Display substrate, display panel and preparation method thereof

Abstract

The invention discloses a display substrate, a display panel and a preparation method thereof, the display substrate comprises a substrate, a bonding pad and an insulating layer, the bonding pad is located on one side of the substrate, and the bonding pad comprises at least two bonding pad layers stacked in the thickness direction of the substrate; the insulating layer is located between the two adjacent bonding pad layers, the insulating layer comprises a via hole, and in the two adjacent bonding pad layers, the bonding pad layer located on the side away from the substrate extends into the via hole and is electrically connected with the bonding pad layer close to the side of the substrate. According to the display substrate, the connection reliability of the welding part and the bonding pad can be improved, and the phenomenon that the welding part and the bonding pad are separated due to the fact that metal elements in the bonding pad are completely alloyed and depleted is improved.

Description

Technical Field

[0001] This application belongs to the field of display technology, and particularly relates to a display substrate, a display panel, and a manufacturing method thereof. Background Art

[0002] With the development of display technology, the performance requirements for display devices are getting higher and higher. Micro-LED display technology, with its characteristics of low power consumption, long lifespan, and high brightness, has gradually become the mainstream product of the next-generation display. However, the performance of current Micro-LED display substrates still needs to be improved. Summary of the Invention

[0003] Embodiments of this application provide a display substrate, a display panel, and a manufacturing method thereof, which can improve the connection reliability between the welding part and the pad, and improve the phenomenon of separation caused by the complete alloying depletion of metal elements in the pad.

[0004] An embodiment of the first aspect of the embodiments of this application provides a display substrate, including:

[0005] A substrate;

[0006] A pad, located on one side of the substrate, including at least two pad layers stacked along the thickness direction of the substrate;

[0007] At least one insulating layer, located between adjacent two pad layers, the insulating layer includes a via hole, and in adjacent two pad layers, the pad layer located on the side away from the substrate extends into the via hole and is electrically connected to the pad layer close to the substrate.

[0008] According to an embodiment of the first aspect of the present invention, the pad includes a first pad layer and a second pad layer stacked along the thickness direction of the substrate, the insulating layer is located between the first pad layer and the second pad layer, the orthographic projection of the via hole on the substrate is located within the orthographic projection of the first pad layer on the substrate, and the second pad layer extends along the inner wall of the via hole and is electrically connected to the first pad layer;

[0009] Preferably, the first pad layer and the second pad layer are made of the same material;

[0010] Preferably, the material of the first pad layer and the second pad layer includes copper and at least one of titanium, molybdenum, and niobium.

[0011] According to any one of the foregoing embodiments of the first aspect of the present invention, the insulating layer extends along the pad layer close to the substrate and covers the periphery of the pad layer close to the substrate;

[0012] Preferably, the insulating layers between adjacent ones of the pads are arranged at intervals;

[0013] Preferably, the insulating layer extends to abut against the substrate, and the insulating layers between adjacent ones of the pads are arranged continuously.

[0014] According to any of the foregoing embodiments of the first aspect of the present invention, it further includes a protective layer, at least partially located on a surface of the pad facing away from the substrate, including at least one first opening, and a positive projection of the first opening on the substrate is located within a positive projection of the pad on the substrate;

[0015] Preferably, the protective layer extends along the pad and covers the periphery of the pad;

[0016] Preferably, the insulating layers between adjacent ones of the pads are arranged at intervals, the insulating layer extends along the pad layer on the side close to the substrate, and covers the periphery of the pad layer on the side close to the substrate, and the protective layer extends to the periphery of the insulating layer;

[0017] Preferably, the insulating layers between adjacent ones of the pads are arranged at intervals, the protective layer extends between the insulating layers between adjacent ones of the pads and abuts against the substrate;

[0018] Preferably, the insulating layer extends to abut against the substrate, the insulating layers between adjacent ones of the pads are arranged continuously, and the protective layer extends between adjacent ones of the pads and abuts against the insulating layer;

[0019] Preferably, the material of the protective layer includes an inorganic material;

[0020] Preferably, the inorganic material includes at least one of silicon nitride and silicon oxide;

[0021] Preferably, the thickness of the protective layer is 2 μm - 3 μm.

[0022] According to any of the foregoing embodiments of the first aspect of the present invention, it further includes a pad elevation layer, located on one side of the substrate and at least partially located between the pad and the substrate, the pad elevation layer includes an opening, and a part of the pad is located within the opening;

[0023] Preferably, the pad elevation layers between adjacent ones of the pads are arranged at intervals to form an isolation gap;

[0024] Preferably, it further includes a protective layer, at least partially located on a surface of the pad facing away from the substrate, including at least one first opening, and a positive projection of the first opening on the substrate is located within a positive projection of the pad on the substrate; the protective layer extends between the pad elevation layers between adjacent ones of the pads and is arranged continuously;

[0025] Preferably, the material of the cushion layer includes an organic material layer and an inorganic material layer;

[0026] Preferably, the second insulating layer includes an organic material layer and an inorganic material layer alternately arranged along the thickness direction of the substrate.

