layer. The plurality of second metal traces 22 may include a plurality of adapters.

[0159] For example, the material of the first insulating layer PVX1, the material of the second insulating layer PVX2, the material of the third insulating layer PVX3, and the material of the fourth insulating layer PVX4 can all be silicon nitride. The material of the first insulating layer PVX1, the material of the second insulating layer PVX2, the material of the third insulating layer PVX3, and the material of the fourth insulating layer PVX4 can be the same or different.

[0160] For example, the material of the first adhesive layer OC1 and the material of the second adhesive layer OC2 may be optically transparent adhesive.

[0161] Step S300: A light-emitting unit 30 is formed on a side of the plurality of metal traces 20 away from the substrate 10. The light-emitting unit 30 is disposed in the light-emitting area EA. The light-emitting unit 30 may include a plurality of light-emitting devices. The plurality of light-emitting devices may be coupled to a plurality of pixel circuits, respectively. For example, the plurality of light-emitting devices may be coupled to a plurality of pixel circuits, respectively, in a one-to-one correspondence. In another example, at least two light-emitting devices may be coupled to a single pixel circuit.

[0162] In some examples, as shown in FIG3 , step S300 may include forming a second through hole partially exposing the second metal trace 22 in the second adhesive layer OC2 and the fourth insulating layer PVX4 using a dry etching process. Thereafter, a light-emitting unit 30 composed of a plurality of light-emitting devices is formed on a surface of the second adhesive layer OC2 away from the base substrate 10 .

[0163] The second through-hole is located within the overlapping region of the orthographic projection of the second metal trace 22 on the base substrate 10 and the orthographic projection of the electrode of the light-emitting device in the light-emitting unit 30 on the base substrate 10. After the second through-hole is formed, a second conductive member (not shown) is further formed within the second through-hole, such that the two ends of the second conductive member are respectively coupled to the second metal trace 22 and the electrode of the light-emitting unit 30. The second conductive member can achieve electrical connection between multiple metal traces 20 and the electrodes of the light-emitting unit 30.

[0164] Exemplarily, the light emitting device may include OLED, Mini LED or Micro LED.

[0165] As shown in FIG14 , the display substrate 100 may be a top-emitting display substrate 100, a bottom-emitting display substrate 100, or a double-sided emission display substrate 100. The method for preparing the display substrate 100 may further include step S400. Step S400: After step S300, a low-reflection film 40 is formed on a side of the light-emitting unit 30 away from the base substrate 10.

[0166] The low-reflection film 40 is disposed in the non-luminous area FA. The low-reflection film 40 may include multiple metal layers 413 and multiple inorganic layers 424. The multiple metal layers 413 and the multiple inorganic layers 424 are alternately stacked. The refractive index of the metal layer 413 is greater than the refractive index of the inorganic layer 424.

[0167] In some examples, as shown in FIG6 , the low-reflection film 40 may include a first metal layer 41, a first inorganic layer 42, a second metal layer 43, and a second inorganic layer 44. The first inorganic layer 42 is located on one side of the first metal layer 41, and the refractive index of the first inorganic layer 42 is lower than the refractive index of the first metal layer 41. The second metal layer 43 is located on a side of the first inorganic layer 42 away from the first metal layer 41, and the refractive index of the second metal layer 43 is higher than the refractive index of the first inorganic layer 42. The second inorganic layer 44 is located on a side of the second metal layer 43 away from the first inorganic layer 42, and the refractive index of the second inorganic layer 44 is lower than the refractive index of the second metal layer 43.

[0168] For example, the first metal layer 41 and the second metal layer 43 may both be made of metal molybdenum. For example, the refractive index of the first metal layer 41 and the refractive index of the second metal layer 43 may both be 2.3.

[0169] For example, the first inorganic layer 42 and the second inorganic layer 44 may both be made of silicon nitride. For example, the refractive index of the first inorganic layer 42 and the refractive index of the second inorganic layer 44 may both be 2.

[0170] As shown in FIG. 15 , forming the low-reflection film 40 in step S400 may include step 451 and step 452 .

[0171] Step 451 : On the side of the light emitting unit 30 away from the base substrate 10 , a first low-reflection base film is formed by sequentially forming a first metal layer 41 , a first inorganic layer 42 , a second metal layer 43 and a second inorganic layer 44 stacked in layers.

