Light-emitting substrate and method for manufacturing the same, display device

Abstract

The present disclosure provides a light-emitting substrate and a manufacturing method thereof, and a display device, the light-emitting substrate comprising: a substrate; a metal trace layer disposed on the substrate; a first protective glue layer covering the metal trace layer and configured to expose a conductive pad of the metal trace layer; and a light-emitting unit electrically connected with the conductive pad.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, and in particular, to a light-emitting substrate, a manufacturing method thereof, and a display device. BACKGROUND

[0002] For a display of passive light-emitting type, a light source is generally included to provide backlight. In the related art, one implementation of a backlight source can be to use array-distributed mini light-emitting diodes (Mini LEDs) to form a light-emitting substrate. When the Mini LEDs are manufactured on the light-emitting substrate, product defects can be caused due to problems such as false soldering. SUMMARY

[0003] Embodiments of the present disclosure provide a light-emitting substrate, a manufacturing method thereof, and a display device.

[0004] In a first aspect, the present disclosure provides a light-emitting substrate, comprising:

[0005] a substrate;

[0006] a metal trace layer disposed on the substrate;

[0007] a first protective glue layer covering the metal trace layer and configured to expose a conductive pad of the metal trace layer; and

[0008] a light-emitting unit electrically connected to the conductive pad.

[0009] In a second aspect, the present disclosure provides a display device, comprising:

[0010] the light-emitting substrate of the first aspect; and

[0011] an optical film layer disposed on a light-emitting direction side of the light-emitting substrate.

[0012] In a third aspect, the present disclosure provides a manufacturing method of a light-emitting substrate, comprising:

[0013] providing a substrate;

[0014] forming a metal trace layer on the substrate;

[0015] forming a first protective glue layer on the metal trace layer and exposing a conductive pad of the metal trace layer; and

[0016] disposing a light-emitting unit on the conductive pad.

[0017] The light-emitting substrate, the manufacturing method thereof, and the display device provided by the present disclosure use the first protective glue layer to insulate and protect the metal trace layer from water and oxygen, thereby reducing the peeling risk and product defects caused by false soldering and liquid leakage. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present disclosure or the related art, the following will briefly introduce the drawings needed to be used in the embodiments or the related art description. Obviously, the drawings in the following description only constitute the embodiments of the present disclosure, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0019] Figure 1 A schematic diagram of an exemplary display device provided by an embodiment of the present disclosure is shown.

[0020] Figure 2A A schematic diagram of an exemplary light-emitting substrate is shown.

[0021] Figure 2B A schematic diagram of an exemplary display module according to an embodiment of the present disclosure is shown.

[0022] Figure 2C A schematic diagram of the force condition of a protective lens according to an embodiment of the present disclosure is shown.

[0023] Figure 2D A schematic diagram of the push force test comparison of a flat display device and a curved display device before and after reliability test according to an embodiment of the present disclosure is shown.

[0024] Figure 2E A schematic diagram of the push force test comparison of a flat display device and a curved display device before and after reliability test according to an embodiment of the present disclosure is shown.

[0025] Figure 2F A schematic diagram of an exemplary light-emitting substrate provided by an embodiment of the present disclosure is shown.

[0026] Figure 2G A schematic diagram of an exemplary spraying device according to an embodiment of the present disclosure is shown.

[0027] Figure 2H A top view schematic diagram of an exemplary first protective adhesive layer according to an embodiment of the present disclosure is shown.

[0028] Figure 2I A top view schematic diagram of an exemplary second protective adhesive layer according to an embodiment of the present disclosure is shown.

[0029] Figure 2J A size ratio schematic diagram of an exemplary second protective adhesive layer according to an embodiment of the present disclosure is shown.

[0030] Figure 2K A schematic diagram of a water vapor intrusion path according to an embodiment of the present disclosure is shown.

[0031] Figure 2LA comparative diagram of dye water boiling test results according to an embodiment of the present disclosure is shown.

[0032] Figure 2M A distribution diagram of thrust test points according to an embodiment of the present disclosure is shown.

[0033] Figure 2N A comparative diagram of thrust tests before and after reliability tests of a curved display device using a combination of a protective lens + a second protective glue layer + a reflection layer and a combination of a protective lens + a reflection layer according to an embodiment of the present disclosure is shown.

[0034] Figure 2O A comparative diagram of thrust tests before and after reliability tests of a curved display device using a combination of a protective lens + a second protective glue layer + a reflection layer and a combination of a protective lens + a reflection layer according to an embodiment of the present disclosure is shown.