[0027] An embodiment of the second aspect of the present application further provides a method for manufacturing a display substrate, including:

[0028] Providing a substrate;

[0029] Forming a pad layer on one side of the substrate;

[0030] Forming an insulating layer on the side of the pad layer facing away from the substrate, the insulating layer including a via;

[0031] Forming another pad layer on the side of the insulating layer facing away from the substrate. Among the two pad layers, the pad layer located on the side far from the substrate extends into the via and is electrically connected to the pad layer close to the substrate.

[0032] According to the embodiment of the second aspect of the present invention, it further includes: forming a protective material layer, at least part of which is located on the surface of the pad facing away from the substrate;

[0033] Forming a mask layer, at least part of which is located on the surface of the protective layer facing away from the pad, and the positive projection of the mask layer on the substrate covers the substrate;

[0034] Simultaneously patterning the protective material layer and the mask layer, forming at least one first opening in the protective material layer to form a protective layer, and forming at least one second opening in the mask layer. The second opening communicates with the second opening, and the positive projection of the first opening on the substrate is located within the positive projection of the pad on the substrate.

[0035] An embodiment of the third aspect of the present application further provides a display panel, including any display substrate provided by the first aspect of the present application, a light-emitting device, and a welding part. The welding part is located in the via and is electrically connected to the pad, and the light-emitting device is located on the side of the welding part facing away from the pad and is electrically connected to the welding part.

[0036] According to the embodiment of the third aspect of the present invention, it further includes a protective layer, at least part of which is located on the surface of the pad facing away from the substrate, including at least one first opening, and the positive projection of the first opening on the substrate is located within the positive projection of the pad on the substrate;

[0037] Preferably, the size of the welding portion in the thickness direction of the substrate is greater than the size of the protective layer in the thickness direction of the substrate.

[0038] Preferably, the first opening includes a first end close to the substrate and a second end far from the substrate, and the first end surrounds the welding portion and is in circumferential contact with the welding portion.

[0039] An embodiment of the fourth aspect of the present application further provides a method for manufacturing a display panel, including:

[0040] Manufacturing a display substrate by the manufacturing method as described in the second aspect;

[0041] Forming a welding material layer on a surface of the mask layer facing away from the substrate, and at least a part of the orthographic projection of the welding material layer on the substrate overlaps with the orthographic projection of the via on the substrate.

[0042] Removing the mask layer to synchronously remove a part of the welding material layer and retain the part of the welding material layer located in the first opening to form a welding portion, and the welding portion is electrically connected to the pad.

[0043] Electrically connecting the light-emitting device to the welding portion.

[0044] The display substrate provided by the present application includes a base substrate, a pad and an insulating layer, wherein the pad is located on one side surface of the base substrate, and the number is one or more, and is used to realize the electrical connection between the light-emitting device and the circuit in the base substrate, so as to realize the light-emitting display. The pad includes at least two pad layers stacked along the thickness direction of the base substrate, so as to increase the thickness of the pad along the thickness direction of the base substrate, increase the volume of the pad, and increase the amount of pad material used, so as to prevent excessive migration of metal elements in the pad to the welding part during the process of electrical connection and alloying between the pad and the welding part, ensure that there are still enough metal elements in the pad, prevent the pad from being completely alloyed and exhausted after the metal elements migrate due to too little pad material, improve the connection reliability between the welding part and the pad, and improve the phenomenon of separation of the two due to complete alloying and exhaustion of metal elements in the pad. On the one hand, the insulating layer plays an insulating role to prevent short circuits between adjacent pads. On the other hand, an insulating layer is arranged between adjacent pad layers. The pad layer located on the side away from the substrate extends along the inner wall of the via and is electrically connected to the pad layer located on the side close to the substrate, so that the portion of the pad layer located on the side away from the substrate is located on the side of the insulating layer away from the substrate, thereby achieving the effect of raising a portion of the pad layer located on the side away from the substrate through the insulating layer, so that the light-emitting device that is subsequently electrically connected to the pad can be higher than the non-pad area, thereby forming a step difference, so as to reduce the probability of dark spots appearing in the display due to the black matrix covering the light-emitting device when the display panel is subsequently packaged. At the same time, the insulating layer can also improve the adhesion between adjacent pad layers, improve the resistance to falling off between adjacent pad layers, and increase the firmness between adjacent pad layers, so as to improve the yield of the display substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 is a cross-sectional view of a display substrate provided in an embodiment of the present application;

[0047] Figure 2 is a cross-sectional view of another display substrate provided in an embodiment of the present application;

[0048] Figure 3 is a cross-sectional view of another display substrate provided in an embodiment of the present application;

[0049] Figure 4 is a cross-sectional view of another display substrate provided in an embodiment of the present application;

[0050] Figure 5 It is a cross-sectional view of another display substrate provided by an embodiment of the present application;

[0051] Figure 6 It is a cross-sectional view of another display substrate provided by an embodiment of the present application;

[0052] Figure 7 It is a flowchart of a method for manufacturing a display substrate provided by an embodiment of the present application;

[0053] Figure 8 It is a cross-sectional view of a display panel provided by an embodiment of the present application;

[0054] Figures 9 to 14 It is a schematic diagram of film layer changes during the manufacturing process of a display substrate provided by an embodiment of the present application;

[0055] Figures 15 to 16 It is a schematic diagram of film layer changes during the manufacturing process of a display panel provided by an embodiment of the present application.

