Display substrate, preparation method and display device

Abstract

The invention relates to a display substrate, a preparation method and a display device, and relates to the technical field of display, the display substrate comprises an array substrate, and an electrode layer and a light-emitting function layer which are sequentially arranged on the array substrate, the electrode layer comprises electrode units distributed in an array, and electrodes of the electrode units comprise a first layer structure electrically connected with the array substrate; a second layer structure located on the outer peripheral side of the first layer structure; the third-layer structure is located on the side, away from the array substrate, of the first-layer structure and electrically connected with the light-emitting functional layer. The second-layer structure blocks the third-layer structure which is melted into the liquid state, and connection of two adjacent electrodes is avoided, so that electrode short circuit is avoided, and the bonding yield is improved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display substrate, a preparation method and a display device. Background Art

[0002] With the development of real technology, display devices are widely used in life. At present, display panels are diversified. Among them, micro light-emitting diode (Micro LED) display panels and sub-millimeter light-emitting diode (Mini LED) display panels have higher resolution than liquid crystal display (LCD) panels, and the color is closer to organic light-emitting diode (OLED). In addition, the size of the light-emitting chip in Micro LED and Mini LED is reduced, and the spacing between the light-emitting chips is also greatly reduced, which reduces the spacing between display pixel units and greatly improves the resolution of the display screen.

[0003] In the related art, when a large number of light-emitting chips in Micro LED or Mini LED are transferred, short circuits are prone to occur during the bonding process due to the small spacing between the light-emitting chips, thereby reducing the bonding yield. Summary of the invention

[0004] The present application aims to provide a display substrate, a preparation method and a display device to solve the technical problem in the related art that when a large number of light-emitting chips in Micro LED or Mini LED are transferred, short circuits are easily caused during the bonding process due to the small spacing between the light-emitting chips, thereby reducing the bonding yield.

[0005] In a first aspect, an embodiment of the present application provides a display substrate, including an array substrate and an electrode layer and a light-emitting functional layer sequentially arranged on the array substrate, wherein the electrode layer includes electrode units distributed in an array, and the electrodes of the electrode units include:

[0006] The first layer structure is electrically connected to the array substrate.

[0007] The second layer structure is located on the outer peripheral side of the first layer structure.

[0008] The third layer structure is located on a side of the first layer structure away from the array substrate and is electrically connected to the light-emitting functional layer.

[0009] In a possible implementation manner, the first layer structure is provided with a first groove.

[0010] In a possible implementation manner, the second layer structure is provided with openings.

[0011] In a possible implementation manner, a second groove is provided on one side of the array substrate where the electrode layer is provided, and the second groove is provided close to the opening.

[0012] In a possible implementation manner, the material of the second layer structure is a metal oxide conductor.

[0013] In a possible embodiment, the light-emitting functional layer includes a first light-emitting unit, a second light-emitting unit and a third light-emitting unit, and the height of the third layer structure electrically connected to the second light-emitting unit along the light-emitting direction is greater than the height of the third layer structure electrically connected to the first light-emitting unit, and is less than the height of the third layer structure electrically connected to the third light-emitting unit.

[0014] In a second aspect, an embodiment of the present application provides a method for preparing a display substrate, wherein the display substrate comprises an array substrate and an electrode layer and a light-emitting functional layer sequentially arranged on the array substrate, wherein the electrode layer comprises electrode units distributed in an array, and the preparation method comprises:

[0015] A patterned first layer structure is disposed on the array substrate, and the first layer structure is electrically connected to the array substrate.

[0016] A patterned second layer structure is disposed on the first layer structure, and the second layer structure is located on the outer peripheral side of the first layer structure.

[0017] A third layer structure is prepared on a side of the first layer structure away from the array substrate to form an electrode of the electrode unit, wherein the third layer structure is electrically connected to the light-emitting functional layer.

[0018] In a possible implementation, the light-emitting functional layer includes a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit, and the third layer structure and the light-emitting functional layer are prepared on a side of the first layer structure away from the array substrate, including:

[0019] A precursor of a patterned third layer structure is prepared on the side of the first layer structure facing away from the array substrate, wherein the volume of the third layer structure precursor corresponding to the second light-emitting unit is larger than the volume of the third layer structure precursor corresponding to the first light-emitting unit, and smaller than the volume of the third layer structure precursor corresponding to the third light-emitting unit.

[0020] The third layer structure precursor is respectively connected to the first light emitting unit, the second light emitting unit and the third light emitting unit through eutectic welding.

[0021] In a possible implementation, a graphical second layer structure is provided on the first layer structure, including:

[0022] A graphic second layer structure is arranged on the first layer structure, and the second layer structure is located on the outer peripheral side of the first layer structure;

[0023] An opening is provided on the second structure.