[0035] Figure 3 A diagram of an exemplary optical film layer according to an embodiment of the present disclosure is shown.

[0036] Figure 4 A flow diagram of an exemplary manufacturing method provided by an embodiment of the present disclosure is shown.

[0037] Figure 5A A diagram of a light-emitting substrate in an exemplary process according to an embodiment of the present disclosure is shown.

[0038] Figure 5B A diagram of a light-emitting substrate in an exemplary process according to an embodiment of the present disclosure is shown.

[0039] Figure 5C A diagram of a light-emitting substrate in an exemplary process according to an embodiment of the present disclosure is shown.

[0040] Figure 5D A diagram of a light-emitting substrate in an exemplary process according to an embodiment of the present disclosure is shown.

[0041] Figure 5E A diagram of a light-emitting substrate in an exemplary process according to an embodiment of the present disclosure is shown.

[0042] Figure 5F A diagram of a light-emitting substrate in an exemplary process according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0043] To make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure is further described in detail below with reference to specific embodiments and the accompanying drawings.

[0044] It should be noted that, unless otherwise defined, technical terms or scientific terms used in the embodiments of the present disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which the present disclosure pertains. The terms "first", "second", and similar terms used in the embodiments of the present disclosure do not denote any order, quantity, or importance, but are used to distinguish different components. The terms "include", "contain", and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like are used only to represent relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships can also be changed accordingly.

[0045] Figure 1 A schematic diagram of an example display device 100 is shown. As shown, the display device 100 can include a backlight module 500 and a display panel 400 arranged in sequence along an light-out direction 102. Figure 1

[0046] The display panel 400 can be a liquid crystal display panel, and can further include a first substrate 402 and a second substrate 404, and a liquid crystal layer 406 sandwiched between the first substrate 402 and the second substrate 404. In some embodiments, the first substrate 402 can be an array substrate, and the second substrate 404 can be a color film substrate.

[0047] The backlight module 500 can be used to provide backlight for the display panel 400, and can further include a light-emitting substrate 200 and an optical film layer 300 arranged on the light-emitting substrate 200 on the light-out direction side. The light-emitting substrate 200 can be provided with arrayed light-emitting units as backlight sources, and the optical film layer 300 can perform brightening processing, diffusion processing, and the like on the light emitted by the light-emitting units based on optical principles, so as to meet the light uniformity while improving the brightness.

[0048] ​In some embodiments, the light-emitting units in the light-emitting substrate 200 may be mini-light-emitting diodes (Mini LEDs) or micro-light-emitting diodes (Micro LEDs). It is understood that in some embodiments, the display device 100 may not be a liquid crystal display device, but may be a display device that utilizes the light-emitting substrate 200 or the light-emitting substrate 200 plus an optical film layer 300 to form the display panel 400, such as a Mini LED display device or a Micro LED display device. It is understood that in this embodiment, the display device 100 may not include a backlight module 500.

[0049] It should be noted that the display device in this embodiment can be any product or component with display function, such as electronic paper, mobile phone, tablet computer, television, laptop computer, digital photo frame, or navigator.

[0050] Figure 2A A schematic diagram of an exemplary light-emitting substrate 200 is shown. (As shown) Figure 2A As shown, the light-emitting substrate 200 may include a substrate 202 and a metal wiring layer 204 formed on the substrate 202. Further, a passivation layer 206 may be disposed on the metal wiring layer 204. This passivation layer 206 can be used to passivate the non-exposed areas of the metal wiring layer 204 to achieve insulation performance in the non-exposed areas. The passivation layer 206 may be SiNO₃. x Materials, generally, are formed to a relatively thin thickness (e.g., When forming the reflective layer on top of the passivation layer 206, a screen printing process may be used. However, because the passivation layer 206 is relatively thin, the wires of the screen can easily damage the circuitry beneath it. Therefore, a protective layer (OC) 208 can be further formed on the passivation layer 206. The protective layer 208 can be made of transparent resin and can be formed relatively thickly to protect the underlying circuitry. However, the fabrication of the passivation layer 206 and the protective layer 208 requires two separate patterning processes, increasing the manufacturing steps and reducing efficiency.

[0051] After forming the protective layer 208, a reflective layer 210 can also be formed on the protective layer 208. The reflective layer 210 can reflect light in the light-emitting direction 102, thereby improving the light efficiency. In some embodiments, the reflective layer 210 can be made of white ink.