[0056] In the drawings:

[0057] 1 - Display substrate; 10 - Substrate substrate; 11 - Pad; 110 - Pad layer; 111 - First pad layer; 112 - Second pad layer; 12 - Protective layer; 121 - First opening; 13 - Insulating layer; 131 - Via hole; 14 - Pad elevation layer; 141 - Opening; H - Isolation gap; 2 - Light-emitting device; 3 - Welding part; 4 - Protective material layer; 5 - Mask layer; 51 - Second opening; 6 - Welding material layer. Detailed implementation manners

[0058] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In the following detailed description, many specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to those skilled in the art that the present application may be practiced without some of these specific details. The description of the embodiments is merely provided to better understand the present application by showing examples of the present application.

[0059] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0060] For a better understanding of the present application, the following will Figures 1 to 16 describe in detail the display substrate and its preparation method according to the embodiments of the present application.

[0061] Please refer to Figure 1 , the embodiment of the present application provides a display substrate, which includes a substrate 10, pads 11 and at least one insulating layer 13. The pads 11 are located on one side of the substrate 10 and include at least two pad layers stacked in the thickness direction of the substrate 10. The insulating layer 13 is located between adjacent pad layers, and the insulating layer 13 includes vias 131. In adjacent pad layers, the pad layer located on the side away from the substrate 10 extends into the vias 131 and is electrically connected to the pad layer on the side close to the substrate 10.

[0062] The display substrate provided in the present application includes a base substrate 10, a pad 11 and an insulating layer 13, wherein the pad 11 is located on one side surface of the base substrate 10, and the number is one or more, and is used to realize the electrical connection between the light-emitting device 41 and the circuit in the base substrate 10, so as to realize the light-emitting display. The pad 11 includes at least two pad layers stacked along the thickness direction of the base substrate 10, so as to increase the thickness of the pad 11 along the thickness direction of the base substrate 10, increase the volume of the pad 11, and increase the amount of material used for the pad 11, so as to prevent excessive migration of metal elements in the pad 11 to the welding part 3 during the process of electrical connection and alloying between the pad 11 and the welding part 3, ensure that there are still enough metal elements in the pad 11, prevent the pad 1 from being completely alloyed and exhausted after the metal elements migrate due to too little material used for the pad 11, improve the connection reliability of the welding part 3 and the pad 11, and improve the phenomenon that the two are separated due to the complete alloying and exhaustion of the metal elements in the pad 11. On the one hand, the insulating layer 13 plays an insulating role to prevent short circuits between adjacent pads 11. On the other hand, the insulating layer 13 is arranged between adjacent pad layers. The pad layer located on the side away from the substrate 10 extends along the inner wall of the via 131 and is electrically connected to the pad layer located on the side close to the substrate 10, so that the portion of the pad layer located on the side away from the substrate 10 is located on the side of the insulating layer 13 away from the substrate 10, thereby achieving the effect of raising a portion of the pad layer located on the side away from the substrate 10 through the insulating layer 13, so that the light-emitting device that is subsequently electrically connected to the pad 11 can be higher than the maximum height of the non-pad area in the display panel, thereby forming a step difference, so as to reduce the probability of dark spots appearing in the display due to the black matrix covering the light-emitting device 41 when the display panel is subsequently packaged. At the same time, the insulating layer 13 can also improve the adhesion between adjacent pad layers, improve the anti-falling property between adjacent pad layers, and increase the firmness between adjacent pad layers, so as to improve the yield of the display substrate.

[0063] It should be noted that the pad 11 includes but is not limited to having two pad layers, and may include three layers or more than three layers. The present application only takes the example that the pad 11 includes two pad layers.

[0064] Specifically, the light emitting device 41 may include Micro-LED, LED, etc., which is not particularly limited in the present application.

[0065] In a possible implementation, Figure 1 As shown, the pad 11 includes a first pad layer 111 and a second pad layer 112 stacked in a thickness direction away from the base substrate 10, the insulating layer 13 is located between the first pad layer 111 and the second pad layer 112, the orthographic projection of the via 131 on the base substrate 10 is located within the orthographic projection of the first pad layer 111 on the base substrate 10, and the second pad layer 112 extends along the inner wall of the via 131 and is electrically connected to the first pad layer 111.

[0066] In the above embodiments, the area of the orthographic projection of the via 131 on the substrate 10 is smaller than the area of the orthographic projection of the first pad layer 111 on the substrate 10, so as to ensure that the insulating layer 13 has a good heightening effect on the pad layer on the side far from the substrate 10.

