Light-emitting substrate, preparation method thereof, backlight module and display device

Abstract

A light emitting substrate includes a circuit board, a plurality of light emitting devices, a reflective layer, and a support layer. The plurality of light emitting devices are disposed on the circuit board. The reflective layer is disposed on the circuit board. The reflective layer has a plurality of openings, one light emitting device being located in one opening. The support layer is disposed on a side of the circuit board distal from the reflective layer.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a light-emitting substrate and its preparation method, a backlight module and a display device. Background Technology

[0002] With the development of LED technology, the use of sub-millimeter or even micrometer-scale LEDs as backlights has become widespread. This allows products using this backlight, such as Liquid Crystal Displays (LCDs), to achieve the same contrast ratio as OLED displays, while retaining the technological advantages of LCDs, thus enhancing the display effect and providing users with a superior visual experience.

[0003] Public content

[0004] On one hand, a light-emitting substrate is provided. The light-emitting substrate includes a circuit board, a plurality of light-emitting devices, a reflective layer, and a support layer. The plurality of light-emitting devices are disposed on the circuit board. The reflective layer is disposed on the circuit board; the reflective layer has a plurality of openings, and one light-emitting device is located in one opening. The support layer is disposed on the side of the circuit board away from the reflective layer.

[0005] In some embodiments, the material of the support layer is the same as the material of the reflective layer; and / or, the thickness of the support layer is approximately the same as the thickness of the reflective layer.

[0006] In some embodiments, the thickness of the reflective layer is 40 μm to 60 μm, and the thickness tolerance of the reflective layer is ±2 μm; and / or, the thickness of the support layer is 40 μm to 60 μm, and the thickness tolerance of the support layer is ±2 μm.

[0007] In some embodiments, the light-emitting substrate further includes a barrier and an encapsulation layer. The barrier is disposed on the surface of the reflective layer away from the circuit board, the orthographic projection of the barrier on the circuit board lies within the orthographic projection of the reflective layer on the circuit board, and the barrier defines a plurality of sub-regions. The encapsulation layer is disposed on the side of the circuit board away from the support layer and at least covers the plurality of light-emitting devices.

[0008] In some embodiments, the encapsulation layer includes a plurality of encapsulation portions spaced apart, each encapsulation portion being located in a sub-region, and the surface of the encapsulation portion away from the circuit board being substantially flush with the surface of the barrier away from the circuit board.

[0009] In some embodiments, the encapsulation layer further includes a sub-encapsulation layer disposed on the side of the plurality of encapsulation portions away from the circuit board, and the sub-encapsulation layer covers the plurality of encapsulation portions and the barrier.

[0010] In some embodiments, the retaining wall includes a plurality of first sub-sections extending along a first direction and spaced apart along a second direction, the first direction and the second direction intersecting.

[0011] In some embodiments, the retaining wall further includes a plurality of second sub-sections extending along the second direction and spaced apart along the first direction.

[0012] In some embodiments, the reflectivity of the retaining wall is greater than or equal to 85%.

[0013] In some embodiments, the retaining wall is made of white glue and / or plastic.

[0014] In some embodiments, the circuit board includes a substrate, circuit traces disposed on the substrate, and a plurality of pads, at least two of which are located within an opening in the reflective layer.

[0015] On the other hand, a method for fabricating a light-emitting substrate is provided. The method for fabricating the light-emitting substrate includes: fabricating a circuit board; simultaneously forming a reflective film and a support layer on opposite sides of the circuit board; and patterning the reflective film such that multiple openings are formed on the reflective film.

[0016] In some embodiments, the simultaneous formation of a reflective film and a support layer on opposite sides of the circuit board includes employing a lamination process to simultaneously press the reflective film and the support layer onto the circuit board.

[0017] In some embodiments, the lamination process, which simultaneously presses the reflective film and the support layer to the circuit board, includes:

[0018] A film to be pressed is provided; the film to be pressed includes a substrate and a first protective film and a second protective film disposed on opposite sides of the substrate; the first protective film of the film to be pressed is removed; on opposite sides of the circuit board, two films to be pressed with the first protective film removed are simultaneously pressed onto the circuit board, so that the substrate is bonded to the circuit board; the second protective film is removed; of the two substrates bonded to the circuit board, one substrate forms the reflective film and the other substrate forms the support layer.

[0019] In some embodiments, the step of simultaneously pressing two films, with the first protective film removed, onto the circuit board on opposite sides of the circuit board, so that the substrate and the circuit board are bonded, includes:

[0020] The circuit board is placed between two films to be pressed after the first protective film has been removed, and is pre-pressed and bonded to the substrates of the two films simultaneously; the pre-pressed substrate is then vacuum-pressed to the substrates on both sides simultaneously.

[0021] In some embodiments, the preparation method further includes preparing the membrane to be pressed before providing the membrane to be pressed.

[0022] The preparation of the film to be laminated includes: providing a first protective film and a second protective film; forming a substrate on the first protective film; and laminating the first protective film, the substrate, and the second protective film together using a lamination process.

[0023] In some embodiments, after patterning the reflective film to form a plurality of openings on the reflective film, the preparation method further includes:

[0024] A light-emitting device is disposed within the opening; a barrier is formed on the reflective layer; the barrier divides the reflective layer into multiple sub-regions; multiple encapsulation portions are formed on the side of the circuit board away from the support layer; each encapsulation portion is located in a sub-region, and the surface of the encapsulation portion away from the circuit board is approximately flush with the surface of the barrier away from the circuit board.