[0052] like Figure 2AAs shown, the passivation layer 206, the protection layer 208 and the reflective layer 210 can also expose the conductive pads of the metal trace layer 204, so that the light emitting unit 212 can be electrically connected to the conductive pads of the metal trace layer 204, and the metal trace layer 204 can be used to provide driving signals for the light emitting unit 212 to turn on the light emitting unit 212.

[0053] In some embodiments, a protective lens 214 can also be formed on the light emitting unit 212, which can protect the light emitting unit 212 and also can focus light to improve the brightness of the light emitting unit 212. In addition, compared with forming a whole layer of protection layer on the light emitting substrate 200, the protective lens 214 formed by dispensing can save production materials and reduce costs.

[0054] Figure 2A In the light emitting substrate 200 shown, the conductive pads can be copper (Cu) pads, and the light emitting unit 212 can be electrically connected to the metal trace layer 204 through the copper pads. However, the copper pads are prone to poor soldering and cannot pass the reliability test. One way to handle this is to gold plate the copper pads, for example, to form a nickel-gold alloy (NiAu) on the copper pads to improve the soldering efficiency. However, whether the passivation layer 206 or the protection layer 208, when gold plating, serious peeling and liquid infiltration problems will occur due to the gold plating liquid, and such defects will cause poor soldering problems in subsequent soldering, and also cause line corrosion problems.

[0055] In some embodiments, when the display device 100 is a curved display device, the backlight module 500 also needs to be made into a curved structure accordingly.

[0056] Figure 2B A schematic diagram of an exemplary display module 500 according to an embodiment of the present disclosure is shown. As shown Figure 2B To match the curved display, the curved light emitting substrate 200 needs to match the corresponding process. For the Mini LED light emitting substrate of the curved glass substrate, the protective lens 214 has a certain diameter, generally 2.5 mm; under the condition of continuous curvature, the protective lens 214 is subjected to the force of being squeezed by the glass substrate from the inside (as shown Figure 2C ), which will more easily cause peeling. In this way, on the one hand, the light efficiency under the curved state is affected, and on the other hand, the protective lens 214 is pulled off with the soldering of the light emitting unit 212, causing peeling of the line as well, and further causing problems such as lamp out.

[0057] Figure 2D and Figure 2EThe push force test contrast diagrams of the flat display device and the curved display device according to the embodiments of the present disclosure before and after the reliability test are shown respectively. As shown in Figure 2D , 15 test points are arranged on the whole light-emitting substrate 200, and the push force before the reliability test is obviously greater than the push force after the reliability test, whether it is the flat display device or the curved display device, which indicates that the peeling of the product will be more serious after the reliability test. Moreover, from Figure 2D , it can be seen that the push force of the curved display device is less than that of the flat display device, whether before or after the reliability test, which indicates that the peeling of the curved display device will be more serious. From Figure 2E , it can be seen that the average value of the push force decreases before and after the reliability test, and the decrease of the flat display device is 31.5%, and the decrease of the curved display device is as high as 37.9%.

[0058] In view of this, the embodiments of the present disclosure further provide a light-emitting substrate which can solve the foregoing problems to some extent.

[0059] Figure 2F The schematic diagram of an exemplary light-emitting substrate 200 provided by the embodiments of the present disclosure is shown.

[0060] As shown in Figure 2F , the light-emitting substrate 200 can include a substrate 202 and a metal trace layer 204 arranged on the substrate 202. Unlike Figure 2A the light-emitting substrate 200, the metal trace layer 204 of the present embodiment forms a first protective glue layer 216. The first protective glue layer 216 can be covered on the metal trace layer 204 and expose the conductive pads (e.g., pads) of the metal trace layer 204. The first protective glue layer 216 can be formed to be relatively thick (e.g., several microns), so as to play an insulating role while protecting the circuit below.

[0061] In some embodiments, the first protective glue layer 216 can be formed by a spraying process, so that a patterning process is not needed, and the passivation layer 206 and the protective layer 208 are not formed by two patterning processes respectively as Figure 2A , so that the process can be saved and the efficiency can be improved. In particular, when the patterning process is patterning by using a mask, because the patterning process is saved, the use of the mask is reduced, and the cost is further saved. Figure 2G The schematic diagram of an exemplary spraying equipment according to the embodiments of the present disclosure is shown. As shown in Figure 2G , for example, the spraying equipment can include 20 spray valves, and a suitable interval is arranged between adjacent spray valves. Figure 2H The top view schematic diagram of an exemplary first protective glue layer 216 according to the embodiments of the present disclosure is shown. As shown in Figure 2HAs shown, the spraying device sprays the area between the LED pads of the light-emitting substrate 200 (the dashed arrow is the direction of the spray valve), so as to cover the part other than the pad area with the first protective glue layer 216.