[0067] Specifically, when the second pad layer 112 extends along the inner wall of the via 131 and is electrically connected to the first pad layer 111, the second pad layer 112 may cover part or all of the first pad layer 111 exposed through the via 131, and the present application does not make a special limitation on this. As an optional manner, the second pad layer 112 extends along the inner wall of the via 131 and completely covers all of the first pad layer 111 exposed by the via 131. At this time, the contact area between the second pad layer 112 and the first pad layer 111 is larger, which can make the connection between the second pad layer 112 and the first pad layer 111 more stable, so as to further improve the reliability of the display substrate.

[0068] In a feasible embodiment, the first pad layer 111 and the second pad layer 112 are made of the same material; using the same material can improve the difference in the transmission of electrical signals in the first pad layer 111 and the second pad layer 112, improve the reliability of electrical signal transmission, and increase the content of the overall metal elements in the pads.

[0069] In a feasible embodiment, the material of the pad 11 (including the first pad layer and the second pad layer) includes at least one of copper, titanium, molybdenum, and niobium. Specifically, the pad 11 may include copper and titanium, or include copper, molybdenum, and niobium, or include molybdenum and copper, or be titanium, copper, titanium, etc. stacked. Specifically, the material of the pad 11 may use metals that are easy to form alloys, so as to facilitate welding and thus improve the yield of electrical connection.

[0070] In a feasible embodiment, as Figure 2 shown, the insulating layer 13 on the side close to the substrate extends and covers the periphery of the pad layer on the side close to the substrate. Specifically, the insulating layer 13 may extend along the first pad layer 111 and cover the periphery of the first pad layer 111. In the above embodiments, the insulating layer 13 extends along the first pad layer 111 and covers the periphery of the first pad layer 111, so as to protect the first pad layer 111 and prevent short circuits caused by contact between adjacent first pad layers 111, that is, realize insulation between adjacent first pad layers 111.

[0071] In the above embodiments, as Figure 1 and Figure 2 shown, the insulating layers 13 between adjacent pads are arranged at intervals, or, as Figure 3 shown, the insulating layer 13 extends to abut against the substrate 10, and the insulating layers 13 between adjacent pads are continuously arranged.

[0072] As Figure 1 and Figure 2 shown, when the insulating layers 13 in the adjacent pads 11 are arranged at intervals, the portion of the substrate 10 located between the adjacent pads 11 can be exposed, which helps to form a height step difference between the pad area and the non-pad area, and further can increase the height difference between the maximum height of the light-emitting device 2 and the non-pad area of the display panel after the light-emitting device 2 is electrically connected to the pad 11, so as to facilitate reducing the probability of display dark spots caused by the black matrix covering the light-emitting device 2 during subsequent packaging of the display panel.

[0073] As Figure 3 shown, when the insulating layer 13 extends to abut against the substrate 10 and the insulating layers 13 in the adjacent pads are continuously arranged, the insulating layer 13 extends to the substrate 10 and is continuously arranged, and the insulating layer 13 can provide a relatively enclosed protection for the portion between the adjacent first pad layers 111, and can further reduce the probability of the first pad layer 111 contacting with water and oxygen.

[0074] In a feasible implementation manner, the insulating layer 13 includes an organic material layer, an inorganic material layer, or the insulating layer 13 includes an organic material layer and an inorganic material layer alternately arranged along the thickness direction of the substrate 10. The inorganic material may include at least one of silicon nitride, silicon oxide, and silicon oxynitride. The organic material can be selected as polyimide, etc. On the one hand, the functions of insulation and protection can be realized, and on the other hand, the adhesion between the first pad layer 111 and the second pad layer 112 can be improved.

[0075] Specifically, the thickness of the insulating layer 13 is 2μm - 3μm. So that the insulating layer 13 can play the role of raising the second pad layer 112, and further can increase the height difference between the maximum height of the light-emitting device 2 and the non-pad area of the display panel after the light-emitting device 2 is electrically connected to the pad 11, so as to facilitate reducing the probability of display dark spots caused by the black matrix covering the light-emitting device 2 during subsequent packaging of the display panel. The thickness of the insulating layer 13 can specifically be 2μm, 2.1μm, 2.3μm, 2.5μm, 2.6μm, 2.8μm, 3μm, etc.

[0076] In a feasible implementation manner, as Figures 1 to 3 shown, the display backplane further includes a protective layer 12, at least partially located on the surface of the pad 11 facing away from the substrate 10, including at least one first opening 121, and the orthographic projection of the first opening 121 on the substrate 10 is located within the orthographic projection of the pad 11 on the substrate 10.

[0077] The protective layer 12 is at least partially located on the surface of the pad 11 facing away from the substrate 10, and includes at least one first opening 121, so as to shield and protect a part of the surface of the pad 11 facing away from the substrate 10, ensure the performance of the pad 11, improve the phenomenon of oxidation due to exposure, and at the same time reduce the probability of being corroded by contact with corrosive materials in subsequent process steps, and enhance its electrical connection stability. At the same time, a part of the surface of the pad 11 facing away from the substrate 10 is exposed through the first opening 121, so as to facilitate the setting of the welding part 3, and further realize the electrical connection between the light-emitting device 2 and the pad 11.

[0078] In the above embodiment, the protective layers 12 between adjacent pads 11 can be connected or spaced apart.

