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

Abstract

Embodiments of the present invention provide a light-emitting substrate and a method for manufacturing same, and a display device, for use in improving the yield of light-emitting substrates. The light-emitting substrate comprises: a wiring substrate comprising a base substrate, a wiring layer, and a first insulating protection layer, wherein the wiring layer comprises a plurality of first bonding pad groups, the first insulating protection layer comprises a plurality of first openings, and the orthographic projections of the first bonding pad groups on the base substrate fall within the orthographic projections of the first openings on the base substrate; a plurality of light-emitting devices located on the side of the first bonding pad groups facing away from the base substrate, wherein each light-emitting device in the plurality of light-emitting devices is bound to one first bonding pad group in the plurality of first bonding pad groups; and a plurality of protection structures located on the side of the light-emitting device facing away from the base substrate, wherein each of the plurality of protection structures comprises a first part and a second part located on the side of the first part facing away from the base substrate, and the orthographic projections of the first parts on the base substrate at least cover the orthographic projections of the areas between the light-emitting devices and the first insulating protection layer on the base substrate.

Description

Luminescent substrate, preparation method thereof, and display device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on May 19, 2023, with application number 202310574279.3 and invention name "Luminescent substrate, preparation method thereof, and display device", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present disclosure relates to the field of display technology, and in particular to a light-emitting substrate and a preparation method thereof, and a display device. Background Art

[0004] Micro light-emitting diodes have a significant increase in usage in the display field due to their smaller size, ultra-high brightness, and long life.

[0005] Summary of the Invention

[0006] The light-emitting substrate, the preparation method thereof, and the display device provided by the embodiments of the present disclosure are used to improve the yield rate of the light-emitting substrate.

[0007] The present disclosure provides a light-emitting substrate, comprising:

[0008] A wiring substrate, comprising: a base substrate, a wiring layer located on one side of the base substrate, and a first insulating protective layer located on a side of the wiring layer facing away from the base substrate; the wiring layer comprising a plurality of first pad groups, the first insulating protective layer comprising a plurality of first openings, the orthographic projections of the first pad groups on the base substrate falling within the orthographic projections of the first openings on the base substrate;

[0009] A plurality of light-emitting devices are located on a side of the first pad group facing away from the substrate; each of the plurality of light-emitting devices is bound to one of the plurality of first pad groups;

[0010] Multiple protective structures are located on the side of the light-emitting device facing away from the substrate; each of the multiple protective structures includes: a first portion, and a second portion located on the side of the first portion facing away from the substrate; the orthographic projection of the first portion on the substrate at least covers the orthographic projection of the area between the light-emitting device and the first insulating protective layer on the substrate.

[0011] In some embodiments, the first part has a first transmittance to visible light, the second part has a second transmittance to visible light, the absolute value of the difference between the first transmittance and the second transmittance is less than or equal to 5%, the first transmittance is greater than or equal to 90%, and the second transmittance is greater than or equal to 90%.

[0012] In some embodiments, the first portion has a first refractive index for visible light, the second portion has a second refractive index for visible light, and an absolute value of a difference between the first refractive index and the second refractive index is less than or equal to 0.2.

[0013] In some embodiments, the material of the first portion includes a first adhesive material, and the material of the second portion includes a second adhesive material; the viscosity of the first adhesive material is lower than the viscosity of the second adhesive material.

[0014] In some embodiments, the viscosity of the first light-transmitting adhesive is greater than or equal to 3000 Pascal seconds and less than 6000 Pascal seconds;

[0015] The viscosity of the second adhesive is greater than or equal to 6000 Pascal seconds and less than or equal to 9000 Pascal seconds.

[0016] In some embodiments, the volume of the first portion is smaller than the volume of the second portion.

[0017] In some embodiments, the maximum distance h1 from the surface of the light-emitting device away from the substrate substrate to the substrate substrate, the maximum distance h2 from the surface of the first part away from the substrate substrate to the substrate substrate, and the maximum distance h3 from the surface of the second part away from the substrate substrate to the substrate substrate satisfy: 0.53≥h2 / h1≥1.33, 3.33≥h3 / h1≥5.

[0018] In some embodiments, a maximum distance h2 from a surface of the first portion facing away from the substrate to the substrate is greater than a maximum distance h4 from a surface of the first insulating protection layer facing away from the substrate to the substrate.

[0019] In some embodiments, 0.13≥h4 / h1≥0.4.

[0020] In some embodiments, 100 microns ≥ h1 ≥ 200 microns, 20 microns ≥ h4 ≥ 60 microns, 80 microns ≥ h2 ≥ 200 microns, and 500 microns ≥ h3 ≥ 750 microns.

[0021] In some embodiments, an orthographic projection of the first portion on the substrate falls within an orthographic projection of the second portion on the substrate.

[0022] In some embodiments, the plurality of light emitting devices are arranged in an array along a first direction and a second direction, and the first direction intersects the second direction;

[0023] In the first direction or in the second direction, the orthographic projection of the first opening on the substrate has a first size L1, the orthographic projection of the light-emitting device on the substrate has a second size L2, the orthographic projection of the first portion on the substrate has a third size L3, and the orthographic projection of the second portion on the substrate has a fourth size L4. The first size L1, the second size L2, the third size L3 and the fourth size L4 satisfy the following relationship: L1>L2, L3>L1, L4>L3.

[0024] In some embodiments, in the first direction or in the second direction, the first dimension L1, the second dimension L2, and the third dimension L3 satisfy:

[0025] L2+150 μm ≥ L1 ≥ L2+50 μm;

[0026] In some embodiments, 700 micrometers ≥ L2 ≥ 100 micrometers; and the fourth dimension L4 satisfies: 1300 micrometers ≥ L4 ≥ 1000 micrometers.