[0172] Illustratively, step 451 may include: forming a first metal layer 41 as a whole layer on a side of the light-emitting unit 30 away from the base substrate 10 using an evaporation process or a deposition process. Thereafter, forming a first inorganic layer 42 as a whole layer on a side of the first metal layer 41 away from the base substrate 10 using a deposition process. Thereafter, forming a second metal layer 43 as a whole layer on a side of the first inorganic layer 42 away from the first metal layer 41 using an evaporation process or a deposition process. Thereafter, forming a second inorganic layer 44 as a whole layer on a side of the second metal layer 43 away from the first inorganic layer 42 using a deposition process. The first metal layer 41, the first inorganic layer 42, the second metal layer 43, and the second inorganic layer 44, stacked in sequence as a whole, together form a first low-reflection base film.

[0173] Step 452 : using a dry etching process to remove the first low-reflection base film located in the light-emitting area EA, and retaining the first low-reflection base film located in the non-light-emitting area FA as the low-reflection film 40 .

[0174] In this way, the refractive index of the first metal layer 41, the refractive index of the first inorganic layer 42, the refractive index of the second metal layer 43, and the refractive index of the second inorganic layer 44 follow a high-low-high-low pattern. Incident light entering the low-reflection film 40 can be refracted or totally reflected at the interfaces between adjacent layers among the second inorganic layer 44, the second metal layer 43, the first inorganic layer 42, and the first metal layer 41. Therefore, incident light entering the low-reflection film 40 can undergo multiple refractions or total reflections within the low-reflection film 40. On the one hand, the multiple refractions or total reflections can consume the energy of the incident light, thereby increasing the amount of incident light absorbed and blocked by the low-reflection film 40, reducing the reflectivity of the low-reflection film 40 to the incident light, and improving the light-shielding effect of the low-reflection film 40. On the other hand, coherent light will be generated during the process of multiple refractions or total reflection, and destructive interference is likely to occur between the two columns of coherent light respectively at the peak and the trough, which can further increase the amount of incident light absorbed and blocked by the low-reflection film 40, further reduce the reflectivity of the low-reflection film 40 to the incident light, and thus further improve the light-shielding effect of the low-reflection film 40.

[0175] Exemplarily, as shown in Figure 6, in the direction perpendicular to the first metal layer 41, the size L of the low-reflection film 40 is greater than or equal to 1800A and less than or equal to 2500A. For example, L can be 1800A, 1850A, 1876.5A, 1895A, 1900A, 1950A, 2000A, 2050A, 2100A, 2200A, 2350A, 2400A, 2450A or 2500A.

[0176] For example, forming the stacked first metal layer 41, first inorganic layer 42, second metal layer 43, and second inorganic layer 44 in step 451 may include: forming the first metal layer 41 with a thickness of 1000 Å using an evaporation process or a deposition process. Then, forming the first inorganic layer 42 with a thickness of 376 Å on the side of the first metal layer 41 away from the base substrate 10 using a deposition process. Then, forming the second metal layer 43 with a thickness of 76.5 Å on the side of the first inorganic layer 42 away from the first metal layer 41 using an evaporation process or a deposition process. Then, forming the second inorganic layer 44 with a thickness of 424 Å on the side of the second metal layer 43 away from the first inorganic layer 42 using a deposition process.

[0177] In some examples, the low-reflection film 40 may include N metal layers 413 and multiple inorganic layers 424, which are alternately stacked in sequence. N is a positive integer greater than or equal to three, for example, three, four, five, or six.

[0178] Step 451 may include forming a first low-reflection base film on a side of the light-emitting unit 30 away from the base substrate 10 by alternately forming a stack of N metal layers 413 and a plurality of inorganic layers 424. For example, in step 451, the N metal layers 413 and the plurality of inorganic layers 424 may be alternately formed in a stacked manner through a deposition process.

[0179] In this way, incident light entering the low-reflection film 40 can be refracted or totally reflected at the interfaces between adjacent layers in the N metal layers 413 and the multiple inorganic layers 424. Therefore, the incident light entering the low-reflection film 40 can undergo multiple refractions or total reflections in the low-reflection film 40. The low-reflection film 40 can consume more energy of the incident light, and destructive interference is more likely to occur during the multiple refractions or total reflections. This can significantly increase the amount of incident light absorbed and blocked by the low-reflection film 40, reduce the reflectivity of the low-reflection film 40 to the incident light, and thus significantly improve the light-shielding effect of the low-reflection film 40.

[0180] 7 and 8 , the display substrate 100 may be a dual-emission display substrate 100. A low-reflection film 40 may be formed on at least one display side of the plurality of metal traces 20 near the dual-emission display substrate 100.

[0181] In some examples, as shown in FIG7 , a low-reflection film 40 is formed on a display side of the dual-emission display substrate 100 near the plurality of metal traces 20. As shown in FIG16 , the method for preparing the display substrate 100 may further include step S500 . Step S500 : Before step S200 , a low-reflection film 40 is formed on one side of the base substrate 10 .