[0079] In the above embodiment, as Figure 3 shown, the protective layer 12 extends along the pad 11 and covers the peripheral side of the pad 11. Thus, on the one hand, the pad 11 can be protected, and on the other hand, insulation between adjacent pads 11 can be achieved.

[0080] When the pad 11 includes a first pad layer 111 and a second pad layer 112, the protective layer 12 can extend along the second pad layer 112, and the protective layer 12 simultaneously covers the peripheral sides of the first pad layer 111 and the second pad layer 112 to protect the peripheral sides of the first pad layer 111 and the second pad layer 112, prevent short circuits caused by contact between adjacent pads 11, that is, achieve insulation between adjacent pads 11. When an insulating layer 13 is provided between the first pad layer 111 and the second pad layer 112, the protective layer 12 also covers the peripheral side of the insulating layer 13 at the same time.

[0081] In a feasible embodiment, the insulating layers 13 between adjacent pads 11 are spaced apart, the insulating layer 13 extends along the pad layer close to the substrate, and covers the peripheral side of the pad layer close to the substrate, and the protective layer 12 extends to the peripheral side of the insulating layer 13.

[0082] In the above embodiment, when the insulating layers 13 are spaced apart, the protective layer 12 can cover the peripheral sides of the pad 11 and the insulating layer 13, and can further protect the pad 11 and the insulating layer 13.

[0083] In a feasible embodiment, as Figure 2 shown, the insulating layers 13 of adjacent pads 11 are spaced apart, and the protective layer 12 extends between the insulating layers 13 of adjacent pads 11 and abuts against the substrate 10.

[0084] In the above-described embodiment, the insulating layers 13 are arranged at intervals, such that the protective layer 12 is in direct contact with the substrate 10. Due to the lack of the height of the insulating layer 13, a height step difference is formed between the pad region and the non-pad region. Furthermore, after the subsequent light-emitting device 2 is electrically connected to the pad 11, the height difference between the maximum height of the light-emitting device 2 and the non-pad region of the display panel can be increased, so as to reduce the probability of display dark spots caused by the black matrix covering the light-emitting device 2 during the subsequent packaging of the display panel.

[0085] In a feasible embodiment, as Figure 3 shown, the insulating layer 13 extends to abut against the substrate 10, and the insulating layers 13 between adjacent pads are arranged continuously. The protective layer 12 extends between adjacent pads 11 and abuts against the insulating layer 13. Thus, the portion between adjacent pads 11 can be encapsulated by the insulating layer 13 and the protective layer 12 to reduce the probability of water and oxygen contacting the pads 11, which helps to improve the performance of the pads 11.

[0086] In the above-described embodiment, the material of the protective layer 12 includes an inorganic material. The inorganic material has better water and oxygen isolation performance, which can reduce the damage to the protective layer 12 in the subsequent process to improve the reliability of the protective layer 12. Specifically, the inorganic material includes at least one of silicon nitride and silicon oxide. The materials are easily available and have good insulation and water and oxygen isolation capabilities.

[0087] In the above-described embodiment, the thickness of the protective layer 12 is 0.1 um to 0.3 um. Specifically, along the thickness direction of the substrate 10, the thickness of the protective layer 12 is lower than the minimum of the thicknesses of the respective pad layers, so that the height of the pad region is higher than that of the non-pad region, which helps to form a height step difference between the pad region and the non-pad region. Furthermore, after the subsequent light-emitting device 2 is electrically connected to the pad 11, the height difference between the maximum height of the light-emitting device 2 and the non-pad region of the display panel can be increased, so as to reduce the probability of display dark spots caused by the black matrix covering the light-emitting device 2 during the subsequent packaging of the display panel.

[0088] In a feasible embodiment, as Figure 4 shown, the display backplane further includes a pad elevation layer 14, which is located on one side of the substrate 10 and at least partially located between the pad 11 and the substrate 10. The pad elevation layer 14 includes an opening 141, and a part of the pad 11 is located within the opening 141.

[0089] In the above embodiment, the padding layer 14 can further raise the edge of the pad 11, and can further increase the height difference between the maximum height of the light emitting device 2 and the non-pad area in the display panel after the subsequent light emitting device 2 is electrically connected to the pad 11, so as to reduce the probability of display dark spots caused by the black matrix covering the light emitting device 2 when the display panel is packaged later. On the other hand, the contact area between the pad 11 and the base substrate 10 can be reduced to reduce the problem of short circuit between the pad 11 and the circuit in the base substrate 10, and the adhesion between the pad 11 and the base substrate 10 can also be improved.

[0090] In a possible implementation, Figure 4 As shown, the padding layers 14 in adjacent pads 11 are arranged at intervals to form an isolation gap H. This can improve the short circuit caused by the lateral short circuit between adjacent pads 11.

[0091] In a possible implementation, Figure 4 and Figure 5 As shown, when the protection layer 12 is further included, the protection layer 12 extends between the pad layers 14 in adjacent pads and is continuously disposed.