[0025] In some embodiments, during the process of forming a plurality of encapsulation portions on the side of the circuit board away from the support layer, a sub-encapsulation layer is also formed; the sub-encapsulation layer is disposed on the side of the plurality of encapsulation portions away from the circuit board, and the sub-encapsulation layer covers the plurality of encapsulation portions and the barrier.

[0026] In another aspect, a backlight module is provided. The backlight module includes a light-emitting substrate and a plurality of optical films as described in any of the above embodiments. The light-emitting substrate has opposing light-emitting and non-light-emitting sides, and the plurality of optical films are disposed on the light-emitting side of the light-emitting substrate.

[0027] In another aspect, a display device is provided. The display device includes the backlight module and display panel described in the above embodiments, wherein the display panel is disposed on the side of the plurality of optical films in the backlight module away from the light-emitting substrate. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0029] Figure 1 This is a structural diagram of a display device according to some embodiments;

[0030] Figure 2A A cross-sectional view of a display device according to some embodiments;

[0031] Figure 2B This is another cross-sectional view of a display device according to some embodiments;

[0032] Figure 3 This is a top view of a light-emitting substrate provided according to some embodiments;

[0033] Figure 4 This is another top view of a light-emitting substrate provided according to some embodiments;

[0034] Figure 5 This is yet another top view of a light-emitting substrate provided according to some embodiments;

[0035] Figure 6 This is yet another top view of a light-emitting substrate provided according to some embodiments;

[0036] Figure 7 This is yet another top view of a light-emitting substrate provided according to some embodiments;

[0037] Figure 8 This is a flowchart of a method for fabricating a light-emitting substrate according to some embodiments;

[0038] Figure 9 This is a flowchart of another method for fabricating a light-emitting substrate according to some embodiments;

[0039] Figure 10 This is a flowchart illustrating another method for fabricating a light-emitting substrate according to some embodiments;

[0040] Figure 11 This is a structural diagram of the film to be pressed according to some embodiments;

[0041] Figure 12 This is a diagram illustrating one step of preparing the film to be pressed according to some embodiments;

[0042] Figure 13 This is a flowchart of a method for preparing a film to be pressed according to some embodiments;

[0043] Figure 14 This is a process diagram for preparing the film to be pressed according to some embodiments;

[0044] Figure 15 This is a flowchart illustrating another method for fabricating a light-emitting substrate according to some embodiments;

[0045] Figure 16 This is a test point diagram of a light-emitting substrate provided according to some embodiments;

[0046] Figure 17 for Figure 16 The warpage of the test points shown is a simulation test result diagram of the light-emitting substrate provided in related technologies and some embodiments of this disclosure. Detailed Implementation

[0047] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0048] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0049] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0050] In describing some embodiments, the terms "coupled" and "connected," and their derivative expressions, may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact with each other. Similarly, the term "coupled" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact. However, the terms "coupled" or "communicatively coupled" may also refer to two or more components that do not have direct contact with each other but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content of this document.

[0051] "At least one of A, B and C" has the same meaning as "at least one of A, B or C", both including the following combinations of A, B and C: only A, only B, only C, combinations of A and B, combinations of A and C, combinations of B and C, and combinations of A, B and C.

[0052] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0053] As used herein, depending on the context, the term “if” may optionally be interpreted as meaning “when”, “in the event of”, “in response to determination”, or “in response to detection”. Similarly, depending on the context, the phrase “if it is determined that…” or “if [the stated condition or event] is detected” may optionally be interpreted as meaning “in the event of determination that…”, “in response to determination that…”, “when [the stated condition or event] is detected”, or “in response to the detection of [the stated condition or event]”.

[0054] The use of “applies to” or “configured to” in this article implies an open and inclusive language that does not preclude applicability to or configuration to devices that perform additional tasks or steps.

[0055] In addition, the use of “based on” implies openness and inclusivity, because processes, steps, calculations or other actions “based on” one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0056] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0057] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0058] This document describes exemplary embodiments with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and regions is enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched regions shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the regions of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0059] like Figure 1 As shown, some embodiments of this disclosure provide a display device 1000, which can be any device that displays either moving (e.g., video) or fixed (e.g., still image) content, and whether it is text or an image.

[0060] For example, the display device 1000 can be any product or component with display function, such as a television, laptop computer, tablet computer, mobile phone, personal digital assistant (PDA), navigator, wearable device, augmented reality (AR) device, virtual reality (VR) device, etc. This disclosure does not limit the scope of the application.

[0061] In some embodiments, the display device 1000 described above may be a liquid crystal display device.

[0062] like Figure 2A As shown, the display device 1000 may include a display panel 100, a backlight module 200, and a glass cover 300.

[0063] The display panel 100 includes a light-emitting side and a non-light-emitting side arranged opposite to each other. The light-emitting side refers to the side of the display panel 100 used for displaying images. Figure 2A The upper side of the display panel 100, the non-light-emitting side refers to the side opposite to the light-emitting side. Figure 2A (Lower side of the central display panel 100).

[0064] The backlight module 200 is located on the non-light-emitting side of the display panel 100, and the backlight module 200 is used to provide a light source for the display panel 100.

[0065] A glass cover 300 is disposed on the light-emitting side of the display panel 100, and the glass cover 300 is used to protect the display panel 100. For example, the glass cover 300 can be made of rigid materials such as glass, quartz, and plastic, or flexible materials such as polymer resin.

[0066] In some examples, please refer to [link / reference]. Figure 2A The backlight module 200 may include a light-emitting substrate 210 and multiple optical films 220.

[0067] The light-emitting substrate 210 can directly emit white light, which is then homogenized before being directed onto the display panel 100. Alternatively, the light-emitting substrate 210 can also emit light of other colors (such as blue light), which is then converted and homogenized before being directed onto the display panel 100.