[0182] For example, as shown in FIG. 17 , forming the low-reflection film 40 in step S500 may include step 551 and step 552 .

[0183] Step 551: On one side of the base substrate 10, a second low-reflection base film is formed by sequentially forming a second inorganic layer 44, a second metal layer 43, a first inorganic layer 42, and a first metal layer 41 in a stacked manner. Exemplarily, step 551 may include: forming the second inorganic layer 44 in a stacked manner on one side of the base substrate 10 using a deposition process. Then, forming the second metal layer 43 in a stacked manner on the side of the second inorganic layer 44 facing away from the base substrate 10 using an evaporation process or a deposition process. Then, forming the first inorganic layer 42 in a stacked manner on the side of the second metal layer 43 facing away from the second inorganic layer 44 using a deposition process. Then, forming the first metal layer 41 in a stacked manner on the side of the first inorganic layer 42 facing away from the second metal layer 43 using an evaporation process or a deposition process. The stacked second inorganic layer 44, the second metal layer 43, the first inorganic layer 42, and the first metal layer 41 in a stacked manner together form the second low-reflection base film.

[0184] Step 552 : using a dry etching process to remove the second low-reflection base film located in the light-emitting area EA, and retaining the second low-reflection base film located in the non-light-emitting area FA as the low-reflection film 40 .

[0185] The structure and material properties of the low-reflection film 40 have been described in detail above and will not be repeated here.

[0186] The low-reflection film 40 can block and absorb the incident light that would originally be emitted from one display side to the metal trace 20, so that less incident light can be reflected from the metal trace 20, thereby reducing the reflectivity of the incident light emitted from one display side to the metal trace 20 in the double-sided emission display substrate 100, and improving the display effect of one display side being completely black in the double-sided emission display substrate 100.

[0187] In some examples, as shown in FIG8 , a low-reflection film 40 is formed on both display sides of the plurality of metal traces 20 near the double-sided emission display substrate 100. As shown in FIG18 , the method for preparing the double-sided emission display substrate 100 may sequentially include steps S100, S500, S200, S300, and S400.

[0188] The low-reflection film 40 can block and absorb the incident light that would originally be emitted from the two display sides to the metal traces 20, so that less incident light can be reflected from the metal traces 20, thereby reducing the reflectivity of the incident light from the two display sides to the metal traces 20 in the double-sided emission display substrate 100, and improving the overall black display effect of the double-sided emission display substrate 100.

[0189] In summary, in the display substrate 100 manufactured by the above-described manufacturing method, on the one hand, because both the metal layer and the inorganic layer in the low-reflection film 40 have excellent thermal stability and high hardness, after the low-reflection film 40 is formed, the laser etching of the metal leads located on the side of the display substrate 100 will not damage the low-reflection film 40, thereby improving the manufacturing yield of the display substrate 100 and the display device 1000. On the other hand, because the low-reflection film 40 has an excellent light-shielding effect, it can absorb a large amount of incident light that would otherwise be directed toward the metal traces 20, resulting in less incident light being reflected from the metal traces 20, thereby reducing the reflectivity of the metal traces 20 in the display substrate 100 to the incident light and improving the integrated black display effect of the display substrate 100 and the display device 1000. Furthermore, since the light shielding effect of the low-reflection film 40 is highly stable and uniform, the reflectivity fluctuation range of the metal traces 20 in the display substrate 100 to the incident light is relatively small, further improving the integrated black display effect of the display substrate 100 and the display device 1000.

[0190] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A low reflection film, comprising: A first metal layer; A first inorganic layer, located on one side of the first metal layer; The refractive index of the first inorganic layer is less than the refractive index of the first metal layer; A second metal layer is located on a side of the first inorganic layer away from the first metal layer; the refractive index of the second metal layer is greater than the refractive index of the first inorganic layer; The second inorganic layer is located on a side of the second metal layer away from the first inorganic layer; the refractive index of the second inorganic layer is smaller than the refractive index of the second metal layer.

2. The low-reflection film according to claim 1, wherein: In a direction perpendicular to the first metal layer, the size of the first metal layer is larger than the size of the first inorganic layer; and / or, In a direction perpendicular to the first metal layer, a size of the first metal layer is larger than a size of the second metal layer; and / or, In a direction perpendicular to the first metal layer, a size of the first metal layer is greater than a size of the second inorganic layer.

3. The low-reflection film according to claim 1 or 2, wherein: In a direction perpendicular to the first metal layer, a ratio of a size of the first metal layer to a size of the first inorganic layer is greater than or equal to 2.5 and less than or equal to 3.5; and / or, In a direction perpendicular to the first metal layer, a ratio of a size of the first metal layer to a size of the second metal layer is greater than or equal to 11.5 and less than or equal to 17.5; and / or, In a direction perpendicular to the first metal layer, a ratio of a size of the first metal layer to a size of the second inorganic layer is greater than or equal to 2 and less than or equal to 3.