[0062] In some embodiments, the material of the first protective glue layer 216 can be a three-proofing glue. The three-proofing glue can be a fluorine-based resin material, for example, meltable polytetrafluoroethylene. Such material has high waterproofness (for example, water absorption rate less than 1 ‰) and can achieve corrosion protection for the metal wiring layer 204.

[0063] The material of the three-proofing glue can be divided into two types: normal-temperature curing and high-temperature curing. Among them, the normal-temperature curing material (for example, curing time of 30-60 s at 25 °C) can be, for example, polymer-soluble polytetrafluoroethylene, and the solvent is ethyl acetate (with irritating odor). The high-temperature curing material (for example, curing time of 3-5 min at 100 °C) can be, for example, polymer-soluble polytetrafluoroethylene, and the solvent is diethylene glycol ether acetate (odorless).

[0064] The waterproof mechanism of the three-proofing glue is mainly that the cured three-proofing glue is polytetrafluoroethylene polymer, which has very low water absorption rate (for example, ≤1 ‰) and very high hydrophobicity on the surface, with water droplet angle greater than 105 °, so that water molecules cannot penetrate, thus having high waterproofness.

[0065] Returning to Figure 2F After the first protective glue layer 216 is formed, a reflective layer 210 can also be formed on the first protective glue layer 216. The reflective layer 210 can reflect light towards the light-emitting direction 102, thereby improving light efficiency. In some embodiments, the reflective layer 210 can be white, so as to achieve high reflectivity. In some embodiments, the material of the reflective layer 210 can be white ink, so as to achieve high reflectivity. Among them, the white ink can include, for example, resin (for example, epoxy resin, polytetrafluoroethylene resin), titanium dioxide (chemical formula TiO2), and organic solvent (for example, dipropylene glycol methyl ether), etc. In some embodiments, the material of the reflective layer 210 can also include silicon-based white glue. In the case where the material of the reflective layer 210 includes white ink or includes silicon-based white glue, a screen printing process can be used to print the white ink or silicon-based white glue to form the reflective layer 210.

[0066] Exemplarily, the thickness of the reflective layer 210 can range from 10 μm to 300 μm, for example, the thickness can be 10 μm, 50 μm, 80 μm, 155 μm, 200 μm or 300 μm. Exemplarily, the reflective layer 210 can be formed by one or more screen printing processes. When the reflective layer 210 is formed by multiple screen printing processes, the sizes of the openings can be different to improve the manufacturing accuracy of the reflective layer near the opening area. In this way, the reflective layer 11 at the edge of the opening area can present a stepped shape.

[0067] As shown in Figure 2F , the first protective adhesive layer 216 and the reflective layer 210 can also expose part of the metal wiring layer 204. In this way, the light emitting unit 212 can be electrically connected to the conductive pads (e.g., solder pads) of the metal wiring layer 204, so that the metal wiring layer 204 can be used to provide driving signals for the light emitting unit 212 to achieve lighting of the light emitting unit 212. In some embodiments, the metal pads (e.g., copper pads) can be subjected to gold plating before electrical connection is achieved. Since the first protective adhesive layer 216 made of the three-proofing glue material has high waterproof performance, it can avoid peeling and liquid penetration problems caused by gold plating liquid. In some embodiments, the light emitting unit 212 can be a mini light emitting diode (Mini LED) or a micro light emitting diode (Micro LED). The size of the Mini LED is about 100-300 μm, and the size of the Micro LED is less than 100 μm.

[0068] In some embodiments, as shown in Figure 2F , a protective lens 214 can also be formed on the light emitting unit 212. The edge of the protective lens 214 has a normal projection on the substrate 202, which is located in the normal projection of the reflective layer 210 on the substrate 202. In this way, on the one hand, the light emitting unit 212 can be protected, and on the other hand, the light emitting unit 212 can be focused, thereby improving the luminous brightness of the light emitting unit 212. In addition, compared with forming a protective layer on the light emitting substrate 200, the protective lens 214 formed by the dispensing method can save manufacturing materials, thereby reducing costs.