[0027] In some embodiments, a surface of the first portion facing away from the substrate and a surface of the second portion facing away from the substrate are curved surfaces.

[0028] The present disclosure provides a method for preparing a light-emitting substrate, comprising:

[0029] A wiring substrate is manufactured; the wiring substrate comprises: a base substrate, a wiring layer located on one side of the base substrate, and a first insulating protective layer located on a side of the wiring layer facing away from the base substrate; the wiring layer comprises a plurality of first pad groups, the first insulating protective layer comprises a plurality of first openings, and the orthographic projections of the first pad groups on the base substrate fall within the orthographic projections of the first openings on the base substrate;

[0030] Binding each of the plurality of light emitting devices to one of the plurality of first pad groups;

[0031] A first portion is sequentially formed on a side of the light-emitting device facing away from the substrate; an orthographic projection of the first portion on the substrate at least covers an orthographic projection of an area between the light-emitting device and the first insulating protective layer on the substrate;

[0032] The second portion is formed on a side of the first portion facing away from the substrate; in a direction perpendicular to the substrate, the maximum thickness of the first portion is smaller than the maximum thickness of the second portion.

[0033] In some embodiments, forming the first portion on a side of the light-emitting device facing away from the substrate specifically includes:

[0034] Printing a first adhesive material on a side of the light emitting device facing away from the base substrate and curing the first adhesive material to form a first portion;

[0035] Forming a second portion on a side of the first portion facing away from the substrate, specifically comprising:

[0036] Printing a second adhesive material on a side of the first portion facing away from the base substrate and curing the second adhesive material to form a second portion;

[0037] The volume of the first part is smaller than the volume of the second part.

[0038] A display device provided by an embodiment of the present disclosure includes the light-emitting substrate provided by an embodiment of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0040] FIG1 is a schematic structural diagram of a light-emitting substrate provided by the related art;

[0041] FIG2 is a schematic structural diagram of a light-emitting substrate provided in an embodiment of the present disclosure;

[0042] FIG3 is a top view of a light-emitting substrate provided in an embodiment of the present disclosure;

[0043] FIG4 is a schematic flow chart of a method for preparing a light-emitting substrate according to an embodiment of the present disclosure;

[0044] FIG5 is a schematic flow chart of another method for preparing a light-emitting substrate provided in an embodiment of the present disclosure;

[0045] FIG6 is a schematic flow chart of another method for preparing a light-emitting substrate provided in an embodiment of the present disclosure;

[0046] FIG7 is a schematic structural diagram of a display device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. And in the absence of conflict, the embodiments in the present disclosure and the features in the embodiments can be combined with each other. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0048] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by persons of ordinary skill in the field to which this disclosure belongs. The words "first", "second" and similar terms used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0049] It should be noted that the sizes and shapes of the figures in the accompanying drawings do not reflect the actual scale and are only for the purpose of illustrating the present disclosure. The same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions.

[0050] In the related art, as shown in FIG1 , a light-emitting substrate includes a wiring substrate 1 and a reflective layer 4 located above the wiring substrate 1. The reflective layer 4 has an opening 401, which exposes a pad 7 on the wiring substrate that is bonded to the light-emitting device 2, as well as a protective structure 5 for protecting the light-emitting device 2. During the printing process to form the protective structure, a transparent slurry in a solid-liquid mixture is deposited on the corresponding area and solidified to form the protective structure. To ensure that the final protective structure has a specific morphology, the transparent slurry used needs to have a high viscosity. The inventors discovered that due to the small size of the opening 401 and the small distance between the light-emitting device and the edge of the opening 401, it is easy for the air below the opening 401 corresponding to the location where the transparent slurry falls to be unable to be smoothly discharged. As shown in FIG1 , this results in the presence of bubbles 6 in the final protective structure. The presence of bubbles 6 causes the brightness uniformity of the light emitted from the light-emitting device 2 through the protective structure to deteriorate, thereby affecting the overall brightness uniformity of the light-emitting substrate.

[0051] The present disclosure provides a light-emitting substrate, as shown in FIG2 , which includes:

[0052] The wiring substrate 1 includes: a base substrate 101, a wiring layer 102 located on one side of the base substrate 101, and a first insulating protective layer 103 located on a side of the wiring layer 102 facing away from the base substrate 101; the wiring layer 102 includes a plurality of first pad groups 1021, and the first insulating protective layer 103 includes a plurality of first openings 1031, wherein the orthographic projections of the first pad groups 1021 on the base substrate 101 fall within the orthographic projections of the first openings 1031 on the base substrate 101;

[0053] A plurality of light-emitting devices 2 are located on a side of the first pad group 1021 away from the base substrate 101; each of the plurality of light-emitting devices 2 is bonded to one of the plurality of first pad groups 1021;

[0054] Multiple protective structures 3 are located on the side of the light-emitting device 2 facing away from the substrate 101; each of the multiple protective structures 3 includes: a first portion 301, and a second portion 302 located on the side of the first portion 301 facing away from the substrate 101; the orthographic projection of the first portion 301 on the substrate 101 at least covers the orthographic projection of the area between the light-emitting device 2 and the first insulating protective layer 103 on the substrate 101.

[0055] The light-emitting substrate provided in the embodiments of the present disclosure has a protective structure comprising a first portion and a second portion, with the second portion located on the side of the first portion facing away from the base substrate. That is, in the embodiments of the present disclosure, the protective structure is fabricated in two steps: first, forming the first portion that at least covers the area between the light-emitting device and the first insulating protective layer, and then forming the second portion. This facilitates the removal of air between the protective structure and the wiring substrate at the first opening, preventing the formation of bubbles between the protective structure and the wiring substrate, thereby preventing abnormal brightness of light emitted from the protective structure, improving the yield of the light-emitting substrate, and enhancing the brightness uniformity of the light-emitting substrate.