[0024] In a third aspect, an embodiment of the present application proposes a display device, comprising a cover plate and a display substrate as mentioned in the first aspect; wherein the cover plate is located on the light emitting side of the display substrate.

[0025] The embodiment of the present application provides a display substrate, a preparation method and a display device, wherein the display substrate includes an array substrate and an electrode layer and a light-emitting functional layer sequentially arranged on the array substrate, wherein the electrode layer includes an array-distributed electrode unit, wherein the electrode unit includes a first electrode and a second electrode, wherein the first electrode and the second electrode both include: a first layer structure, electrically connected to the array substrate; a second layer structure, located on the outer peripheral side of the first layer structure, used to prevent the first electrode from being connected to the second electrode during welding; and a third layer structure, located on the side of the first layer structure away from the array substrate, electrically connected to the light-emitting functional layer. Related technology During the bonding process, when the light-emitting functional layer is welded on the third layer structure, the third layer structure is melted at high temperature, and the liquid third layer structure connects the first electrode and the second electrode, causing a short circuit. However, the present application arranges the second layer structure on the outer peripheral side of the first layer structure, and the second layer structure blocks the melted third layer structure into a liquid state, thereby preventing the first electrode from being connected to the second electrode, thereby preventing the first electrode from being short-circuited with the second electrode, so as to improve the bonding yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The features, advantages and technical effects of the exemplary embodiments of the present application will be described below with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals are used for the same components. The accompanying drawings are not drawn according to the actual scale, but are only used to illustrate the relative position relationship. The layer thickness of some parts is exaggerated for easy understanding, and the layer thickness in the accompanying drawings does not represent the proportional relationship of the actual layer thickness.

[0027] Figure 1 A schematic structural diagram of a display substrate provided in a first embodiment of the present application is shown;

[0028] Figure 2 A top view of an electrode layer provided in the first embodiment of the present application is shown;

[0029] Figure 3 A side view of a precursor of the third layer structure provided in the first embodiment of the present application is shown;

[0030] Figure 4 A front view of a precursor of a third layer structure provided in the first embodiment of the present application is shown;

[0031] Figure 5 A schematic flow chart showing a method for preparing a display substrate provided in a second embodiment of the present application;

[0032] Figure 6A schematic structural diagram of a display device provided in the third embodiment of the present application is shown.

[0033] Reference numerals:

[0034] 100. Display substrate;

[0035] 10. array substrate; 11. second groove;

[0036] 20. electrode layer; 21. electrode unit; 210. electrode; 211. first electrode; 212. second electrode; 22. first layer structure; 221. first groove;

[0037] 23. Second layer structure; 231. Opening;

[0038] 24. The third layer structure;

[0039] 25. Precursor;

[0040] 30. Light-emitting functional layer; 31. First light-emitting unit; 32. Second light-emitting unit; 33. Third light-emitting unit;

[0041] 200, cover plate;

[0042] 300. Display device. DETAILED DESCRIPTION

[0043] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present application. However, it is obvious to those skilled in the art that the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating examples of the present application. In the accompanying drawings and the following description, at least part of the known structures and technologies are not shown to avoid unnecessary ambiguity in the present application; and, for clarity, the size of the regional structure may be exaggerated. In addition, the features, structures or characteristics described below may be combined in one or more embodiments in any suitable manner.

[0044] During the bonding process of the related technology, when the light-emitting functional layer is welded on the electrode, the high temperature melts the electrode structure, and the liquid electrode connects the two adjacent electrodes, causing a short circuit.

[0045] In view of this, the embodiments of the present application provide a display substrate, a preparation method and a display device, wherein a second layer structure is arranged on the outer peripheral side of the first layer structure of the electrode, and the second layer structure blocks the third layer structure from melting into a liquid state, thereby avoiding connection between two adjacent electrodes and thus short-circuiting, so as to improve the bonding yield.

[0046] The specific structure of the display substrate, the specific process of the preparation method and the specific structure of the display device provided in each embodiment of the present application are described below in conjunction with the accompanying drawings.

[0047] First embodiment

[0048] Figure 1 A schematic structural diagram of a display substrate 100 provided in a first embodiment of the present application is shown.

[0049] like Figure 1 As shown, the first embodiment of the present application provides a display substrate 100, including an array substrate 10 and an electrode layer 20 and a light-emitting functional layer 30 sequentially arranged on the array substrate 10, the electrode layer 20 includes an array-distributed electrode unit 21, and the electrode 210 of the electrode unit 21 includes:

[0050] The first layer structure 22 is electrically connected to the array substrate 10 .

[0051] The second layer structure 23 is located on the outer peripheral side of the first layer structure 22 .