[0069] The main function of the protective lens 214 is to encapsulate and protect the light-emitting unit 212, achieving high luminous efficiency and water / oxygen resistance. In some cases, when white ink is used as the reflective layer 210, the water / oxygen resistance at the interface between the reflective layer 210 and the protective lens 214 is poor. Therefore, directly allowing the reflective layer 210 to contact the protective lens 214 will reduce the water / oxygen resistance of the protective lens 214. Thus, as... Figure 2F As shown, in some embodiments, the light-emitting substrate 200 may further include a second protective adhesive layer 218 disposed between the reflective layer 210 and the protective lens 214. Thus, the second protective adhesive layer 218 forms a sealed interface between the reflective layer 210 and the protective lens 214, thereby ensuring waterproof and oxygen-resistant performance. In some embodiments, the material used to make the second protective adhesive layer 218 may also be conformal coating, thereby ensuring the waterproof performance of the second protective adhesive layer 218. Furthermore, the conformal coating material of the second protective adhesive layer 218 can also improve thrust reliability. Its working mechanism is mainly that the soluble polytetrafluoroethylene material of the conformal coating is a fluorine-based resin material, and the electronegativity of element F is the highest among all elements. As a material for bonding the white ink and the protective lens, the acrylic resin material of the white ink or the silicone resin material of the protective lens can combine with either hydroxyl or hydrogen groups, thereby improving adhesion and thus improving thrust reliability.

[0070] In some embodiments, the second protective adhesive layer 218 may be disposed around the periphery of the protective lens 214, and the orthographic projection of the second protective adhesive layer 218 on the substrate 202 at least partially overlaps with the orthographic projection of the protective lens 214 on the substrate 202, thereby forming a waterproof and oxygen-resistant barrier around the protective lens 214 while saving manufacturing materials. For example, as Figure 2I As shown, the second protective adhesive layer 218 can be formed in a U-shape, and as... Figure 2F As shown, the second protective adhesive layer 218 partially overlaps with the protective lens 214.

[0071] In some embodiments, the dimensions of the second protective adhesive layer 218 satisfy:

[0072] L=D+d+t1+t2+t3

[0073] Where L is the distance between the opposite outer edges of the second protective adhesive layer 218, D is the diameter of the protective lens 214, d is the distance between the outer edges of the second protective adhesive layer 218 and the outer edges of the protective lens 214, t1 is the positional allowance of the protective lens 214, t2 is the shape allowance of the protective lens, and t3 is the positional allowance of the second protective adhesive layer. For example, t1 can be the positional tolerance of the protective lens 214 (e.g., 0.1 mm), t2 can be the shape tolerance of the protective lens 214 (e.g., 0.1 mm), and t3 can be the positional tolerance of the second protective adhesive layer 218 (e.g., 0.1 mm).

[0074] The dimensions of the second protective adhesive layer 218 obtained using the above calculation formula can achieve the dual effects of waterproof and oxygen protection and saving on manufacturing materials.

[0075] like Figure 2J As shown, for example, with the diameter D of the protective lens 214 being 2.5 mm, the distance L between the opposite outer edges of the second protective adhesive layer 218 is calculated as follows: L = 2.5 + 0.1 (positional tolerance of the protective lens 214) + 0.1 (shape tolerance of the protective lens 214) + 0.2 (distance between the outer edges of the second protective adhesive layer 218 and the outer edges of the protective lens 214) + 0.1 (positional tolerance of the second protective adhesive layer 218) = 3.0 mm. Wherein, the length A of the light-emitting unit 212 is 0.51 + 0.2 = 0.71 mm, and the width B of the light-emitting unit 212 is 0.15 + 0.2 = 0.35 mm.

[0076] The following describes the waterproof capabilities of the combination of protective lens 214 + second protective adhesive layer 218 + reflective layer 210 and the combination of protective lens 214 + reflective layer 210, verified by boiling water test.

[0077] Boiling water test procedure: Two 10×10cm substrates were prepared using the combination of protective lens 214 + second protective adhesive layer 218 + reflective layer 210 and the combination of protective lens 214 + reflective layer 210, respectively. They were placed in a 100℃ water bath for heating, and the water stains on the back were observed with a microscope every 30 minutes.

[0078] During the boiling water test, the combination of protective lens 214 and reflective layer 210... Figure 2K Water stains were first observed at location ①, and then gradually extended to location ②. Specifically, after boiling for 4 hours, water stains were observed at the interface of the protective lens 214 and the reflective layer 210, while the combination of the protective lens 214, the second protective adhesive layer 218, and the reflective layer 210 showed no abnormalities after boiling for 4 hours, and water vapor only appeared after boiling for 6 hours. Therefore, it can be seen that the introduction of the second protective adhesive layer 218 improves the water resistance by approximately 50%.