[0068] It should be noted that the light-emitting substrate 210 has opposing light-emitting and non-light-emitting sides. The light-emitting side refers to the side of the light-emitting substrate 210 that provides the light source. Figure 2A The upper side of the light-emitting substrate 210), the non-light-emitting side refers to the side opposite to the light-emitting side ( Figure 2A (Lower side of the light-emitting substrate 210).

[0069] Multiple optical films 220 are disposed on the light-emitting side of the light-emitting substrate 210. For example, such as... Figure 2AAs shown, the plurality of optical films 220 include a diffuser plate 221, a quantum dot film 222, a diffuser sheet 223, and a composite film 224 arranged sequentially. The diffuser plate 221 blurs the light emitted from the light-emitting substrate 210 and provides support for the quantum dot film 222, the diffuser sheet 223, and the composite film 224. The quantum dot film 222, when excited by light of a certain color emitted from the light-emitting substrate 210, converts that light into white light, thereby improving the utilization rate of the light energy of the light-emitting substrate 210. The diffuser sheet 223 homogenizes the light passing through it. The composite film 224 improves the light extraction efficiency of the backlight module 200 and increases the display brightness of the display device 1000. For example, the composite film 224 includes a brightness enhancement film (BEF) and a reflective polarized brightness enhancement film (DBEF), which utilizes the principles of total internal reflection, refraction and polarization to increase the light flux within a certain angle range, thereby improving the brightness of the display device 1000.

[0070] For example, the light-emitting substrate 210 emits blue light in a direction away from the light-emitting substrate 210. The quantum dot film 222 may include red quantum dot material, green quantum dot material, and transparent material. When the blue light emitted by the light-emitting substrate 210 passes through the red quantum dot material, it is converted into red light; when the blue light passes through the green quantum dot material, it is converted into green light; the blue light can pass directly through the transparent material; then, the blue light, red light, and green light are mixed and superimposed in a certain proportion to produce white light. The diffuser plate 221 and the diffuser sheet 223 can mix the white light to improve the shadow produced by the light-emitting substrate 210 and improve the display quality of the display device 1000.

[0071] However, in related technologies, the light-emitting substrate includes a substrate and various film layers disposed on one side of the substrate. The tensile force on one side of the substrate is relatively large, especially the reflective layer formed on one side of the substrate by screen printing process. The internal tension of the reflective layer is relatively large, and the tensile force applied to one side of the substrate is relatively large, which increases the risk of substrate warping or breakage.

[0072] To solve the above technical problems, please refer to Figure 2A , Figure 3 and Figure 4 This disclosure provides a light-emitting substrate 210 in some embodiments. The light-emitting substrate 210 includes a circuit board 10, a plurality of light-emitting devices 20, a reflective layer 30, and a support layer 40.

[0073] In some embodiments, such as Figure 2A As shown, the circuit board 10 includes a substrate 101.

[0074] In some examples, substrate 101 may be any of the following: glass substrate, quartz substrate, sapphire substrate, ceramic substrate, etc.; or semiconductor substrate such as single crystal semiconductor substrate or polycrystalline semiconductor substrate made of silicon or silicon carbide, compound semiconductor substrate such as silicon germanium, silicon on insulator (SOI) substrate, etc.; substrate 101 may also be a film layer made of one or more organic resin materials such as epoxy resin, triazine, silicone resin and polyimide.

[0075] Accordingly, the circuit board 10 further includes at least one conductive layer 102 disposed on the substrate 101. The conductive layer 102 is made of one or more of the following materials: copper, molybdenum-niobium alloy (MoNb), nickel, and indium tin oxide.

[0076] For example, see Figure 2A and Figure 3 The conductive layer 102 may include pads 1021 and circuit traces 1022. The pads 1021 are configured to connect to the light-emitting device 20 or the microchip 70, and the circuit traces 1022 are configured to connect to different pads 1021 or transmit signals.

[0077] In other examples, substrate 101 may be an FR4 type printed circuit board (PCB) or a flexible PCB that is easily deformable. Exemplarily, the material used for substrate 101 may include one or more ceramic materials such as silicon nitride, AlN, and Al2O3, or it may include metals or metal compounds, such as metal core PCBs or metal copper clad laminates (MCCLs).

[0078] In some embodiments, the light-emitting device 20 may include one or more of a micro light-emitting diode (Micro LED) and a mini light-emitting diode (MiniLED).

[0079] It should be noted that the size (e.g., length) of a Micro LED is less than 50 micrometers, for example, 10 micrometers to 50 micrometers. The size (e.g., length) of a Mini LED is 50 micrometers to 150 micrometers, for example, 80 micrometers to 120 micrometers. In this embodiment, different light-emitting devices can be selected according to actual needs. Multiple light-emitting devices 20 are disposed on the circuit board 10.

[0080] In some embodiments, such as Figure 2A and Figure 3 As shown, the reflective layer 30 is disposed on the circuit board 10. The reflective layer 30 is configured to reflect the light emitted by the light-emitting device 20 toward the circuit board 10, so that more of the light emitted by the light-emitting device 20 is directed toward the display panel 100, thereby improving the light emission efficiency of the light-emitting substrate 210 and improving the display effect.

[0081] The reflective layer 30 has multiple openings 201, and each opening 201 contains at least two pads 1021. The pads 1021 are used for electrical connection with the pins of the light-emitting device 20 or the pins of the microchip 70.