[0052] The third layer structure 24 is located on a side of the first layer structure 22 away from the array substrate 10 and is electrically connected to the light emitting functional layer 30 .

[0053] The array substrate 10 includes a glass substrate and a driving circuit located on the glass substrate. The light-emitting functional layer 30 is electrically connected to the driving circuit through the electrode layer 20 .

[0054] An electrode unit 21 includes a first electrode 211 and a second electrode 212, wherein the first electrode 211 is an anode and the second electrode 212 is a cathode; or, the first electrode 211 is a cathode and the second electrode 212 is an anode. This application does not specifically limit the electrode polarity of the first electrode 211 and the second electrode 212.

[0055] The first electrode 211 and the second electrode 212 have the same structure, and both include a first layer structure 22, a second layer structure 23, and a third layer structure 24. The first layer structure 22 is a metal conductive film layer, and its material can be silver (Ag), aluminum (Al), titanium (Ti), molybdenum (Mo), etc.; the second layer structure 23 is a metal oxide conductor film layer, and its material can be indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), etc.; the third layer structure 24 is a bonding alloy layer, and its material can be gold-tin alloy (AuSn), silver-tin alloy (AgSn), gold-silicon alloy (AuSi), gold-germanium alloy (AuGe), etc. The second layer structure 23 is located on the outer peripheral side of the first layer structure 22 and is connected to the array substrate 10. The top of the third layer structure 24 is electrically connected to the light-emitting functional layer 30 through metal bonding technology, that is, the light-emitting functional layer 30 is welded to the top of the third layer structure 24 by welding.

[0056] Specifically, metal bonding technology refers to bonding a wafer to a target substrate electrode through pure metal or alloy, relying on metal bonds, diffusion between the metal and the wafer surface, metal melting, etc. Metal bonding can replace the epitaxial growth of thick epitaxial thin film materials and directly bond the required epitaxial layer materials or devices to the target substrate, thereby simplifying the device process, reducing costs, and improving the electrical and thermal conductivity of the device. The key to metal bonding is that the selected metal film maintains good ohmic contact with the wafer material, a small diffusion coefficient, and a low metal melting point. The temperature, pressure and time of metal bonding of optoelectronic devices are important bonding parameters that directly affect the thermal, electrical, optical and other properties of the optoelectronic devices after bonding.

[0057] A large amount of heat is generated during bonding, which causes the third layer structure 24 of the bond and region, i.e., the bonding alloy layer, to melt into a liquid state and flow onto the array substrate 10, so that the first electrode 211 is connected to the second electrode 212, causing a short circuit, and causing the light-emitting unit to fail to work properly. In particular, within the same electrode unit, the distance between the cathode and the anode is smaller, and it is more likely to cause a short circuit due to the melting and flow of the electrodes, causing the light-emitting unit to fail to work properly. The present application blocks the third layer structure 24 that is melted into a liquid state during bonding by setting a second layer structure 23 on the outer peripheral side of the first layer structure 22, so as to prevent the third layer structure 24 that is melted into a liquid state from connecting the first electrode 211 to the second electrode 212, thereby avoiding a short circuit of the light-emitting unit, improving the welding yield during product production, and improving the product production yield.

[0058] Continue to view Figure 1For each electrode, such as the first electrode 211 or the second electrode 212, the first layer structure is directly disposed on the array substrate, the second layer structure is disposed on the periphery of the first layer structure, and the top of the second layer structure is higher than the top of the first layer structure, that is, the second layer structure 23 covers part of the top of the first layer structure 22. The third layer structure 24 is connected to the first layer structure 22, and the connection between the two is located in the area surrounded by the second layer structure 23 and is lower than the top of the second layer structure 23. When the first layer structure 22 and the third layer structure 24 are welded, the high temperature causes part of the first layer structure 22 and / or part of the third layer structure 24 to melt into liquid, and the part of the second layer structure 23 that is higher than the top of the first layer structure 22 can block the first layer structure 22 and / or the third layer structure 24 that are melted into liquid, so as to prevent the liquid metal from connecting the first electrode 211 and the second electrode 212, thereby causing a short circuit in the light-emitting unit.

[0059] Specifically, in the related art, the first layer structure 22 and the third layer structure 24 are welded together, and the third layer structure 24 partially melts at high temperature, causing the first electrode 211 to be conductive with the second electrode 212, resulting in a short circuit in the light-emitting unit. In addition, in the related art, as the pixel density increases, manufacturers pursue smaller light-emitting unit sizes, but reducing the size of the light-emitting unit will reduce the distance between the first electrode 211 and the second electrode 212, increase the difficulty of picking up and transporting during mass transfer, and more easily cause a short circuit in the light-emitting unit. However, the present application provides a second layer structure 23 surrounding the outer peripheral side of the first layer structure 22 to prevent the molten third layer structure 24 from causing the first electrode 211 to be connected with the second electrode 212 when the first layer structure 22 and the third layer structure 24 are welded, thereby preventing the light-emitting unit from being short-circuited and improving the product production yield.