[0092] In the above implementation, if Figure 5 and Figure 6 As shown, an insulating layer 13 may be formed between adjacent padding layers 14, and the protective layer 12 may directly contact the insulating layer 13. Alternatively, as Figure 4 As shown, there may be no insulating layer 13 between adjacent padding layers 14 , and the protection layer 12 is in direct contact with the base substrate 10 .

[0093] In the above-mentioned embodiment, the material of the padding layer 14 includes an organic material layer and an inorganic material layer, or the padding layer 14 includes an organic material layer and an inorganic material layer alternately arranged along the thickness direction of the base substrate 10. Specifically, the inorganic material includes at least one of silicon nitride and silicon oxide. The organic material can be selected from polyimide and the like. On the one hand, the insulation function can be realized to reduce the probability of short circuit between the pad 11 and the base substrate 10, and on the other hand, the adhesion between the pad 11 and the base substrate 10 can be improved.

[0094] The present application also provides a display panel, such as Figure 7 As shown, it includes the display substrate provided in the above embodiment of the present application.

[0095] The display panel provided in the present application also includes a light-emitting device 2 and a welding portion 3. The welding portion 3 is located in the via hole 131 and is electrically connected to the pad 11. The light-emitting device 2 is located on the side of the welding portion 3 away from the pad 11 and is electrically connected to the welding portion 3.

[0096] In the display substrate, the pad 11 includes at least two pad layers stacked along the thickness direction of the base substrate 10, so that the thickness of the pad 11 along the thickness direction of the base substrate 10 can be increased, the volume of the pad 11 can be increased, and the amount of material used in the pad 11 can be increased to prevent excessive migration of metal elements in the pad 11 to the welding part 3 during the process of electrical connection and alloying between the pad 11 and the welding part 3, to ensure that sufficient metal elements remain in the pad 11, to prevent the formation of a brittle layer at the connection position between the pad 11 and the welding part 3 after the migration of metal elements due to too little material used in the pad 11, to improve the connection reliability between the welding part 3 and the pad 11, and to improve the phenomenon of separation between the two due to the formation of a brittle layer, thereby further improving the electrical connection yield between the light-emitting device 2 and the display substrate, so as to improve the stability and reliability of the display panel. On the one hand, the insulating layer 13 plays an insulating role to prevent short circuits between adjacent pads 11. On the other hand, the insulating layer 13 is arranged between adjacent pad layers. The pad layer located on the side away from the substrate 10 extends along the inner wall of the via 131 and is electrically connected to the pad layer located on the side close to the substrate 10, so that the portion of the pad layer located on the side away from the substrate 10 is located on the side of the insulating layer 13 away from the substrate 10, thereby achieving the effect of raising the partial area of ​​the pad layer located on the side away from the substrate 10 by the insulating layer 13, so that the light-emitting device 2 can be higher than the maximum height of the non-pad area in the display panel after being connected to the display substrate, thereby forming a step difference, so that when the display panel is subsequently packaged, the probability of dark spots appearing in the display due to the black matrix covering the light-emitting device 2 is reduced, thereby improving the display effect of the display panel. At the same time, the insulating layer 13 can also improve the adhesion between adjacent pad layers, improve the anti-falling property between adjacent pad layers, and increase the firmness between adjacent pad layers, so as to improve the yield of the display substrate, so as to further improve the yield of the display panel.

[0097] When the display substrate includes a protective layer 12, the size of the welding portion 3 along the thickness direction of the base substrate 10 is larger than the size of the protective layer 12 along the thickness direction of the base substrate 10, so as to improve the yield of the electrical connection between the welding portion 3 and the light-emitting device 2 and improve the stability of the electrical connection.

[0098] When the display substrate includes the protective layer 12, the first opening 121 of the protective layer 12 includes a first end close to the base substrate 10 and a second end away from the base substrate 10, and the first end surrounds the soldering portion 3 and contacts the circumference of the soldering portion 3. Specifically, the first end can be in full contact with the circumference of the soldering portion 3, so that the soldering portion 3 and the protective layer 12 can completely cover the surface of the soldering pad 11 on the side away from the base substrate 10, so as to improve the protection effect of the soldering pad 11.

[0099] The present application also provides a method for preparing a display substrate, such as Figure 8 As shown, including:

[0100] S100, provide a substrate 10.

[0101] S200, form a pad layer 110 on one side of the substrate 10;

[0102] S300, form an insulating layer 13 on the side of the pad layer 110 facing away from the substrate 10, and the insulating layer 13 includes a via 131;

[0103] S400, form another pad layer 110 on the side of the insulating layer 13 facing away from the substrate 10. Among the two pad layers 110, the pad layer 110 located on the side far from the substrate 10 extends into the via 131 and is electrically connected to the pad layer 110 close to the substrate 10.

[0104] In the above step S200, it may specifically include:

[0105] S201, as Figure 9 shown, form a first pad material layer on one side of the substrate 10 and pattern it to form spaced-apart first pad layers 111.

[0106] S202, as Figure 10 shown, form an insulating material layer on the side of the first pad layer 111 facing away from the substrate 10 and pattern it to form an insulating layer 13 having a via 131. The orthogonal projection of the via 131 on the substrate 10 is located within the orthogonal projection of the first pad layer 111 on the substrate 10.