[0082] For example, if two pads 1021 are provided in an opening 201, then a light-emitting device 20 corresponds to one opening 201, and two pins of the light-emitting device 20 are electrically connected to the two pads 1021. If multiple pads 1021 are provided in an opening 201, then a microchip 70 corresponds to one opening 201, and multiple pins of the microchip 70 correspond one-to-one with and are electrically connected to the multiple pads 1021.

[0083] It should be noted that the shape of the outline of the orthographic projection of the opening 201 on the circuit board 10 can be a circle, a polygon, etc., and this embodiment of the present disclosure does not make specific limitations.

[0084] In some embodiments, the support layer 40 is disposed on the side of the circuit board 10 away from the reflective layer 30. The support layer 40 and the reflective layer 30 are respectively disposed on opposite sides of the circuit board 10, and the tensile force exerted by the reflective layer 30 on the circuit board 10 can at least partially cancel out the tensile force exerted by the support layer 40 on the circuit board 10, thereby reducing the risk of warping or breakage of the circuit board 10.

[0085] In addition, the support layer 40 and the reflective layer 30 can be formed simultaneously on opposite sides of the circuit board 10 to reduce the risk of warping or breaking of the circuit board 10 due to pressure on one side during the manufacturing process.

[0086] It should be noted that the formation process of the support layer 40 and the reflective layer 30 can be referred to below, and will not be repeated here in the embodiments disclosed herein.

[0087] The materials of the support layer 40 and the reflective layer 30 can be the same, and / or the thickness of the support layer 40 can be approximately the same as the thickness of the reflective layer 30. This helps to reduce the complexity and difficulty of the manufacturing process and improve the manufacturing efficiency.

[0088] For example, the material of the support layer 40 can be the same as the material of the reflective layer 30. This allows the support layer 40 and the reflective layer 30 to be manufactured using the same process, reducing process complexity. For instance, the materials used for both the reflective layer 30 and the support layer 40 can be insulating materials. For example, the material of the reflective layer 30 could be any of a photosensitive white ink or a curable white ink, while the material of the support layer 40 could be a photosensitive white ink, a curable white ink, plastic, glass fiber composite material, or carbon fiber composite material. Of course, the material of the support layer 40 can be a different material from the material of the reflective layer 30. For example, the material of the support layer 40 could be silver, stainless steel, or titanium alloy, as long as the tensile forces exerted on the circuit board 10 by the support layer 40 and the reflective layer 30 at least partially cancel each other out.

[0089] For example, the thickness of the reflective layer 30 is 40 μm to 60 μm to ensure high reflectivity and improve the light extraction efficiency of the light-emitting substrate 210. For example, the thickness of the reflective layer 30 is 40 μm, 50 μm, or 60 μm. For instance, the thickness of the reflective layer 30 is 40 μm.

[0090] For example, the thickness tolerance of the reflective layer 30 is ±2μm, which makes the thickness uniformity of the reflective layer 30 higher, which is beneficial to improving the brightness uniformity and color uniformity of the display device 1000.

[0091] Thus, the thickness of the support layer 40 is 40 μm to 60 μm. For example, the thickness of the support layer 40 is 40 μm, 50 μm, or 60 μm. For instance, the thickness of the support layer 40 is 40 μm. Furthermore, the thickness tolerance of the support layer 40 is ±2 μm. This allows the support layer 40 and the reflective layer 30 to be set to the same thickness, facilitating the use of the same manufacturing process and reducing manufacturing costs. Moreover, the tensile force exerted by the reflective layer 30 on the circuit board 10 can largely offset the tensile force exerted by the support layer 40 on the circuit board 10, thereby reducing the risk of warping or breakage of the circuit board 10.

[0092] In addition, please continue to refer to Figure 3 The light-emitting substrate 210 includes multiple light-emitting regions 230 arranged in an array, and each light-emitting region 230 includes multiple light-emitting devices 20 connected in series and / or in parallel.

[0093] For example, such as Figure 3 As shown, each light-emitting area 230 includes six light-emitting devices 20 connected in series. Of course, each light-emitting area 230 may also include two, three, four or eight light-emitting devices 20; and the connection method of multiple light-emitting devices 20 in the light-emitting area 230 is not limited to series connection, but may also be parallel connection, or a combination of series and parallel connection. This disclosure does not limit this.

[0094] like Figure 3 As shown, the following description takes as an example that each light-emitting area 230 includes 6 light-emitting devices 20 connected in series.

[0095] By way of example, the light-emitting substrate 210 may also include a microchip 70, which is fixed on the circuit board 10 and electrically connected to the circuit board 10 via a pad 1021. A microchip 70 is fixed within an opening 201.

[0096] It should be noted that the microchip 70 includes a sensing chip and a driving chip. For example, the sensing chip can be a photosensor chip or a thermistor chip. The driving chip is used to provide driving signals to the light-emitting device 20. For example, Figure 3 The microchip 70, including the driver chip, is illustrated as an example. The driver chip is electrically connected to the circuit board 10 via four pads 1021.

[0097] In some embodiments, such as Figure 2A and Figure 2B As shown, the light-emitting substrate 210 also includes a barrier 50 and an encapsulation layer 60.

[0098] In some examples, such as Figure 2A and Figure 2B As shown, the barrier 50 is disposed on the surface of the reflective layer 30 away from the circuit board 10, and the orthographic projection of the barrier 50 on the circuit board 10 lies within the orthographic projection of the reflective layer 30 on the circuit board 10, and as... Figures 4-7 As shown, retaining wall 50 defines multiple sub-regions 501.

[0099] In some examples, such as Figure 4 and Figure 5 As shown, the retaining wall 50 includes a plurality of first sub-parts 51 extending along a first direction X and spaced apart along a second direction Y, the first direction X and the second direction Y intersecting.