[0060] Figure 2 A top view of the electrode layer 20 provided in the first embodiment of the present application is shown.

[0061] like Figure 2 As shown, in some embodiments, the first layer structure 22 is provided with a first groove 221. The first groove 221 is used to store the third layer structure 24 melted into liquid during bonding, further avoiding the first electrode 211 and the second electrode 212 from connecting to cause a short circuit, and further improving the yield.

[0062] There is generally a certain interval between the first electrode 211 and the second electrode 212. In the arrangement direction of the first electrode 211 and the second electrode 212, if the first groove 221 corresponding to the first electrode 211 is arranged on the left side of the first electrode 211, and the first groove 221 corresponding to the second electrode 212 is arranged on the right side of the second electrode 212, and the two first grooves 221 are at the same position in the up-down direction, then the two are considered to be arranged oppositely. In this embodiment, preferably, reference Figure 2As shown, the first groove 221 corresponding to the first electrode 211 is not arranged opposite to the first groove 221 corresponding to the second electrode 212. However, the specific positions of the first groove 221 corresponding to the first electrode 211 and the first groove 221 corresponding to the second electrode 212 are not limited.

[0063] For example, the first groove 221 can be set at the edge of the first layer structure 22. For example, the first electrode 211 is located on the left side of the second electrode 212, and the first grooves 221 of the first electrode 211 and the second electrode 212 can be set at the upper edge, the lower edge, the left edge or the right edge. If the first groove 221 of the first electrode 211 is set at the right edge, the first groove 221 of the second electrode 212 should be avoided from being set at its left edge, so as to prevent the third layer structure 24 of the first electrode 211 from melting into liquid during bonding, overflowing the first groove 221 and contacting with the liquid third layer structure 24 overflowing the first groove 221 of the second electrode 212, causing a short circuit.

[0064] For example, the first groove 221 can be disposed at a top corner of the first layer structure 22. For example, the first groove 221 can be disposed at the upper left corner, the lower left corner, the upper right corner, or the lower right corner of the first layer structure 22. If the first groove 221 of the first electrode 211 is disposed at the upper right corner, the first groove 221 of the second electrode 212 should avoid being disposed at the upper left corner thereof.

[0065] Preferably, reference Figure 2 As shown, the first grooves 221 corresponding to the first electrodes 211 and the first grooves 221 corresponding to the second electrodes 212 are distributed along the diagonal line of the electrode unit 21 .

[0066] It should be noted that Figure 2 The position of the first groove 221 is only one possible implementation and is not particularly limited.

[0067] In this application, “up, down, left, right, front, and back” are only used for reference. Figure 1 / 2 / 3”, and does not limit the direction of the specific usage status of the corresponding product.

[0068] In some embodiments, the second layer structure 23 is provided with an opening 231. The opening 231 is used to drain the melted third layer structure 24. In a first embodiment, the second layer structure 23 with the opening 231 is provided on the outer peripheral side of the first layer structure 22 without the first groove 221; in a second embodiment, the second layer structure 23 with the opening 231 is provided on the outer peripheral side of the first layer structure 22 with the first groove 221.

[0069] With respect to the first embodiment, the opening 231 corresponding to the first electrode 211 and the opening 231 corresponding to the second electrode 212 may not be arranged opposite to each other.

[0070] The opening 231 can be arranged at the edge of the second layer structure 23 or at the top corner of the second layer structure 23. Preferably, the opening 231 corresponding to the first electrode 211 and the opening 231 corresponding to the second electrode 212 are not arranged opposite to each other. This is to prevent the third layer structure 24 of the first electrode 211 from melting into liquid during bonding, flowing out through the opening 231 and contacting with the liquid third layer structure 24 flowing out of the second electrode 212, causing a short circuit. Preferably, the opening 231 corresponding to the first electrode 211 and the opening 231 corresponding to the second electrode 212 are distributed along the diagonal line of the electrode unit 21.