[0079] To quantitatively characterize the waterproof property, dye water boiling verification can also be used. R6G is one of the most commonly used dyes, and a 0.1 mol / L R6G solution is prepared. The solution is heated to 100°, and then two 10x10 cm substrates prepared with the combination of protective lens 214+second protective glue layer 218+reflective layer 210 and the combination of protective lens 214+reflective layer 210 are placed in the solution and kept for 4 h. Then, a single protective lens 214 and a fixed area of reflective layer 210 are cut out from the two substrates placed in the foregoing solution and placed in 10 ml of deionized water and left for 1 h. Then, the waterproof property is quantitatively characterized according to the concentration of the 10 ml R6G solution. The higher the concentration, the more dye molecules penetrate, and the poorer the waterproof property. The lower the concentration, the fewer dye molecules penetrate, and the better the waterproof property. Generally, the concentration of the R6G solution is not easy to test, but the absorption spectrum of the solution has a clear absorption peak at 526 nm, and the absorption value at this position will also decrease as the concentration decreases, so the absorption value of R6G at 526 nm can be used as a representation of the concentration. As shown in Figure 2L the absorption peak value of the combination of protective lens 214+reflective layer 210 is significantly higher than that of the combination of protective lens 214+second protective glue layer 218+reflective layer 210, indicating that the waterproof performance of the combination of protective lens 214+reflective layer 210 is inferior to that of the combination of protective lens 214+second protective glue layer 218+reflective layer 210.

[0080] After introducing the second protective glue layer 218, the pushing force of the protective lens 214 also has a certain increase, mainly the increase in the pushing force under the curved surface state and the decrease in the decline rate after reliability.

[0081] The pushing force test point distribution is shown in Figure 2M 15 protective lenses 214 are uniformly selected on the whole plate to reduce the difference between the whole plate point positions.

[0082] The R1900 curvature verification results are shown in Figure 2N the pushing force values of the combination of protective lens 214+second protective glue layer 218+reflective layer 210 before and after reliability are higher than those of the combination of protective lens 214+reflective layer 210; and the combination of protective lens 214+second protective glue layer 218+reflective layer 210 has excellent environmental reliability capability. As shown in Figure 2O in the TST500 cycle time of the reliability condition, the pushing force of the combination of protective lens 214+second protective glue layer 218+reflective layer 210 only decreases by 6.4%, and the average value after the decrease also exceeds that of the combination of protective lens 214+reflective layer 210. The pushing force of the combination of protective lens 214+reflective layer 210 decreases by 37.9% after reliability, and the light-emitting substrate also has multiple light-out places.

[0083] In some embodiments, the substrate 202 can be a curved glass, so that the light-emitting substrate 200 can also be correspondingly formed into a curved shape. The light-emitting substrate 200 adopting the foregoing embodiments can also improve the reliability of the light-emitting substrate 200 in a curved shape.

[0084] Returning to Figure 1 , in addition to the light-emitting substrate 200, the backlight module 500 can also include an optical film layer 300 arranged on the light-emitting side of the light-emitting substrate 200.

[0085] Figure 3 A schematic diagram of an exemplary optical film layer 300 according to an embodiment of the present disclosure is shown. As Figure 3 shown, the optical film layer 300 can include a substrate layer 302, both sides of which can be coated with diffusion ink 3022 and 3024, respectively, so that efficient light mixing can be achieved.

[0086] In some embodiments, considering the performance difference of LEDs of different colors, a blue Mini LED with relatively long service life can be selected as the light-emitting unit 212. On this basis, a light conversion film 304 can be arranged on the light-emitting side of the light-emitting unit 212 to convert part of the blue light into red light and green light to emit white light under the mixing of three-color light. Therefore, the optical film layer 300 can also include a light conversion film 304 arranged on the light-emitting side of the substrate layer 302. The light conversion film 304 can be a phosphor conversion film or a quantum dot conversion film.

[0087] The phosphor conversion film can include a phosphor for emitting yellow light under excitation of blue light.

[0088] The quantum dot conversion film can include first quantum dots for emitting red light under excitation of blue light and second quantum dots for emitting green light under excitation of blue light. As Figure 3 shown, the light conversion film 304 can be distributed with first quantum dots 3046 and second quantum dots 3048, wherein the first quantum dots 3046 can emit red light under excitation of the blue light emitted by the light-emitting unit 212, and the second quantum dots 3048 can emit green light under excitation of the blue light emitted by the light-emitting unit 212. In this way, the blue light can be converted into red light or green light by quantum dots, so that the color purity of the emitted light can be higher.