[0100] Each first sub-section 51 has an elongated projection on the circuit board 10, and multiple first sub-sections 51 are arranged side by side. Here, a first sub-section 51 may be provided between every two adjacent rows or columns of light-emitting areas 230; or, a first sub-section 51 may be provided between every two adjacent rows or columns of light-emitting devices 20. It is understood that "row" and "column" are described according to the example in the figure and do not limit the extension direction and arrangement direction of the first sub-sections 51. The following embodiment is illustrated by taking multiple light-emitting areas 230 arranged parallel to the first direction X as a column and multiple light-emitting areas 230 arranged perpendicular to the first direction X (generally parallel to the second direction Y) as a row.

[0101] For example, such as Figure 4As shown, multiple light-emitting areas 230 are arranged in multiple rows and columns. Each row includes multiple light-emitting areas 230 arranged approximately along the second direction Y, and each column includes multiple light-emitting areas 230 arranged approximately along the first direction X. The first direction X is approximately perpendicular to the second direction Y. In this case, the aforementioned first sub-section 51 can extend approximately along the first direction X, and a first sub-section 51 is provided between every two columns of light-emitting areas 230.

[0102] For example, such as Figure 5 As shown, multiple light-emitting areas 230 are arranged in multiple rows and columns. Each row includes multiple light-emitting areas 230 arranged approximately along the second direction Y, and each column includes multiple light-emitting areas 230 arranged approximately along the first direction X. The first direction X is approximately perpendicular to the second direction Y. In this case, the aforementioned first sub-section 51 can extend approximately along the first direction X, and each first sub-section 51 is located between two adjacent columns of light-emitting areas 230.

[0103] In other examples, such as Figure 6 and Figure 7 As shown, the barrier 50 includes multiple first sub-parts 51 extending along a first direction X and spaced apart along a second direction Y, and multiple second sub-parts 52 extending along a second direction Y and spaced apart along the first direction X. That is, the orthographic projection of the barrier 50 onto the circuit board 10 is a grid. Here, each grid of the grid-shaped barrier 50 may contain only one light-emitting device 20, or it may contain multiple light-emitting devices 20.

[0104] For example, such as Figure 6 As shown, multiple light-emitting areas 230 are arranged in multiple rows and columns. Each row includes multiple light-emitting areas 230 arranged approximately along the second direction Y, and each column includes multiple light-emitting areas 230 arranged approximately along the first direction X. The first direction X is approximately perpendicular to the second direction Y.

[0105] At this time, the aforementioned retaining wall 50 includes a plurality of first sub-sections 51 extending generally along a first direction X and a plurality of second sub-sections 52 extending generally along a second direction Y. Each first sub-section 51 is located between two adjacent columns of light-emitting areas 230, and each second sub-section 52 is located between two adjacent rows of light-emitting areas 230. For example, if each light-emitting area 230 is provided with 6 light-emitting devices 20, then each grid corresponds to one light-emitting area 230, and each grid is provided with 6 light-emitting devices 20.

[0106] For example, such as Figure 7 As shown, multiple light-emitting areas 230 are arranged in multiple rows and columns. Each row includes multiple light-emitting areas 230 arranged approximately along the second direction Y, and each column includes multiple light-emitting areas 230 arranged approximately along the first direction X. The first direction X is approximately perpendicular to the second direction Y.

[0107] At this time, the aforementioned retaining wall 50 includes multiple first sub-sections 51 extending generally along a first direction X, and multiple second sub-sections 52 extending generally along a second direction Y. One first sub-section 51 is provided every two columns of light-emitting areas 230, and one second sub-section 52 is provided every two rows of light-emitting areas 230. For example, if each light-emitting area 230 contains one light-emitting device 20, then each grid corresponds to four light-emitting areas 230, and each grid contains four light-emitting devices 20.

[0108] The reflectivity of the aforementioned barrier 50 can be greater than or equal to 85%. For example, the reflectivity of the barrier 50 can be 85%, 90%, or 93%. The material of the barrier 50 can include a white polymer. Exemplarily, the material of the barrier 50 can include white glue and / or plastic. For example, the material of the barrier 50 includes one or more of white polycarbonate, resin (e.g., epoxy resin, polytetrafluoroethylene resin), titanium dioxide (chemical formula TiO2), and organic solvents (e.g., dipropylene glycol methyl ether).

[0109] In this configuration, the light emitted by the light-emitting device 20 is reflected by the barrier 50, so that the light can only be emitted from the sub-region where the light-emitting device 20 is located, and cannot leak into the adjacent sub-region. This can improve the contrast between the brightness of each sub-region, thereby improving the contrast of the display device 1000 and thus improving the display effect of the display device 1000.

[0110] In some embodiments, such as Figure 2A and Figure 2B As shown, the encapsulation layer 60 is disposed on the side of the circuit board 10 away from the support layer 40, and covers at least a plurality of light-emitting devices 20.

[0111] In some examples, such as Figure 2A As shown, the encapsulation layer 60 includes a plurality of encapsulation portions 61 spaced apart, each encapsulation portion 61 being located within a sub-region 501, and the surface of the encapsulation portion 61 away from the circuit board 10 being approximately flush with the surface of the barrier 50 away from the circuit board 10.

[0112] In this case, the encapsulation layer 60 is divided by the barrier 50 into a plurality of encapsulation portions 61 spaced apart. The tensile force applied to the circuit board 10 by the plurality of encapsulation portions 61 is distributed to a plurality of sub-regions 501, thereby further reducing the risk of warping or breakage of the circuit board 10.