[0056] In some embodiments, the number of light emitting devices is equal to the number of protection structures.

[0057] In a specific implementation, each light emitting device is covered by a protective structure, which can be used to prevent the light emitting device from being damaged.

[0058] In some embodiments, as shown in FIG2 , the surface of the second portion 302 facing away from the substrate 101 is curved. That is, the surface of the protective structure 3 facing away from the substrate 101 is curved. This shape of the protective structure 3, as shown in FIG2 , can modulate light emitted by the light-emitting device, improving brightness and efficiency at normal viewing angles.

[0059] In some embodiments, as shown in FIG. 2 , the surface of the first portion 301 facing away from the base substrate 101 may also be a curved surface.

[0060] In some embodiments, both the first portion and the second portion include adhesive.

[0061] In some embodiments, the first portion and the second portion include the same adhesive material.

[0062] Alternatively, in some embodiments, the first portion and the second portion include different adhesive materials.

[0063] In some embodiments, the material of the first portion includes a first adhesive material, and the material of the second portion includes a second adhesive material; the viscosity of the first adhesive material is lower than the viscosity of the second adhesive material.

[0064] In the light-emitting substrate provided by the embodiment of the present disclosure, in the protective structure, the first adhesive material included in the first part covering the area between the light-emitting device and the first insulating protective layer has a lower viscosity, which is more conducive to air discharge and can further avoid the formation of bubbles between the protective structure and the wiring substrate, thereby avoiding abnormal brightness of light emitted from the protective structure, and is more conducive to improving the yield of the light-emitting substrate and improving the brightness uniformity of the light-emitting substrate.

[0065] In some embodiments, the viscosity of the second adhesive is greater than or equal to 6000 Pascal seconds and less than or equal to 9000 Pascal seconds;

[0066] The viscosity of the first light-transmitting adhesive is greater than or equal to 3000 Pascal seconds and less than 6000 Pascal seconds.

[0067] In specific implementation, the aspect ratio of the protective structure 3 is related to the thixotropy of the adhesive. Materials with different viscosities form protective structures 3 with different aspect ratios. The first adhesive and the second adhesive with corresponding viscosities can be selected according to the required aspect ratio of the protective structure 3 .

[0068] In some embodiments, the adhesive materials included in the first portion and the second portion are both light-transmitting adhesive materials.

[0069] In some embodiments, the first portion has a first transmittance for visible light, and the second portion has a second transmittance for visible light, wherein the first transmittance is greater than or equal to 90%, and the second transmittance is greater than or equal to 90%. This ensures that the first and second portions have high transmittances for visible light, increases the brightness of light emitted from the protective structure, and facilitates improving the light utilization efficiency of the light-emitting substrate.

[0070] In a specific implementation, the first transmittance and the second transmittance may be equal. Of course, the first transmittance and the second transmittance may also be unequal.

[0071] In some embodiments, an absolute value of a difference between the first transmittance and the second transmittance is less than or equal to 5%.

[0072] The light-emitting substrate provided by the embodiment of the present disclosure has an absolute value of the difference between the first transmittance and the second transmittance that is less than or equal to 5%, that is, the difference in transmittance between the first part and the second part is small, so that light can pass through the protective structure smoothly and avoid affecting the overall transmittance of the protective structure.

[0073] In some embodiments, to reduce the probability of total internal reflection of the light emitted from the light emitting device at the interface between the protection structure and air, the refractive index of the protection structure may be between the refractive index of the light emitting device and the refractive index of air.

[0074] In some embodiments, the first portion has a first index of refraction for visible light and the second portion has a second index of refraction for visible light.

[0075] In some embodiments, the first refractive index is equal to the second refractive index, thereby avoiding the need to adjust different parameters when manufacturing the first part and the second part, thereby saving costs.

[0076] Alternatively, in some embodiments, the first refractive index is not equal to the second refractive index.

[0077] In some embodiments, the absolute value of the difference between the first refractive index and the second refractive index is less than or equal to 0.2.

[0078] In the light-emitting substrate provided by the embodiment of the present disclosure, the absolute value of the difference between the first refractive index and the second refractive index is less than or equal to 0.2, that is, the difference in refractive index between the first part and the second part is small, thereby preventing light from being deflected at a large angle when passing through the interface between the first part and the second part.

[0079] In some embodiments, as shown in FIG. 2 , the volume of the first portion 301 is smaller than the volume of the second portion 302 .

[0080] That is, the volume of the first part of the light-emitting substrate provided in the embodiment of the present disclosure is less than half of the volume of the entire protective structure. The smaller volume of the first part is more conducive to discharging the air between the protective structure and the wiring substrate at the first opening, avoiding the presence of bubbles between the protective structure and the wiring substrate, thereby avoiding abnormal brightness of light emitted from the protective structure, improving the yield of the light-emitting substrate, and improving the brightness uniformity of the light-emitting substrate.

[0081] In some embodiments, as shown in Figure 2, the maximum distance h1 between the surface of the light-emitting device 2 away from the substrate substrate 101 and the substrate substrate 101, the maximum distance h2 between the surface of the first portion 301 away from the substrate substrate 101 and the substrate substrate 101, and the maximum distance h3 between the surface of the second portion 302 away from the substrate substrate 101 and the substrate substrate 101 satisfy: 0.53≥h2 / h1≥1.33, 3.33≥h3 / h1≥5.