[0107] Specifically, the insulating material layer may include an organic material or an inorganic material, or both an organic material and an inorganic material, and the organic material and the inorganic material are stacked.

[0108] S203, as Figure 11 shown, form a second pad material layer on the side of the insulating layer 13 facing away from the substrate 10 and pattern it to form spaced-apart second pad layers 112. The second pad layers 112 extend into the via 131 and are electrically connected to the first pad layers 111.

[0109] Specifically, the materials of the first pad material layer and the second pad material layer may be the same or different, preferably the same, to improve the transmission difference of electrical signals between different pad layers 110.

[0110] Specifically, the above only takes the pad 11 including two pad layers 110 as an example. When including multiple pad layers 110, steps S202 and S203 can be repeated to prepare multiple pad layers 110 and ensure that an insulating layer 13 is formed between adjacent pad layers 100.

[0111] In the above embodiments, it further includes:

[0112] S300, as shown in Figure 12 , a protective material layer 4 is formed, and at least a part of the protective material layer 4 is located on the surface of the pad 11 facing away from the substrate 10.

[0113] S400, as shown in Figure 13 , a mask layer 5 is formed, and at least a part of the mask layer 5 is located on the surface of the protective layer 12 facing away from the pad 11, and the orthographic projection of the mask layer 5 on the substrate 10 covers the substrate 10;

[0114] S500, as shown in Figure 13 and Figure 14 , the protective material layer 4 and the mask layer 5 are simultaneously patterned. At least one first opening 121 is formed in the protective material layer 4 to form the protective layer 12, and at least one second opening 51 is formed on the mask layer 5. The second opening 51 communicates with the first opening 121, and the orthographic projection of the first opening 121 on the substrate 10 is located within the orthographic projection of the pad 11 on the substrate 10.

[0115] In the above preparation method, by providing the mask layer 5 and using the mask layer 5 as a sacrificial layer, it can be simultaneously patterned with the protective layer 12 to form the second opening 51 and the first opening 121, and the sizes of the two are close. When forming a whole layer of welding material layer on the display substrate subsequently, by removing the mask layer 5, only the part of the welding material located within the first opening 121 and the second opening 51 is retained, thereby reducing the residue on the surface of the protective layer 12 facing away from the substrate 10 after the welding material layer contacts the protective layer 12, improving the preparation yield, and reducing the probability of short - circuit between adjacent pads.

[0116] The present application also provides a method for preparing a display panel, including preparing a display substrate according to the above - mentioned method for preparing a display substrate, and further including:

[0117] S600, as shown in Figure 15 , a welding material layer 6 is formed on the surface of the mask layer 5 facing away from the substrate 10, and the orthographic projection of the welding material layer 6 on the substrate 10 overlaps at least partially with the orthographic projection of the via on the substrate 10.

[0118] S700, as shown in Figure 16 , the mask layer 5 is removed to simultaneously remove a part of the welding material layer 6, and the part of the welding material layer 6 located within the first opening 121 is retained to form a welding portion 3, and the welding portion 3 is electrically connected to the pad 11.

[0119] S800, electrically connect the light - emitting device 2 to the welding portion 3.

[0120] Since the second opening 51 and the first opening 121 prepared in steps S300-S500 are of similar sizes, after the entire welding material layer 6 is set, part of it enters the second opening 51 and the first opening 121 to form the welding portion 3. Therefore, it is convenient to achieve complete contact between the peripheral side of the welding portion 3 and the first end of the first opening 121, so that the welding portion 3 and the protective layer 12 can achieve complete coverage of the surface of the pad 11 facing away from the base substrate 10, so as to enhance the protection effect of the welding pad 11.

[0121] In the above embodiment, since the welding portion 3 is defined in the welding material layer 6 by the first opening 121 of the protective layer 12 and the second opening 51 of the mask layer 5, and then the mask layer 5 is removed, the size of the welding portion 3 along the thickness direction of the base substrate 10 can be larger than the size of the protective layer 12 along the thickness direction of the base substrate 10. This is to improve the yield of the electrical connection between the welding portion 3 and the light-emitting device 2 and improve the stability of the electrical connection.

[0122] The present application also provides a display device, including any one of the display substrates provided in the above embodiments, or including any one of the display panels provided in the above embodiments. The display device can be a mobile terminal such as a mobile phone or a laptop computer, or a fixed terminal such as a television or a computer monitor, or a wearable device such as a watch, etc., which is not particularly limited in the present application.

[0123] According to the embodiments of the present application as above, these embodiments do not describe all the details in detail, nor do they limit the invention to specific embodiments. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can make good use of the present application and the modifications based on the present application. The present application is only limited by the claims and their full scope and equivalents.

Claims

1. A display substrate, characterized in that, Comprising: A substrate; A pad, located on one side of the substrate, comprising at least two pad layers stacked in the thickness direction of the substrate; At least one insulating layer, located between two adjacent pad layers, the insulating layer comprising a via, in two adjacent pad layers, the pad layer located on the side away from the substrate extends into the via and is electrically connected to the pad layer close to the substrate side.