[0113] In other examples, such as Figure 2B As shown, the encapsulation layer 60 includes a plurality of encapsulation portions 61 and a sub-encapsulation layer 62. Each encapsulation portion 61 is located in a sub-region. The sub-encapsulation layer 62 is disposed on the side of the plurality of encapsulation portions 61 away from the circuit board 10, and the sub-encapsulation layer 62 covers the plurality of encapsulation portions 61 and the barrier 50.

[0114] In this case, the portion of the encapsulation layer 60 closest to the circuit board 10 is divided by the barrier 50 into a plurality of encapsulation portions 61 spaced apart. The tension exerted by the encapsulation layer 60 on the circuit board 10 is distributed to the plurality of sub-regions 501, thereby further reducing the risk of warping or breakage of the circuit board 10.

[0115] Some embodiments of this disclosure also provide a method for preparing a light-emitting substrate 210, such as... Figure 8 As shown, the preparation method includes steps S100 to S300.

[0116] S100: Fabrication of circuit board 10.

[0117] In the above steps, the circuit board 10 may include a substrate 101 and circuit traces 1022 and pads 1021 disposed on the substrate 101.

[0118] The process for fabricating the circuit board 10 is not unique. For example, a conductive film is formed on the substrate 101 by coating or chemical deposition, and the conductive film is exposed, developed, and etched to form circuit traces 1022 and pads 1021.

[0119] S200: A reflective film 30' and a support layer 40 are simultaneously formed on opposite sides of the circuit board 10.

[0120] In the above steps, referring to the figure, the reflective film 30' is used to form the aforementioned reflective layer 30. That is, the reflective film 30' covers the circuit traces 1022 and pads 1021 in the circuit board 10.

[0121] At this time, the reflective film 30' and the support layer 40 are formed simultaneously on opposite sides of the circuit board 10, which can reduce the risk of the circuit board 10 warping or breaking due to pressure on one side during the manufacturing process.

[0122] The process for forming the reflective film 30' and the support layer 40 is not unique. For example, see [link to relevant documentation]. Figure 9 The above S200 includes S210.

[0123] S210: Using a lamination process, the reflective film 30' and the support layer 40 are simultaneously pressed onto the circuit board 10.

[0124] It should be understood that, compared to screen printing, lamination bonding presses the entire reflective film 30' and support layer 40 onto the circuit board 10, which can avoid the screen used in screen printing damaging the circuit traces 1022 or pads 1021, thus improving yield.

[0125] like Figures 10-13 As shown, S210 includes S211 to S214.

[0126] S211: As Figure 11 As shown, a film 80 to be pressed is provided. The film 80 to be pressed includes a substrate 81 and a first protective film 82 and a second protective film 83 disposed on opposite sides of the substrate 81.

[0127] It should be noted that the substrate 81 is used to form the aforementioned reflective film 30' and support layer 40. That is, the material of the substrate 81 is, for example, photosensitive white ink.

[0128] The first protective film 82 and the second protective film 83 are used to protect the substrate 81, and the materials of the first protective film 82 and the second protective film 83 can be the same to reduce the types of materials.

[0129] For example, the materials of the first protective film 82 and the second protective film 83 include plastics, such as polyethylene terephthalate (PET).

[0130] S212: Remove the first protective film 82 from the film to be pressed 80.

[0131] In the above steps, the first protective film 82 can be torn off manually or peeled off by mechanical equipment using rollers.

[0132] S213: On opposite sides of the circuit board 10, two films 80 to be pressed with the first protective film 82 removed are pressed together with the circuit board 10 simultaneously, so that the substrate 81 is bonded to the circuit board 10.

[0133] In the above steps, a vacuum pressing process can be used to simultaneously press the two films 80 to be pressed with the circuit board 10 after the first protective film 82 has been removed.

[0134] For example, such as Figure 13 As shown, S213 includes S2131 to S2132.

[0135] S2131: Place the circuit board 10 between two films 80 to be pressed after removing the first protective film 82, and pre-press and bond it synchronously with the substrate 81 of the two films 80 to be pressed.

[0136] In the above steps, the circuit board 10 and the substrates 81 of the two films to be pressed 80 with the first protective film 82 removed can be pre-pressed by manual pressing or by pressing with a film pressing device, so that the circuit board 10 and the substrates 81 of the two films to be pressed 80 are aligned and pre-pressed together.

[0137] S2132: Simultaneously vacuum press the pre-pressed circuit board 10 with the substrates 81 on both sides.

[0138] In the above steps, the pre-pressed and bonded circuit board 10 and the substrates 81 on both sides can be placed in a vacuum lamination equipment and pressed for 20s to 40s under vacuum conditions of less than 2hPa and temperatures of 50℃ to 60℃.

[0139] S214: Remove the second protective film 83.

[0140] In the above steps, the second protective film 83 can be peeled off manually or by mechanical equipment using rollers.

[0141] At this time, among the two substrates 81 that are combined with the circuit board 10, one substrate 81 forms the aforementioned reflective film 30', and the other substrate 81 forms the aforementioned support layer 40.

[0142] S300: Patterned reflective film 30', so that multiple openings 201 are formed on reflective film 30'.

[0143] In the above steps, if the material of the substrate 81 is photosensitive white ink, the reflective film 30' can be subjected to mask exposure, development, and etching processes to form multiple openings 201. At this time, the patterned reflective film 30' forms the reflective layer 30 mentioned above. Each opening 201 exposes at least two pads 1021.