[0082] It should be noted that in Figure 2, h1>h2 is used as an example for illustration. In specific implementation, h2>h1 can also be set, that is, the first portion also covers the light-emitting device. Alternatively, h1=h2 can also be set.

[0083] In some embodiments, as shown in FIG2 , a maximum distance h2 between the surface of the first portion 301 facing away from the substrate 101 and the substrate 101 is greater than a maximum distance h4 between the surface of the first insulating protective layer 103 facing away from the substrate 101 and the substrate 101. That is, the maximum thickness of the first portion is greater than the maximum thickness of the first insulating protective layer, which facilitates the first portion covering the area between the light-emitting device and the first insulating protective layer at the first opening.

[0084] In some embodiments, 0.13≥h4 / h1≥0.4.

[0085] In some embodiments, 100 microns ≥ h1 ≥ 200 microns, 20 microns ≥ h4 ≥ 60 microns, 80 microns ≥ h2 ≥ 200 microns, and 500 microns ≥ h3 ≥ 750 microns.

[0086] In some embodiments, as shown in FIG. 2 and FIG. 3 , the orthographic projection of the first portion 301 on the base substrate 101 falls within the orthographic projection of the second portion 302 on the base substrate 101 .

[0087] That is, the second portion completely covers the first portion, which can improve the protection effect of the protection structure on the light-emitting device. The morphology of the surface of the second portion facing away from the substrate is the morphology of the protection structure.

[0088] In some embodiments, as shown in FIG. 3 , the orthographic projection of the first portion 301 on the base substrate 101 and the orthographic projection of the second portion 302 on the base substrate 101 are circular.

[0089] In some embodiments, as shown in FIG3 , the orthographic projection of the light emitting device 2 on the substrate 101 and the orthographic projection of the first opening 1031 on the substrate 101 are rectangular. FIG3 illustrates an example in which the orthographic projection of the light emitting device 2 on the substrate 101 and the orthographic projection of the first opening 1031 on the substrate 101 are square.

[0090] In some embodiments, as shown in Figure 3 , the center of the pattern of the orthographic projection of the first portion 301 on the substrate 101, the center of the pattern of the orthographic projection of the second portion 302 on the substrate 101, the center of the orthographic projection of the light-emitting device 2 on the substrate 101, and the center of the orthographic projection of the first opening 1031 on the substrate 101 coincide with each other. In Figure 3 , the center of the pattern of the orthographic projection of the first portion 301 on the substrate 101, the center of the pattern of the orthographic projection of the second portion 302 on the substrate 101, the center of the orthographic projection of the light-emitting device 2 on the substrate 101, and the center of the orthographic projection of the first opening 1031 on the substrate 101 coincide with point A in the figure.

[0091] In some embodiments, as shown in Figure 3 , a plurality of light emitting devices 2 are arranged in an array along a first direction X and a second direction Y, and the first direction X intersects the second direction Y. Figure 3 illustrates an example where the first direction X and the second direction Y are perpendicular.

[0092] In some embodiments, as shown in FIG3 , in the first direction X or in the second direction Y, the orthographic projection of the first opening 1031 on the substrate has a first size L1, the orthographic projection of the light-emitting device 2 on the substrate has a second size L2, the orthographic projection of the first portion 301 on the substrate has a third size L3, and the orthographic projection of the second portion 302 on the substrate has a fourth size L4. The first size L1, the second size L2, the third size L3, and the fourth size L4 satisfy the following relationship: L1>L2, L3>L1, L4>L3.

[0093] It should be noted that if the shape of the orthographic projection of the first opening or the light-emitting device or the first part or the second part on the substrate is a rectangle and its sides are parallel to the first direction or the second direction, then the corresponding first dimension L1 or second dimension L2 or third dimension L3 or fourth dimension L4 is half of the side length of the above-mentioned rectangle; if the shape of the orthographic projection of the first opening or the light-emitting device or the first part or the second part on the substrate is a polygon, then the corresponding first dimension L1 or second dimension L2 or third dimension L3 or fourth dimension L4 is half of the diagonal of the above-mentioned polygon; if the shape of the orthographic projection of the first opening or the light-emitting device or the first part or the second part on the substrate is a circle, then the first dimension L1 or second dimension L2 or third dimension L3 or fourth dimension L4 is the radius of the above-mentioned circle; if the shape of the orthographic projection of the first opening or the light-emitting device or the first part or the second part on the substrate is an ellipse, then the first dimension L1 or second dimension L2 or third dimension L3 or fourth dimension L4 is half of the major axis or minor axis of the above-mentioned ellipse.

[0094] In the light-emitting substrate provided in the embodiment of the present disclosure, the third dimension L3 is greater than the first dimension L1, and the fourth dimension L4 is greater than the first dimension L1. That is, in addition to covering the area between the light-emitting device and the first insulating protective layer at the first opening, the first part also covers a partial area of ​​the first insulating protective layer near the first opening, and the second part also covers a partial area of ​​the first insulating protective layer near the first opening, which is beneficial to improving the protection effect of the light-emitting device and avoiding damage to the light-emitting device.