[0071] For the second case, preferably, the opening 231 is connected to the first groove 221. In the case where there is too much molten third layer structure 24, the capacity of the first groove 221 is less than the volume of the molten third layer structure 24, that is, the molten third layer structure 24 overflows from the first groove 221. Since the opening 231 is connected to the first groove 221, the overflowed molten third layer structure 24 flows from the opening 231 to the outside of the second layer structure 23, and the overflowed third layer structure 24 is prevented from flowing out from the top of the second layer structure 23. Since the flow direction of the third layer structure 24 flowing out from the top of the second layer structure 23 is difficult to control, if it flows from the first electrode 211 to the second electrode 212, it causes the first electrode 211 and the second electrode 212 to be connected, causing the light-emitting unit to short-circuit. Therefore, the opening 231 is connected to the first groove 221, further avoiding the light-emitting unit short-circuit and improving the product yield.

[0072] At this time, the first opening 231 corresponding to the first electrode 211 and the opening 231 corresponding to the second electrode 212 are distributed along the diagonal of the electrode unit 21. In the case where too much molten third layer structure 24 overflows from the opening 231, there is still a situation where the third layer structure 24 overflowing from the first electrode 211 is connected to the third layer structure 24 overflowing from the second electrode 212. When the first opening 231 and the opening 231 corresponding to the second electrode 212 are distributed along the diagonal of the electrode unit 21, the two openings 231 are farthest apart, that is, the most molten third layer structure 24 is required to conduct the first electrode 211 and the second electrode 212, further avoiding short circuit of the light-emitting unit and improving product yield.

[0073] In some embodiments, a second groove 11 is provided on one side of the array substrate 10 where the electrode layer 20 is provided, and the second groove 11 is provided near the opening 231. The second groove 11 is used to store the third layer structure 24 melted into a liquid state. This further prevents the third layer structure 24 melted into a liquid state corresponding to the first electrode 211 and the second electrode 212 in two adjacent light-emitting units from being connected together, so that the first electrode 211 and the second electrode 212 in the two adjacent light-emitting units are connected, causing a short circuit between adjacent light-emitting units.

[0074] The second groove 11 is arranged on the array substrate 10. In one embodiment, a wiring is arranged below the second groove 11, and the wiring receives the same signal as the first electrode 211 or the second electrode 212 above the position; in another embodiment, a wiring is arranged below the second groove 11, and an insulating layer is arranged below the second groove to isolate the wiring arranged below the second groove 11 from the electrode at the upper position to prevent the first electrode 211 or the second electrode 212 from short-circuiting with the wiring signal.

[0075] In some embodiments, the material of the second layer structure 23 is a metal oxide conductor. The second layer structure 23 is a metal oxide conductor film layer, and its material can be indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), etc. The metal oxide conductor can be processed into a smaller size, thereby reducing the space occupied by the second layer structure 23, shortening the distance between the light-emitting chips, and improving the light brightness.

[0076] In some embodiments, the light-emitting functional layer 30 includes a first light-emitting unit 31, a second light-emitting unit 32 and a third light-emitting unit 33, and the height of the third layer structure 24 electrically connected to the second light-emitting unit 32 along the light-emitting direction is greater than the height of the third layer structure 24 electrically connected to the first light-emitting unit 31, and is less than the height of the third layer structure 24 electrically connected to the third light-emitting unit 33.

[0077] The first light emitting unit 31 emits red light, the second light emitting unit 32 emits green light, and the third light emitting unit 33 emits blue light.

[0078] Figure 3 A side view of a precursor 25 of the third layer structure 24 provided in the first embodiment of the present application is shown. Figure 4 A front view of a precursor 25 of the third layer structure 24 provided in the first embodiment of the present application is shown.

[0079] like Figure 3 , 4 As shown, before bonding the light-emitting functional layer 30, a precursor 25 of the third layer structure 24 is disposed on the second layer structure 23 of the first electrode 211 and the second electrode 212, and the third layer structure 24 is formed after bonding. The precursor 25 refers to the third layer structure 24 before welding.

[0080] The precursor 25 of the third layer structure 24 corresponding to the first light-emitting unit 31, the second light-emitting unit 32 and the third light-emitting unit 33 has the same height. Figure 3It can be seen that the cross-sectional area of ​​the side view of the precursor 25 of the third layer structure 24 electrically connected to the second light-emitting unit 32 is recorded as the second area; the cross-sectional area of ​​the side view of the precursor 25 of the third layer structure 24 electrically connected to the first light-emitting unit 31 is recorded as the first area; the cross-sectional area of ​​the side view of the precursor 25 of the third layer structure 24 electrically connected to the third light-emitting unit 33 is recorded as the third area. The above second area is larger than the first area and smaller than the third area. Figure 4 It can be seen that the cross-sectional areas of the three in the front view are equal, that is, the volume of the precursor 25 of the third layer structure 24 corresponding to the first light-emitting unit 31 is the smallest, and the volume of the precursor 25 of the third layer structure 24 corresponding to the third light-emitting unit 33 is the largest.