[0144] In some embodiments, such as Figure 14 and Figure 15 As shown, prior to S211, the above preparation method further includes S400: preparing the membrane to be pressed 80. The process for preparing the membrane to be pressed 80 is not unique. Exemplarily, S400 includes S410 to S430.

[0145] S410: Provides a first protective film 82 and a second protective film 83.

[0146] In the above steps, the first protective film 82 can be a roll formed from multiple consecutive first protective films 82, that is, the continuous roll can be cut to form multiple first protective films 82. The multiple second protective films 83 can be a roll formed from multiple consecutive second protective films 83, that is, the roll can be cut to form multiple second protective films 83.

[0147] It should be noted that the materials of the first protective film 82 and the second protective film 83 can be referred to above, and will not be repeated here in this embodiment.

[0148] S420: A substrate 81 is disposed on the first protective film 82.

[0149] In the above steps, the substrate 81 can be formed on the first protective film 82 by coating and drying processes.

[0150] S430: The first protective film 82, the substrate 81 and the second protective film 83 are laminated together using a lamination process.

[0151] In the above steps, the first protective film 82, on which the substrate 81 is formed, can be conveyed on the first conveyor belt, and the second protective film 83 can be conveyed on the second conveyor belt. Furthermore, in the lamination process, the first conveyor belt and the second conveyor belt are located between two rollers, and the first protective film 82, the substrate 81, and the second protective film 83 are pressed together by the two rollers.

[0152] In this case, the lamination process can precisely control the thickness of the substrate 81, that is, it can precisely control the thickness of the reflective layer 30, reduce the thickness tolerance of the reflective layer 30, for example, control the thickness tolerance of the reflective layer 30 within ±2μm, thereby improving brightness uniformity, reducing color difference, and improving display effect.

[0153] It should be understood that screen printing is limited by thickness, and a single printing can form a film layer of up to 30μm. Therefore, when preparing a substrate 81 with a thickness of 40μm to 60μm using screen printing, two printing processes are required. The process involves two printing steps. If the substrate 81 is a curable white ink, two pre-curing processes are also required, making the overall process complex.

[0154] Here, the lamination process is not limited by thickness; by adjusting the lamination parameters, substrates with any thickness between 20μm and 60μm can be directly obtained. Compared to screen printing, this reduces the number of processes and simplifies the workflow. For example, lamination can reduce two printing steps and one pre-curing step.

[0155] In some embodiments, such as Figure 15 As shown, after S300, the preparation method also includes S500 to S700.

[0156] S500: A light-emitting device 20 is provided inside the opening 201.

[0157] In the above steps, the two pins of the light-emitting device 20 can be soldered to the two pads 1021 in the corresponding opening 201 respectively, so that the light-emitting device 20 is fixed on the circuit board 10.

[0158] S600: A barrier 50 is formed on the reflective layer 30.

[0159] In the above steps, the barrier 50 divides the circuit board 10 into multiple sub-regions 501. Here, the barrier 50 can be formed by printing or applying adhesive.

[0160] For example, the orthographic projection of the barrier 50 on the circuit board 10 is a grid, and the barrier 50 includes a plurality of first sub-parts 51 extending generally along a first direction X, and a plurality of second sub-parts 52 extending generally along a second direction Y.

[0161] In this case, the glue valve can be moved along the first direction X and glue can be dispensed to form a first sub-section 51 extending along the first direction X; then the glue valve can be moved along the second direction Y and glue can be dispensed to form a second sub-section 52 extending along the second direction Y, thereby forming a grid-like retaining wall 50.

[0162] S700: Multiple encapsulation sections 61 are formed on the side of the circuit board 10 away from the support layer 40.

[0163] In the above steps, each package 61 is located in a sub-region 501, and the surface of the package 61 away from the circuit board 10 is approximately flush with the surface of the barrier 50 away from the circuit board 10. Here, the package 61 can also be formed by printing or applying adhesive.

[0164] In some embodiments, a sub-encapsulation layer 62 is also formed during the S700 process. That is, the encapsulation portion 61 and the sub-encapsulation layer 62 can be formed simultaneously by printing or applying adhesive. The sub-encapsulation layer 62 is disposed on the side of the plurality of encapsulation portions 61 away from the circuit board 10, and the sub-encapsulation layer 62 covers the plurality of encapsulation portions 61 and the barrier 50.

[0165] In order to objectively evaluate the technical effects of the embodiments of this disclosure, the warpage test of the light-emitting substrate 210 provided in the above embodiments is performed below, and the test results are shown in [the table below]. Figure 16 and Figure 17 Example, Figure 16 This is a schematic diagram showing the location of each test point on the light-emitting substrate 210. Figure 17 This is a graph showing the test results comparing the warpage of a light-emitting substrate 210 according to some embodiments with that of a light-emitting substrate in the related art. Figure 17 The horizontal axis of the line graph represents the test point, and the vertical axis represents the warping deformation. Figure 17 The light-emitting substrate 210 of this disclosure has a structure that employs a circuit board 10 and a reflective layer 30 and a support layer 40 located on opposite sides of the circuit board 10. Figure 17 The light-emitting substrate in the related technology is a structure in which at least one film layer is provided on one side of the circuit board.

[0166] Depend on Figure 16 and Figure 17As can be seen, compared with related technologies, the warpage of the light-emitting substrate 210 in the embodiments of this disclosure is reduced at all eight test points, and the warpage of all eight test points is less than 1 mm. Moreover, the difference between the warpage deformation at the eight test points is small, that is, the surface flatness of the light-emitting substrate is high. This is beneficial to improving the brightness and uniformity of the light emitted by the light-emitting substrate 210 onto the display panel 100, and is beneficial to improving the brightness uniformity and color uniformity of the display device 1000.