[0095] It should be noted that in FIG3 , the orthographic projections of the first opening and the light-emitting device on the substrate are both rectangular, with sides of the rectangles parallel to the first direction or the second direction. The orthographic projections of the first portion and the second portion on the substrate are both circular. That is, the first dimension L1_x in the first direction X is equal to the first dimension L1_y in the second direction Y, the second dimension L2_x in the first direction X is equal to the second dimension L2_y in the second direction Y, the third dimension L3_x in the first direction X is equal to the third dimension L3_y in the second direction Y, and the fourth dimension L4_x in the first direction X is equal to the fourth dimension L4_y in the second direction Y. Of course, in specific implementations, the orthographic projections of the first opening, the light-emitting device, the first portion, and the second portion on the substrate may also have other shapes. That is, the second dimension L1_x in the first direction may be unequal to the second dimension L2_y in the second direction, the first dimension L1_x in the first direction may be unequal to the first dimension L1_y in the second direction, the third dimension L3_x in the first direction may be unequal to the third dimension L3_y in the second direction, and the fourth dimension L4_x in the first direction may be unequal to the fourth dimension L4_y in the second direction.

[0096] In some embodiments, in the first direction or in the second direction, the first dimension L1, the second dimension L2, and the third dimension L3 satisfy:

[0097] L2+150 μm ≥ L1 ≥ L2+50 μm;

[0098] In the light-emitting substrate provided by the embodiments of the present disclosure, L1 ≥ L2 + 50 microns can prevent the first insulating protective layer from interfering with the light output of the light-emitting device due to a narrow first opening width. L2 + 150 microns ≥ L1 can also prevent the first opening from being too large, which would lead to an oversized protective structure and affect the light utilization efficiency of the light-emitting device, resulting in significant brightness loss.

[0099] It should be noted that L3 is the radius of the circle when the outer contour of the orthographic projection of the first part on the substrate is a circle. Therefore, L3 is not less than half of the diagonal of the orthographic projection of the light-emitting device on the substrate. When the orthographic projection of the light-emitting device on the substrate is a square, On this basis, Micrometers can ensure that the first part at least completely covers the area between the first insulating protection layer and the light-emitting device, thereby avoiding the problem of bubbles still being generated when forming the second part.

[0100] In some embodiments, 700 micrometers ≥ L2 ≥ 100 micrometers; and the fourth dimension L4 satisfies: 1300 micrometers ≥ L4 ≥ 1000 micrometers.

[0101] In some embodiments, the distance between the centers of two adjacent light-emitting devices in the first direction is L5_x, where L5_x = the total length of the substrate in the first direction / (the total number of light-emitting devices in a row in the first direction - 1); and the distance between the centers of two adjacent light-emitting devices in the second direction is L5_y, where L5_y = the total length of the substrate in the second direction / (the total number of light-emitting devices in a column in the second direction - 1).

[0102] In some embodiments, as shown in FIG. 3 , a distance L5_x between centers A of two adjacent light emitting devices 2 in the first direction X is equal to a distance L5_y between centers A of two adjacent light emitting devices 2 in the second direction Y.

[0103] In some embodiments, in the first direction or in the second direction, the minimum distance between the orthographic projections of two adjacent second portions on the substrate is L6, L6 = L5-2×L4; the distance L5 between the centers of two adjacent light-emitting devices needs to be greater than twice the fourth dimension L4, that is, L5_x>2×L4_x, L5_y>2×L4_y, so that in the first direction or in the second direction, the minimum distance L6 between the orthographic projections of two adjacent second portions on the substrate is greater than 0, thereby avoiding overlapping of two adjacent protective structures.

[0104] It should be noted that to prevent overlapping of adjacent protective structures, L6 must be greater than the safety distance between the protective structures. This safety distance is generally related to the positioning accuracy of the protective structures. If the positioning accuracy of the protective structures in the first or second direction is ±0.1 micron, the safety distance is 0.2 micron, meaning L6 must be greater than 0.2 micron.

[0105] In some embodiments, 10 mm ≥ L5_x ≥ 3 mm, and 10 mm ≥ L5_y ≥ 3 mm. This ensures the brightness of the light-emitting substrate while avoiding excessive light-emitting devices that increase the power consumption of the light-emitting substrate. When 10 mm ≥ L5 ≥ 3 mm and 1300 μm ≥ L4 ≥ 1000 μm, L6 is no less than 400 μm, meaning L6 is significantly greater than the safe distance, thus preventing interference between the light emitted by two adjacent protective structures.

[0106] In some embodiments, the light emitting device is a micro-sized inorganic light emitting diode.

[0107] In a specific implementation, the micro-sized inorganic light-emitting diode is, for example, a mini light-emitting diode (Mini Light Emitting Diode, Mini-LED) or a micro light-emitting diode (Micro Light Emitting Diode, Micro-LED). Mini-LED and Micro-LED are small in size and high in brightness, and can be widely used in display devices or their backlight modules. For example, the typical size (such as length) of Micro-LED is less than 100 microns, such as 10 microns to 80 microns; the typical size (such as length) of Mini-LED is 80 microns to 350 microns, such as 80 microns to 120 microns. The light-emitting device can be at least one of Micro-LED or Mini-LED.

[0108] 2 , the first pad group 1021 includes a first sub-pad 1021-1 and a second sub-pad 1021-2. The light emitting device 2 includes two pins (not shown), which are electrically connected to the first sub-pad 1021-1 and the second sub-pad 1021-2 of the first pad group 1021, respectively.

[0109] In a specific implementation, the light-emitting device further includes an anode, a light-emitting layer, and a cathode. One of the two pins is electrically connected to the anode, and the other of the two pins is electrically connected to the cathode.