[0089] In some embodiments, the optical film layer 300 can also include an optical film sheet 306 arranged on the light-emitting side of the light conversion film 304 to achieve brightness enhancement. The optical film sheet 306 can be a composite film layer and can further include two prism sheets and a brightness enhancement film sandwiched between the two prism sheets, thereby forming a QPP film sheet composed of one polarized brightness enhancement film and two prism sheets, wherein "Q" is the brightness enhancement film and "P" is the prism sheet.

[0090] In some embodiments, the adhesion between the substrate layer 302 and the light conversion film 304, and between the light conversion film 304 and the optical film 306 can be achieved by the adhesion layers 3042 and 3044 respectively. The adhesion layers 3042 and 3044 can be OCA, for example.

[0091] In some embodiments, the substrate layer 302 can be a curved glass, so that the curved backlight module can be achieved by matching the curved light-emitting substrate 200, and thus the curved display device. In addition, the glass has good strength and flatness.

[0092] In this way, the backlight module 500 achieves the integration of the three film layers through two layers of OCA, and the glass has strong flatness, which can compensate for the poor uniformity caused by the increase in the thickness of the optical film layer 300, achieve high uniformity of the curved backlight, and reduce the difficulty of backlight assembly.

[0093] The disclosure also provides a manufacturing method of a light-emitting substrate. Figure 4 A flowchart of an example manufacturing method 600 provided by the embodiments of the disclosure is shown. As shown in the figure, the method 600 can include the following steps. Figure 4

[0094] In step 602, a substrate 202 is provided, as shown in the figure. Figure 5A

[0095] In step 604, a metal trace layer 204 is formed on the substrate 202, as shown in the figure. Figure 5B

[0096] In step 606, a first protective glue layer 216 is formed on the metal trace layer 204 and exposes the conductive pads of the metal trace layer 204, as shown in the figure. Figure 5C

[0097] In some embodiments, the first protective glue layer 216 is formed on the metal trace layer 204 by using a spraying process, so that the use of mask can be reduced.

[0098] In some embodiments, the method 600 further includes:

[0099] In some embodiments, the first protective glue layer 216 is formed on the metal trace layer 204 by using a spraying process, so that the use of mask can be reduced. Figure 5D

[0100] In some embodiments, the first protective glue layer 216 is formed on the metal trace layer 204 by using a spraying process, so that the use of mask can be reduced.​​​​​

[0101] At step 608, a light emitting unit 212 is disposed on the conductive pad of the metal trace layer 204, and the light emitting unit 212 is electrically connected with the metal trace layer 204, as shown in FIG. 6B. Figure 5E

[0102] In some embodiments, the method 600 further includes:

[0103] A protective lens 214 is formed on the light emitting unit 212, and a normal projection of the protective lens 214 on the substrate 202 is located in a normal projection of the reflective layer 210 on the substrate 214, and a normal projection of the protective lens 214 on the substrate 202 at least partially overlaps with a normal projection of the second protective adhesive layer 218 on the substrate 202, as shown in FIG. 6C. Figure 5F

[0104] It can be understood that the above-mentioned embodiments of the light emitting substrate manufacturing method have a certain correspondence with the aforementioned embodiments of the light emitting substrate, and accordingly have corresponding technical effects, which will not be described here again.

[0105] As can be seen from the embodiments of the present disclosure, the light emitting substrate and the manufacturing method thereof and the display device provided by the embodiments of the present disclosure mainly provide an improvement scheme for waterproof and corrosion resistance of Mini LED substrate, while reducing the number of masks of the light emitting substrate and reducing the process; at the same time, the thrust of the protective lens of the existing light emitting substrate is improved, and R1500-1900 curved backlight is achieved.

[0106] The embodiments of the present disclosure realize the replacement of the SiNO x (or SiN) layer and the OC resin layer by introducing two layers of protective adhesive (for example, three-proofing adhesive) film, reducing 2mask to 1mask; at the same time, the introduction of the protective adhesive increases the bonding force between the protective lens and the white ink, and the protective lens still has good adhesion with the light emitting substrate in the curved light emitting substrate, reducing the risk of light out caused by peeling of the protective lens.