[0167] In order to objectively evaluate the technical effects of the embodiments of this disclosure, the display device 1000 provided in the above embodiments is subjected to brightness uniformity and color uniformity tests, and the test results are shown in Table 1.

[0168] Table 1:

[0169] property Related technologies This disclosure Brightness uniformity 85％ 95％ Color uniformity (ΔE) 0.6～1.0 0.2～0.4

[0170] As can be seen from Table 1, the display device of the present disclosure has improved brightness uniformity by 10% and reduced chromaticity uniformity ΔE by approximately half compared to related technologies. The display device provided by the present disclosure has better performance.

[0171] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A light-emitting substrate, comprising: Circuit board; Multiple light-emitting devices are disposed on the circuit board; A reflective layer is disposed on the circuit board; the reflective layer has multiple openings, and a light-emitting device is located in one opening. A support layer is disposed on the side of the circuit board away from the reflective layer; the tensile force exerted by the reflective layer on the circuit board and the tensile force exerted by the support layer on the circuit board can at least partially cancel each other out. A barrier is disposed on the surface of the reflective layer away from the circuit board, the orthographic projection of the barrier on the circuit board is located within the orthographic projection of the reflective layer on the circuit board, and the barrier defines multiple sub-regions; An encapsulation layer is disposed on the side of the circuit board away from the support layer and covers at least the plurality of light-emitting devices; the encapsulation layer includes a plurality of encapsulation portions spaced apart, each encapsulation portion being located in a sub-region, and the surface of the encapsulation portion away from the circuit board is flush with the surface of the barrier wall away from the circuit board.

2. The light-emitting substrate according to claim 1, wherein, The material of the support layer is the same as that of the reflective layer; and / or, the thickness of the support layer is the same as that of the reflective layer.

3. The light-emitting substrate according to claim 1, wherein, The thickness of the reflective layer is 40μm~60μm, and the thickness tolerance of the reflective layer is ±2μm; and / or, the thickness of the support layer is 40μm~60μm, and the thickness tolerance of the support layer is ±2μm.

4. The light-emitting substrate according to claim 1, wherein, The retaining wall includes a plurality of first sub-sections extending along a first direction and spaced apart along a second direction, the first direction and the second direction intersecting.

5. The light-emitting substrate according to claim 4, wherein, The retaining wall also includes a plurality of second sub-sections extending along the second direction and spaced apart along the first direction.

6. The light-emitting substrate according to claim 1, wherein, The reflectivity of the retaining wall is greater than or equal to 85%.

7. The light-emitting substrate according to claim 6, wherein, The retaining wall is made of materials including white glue and / or plastic.

8. The light-emitting substrate according to any one of claims 1 to 7, wherein, The circuit board includes a substrate, circuit traces disposed on the substrate, and a plurality of pads, at least two of which are located within an opening in the reflective layer.

9. A method for preparing a light-emitting substrate, comprising: Fabrication of circuit boards; A reflective film and a support layer are simultaneously formed on opposite sides of the circuit board; The tension exerted by the reflective film on the circuit board can at least partially cancel out the tension exerted by the support layer on the circuit board. The reflective film is patterned to form multiple openings, thus forming a reflective layer; After patterning the reflective film to form multiple openings on the reflective film, the preparation method further includes: A light-emitting device is disposed within the opening; A barrier is formed on the reflective layer; the barrier divides the reflective layer into multiple sub-regions. Multiple encapsulation portions are formed on the side of the circuit board away from the support layer; each encapsulation portion is located in a sub-region, and the surface of the encapsulation portion away from the circuit board is flush with the surface of the barrier wall away from the circuit board.

10. The method for preparing a light-emitting substrate according to claim 9, wherein, The simultaneous formation of a reflective film and a support layer on opposite sides of the circuit board includes: A lamination process is used to simultaneously press the reflective film and the support layer onto the circuit board.

11. The method for preparing a light-emitting substrate according to claim 10, wherein, The lamination process, which simultaneously presses the reflective film and the support layer onto the circuit board, includes: A film to be pressed is provided; the film to be pressed includes a substrate and a first protective film and a second protective film disposed on opposite sides of the substrate; Remove the first protective film from the film to be pressed; On opposite sides of the circuit board, two films to be pressed together, with the first protective film removed, are pressed together with the circuit board simultaneously, so that the substrate is bonded to the circuit board; Remove the second protective film; of the two substrates bonded to the circuit board, one substrate forms the reflective film and the other substrate forms the support layer.

12. The method for preparing a light-emitting substrate according to claim 11, wherein, The process involves simultaneously pressing two films, with the first protective film removed, onto the circuit board on opposite sides, thereby bonding the substrate to the circuit board. The circuit board is placed between two films to be pressed after the first protective film has been removed, and is pre-pressed and bonded synchronously with the substrates of the two films to be pressed. The pre-pressed substrate is simultaneously vacuum-pressed with the substrates on both sides.

13. The method for preparing a light-emitting substrate according to claim 12, wherein, Before providing the film to be pressed, the preparation method further includes: The preparation of the film to be pressed includes: providing a first protective film and a second protective film; forming a substrate on the first protective film; and pressing the first protective film, the substrate, and the second protective film together using a lamination process.

14. A backlight module, comprising: The light-emitting substrate as described in any one of claims 1 to 8 has opposing light-emitting sides and non-light-emitting sides; Multiple optical films are disposed on the light-emitting side of the light-emitting substrate.

15. A display device, comprising: The backlight module as described in claim 14; The display panel is disposed on the side of the backlight module away from the light-emitting substrate, where multiple optical films are located.

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