[0110] In some embodiments, the wiring layer further includes multiple second pad groups, multiple common voltage signal lines, and multiple fixed voltage signal lines; the light-emitting substrate further includes multiple driver chips. The driver chips are bonded to the second pad groups. In a specific implementation, the second pad group includes: address pads, power pads, ground pads, and output pads. The driver chip includes: a ground pin electrically connected to the ground pads, an output pin electrically connected to the output pads, an address pin electrically connected to the address pads, and a power pin electrically connected to the power pads. The address pads are electrically connected to the common voltage signal lines. The multiple light-emitting devices are divided into multiple light-emitting zones, each light-emitting zone including at least one light-emitting device. At least one light-emitting device in each light-emitting zone is electrically connected to the fixed voltage signal lines via a first sub-pad included in the first pad group, and at least one light-emitting device in each light-emitting zone is electrically connected to the output pads via a second sub-pad included in the first pad group. For example, each second pad group corresponds to a light-emitting zone, and a corresponding driver chip can control the operation of each light-emitting device in the corresponding light-emitting zone. In a specific implementation, the power supply pad can provide an operating voltage for the driver chip. The output end of the driver chip outputs a driving signal through the output pad. The driving signal is a driving current used to drive the light-emitting device in the light-emitting area electrically connected to the output pad. The driver chip provides an operating voltage to the next-level driver chip through the power supply pad. The address pad includes, for example, a first address pad and a second address pad. The first address pad can receive an address signal for selecting the driver chip with the corresponding address. The driver chip also generates a relay signal and outputs the relay signal through the second address pad. The relay signal serves as the address signal of the first address pad in the second pad group of the next level. The ground pad receives a common voltage signal transmitted by the common voltage signal line.

[0111] In some embodiments, the material of the first insulating protective layer includes white oil.

[0112] In some embodiments, the material of the first pad group, the second pad group, and each signal line in the wiring layer includes copper.

[0113] In a specific implementation, the first pad group, the second pad group, and each signal line in the wiring layer may include a single layer of copper or a double layer of copper. When the wiring layer includes a double layer of copper, the wiring layer further includes an insulating layer located between the double layers of copper, and the double layers of copper are electrically connected via vias penetrating the insulating layer.

[0114] In a specific implementation, the first pad group, the second pad group, and each signal line in the wiring layer can include a single layer of copper, and the single layer of copper included in the first pad group, the second pad group, and each signal line can be arranged in the same layer. The first pad group, the second pad group, and each signal line in the wiring layer can include a double layer of copper, and each layer of copper included in the first pad group, the second pad group, and each signal line can be arranged in the same layer. This can facilitate the production of the wiring substrate.

[0115] Based on the same inventive concept, the present disclosure also provides a method for preparing a light-emitting substrate, as shown in FIG4 , comprising:

[0116] S101. Fabricate a wiring substrate; the wiring substrate comprises: a base substrate, a wiring layer located on one side of the base substrate, and a first insulating protective layer located on a side of the wiring layer facing away from the base substrate; the wiring layer comprises a plurality of first pad groups, the first insulating protective layer comprises a plurality of first openings, and an orthographic projection of the first pad groups on the base substrate falls within an orthographic projection of the first openings on the base substrate;

[0117] S102, binding each of the plurality of light-emitting devices to one of the plurality of first pad groups;

[0118] S103, forming a first portion on a side of the light-emitting device facing away from the base substrate; the orthographic projection of the first portion on the base substrate at least covers the orthographic projection of the area between the light-emitting device and the first insulating protective layer on the base substrate;

[0119] S104 , forming a second portion on a side of the first portion facing away from the base substrate; in a direction perpendicular to the base substrate, a maximum thickness of the first portion is smaller than a maximum thickness of the second portion.

[0120] The method for manufacturing a light-emitting substrate provided by the embodiments of the present disclosure first forms a first portion that covers at least the area between the light-emitting device and the first insulating protective layer, and then forms a second portion. The first and second portions form a protective structure that protects the light-emitting device. This method is more conducive to expelling air between the first portion and the wiring substrate at the first opening, preventing bubbles from forming between the first portion and the wiring substrate, and thus preventing abnormal brightness of light emitted from the protective structure formed by the first and second portions. This improves the manufacturing yield of the light-emitting substrate and enhances the brightness uniformity of the light-emitting substrate.

[0121] In some embodiments, forming the first portion sequentially on a side of the light-emitting device facing away from the substrate specifically includes:

[0122] Printing a first adhesive material on a side of the light emitting device facing away from the base substrate and curing the first adhesive material to form a first portion;

[0123] Forming a second portion on a side of the first portion facing away from the substrate, specifically comprising:

[0124] Printing a second adhesive material on a side of the first portion facing away from the base substrate and curing the second adhesive material to form a second portion;

[0125] The volume of the first part is smaller than the volume of the second part.

[0126] In the method for preparing the light-emitting substrate provided by the embodiment of the present disclosure, the volume of the first part is smaller than the volume of the second part, that is, the volume of the printed first adhesive is smaller than the volume of the printed second adhesive, and the volume of the printed first adhesive is less than half of the volume of the entire protective structure composed of the first part and the second part. The smaller volume of the printed first adhesive is more conducive to discharging the air between the first part and the wiring substrate at the first opening, avoiding the presence of bubbles between the first part and the wiring substrate, thereby avoiding abnormal brightness of light emitted from the protective structure composed of the first part and the second part, improving the preparation yield of the light-emitting substrate, and improving the brightness uniformity of the light-emitting substrate.

[0127] In some embodiments, the first adhesive and the second adhesive include the same material.

[0128] Alternatively, in some embodiments, the first adhesive and the second adhesive include different materials.

[0129] In some embodiments, the viscosity of the first adhesive is lower than the viscosity of the second adhesive.

[0130] In the method for preparing the light-emitting substrate provided by the embodiment of the present disclosure, the viscosity of the first glue material printed first is relatively low, which is more conducive to air discharge, and can further avoid the presence of bubbles between the first part and the wiring substrate, thereby avoiding abnormal brightness of the light emitted from the protective structure composed of the first part and the second part, and is more conducive to improving the preparation yield of the light-emitting substrate and improving the brightness uniformity of the light-emitting substrate.