[0081] In one case, the volume of the third layer structure 24 consumed during bonding is the same, so after bonding is completed, the heights of the third layer structure 24 corresponding to the first light-emitting unit 31, the second light-emitting unit 32, and the third light-emitting unit 33 are different, resulting in different heights of the first light-emitting unit 31, the second light-emitting unit 32, and the third light-emitting unit 33 after welding. Therefore, the first light-emitting unit 31 after bonding is the lowest, the second light-emitting unit 32 is the second, and the third light-emitting unit 33 is the highest.

[0082] In another case, the volume of the third layer structure 24 consumed during bonding is different. The third layer structure 24 corresponding to the first light-emitting unit 31 consumes the most, the third layer structure 24 corresponding to the second light-emitting unit 32 consumes the second, and the third layer structure 24 corresponding to the third light-emitting unit 33 consumes the least. Therefore, after bonding, the first light-emitting unit 31 is the lowest, the second light-emitting unit 32 is the second, and the third light-emitting unit 33 is the highest.

[0083] It is worth noting that since the heights of the third layer structure 24 corresponding to the first light-emitting unit 31, the second light-emitting unit 32 and the third light-emitting unit 33 are different, it is beneficial to avoid the electrodes of each light-emitting unit from contacting each other and causing a short circuit when the first light-emitting unit 31, the second light-emitting unit 32 and the third light-emitting unit 33 are bonded in sequence.

[0084] In this embodiment, by setting the second layer structure 23 on the outer peripheral side of the first layer structure 22, the third layer structure 24 melted into liquid during bonding is blocked to prevent the first electrode 211 from connecting with the second electrode 212, thereby avoiding short circuit and improving the yield. Further, the first layer structure 22 is provided with a first groove 221 to store the third layer structure 24 melted into liquid during bonding, to prevent the first electrode 211 from connecting with the second electrode 212, thereby causing a short circuit and improving the bonding yield. Further, the second layer structure 23 is provided with an opening 231 to drain the third layer structure 24 melted into liquid. Further, a second groove 11 is provided on the side of the array substrate 10 where the electrode layer 20 is provided, and the second groove 11 is provided close to the opening 231. The second groove 11 is used to store the third layer structure 24 melted into liquid, further preventing the third layer structure 24 melted into liquid from connecting with the first electrode 211 and the second electrode 212, thereby causing a short circuit. The third layer structure 24 corresponding to the first light emitting unit 31 , the second light emitting unit 32 and the third light emitting unit 33 has different heights, which helps to avoid the electrodes of the first light emitting unit 31 , the second light emitting unit 32 and the third light emitting unit 33 contacting each other during bonding to cause a short circuit.

[0085] Second embodiment

[0086] Figure 5 A schematic flow chart of a method for preparing a display substrate provided in a second embodiment of the present application is shown.

[0087] like Figure 4 As shown, the second embodiment of the present application provides a method for preparing a display substrate, the display substrate comprising an array substrate and an electrode layer and a light-emitting functional layer sequentially arranged on the array substrate, the electrode layer comprising electrode units distributed in an array, and the preparation method comprising:

[0088] Step S101: a patterned first layer structure is provided on an array substrate, wherein the first layer structure is electrically connected to the array substrate.

[0089] The first layer structure is a metal conductive film layer, and its material can be silver (Ag), aluminum (Al), titanium (Ti), molybdenum (Mo) and the like.

[0090] Step S102: providing a patterned second layer structure on the first layer structure, wherein the second layer structure is located on the outer periphery of the first layer structure.

[0091] Step S103: preparing a third layer structure on a side of the first layer structure away from the array substrate to form an electrode of the electrode unit, wherein the third layer structure is electrically connected to the light-emitting functional layer.

[0092] The third layer structure is a bonding alloy layer, and its material can be gold-tin alloy (AuSn), silver-tin alloy (AgSn), gold-silicon alloy (AuSi), gold-germanium alloy (AuGe), etc.

[0093] The first layer structure, the second layer structure and the third layer structure together constitute the first electrode and the second electrode, the first electrode and the second electrode constitute an electrode unit, and the electrode units distributed in an array form an electrode layer.

[0094] In the related art, a large amount of heat is generated when bonding the light-emitting functional layer, and the heat will melt the third layer structure, and the liquid third layer structure will flow, connecting the first electrode with the second electrode, causing a short circuit. The present application provides a second layer structure on the outer peripheral side of the first layer structure to block the third layer structure that melts into a liquid state during bonding, thereby preventing the first electrode from connecting with the second electrode, thereby avoiding a short circuit and improving the yield.

