Display panel, manufacturing method thereof and display device

Abstract

The present disclosure provides a display panel, a manufacturing method thereof and a display device, wherein the display panel comprises a substrate and a pixel defining layer on the substrate; the pixel defining layer comprises a plurality of first barriers extending along a first direction and arranged along a second direction intersecting the first direction, and a plurality of second barriers extending along the second direction and arranged along the first direction; the plurality of first barriers and the plurality of second barriers divide a plurality of openings for defining sub-pixel units, one sub-pixel unit is arranged in one opening; at least part of the plurality of second barriers is provided with a first groove, and the depth of the first groove is less than or equal to the height of the corresponding second barrier.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a display panel, its manufacturing method, and a display device. Background Technology

[0002] Organic light-emitting diode (OLED) display devices have advantages over liquid crystal displays (LCDs) such as self-illumination, fast response, wide viewing angle, high brightness, vibrant colors, and thinness, and are therefore widely used.

[0003] OLED film formation primarily involves two methods: vapor deposition and solution processing. While vapor deposition is already in mass production, its expensive materials and low material utilization increase product development costs. Solution processing methods for OLED film formation include inkjet printing (IJP), inkjet coating, spin coating, and screen printing. In particular, inkjet printing dissolves the materials used to create the OLED film layers in an inkjet printing solvent to form inkjet ink. This ink is then sprayed onto the substrate through the printhead of an inkjet printer to print the required pixel patterns. However, inkjet printing is highly prone to producing uneven film thickness in OLED fabrication. Summary of the Invention

[0004] This disclosure provides a display panel, its manufacturing method, and a display device, the specific solutions of which are as follows:

[0005] In a first aspect, embodiments of this disclosure provide a display panel, comprising:

[0006] A substrate, and a pixel defining layer located on the substrate; the pixel defining layer includes:

[0007] A plurality of first barriers extending along a first direction and arranged along a second direction intersecting the first direction, and a plurality of second barriers extending along the second direction and arranged along the first direction; the plurality of first barriers and the plurality of second barriers divide a plurality of openings for defining sub-pixel units, and one sub-pixel unit is correspondingly disposed in one of the openings;

[0008] Among them, at least some of the second retaining walls have a first groove, and the depth of the first groove is less than or equal to the height of the corresponding second retaining wall.

[0009] Optionally, the first retaining wall includes a plurality of intermediate retaining walls and two edge retaining walls located on opposite sides of the plurality of intermediate retaining walls; the height of each of the second retaining walls and each of the edge retaining walls is greater than the height of each of the intermediate retaining walls.

[0010] Optionally, in this embodiment of the disclosure, at least one of the two edge retaining walls is provided with a second groove, the depth of the second groove is less than or equal to the height of the corresponding edge retaining wall, and the second groove is connected to the first groove.

[0011] Optionally, in this embodiment of the disclosure, the heights of each of the edge retaining walls and each of the second retaining walls are equal.

[0012] Optionally, in embodiments of this disclosure, the depth of each of the second trenches is equal to the depth of each of the first trenches.

[0013] Optionally, in embodiments of this disclosure, each of the intermediate barriers includes a first hydrophilic material, and each of the edge barriers and each of the second barriers includes a hydrophobic material.

[0014] Optionally, in this embodiment of the disclosure, each of the edge barriers further includes a second hydrophilic material, and the second hydrophilic material is located on the side of the corresponding hydrophobic material close to the substrate, and the orthographic projection of the hydrophobic material on the substrate falls completely within the area of ​​the orthographic projection of the corresponding second hydrophilic material on the substrate.

[0015] Optionally, in this embodiment of the present disclosure, the emitted light colors of two adjacent sub-pixel units in the second direction are the same, while the emitted light colors of two adjacent sub-pixel units in the first direction are different.

[0016] Optionally, in an embodiment of this disclosure, the sub-pixel unit includes an anode, a light-emitting functional layer, and a cathode sequentially disposed in the opening.

[0017] Secondly, embodiments of this disclosure also provide a display device, comprising:

[0018] Display panel as described in any of the above items.

[0019] Thirdly, embodiments of this disclosure also provide a method for manufacturing a display panel, comprising:

[0020] A pixel defining layer is formed on the substrate. The pixel defining layer includes: a plurality of first barriers extending along a first direction and arranged along a second direction intersecting the first direction, and a plurality of second barriers extending along the second direction and arranged along the first direction; the plurality of first barriers and the plurality of second barriers divide a plurality of openings for defining sub-pixel units, and one sub-pixel unit is correspondingly disposed in one of the openings.