[0131] In specific implementation, the transmittance, refractive index, viscosity-related settings of the first adhesive and the second adhesive to visible light, as well as the size of the first part, the size of the second part, the size of the first opening, the size of the light-emitting device, etc., can be found in the light-emitting substrate embodiment and will not be repeated here.

[0132] In some embodiments, printing a first adhesive material on a side of the light-emitting device facing away from the substrate, as shown in FIG5 , specifically includes:

[0133] A first adhesive 3011 is printed on each side of the light emitting device 2 to fill the area between the light emitting device 2 and the first insulating protective layer 103 to form a first portion 301 .

[0134] Alternatively, in some embodiments, printing a first adhesive material on a side of the light-emitting device facing away from the substrate, as shown in FIG6 , includes:

[0135] The first adhesive 3011 is printed above the light emitting device 2 facing away from the base substrate 1 so that the first adhesive 3011 drips to at least cover the area between the light emitting device 2 and the first insulating protective layer 103 to form a first portion.

[0136] It should be noted that the reference numeral 8 in FIG. 5 and FIG. 6 represents the nozzle of the printing device.

[0137] In some embodiments, manufacturing a wiring substrate specifically includes:

[0138] A conductive layer is formed on the base substrate and a patterning process is performed on the conductive layer to form patterns of a plurality of first pad groups.

[0139] In a specific implementation, the wiring substrate further includes a second pad group and a plurality of signal lines; while performing a patterning process to form the patterns of the plurality of first pad groups, the patterning process also includes forming the patterns of the second pad group and the plurality of signal lines.

[0140] In a specific implementation, the wiring substrate may include a single conductive layer, or the wiring substrate may include a double conductive layer. The material of the conductive layer includes, for example, copper. If the wiring substrate includes a double conductive layer, forming the conductive layer on the base substrate and performing a patterning process on the conductive layer to form a pattern of a plurality of first pad groups and a pattern of a second pad group and a plurality of signal lines specifically includes:

[0141] Forming a first conductive layer on the base substrate, and performing a patterning process to form a first conductive layer pattern of a first pad group, a second pad group, and a plurality of signal lines;

[0142] forming a pattern of an insulating layer on a side of the first conductive layer facing away from the substrate;

[0143] A second conductive layer is formed on a side of the insulating layer facing away from the base substrate, and a patterning process is performed to form a first pad group, a second pad group and second conductive layer patterns of various signal lines.

[0144] In a specific implementation, the method for preparing the light-emitting substrate provided in the embodiment of the present disclosure further includes:

[0145] preparing a plurality of light-emitting devices;

[0146] Binding each of the plurality of light-emitting devices to one of the plurality of first pad groups specifically includes:

[0147] The plurality of light emitting devices are transferred to the wiring substrate so that the light emitting devices are bound to the first pad groups in a one-to-one correspondence.

[0148] A display device provided by an embodiment of the present disclosure, as shown in FIG7 , includes a light-emitting substrate 9 provided by an embodiment of the present disclosure.

[0149] In some embodiments, as shown in FIG. 7 , the display device further includes a display panel 10 located on the light emitting side of the light emitting substrate 9 .

[0150] That is, in a specific implementation, the light-emitting substrate provided in the embodiment of the present disclosure serves as a backlight source of a display panel.

[0151] In a specific implementation, the display panel is a liquid crystal display panel. As shown in FIG7 , the display panel 10 includes an array substrate 1001 and an opposite substrate 1002 disposed opposite to each other, and a liquid crystal layer 1003 located between the array substrate 1001 and the opposite substrate 1002 .

[0152] In a specific implementation, the array substrate includes a plurality of sub-pixel units, each of which includes a thin film transistor and a pixel electrode electrically connected to the thin film transistor. The counter substrate includes a black matrix and a plurality of color resists. The black matrix includes a plurality of openings corresponding to the sub-pixel units, and the color resists are located at least within the openings. The array substrate or the counter substrate also includes a common electrode. The color resists include, for example, red, blue, and green resists.

[0153] The display device provided in the embodiments of the present disclosure is any product or component with a display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigation system. Other essential components of the display device are readily understood by those skilled in the art and are not described here in detail, nor should they be construed as limitations of the present disclosure. The implementation of the display device can be referenced to the aforementioned embodiments of the light-emitting substrate, and any repetitive details will be omitted.

[0154] In summary, the light-emitting substrate, its preparation method, and display device provided in the embodiments of the present disclosure include a protective structure comprising a first portion and a second portion, with the second portion located on the side of the first portion facing away from the base substrate. That is, in the embodiments of the present disclosure, the protective structure is fabricated in two steps: first, forming the first portion that at least covers the area between the light-emitting device and the first insulating protective layer, and then forming the second portion. This facilitates the removal of air between the protective structure and the wiring substrate at the first opening, preventing bubbles from forming between the protective structure and the wiring substrate, thereby preventing abnormal brightness of light emitted from the protective structure, improving the yield of the light-emitting substrate, and enhancing the brightness uniformity of the light-emitting substrate.

[0155] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0156] Obviously, those skilled in the art may make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is intended to include these modifications and variations.