[0095] In some embodiments, the light-emitting functional layer includes a first light-emitting unit, a second light-emitting unit and a third light-emitting unit, and the third layer structure and the light-emitting functional layer are prepared on a side of the first layer structure away from the array substrate, including:

[0096] Step S201: preparing a precursor of a patterned third layer structure on a side of the first layer structure facing away from the array substrate.

[0097] The volume of the precursor of the third layer structure corresponding to the second light-emitting unit is larger than the volume of the precursor of the third layer structure corresponding to the first light-emitting unit, and smaller than the volume of the precursor of the third layer structure corresponding to the third light-emitting unit.

[0098] In this embodiment, a patterned third layer structure is prepared by a lift-off process.

[0099] Specifically, a precursor of the third layer structure is first prepared, and then the precursor is processed to form the third layer structure.

[0100] The cross-sectional area of ​​the side view of the precursor of the third layer structure electrically connected to the second light-emitting unit is recorded as the second area; the cross-sectional area of ​​the side view of the precursor of the third layer structure electrically connected to the first light-emitting unit is recorded as the first area; the cross-sectional area of ​​the side view of the precursor of the third layer structure electrically connected to the third light-emitting unit is recorded as the third area. The above-mentioned second area is larger than the first area and smaller than the third area. The cross-sectional areas in the main views of the three are equal. That is, the volume of the precursor of the third layer structure corresponding to the first light-emitting unit is the smallest, and the volume of the precursor of the third layer structure corresponding to the third light-emitting unit is the largest.

[0101] Step S202: the third layer structure is respectively connected to the first light emitting unit, the second light emitting unit and the third light emitting unit by eutectic welding.

[0102] Specifically, they include:

[0103] Step S2021: bonding a first light-emitting unit on the third layer structure precursor at a first temperature, a first pressure, and a first time.

[0104] Step S2022: bonding a second light-emitting unit on the third layer structure precursor at a second temperature, a second pressure, and a second time.

[0105] Step S2023: bonding a third light-emitting unit on the third layer structure precursor at a third temperature, a third pressure, and a third time.

[0106] The second temperature is greater than the third temperature and less than the first temperature, the second pressure is greater than the third pressure and less than the first pressure, and the second time is greater than the third time and less than the first time.

[0107] The third layer structure corresponding to the first light emitting unit consumes the most, the third layer structure corresponding to the second light emitting unit consumes the second most, and the third layer structure corresponding to the third light emitting unit consumes the least.

[0108] The height of the third layer structure electrically connected to the second light-emitting unit along the light-emitting direction is greater than the height of the third layer structure electrically connected to the first light-emitting unit, and less than the height of the third layer structure electrically connected to the third light-emitting unit, resulting in different heights of the first light-emitting unit, the second light-emitting unit, and the third light-emitting unit after welding. That is, the first light-emitting unit after bonding is the lowest, the second light-emitting unit is the second, and the third light-emitting unit is the highest. This is beneficial to avoid the electrodes of each light-emitting unit from contacting each other when bonding the first light-emitting unit, the second light-emitting unit, and the third light-emitting unit in sequence, causing a short circuit.

[0109] In some embodiments, a graphic second layer structure is provided on the upper side of the first layer structure, including:

[0110] Step S301: Setting a graphical second layer structure on the first layer structure.

[0111] The second layer structure is located on the outer peripheral side of the first layer structure.

[0112] Step S302: Setting an opening on the second layer structure.

[0113] Alternatively, step S303: preparing a second layer structure having an opening on the outer peripheral side of the first layer structure.

[0114] In this embodiment, the second layer structure is provided with an opening to drain the third layer structure that has melted into a liquid state. Specifically, there can be two preparation methods. The first is to first form a closed second layer structure and then cut it to form an opening; the second is to directly form an unclosed second layer structure. It is worth noting that the opening can be set at the edge position of the second layer structure, or at the top corner position of the second layer structure. Preferably, the opening corresponding to the first electrode and the opening corresponding to the second electrode are not arranged opposite to each other; preferably, the opening corresponding to the first electrode and the opening corresponding to the second electrode are distributed along the diagonal of the electrode unit, further avoiding the third layer structure that has melted into a liquid state from connecting the first electrode and the second electrode to cause a short circuit, thereby improving the yield.

[0115] In this embodiment, an array substrate is provided; a first layer structure is arranged on the array substrate, and the first layer structure is electrically connected to the array substrate; a second layer structure is arranged on the outer periphery of the first layer structure; and a third layer structure and a light-emitting functional layer are prepared on the side of the first layer structure away from the array substrate to prepare a display substrate. By arranging the second layer structure on the outer periphery of the first layer structure, the third layer structure melted into a liquid state during bonding is blocked to prevent the first electrode from being connected to the second electrode, thereby avoiding a short circuit and improving the yield.