[0021] A light-emitting functional layer for each of the sub-pixel units is formed within the opening;

[0022] The height of each of the second retaining walls and each of the edge retaining walls is greater than the height of each of the intermediate retaining walls; at least some of the second retaining walls have a first groove, the depth of which is less than or equal to the height of the corresponding second retaining wall.

[0023] Optionally, in this embodiment of the disclosure, the first barrier wall includes a plurality of intermediate barrier walls and two edge barrier walls located on opposite sides of the plurality of intermediate barrier walls, and a pixel defining layer is formed on the substrate, including:

[0024] A full-length first hydrophilic material layer is formed on the substrate;

[0025] The first hydrophilic material layer is patterned to form the plurality of intermediate baffles;

[0026] A full layer of hydrophobic material is formed on the side of the plurality of intermediate baffles away from the substrate;

[0027] The entire hydrophobic material layer is patterned to form the two edge barriers and the plurality of second barriers;

[0028] A first groove is formed in at least a portion of the plurality of second retaining walls.

[0029] Optionally, in this embodiment of the disclosure, after patterning the entire hydrophobic material layer to form the two edge barriers and the plurality of second barriers, the method further includes:

[0030] A second groove is formed in at least one of the two edge retaining walls. The depth of the second groove is less than or equal to the height of the corresponding edge retaining wall, and the second groove communicates with the first groove.

[0031] Optionally, in an embodiment of this disclosure, the light-emitting functional layer includes a hole injection layer or a hole transport layer, and forming the hole injection layer or the hole transport layer within the opening includes:

[0032] Using inkjet printing technology, a first solution containing only a first solvent is printed in the first trench of the light-emitting functional layer, and a second solution of the light-emitting functional layer is printed in the opening. The second solution includes a first solute and a second solvent. The first solute includes an organic functional material. The saturated vapor pressure of the second solvent in the opening corresponding to the sub-pixel unit of different colors is equal to the saturated vapor pressure of the first solvent.

[0033] The first solution and the second solution are dried to form the light-emitting functional layer.

[0034] Optionally, in an embodiment of this disclosure, the light-emitting functional layer includes a light-emitting material layer, and the light-emitting material layer forming each of the sub-pixel units within the opening includes:

[0035] Using an inkjet printing process, a third solution comprising only a third solvent is printed in the first trench of the luminescent material layer, and a fourth solution of the luminescent material layer is printed in the opening. The fourth solution comprises a second solute and a fourth solvent. The second solute comprises an organic material for forming the luminescent material layer. The average saturated vapor pressure of the fourth solvent in the opening corresponding to different color sub-pixel units is equal to the saturated vapor pressure of the third solvent. Attached Figure Description

[0036] Figure 1 This is a top-view schematic diagram of one type of pixel definition structure in related technologies;

[0037] Figure 2 For along Figure 1 A schematic diagram of one type of cross-sectional structure in the direction shown in MM;

[0038] Figure 3 This is a top view schematic diagram of one embodiment of a display panel provided in this disclosure;

[0039] Figure 4 For along Figure 3 A schematic diagram of one type of cross-sectional structure in the direction shown in the middle NN;

[0040] Figure 5 This is a top view schematic diagram of one embodiment of a display panel provided in this disclosure;

[0041] Figure 6 For along Figure 3 A schematic diagram of one type of cross-sectional structure in the direction shown in the middle OO;

[0042] Figure 7 For along Figure 3 A schematic diagram of one type of cross-sectional structure in the direction shown in PP;

[0043] Figure 8 For along Figure 3 A schematic diagram of another cross-sectional structure in the direction shown in PP;

[0044] Figure 9 For along Figure 3 A schematic diagram of one type of cross-sectional structure in the direction shown in QQ;

[0045] Figure 10 For along Figure 3 A schematic diagram of one type of cross-sectional structure in the direction shown by RR;

[0046] Figure 11 This is a schematic diagram of one structure of a display device provided in an embodiment of the present disclosure;

[0047] Figure 12 A flowchart illustrating one method of manufacturing a display panel according to an embodiment of this disclosure;

[0048] Figure 13 for Figure 12 Flowchart of one method for step S101;

[0049] Figure 14 for Figure 12 A flowchart of one method for step S102. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Furthermore, the embodiments and features in the embodiments of this disclosure can be combined with each other without conflict. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0051] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains. As used in this disclosure, the words “comprising” or “including” and similar terms mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, but do not exclude other elements or objects.