2. The display substrate according to claim 1, characterized in that, The pad comprises a first pad layer and a second pad layer stacked in the thickness direction of the substrate, the insulating layer is located between the first pad layer and the second pad layer, the orthographic projection of the via on the substrate is located within the orthographic projection of the first pad layer on the substrate, and the second pad layer extends along the inner wall of the via and is electrically connected to the first pad layer; Preferably, the first pad layer and the second pad layer are made of the same material; Preferably, the materials of the first pad layer and the second pad layer include copper and at least one of titanium, molybdenum, and niobium.

3. The display substrate according to claim 1, characterized in that, The insulating layer extends along the insulating layer close to the substrate side and covers the periphery of the pad layer close to the substrate side; Preferably, the insulating layers in adjacent pads are arranged at intervals; Preferably, the insulating layer extends to abut against the substrate, and the insulating layers in adjacent pads are continuously arranged.

4. The display substrate according to claim 1, characterized in that, Further comprising a protective layer, at least partially located on the surface of the pad facing away from the substrate, comprising at least one first opening, the orthographic projection of the first opening on the substrate is located within the orthographic projection of the pad on the substrate; Preferably, the protective layer extends along the pad and covers the periphery of the pad; Preferably, the insulating layers in adjacent pads are arranged at intervals, the insulating layer extends along the pad layer close to the substrate side and covers the periphery of the pad layer close to the substrate side, and the protective layer extends to the periphery of the insulating layer; Preferably, the insulating layers in adjacent pads are arranged at intervals, the protective layer extends between the insulating layers in adjacent pads and abuts against the substrate; Preferably, the insulating layer extends to abut against the substrate, the insulating layers in adjacent pads are continuously arranged, and the protective layer extends between adjacent pads and abuts against the insulating layer; Preferably, the material of the protective layer comprises an inorganic material; Preferably, the inorganic material comprises at least one of silicon nitride and silicon oxide; Preferably, the thickness of the protective layer is 2μm - 3μm.

5. The display substrate according to claim 1, characterized in that, Further comprising a pad elevation layer, located on one side of the substrate and at least partially located between the pad and the substrate, the pad elevation layer comprises an opening, and a part of the pad is located within the opening; Preferably, the pad elevation layers in adjacent pads are arranged at intervals to form an isolation gap; Preferably, it further includes a protective layer, at least partially located on a surface of the pad facing away from the substrate, including at least one first opening, and a positive projection of the first opening on the substrate is located within a positive projection of the pad on the substrate; the protective layer extends between the pad layers adjacent to the pads and is continuously provided; Preferably, the material of the pad layer includes an organic material layer and an inorganic material layer; Preferably, the pad layer includes an organic material layer and an inorganic material layer alternately arranged along the thickness direction of the substrate; 6. A method for manufacturing a display substrate, characterized in that, It includes: Providing a substrate; Forming a pad layer on one side of the substrate; Forming an insulating layer on a side of the pad layer facing away from the substrate, the insulating layer including a via; Forming another pad layer on a side of the insulating layer facing away from the substrate, and in the two pad layers, the pad layer located on the side far from the substrate extends into the via and is electrically connected to the pad layer close to the substrate; 7. The method for manufacturing a display substrate according to claim 6 further includes: Forming a protective material layer, at least part of which is located on a surface of the pad facing away from the substrate; Forming a mask layer, at least part of which is located on a side surface of the protective layer facing away from the pad, and a positive projection of the mask layer on the substrate covers the substrate; Simultaneously patterning the protective material layer and the mask layer, forming at least one first opening in the protective material layer to form a protective layer, and forming at least one second opening on the mask layer, the second opening communicating with the first opening, and a positive projection of the first opening on the substrate is located within a positive projection of the pad on the substrate; 8. A display panel, characterized in that, It includes a display substrate, a light-emitting device, and a welding part as described in any one of claims 1-5, the welding part is located in the via and is electrically connected to the pad, and the light-emitting device is located on a side of the welding part away from the pad and is electrically connected to the welding part; 9. The display panel according to claim 8, wherein It further includes a protective layer, at least partially located on a surface of the pad facing away from the substrate, including at least one first opening, and a positive projection of the first opening on the substrate is located within a positive projection of the pad on the substrate; Preferably, a dimension of the welding part along the thickness direction of the substrate is greater than a dimension of the protective layer along the thickness direction of the substrate; Preferably, the first opening includes a first end close to the substrate and a second end far from the substrate, and the first end surrounds the welding part and is in circumferential contact with the welding part; 10. A method for manufacturing a display panel, wherein It includes: Preparing a display substrate by the preparation method as described in claim 7; Forming a welding material layer on a side surface of the mask layer facing away from the substrate, and a positive projection of the welding material layer on the substrate at least partially overlaps with a positive projection of the via on the substrate; Removing the mask layer to simultaneously remove a part of the welding material layer, and retaining a part of the welding material layer located within the first opening to form a welding part, the welding part being electrically connected to the pad; Electrically connecting the light-emitting device to the welding part.

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