4. The low-reflection film according to any one of claims 1 to 3, wherein In a direction perpendicular to the first metal layer, the size of the first inorganic layer is larger than the size of the second metal layer; and / or, In a direction perpendicular to the first metal layer, a size of the second inorganic layer is larger than a size of the second metal layer.

5. The low-reflection film according to any one of claims 1 to 4, wherein In a direction perpendicular to the first metal layer, a ratio of a size of the first inorganic layer to a size of the second metal layer is greater than or equal to 4 and less than or equal to 6.5; and / or, In a direction perpendicular to the first metal layer, a ratio of a size of the second inorganic layer to a size of the second metal layer is greater than or equal to 4.5 and less than or equal to 7.

6. The low reflection film according to any one of claims 1 to 5, wherein In a direction perpendicular to the first metal layer, a size of the low-reflection film is greater than or equal to 1800 Å and less than or equal to 2500 Å.

7. The low-reflection film according to any one of claims 1 to 6, comprising N metal layers and multiple inorganic layers, the refractive index of the metal layer is greater than the refractive index of the inorganic layer; the N metal layers and the multiple inorganic layers are alternately stacked in sequence; wherein N is a positive integer greater than or equal to three.

8. A display substrate, the display substrate comprising at least one display side, the display substrate further comprising: A base substrate, wherein the base substrate defines a light-emitting area and a non-light-emitting area other than the light-emitting area; A plurality of metal traces are located on one side of the substrate and are arranged in the non-luminous area; A light emitting unit, located at a side of the plurality of metal traces away from the base substrate, and arranged in the light emitting area; The low-reflection film according to any one of claims 1 to 7, located on at least one side of the plurality of metal traces close to the display side, and arranged in the non-luminous area.

9. The display substrate according to claim 8, wherein the display substrate is a top emission type display substrate or a bottom emission type display substrate, wherein: The low-reflection film is located on a side of the light-emitting unit away from the base substrate.

10. The display substrate according to claim 8, wherein the display substrate is a double-sided emission type display substrate, wherein: The low reflection film comprises: a first low-reflection film, located between the substrate and the plurality of metal traces; and / or, The second low-reflection film is located on a side of the light-emitting unit away from the base substrate.

11. A method for preparing a display substrate, comprising: forming a substrate base; The base substrate defines a light emitting area and a non-light emitting area except the light emitting area; A plurality of metal traces are formed on one side of the substrate; the plurality of metal traces are arranged in the non-luminous area; A light-emitting unit is formed on a side of the plurality of metal traces away from the base substrate; the light-emitting unit is arranged in the light-emitting area; The method further comprises: After forming the light-emitting unit, forming a low-reflection film on a side of the light-emitting unit away from the base substrate; and / or, before forming the plurality of metal traces, forming a low-reflection film on one side of the base substrate; Wherein, the low-reflection film is arranged in the non-luminous area; the low-reflection film includes a first metal layer, a first inorganic layer, a second metal layer and a second inorganic layer; the first inorganic layer is located on one side of the first metal layer, and the refractive index of the first inorganic layer is smaller than the refractive index of the first metal layer; the second metal layer is located on the side of the first inorganic layer away from the first metal layer, and the refractive index of the second metal layer is greater than the refractive index of the first inorganic layer; the second inorganic layer is located on the side of the second metal layer away from the first inorganic layer, and the refractive index of the second inorganic layer is smaller than the refractive index of the second metal layer.

12. The method for preparing a display substrate according to claim 11, wherein: The step of forming a low-reflection film on a side of the light-emitting unit away from the substrate includes: On a side of the light-emitting unit away from the base substrate, a first low-reflection base film is formed by sequentially forming the first metal layer, the first inorganic layer, the second metal layer and the second inorganic layer stacked in layers; removing the first low-reflection base film in the light-emitting area by a dry etching process, and retaining the first low-reflection base film in the non-light-emitting area as a low-reflection film; and / or, The step of forming a low-reflection film on one side of the substrate comprises: On one side of the base substrate, a second low-reflection base film is formed by sequentially forming the second inorganic layer, the second metal layer, the first inorganic layer and the first metal layer stacked in layers; The second low-reflection base film in the light-emitting area is removed by a dry etching process, and the second low-reflection base film in the non-light-emitting area is retained as a low-reflection film.

13. A display device, comprising: Circuit boards; The display substrate according to any one of claims 8 to 10; The display substrate is located at one side of the circuit board, and the display substrate is coupled to the circuit board.

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