[0107] It should be noted that in the drawings, the sizes of the layers and regions can be exaggerated for clarity. Also, it can be understood that when an element or layer is referred to as being "on" another element or layer, it can be directly on the other element or layer, or intervening layers can also be present. Further, it can be understood that when an element or layer is referred to as being "under" another element or layer, it can be directly under the other element or layer, or one or more intervening layers or elements can also be present. In addition, it can be understood that when a layer or element is referred to as being "between" two layers or elements, it can be the only layer or element between the two layers or elements, or one or more intervening layers or elements can also be present. Similar reference numerals denote like elements throughout.

[0108] ​​Those skilled in the art should understand: the discussion of the above any embodiment is only exemplary, and is not intended to imply that the scope of the disclosure (including claims) is limited to these examples; the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the embodiments of the disclosure as described above, which are not provided in details for the sake of brevity.

[0109] Embodiments of the present disclosure are intended to cover all such alternatives, modifications, and variations as fall within the broad scope of the appended claims. Accordingly, any one of the above-mentioned alternatives, modifications, equivalents, improvements, etc. made within the spirit and principle of the embodiments of the present disclosure should be included in the scope of the present disclosure.

Claims

1. A light-emitting substrate, comprising: a substrate; a metal trace layer disposed on the substrate; a first protective adhesive layer covering the metal trace layer and configured to expose a conductive pad of the metal trace layer; and a light-emitting unit electrically connected to the conductive pad; wherein the light-emitting substrate further comprises a reflective layer disposed on the first protective adhesive layer, the first protective adhesive layer is made of a three-proofing adhesive, and the reflective layer comprises white ink; wherein the light-emitting substrate further comprises a protective lens disposed on the light-emitting unit, a projection of an edge of the protective lens on the substrate is located in a projection of the reflective layer on the substrate, the light-emitting substrate further comprises a second protective adhesive layer disposed between the reflective layer and the protective lens, and a size of the second protective adhesive layer satisfies: L = D + d + t1 + t2 + t3 wherein L is a distance between opposite outer edges of the second protective adhesive layer, D is a diameter of the protective lens, d is a distance between an outer edge of the second protective adhesive layer and an outer edge of the protective lens, t1 is a position allowance of the protective lens, t2 is a shape allowance of the protective lens, and t3 is a position allowance of the second protective adhesive layer. The second protective adhesive layer is disposed around a periphery of the protective lens, and a projection of the second protective adhesive layer on the substrate at least partially overlaps a projection of the protective lens on the substrate.

2. The light-emitting substrate according to claim 1, wherein The first protective adhesive layer and the second protective adhesive layer are made of a three-proofing adhesive.

3. The light-emitting substrate according to claim 1 or 2, wherein The light-emitting unit is a sub-millimeter light-emitting diode or a micro light-emitting diode.

4. The light emitting substrate of claim 1, wherein, 5. A display device, comprising: the light-emitting substrate according to any one of claims 1-4; and an optical film layer disposed on a light-emitting direction side of the light-emitting substrate. The display device comprises a backlight module, and the light-emitting substrate and the optical film layer are disposed in the backlight module. The optical film layer comprises a substrate layer, and both surfaces of the substrate layer are coated with diffusion ink.

6. The display device of claim 5, wherein, The substrate layer is a curved glass.

7. The display device according to claim 5 or 6, wherein 9. A manufacturing method of a light-emitting substrate, comprising:

8. The display device of claim 7, wherein, providing a substrate; forming a metal trace layer on the substrate; forming a first protective adhesive layer on the metal trace layer and exposing a conductive pad of the metal trace layer; and disposing a light-emitting unit on the conductive pad; wherein the light-emitting substrate further comprises a reflective layer disposed on the first protective adhesive layer, the first protective adhesive layer is made of a three-proofing adhesive, and the reflective layer comprises white ink; wherein the method further comprises: forming a reflective layer and a second protective adhesive layer on the first protective adhesive layer in sequence; and forming a protective lens on the light-emitting unit, a projection of an edge of the protective lens on the substrate is located in a projection of the reflective layer on the substrate, and a projection of the protective lens on the substrate at least partially overlaps a projection of the second protective adhesive layer on the substrate; a size of the second protective adhesive layer satisfies: L = D + d + t1 + t2 + t3 ​ ​ ​ Wherein, L is the distance between opposite outer edges of the second protective glue layer, D is the diameter of the protective lens, d is the distance between the outer edge of the second protective glue layer and the outer edge of the protective lens, t1 is the position allowance of the protective lens, t2 is the shape allowance of the protective lens, and t3 is the position allowance of the second protective glue layer.

10. The method of claim 9, wherein, Forming a first protective glue layer on the metal trace layer, comprising: Forming the first protective glue layer on the metal trace layer by using a spraying process.

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