[0116] Third embodiment

[0117] Figure 6 A schematic structural diagram of a display device provided in the third embodiment of the present application is shown.

[0118] like Figure 6 As shown, the third embodiment of the present application provides a display device 300 , comprising: a cover plate 200 and a display substrate 100 as mentioned in the first embodiment or the second embodiment; wherein the cover plate 200 is located at the light emitting side of the display substrate 100 .

[0119] It should be easily understood that “on,” “above,” and “over” in this application should be interpreted in the broadest manner, so that “on” not only means “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “above” or “over” not only includes the meaning of “above something” or “over,” but also may include the meaning of “above something” or “over” with no intervening features or layers therebetween (i.e., directly on something).

[0120] The term "layer" used in the text may refer to a material portion including an area with a certain thickness. A layer may extend over the entire underlying structure or overlying structure, or may have a range smaller than the range of the underlying or overlying structure. In addition, a layer may be an area of ​​a homogeneous or inhomogeneous continuous structure, the thickness of which is less than the thickness of the continuous structure. For example, a layer may be located between the top surface and the bottom surface of the continuous structure or between any paired lateral planes at the top surface and the bottom surface. A layer may extend laterally, vertically and / or along a tapered surface. A substrate substrate may be a layer, may include one or more layers therein, and / or may have one or more layers located thereon, above it and / or below it. A layer may include multiple layers. For example, an interconnect layer may include one or more conductors and a contact layer (forming contacts, interconnects and / or vias therein) and one or more dielectric layers.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A display substrate, comprising an array substrate and an electrode layer and a light-emitting functional layer sequentially arranged on the array substrate, wherein the electrode layer comprises electrode units distributed in an array, characterized in that: The electrodes of the electrode unit include: A first layer structure, electrically connected to the array substrate; A second layer structure is located on the outer peripheral side of the first layer structure; The third layer structure is located on a side of the first layer structure away from the array substrate and is electrically connected to the light-emitting functional layer.

2. The display substrate according to claim 1, characterized in that: The first layer structure is provided with a first groove.

3. The display substrate according to claim 1 or 2, characterized in that: The second layer structure is provided with an opening.

4. The display substrate according to claim 3, characterized in that: A second groove is disposed on one side of the array substrate where the electrode layer is disposed, and the second groove is disposed close to the opening.

5. The display substrate according to claim 1, characterized in that: The material of the second layer structure is a metal oxide conductor.

6. The display substrate according to claim 1, characterized in that: The light-emitting functional layer includes a first light-emitting unit, a second light-emitting unit and a third light-emitting unit. The height of the third layer structure electrically connected to the second light-emitting unit along the light-emitting direction is greater than the height of the third layer structure electrically connected to the first light-emitting unit, and is less than the height of the third layer structure electrically connected to the third light-emitting unit.

7. A method for preparing a display substrate, wherein the display substrate comprises an array substrate and an electrode layer and a light-emitting functional layer sequentially arranged on the array substrate, wherein the electrode layer comprises electrode units distributed in an array, characterized in that: The preparation method comprises: A patterned first layer structure is provided on the array substrate, wherein the first layer structure is electrically connected to the array substrate; Arranging a graphic second layer structure on the first layer structure, wherein the second layer structure is located on the outer peripheral side of the first layer structure; A third layer structure is prepared on a side of the first layer structure away from the array substrate to form an electrode of the electrode unit, wherein the third layer structure is electrically connected to the light-emitting functional layer.

8. The method for preparing a display substrate according to claim 7, characterized in that: The light-emitting functional layer includes a first light-emitting unit, a second light-emitting unit and a third light-emitting unit, and the third layer structure and the light-emitting functional layer are prepared on a side of the first layer structure away from the array substrate, including: A precursor of a patterned third layer structure is prepared on a side of the first layer structure away from the array substrate, wherein the volume of the precursor of the third layer structure corresponding to the second light-emitting unit is larger than the volume of the precursor of the third layer structure corresponding to the first light-emitting unit, and smaller than the volume of the precursor of the third layer structure corresponding to the third light-emitting unit; The third layer structure precursor is connected to the first light emitting unit, the second light emitting unit and the third light emitting unit respectively through eutectic welding to form a third layer structure.

9. The method for preparing a display substrate according to claim 7, characterized in that: The step of providing a graphical second layer structure on the first layer structure comprises: Arranging a graphic second layer structure on the first layer structure, wherein the second layer structure is located on the outer peripheral side of the first layer structure; An opening is arranged on the second layer structure.

10. A display device, characterized in that: The display device comprises a cover plate and the display substrate according to any one of claims 1 to 6, wherein the cover plate is located at a light emitting side of the display substrate.

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