Claims

1. A light-emitting substrate, wherein: The light-emitting substrate comprises: A wiring substrate, comprising: a base substrate, a wiring layer located on one side of the base substrate, and a first insulating protection layer located on a side of the wiring layer away from the base substrate; the wiring layer comprises a plurality of first pad groups, the first insulating protection layer comprises a plurality of first openings, and the orthographic projection of the first pad group on the base substrate falls within the orthographic projection of the first opening on the base substrate; A plurality of light-emitting devices are located on a side of the first pad group away from the base substrate; each of the plurality of light-emitting devices is bound to one of the plurality of first pad groups; A plurality of protective structures are located on a side of the light-emitting device away from the substrate; each of the plurality of protective structures comprises: a first portion, and a second portion located on a side of the first portion away from the substrate; an orthographic projection of the first portion on the substrate at least covers an orthographic projection of an area between the light-emitting device and the first insulating protective layer on the substrate.

2. The light-emitting substrate according to claim 1, wherein: The first part has a first transmittance to visible light, the second part has a second transmittance to visible light, the absolute value of the difference between the first transmittance and the second transmittance is less than or equal to 5%, the first transmittance is greater than or equal to 90%, and the second transmittance is greater than or equal to 90%.

3. The light-emitting substrate according to claim 1, wherein: The first portion has a first refractive index for visible light, the second portion has a second refractive index for visible light, and an absolute value of a difference between the first refractive index and the second refractive index is less than or equal to 0.

2.

4. The light-emitting substrate according to claim 1, wherein: The material of the first part includes a first adhesive material, and the material of the second part includes a second adhesive material; the viscosity of the first adhesive material is lower than the viscosity of the second adhesive material.

5. The light emitting substrate according to claim 4, wherein: The viscosity of the first light-transmitting adhesive is greater than or equal to 3000 Pas and less than 6000 Pas; The viscosity of the second adhesive is greater than or equal to 6000 Pas and less than or equal to 9000 Pas.

6. The light-emitting substrate according to any one of claims 1 to 5, wherein: The volume of the first portion is smaller than the volume of the second portion.

7. The light-emitting substrate according to claim 6, wherein: The maximum distance h1 from the surface of the light emitting device away from the substrate to the substrate, the maximum distance h2 from the surface of the first part away from the substrate to the substrate, and the maximum distance h3 from the surface of the second part away from the substrate to the substrate satisfy: 0.53≥h2 / h1≥1.33, 3.33≥h3 / h1≥5.

8. The light-emitting substrate according to claim 7, wherein: A maximum distance h2 from a surface of the first portion away from the substrate to the substrate is greater than a maximum distance h4 from a surface of the first insulating protection layer away from the substrate to the substrate.

9. The light emitting substrate according to claim 8, wherein: 0.13≥h4 / h1≥0.

4.

10. The light emitting substrate according to claim 9, wherein: 100 microns ≥ h1 ≥ 200 microns, 20 microns ≥ h4 ≥ 60 microns, 80 microns ≥ h2 ≥ 200 microns, 500 microns ≥ h3 ≥ 750 microns.

11. The light emitting substrate according to any one of claims 1 to 5 and 7 to 10, wherein: The orthographic projection of the first portion on the substrate falls within the orthographic projection of the second portion on the substrate.

12. The light emitting substrate according to claim 11, wherein: The plurality of light emitting devices are arranged in an array along a first direction and a second direction, and the first direction intersects the second direction; In the first direction or in the second direction, the orthographic projection of the first opening on the substrate has a first size L1, the orthographic projection of the light-emitting device on the substrate has a second size L2, the orthographic projection of the first part on the substrate has a third size L3, and the orthographic projection of the second part on the substrate has a fourth size L4, and the first size L1, the second size L2, the third size L3 and the fourth size L4 satisfy the following relationship: L1>L2, L3>L1, L4>L3.

13. The light emitting substrate according to claim 12, wherein: In the first direction or in the second direction, the first size L1, the second size L2, and the third size L3 satisfy: L2+150 μm ≥ L1 ≥ L2+50 μm; L3≥ L2+50 microns.

14. The light emitting substrate according to claim 13, wherein: 700 microns ≥ L2 ≥ 100 microns; the fourth size L4 satisfies: 1300 microns ≥ L4 ≥ 1000 microns.

15. The light emitting substrate according to any one of claims 1 to 5, 7 to 10, and 12 to 14, wherein: A surface of the first portion facing away from the base substrate and a surface of the second portion facing away from the base substrate are curved surfaces.

16. A method for preparing a light-emitting substrate, wherein: The method comprises: A wiring substrate is manufactured; the wiring substrate comprises: a base substrate, a wiring layer located on one side of the base substrate, and a first insulating protection layer located on a side of the wiring layer away from the base substrate; the wiring layer comprises a plurality of first pad groups, the first insulating protection layer comprises a plurality of first openings, and the orthographic projection of the first pad group on the base substrate falls within the orthographic projection of the first opening on the base substrate; Binding each of the plurality of light emitting devices to one of the plurality of first solder pad groups; A first portion is formed on a side of the light emitting device away from the base substrate; an orthographic projection of the first portion on the base substrate at least covers an orthographic projection of a region between the light emitting device and the first insulating protective layer on the base substrate; A second portion is formed on a side of the first portion facing away from the substrate; in a direction perpendicular to the substrate, a maximum thickness of the first portion is smaller than a maximum thickness of the second portion.

17. The method according to claim 16, wherein: A first portion is sequentially formed on a side of the light emitting device away from the substrate, specifically comprising: Printing the first adhesive material on a side of the light emitting device away from the base substrate and curing the first adhesive material to form a first part; Forming a second portion on a side of the first portion away from the substrate, specifically comprising: Printing the second adhesive material on a side of the first part away from the base substrate and curing the second adhesive material to form a second part; The volume of the first portion is smaller than the volume of the second portion.

18. A display device, wherein: The display device comprises the light-emitting substrate according to any one of claims 1 to 15.

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