[0052] In related technologies, inkjet printing processes require the pre-fabrication of pixel-defining structures on the electrodes of a substrate to precisely direct ink droplets into designated sub-pixel areas, thereby forming the corresponding sub-pixels. Combined with... Figure 1 and Figure 2 As shown, where, Figure 1 This is a top view schematic diagram of one type of pixel-defining structure 01. Figure 2 For along Figure 1 The diagram shows one possible cross-sectional structure along the MM direction, where 01 represents a pixel defining structure, 02 represents a groove, 03 represents a sub-pixel, 04 represents a barrier, and 05 represents a substrate. Specifically, the pixel defining structure 01 includes multiple grooves 02 arranged in an array, with one sub-pixel 03 corresponding to each groove 02. Adjacent grooves 02 are separated by barriers 04 of the same height.

[0053] In Adoption Figure 1 As shown in the pixel-defining structure, during the fabrication of OLEDs, the uniformity of film formation within each pixel decreases continuously with increasing display resolution, thus affecting product lifespan and quality. Furthermore, due to limitations in the inkjet printer printhead hardware, the stability of each nozzle cannot guarantee consistent volume distribution within each recess 02. Although hybrid printing algorithms can be used, Suji Mura (a phenomenon where ink droplets evaporate rapidly) cannot be avoided. Moreover, after printing ink droplets within the relevant recess 02, a vacuum drying unit (VCD) process is required to dry and form the desired film structure. However, in the VCD process, the inkjet printing solvent in the edge region of substrate 05 evaporates relatively quickly, failing to guarantee uniform drying across the entire substrate and resulting in edge effects, thereby reducing film uniformity.

[0054] In view of this, embodiments of the present disclosure provide a display panel, a method for manufacturing the same, and a display device for improving film uniformity during inkjet printing.

[0055] Combination Figure 3 and Figure 4 As shown, where, Figure 3 This is a top view schematic diagram of one embodiment of a display panel provided in this disclosure. Figure 4 For along Figure 3 A schematic diagram of one cross-sectional structure along the direction shown in the diagram (NN). Specifically, the display panel includes:

[0056] Substrate 10, and pixel defining layer 20 located on substrate 10;

[0057] In specific implementation, the substrate 10 is located at the bottom of the display panel and serves to support the relevant film layers and drive the relevant sub-pixel units 50. Furthermore, the substrate 10 can be rectangular or circular in shape; of course, the shape of the substrate 10 can also be set according to actual application needs, and is not limited here. In one exemplary embodiment, the substrate 10 may include a substrate 10 and a driving circuit layer located on the substrate 10, wherein the pixel defining layer 20 is located on the side of the driving circuit layer facing away from the substrate 10. Moreover, the specific structure of the substrate 10 can be implemented with reference to related technologies, and will not be detailed here.

[0058] The pixel defining layer 20 includes:

[0059] A plurality of first barrier walls 30 extending along a first direction and arranged along a second direction intersecting the first direction, and a plurality of second barrier walls 40 extending along the second direction and arranged along the first direction; the plurality of first barrier walls 30 and the plurality of second barrier walls 40 divide a plurality of openings H for defining sub-pixel units 50, and one sub-pixel unit 50 is correspondingly disposed in one opening H.

[0060] Among them, at least some of the second retaining walls 40 have a first groove 60, and the depth of the first groove 60 is less than or equal to the height of the corresponding second retaining wall 40.

[0061] Still combined Figure 3 As shown, the pixel defining layer 20 includes a plurality of first barrier walls 30 extending along a first direction and arranged along a second direction intersecting the first direction, and a plurality of second barrier walls 40 extending along the second direction and arranged along the first direction. In this embodiment, unless otherwise specified, the direction indicated by arrow X represents the first direction, and the direction indicated by arrow Y represents the second direction. The specific number of the plurality of first barrier walls 30 and the plurality of second barrier walls 40 can be set according to actual application needs and is not limited here. Furthermore, the plurality of first barrier walls 30 and the plurality of second barrier walls 40 divide a plurality of openings H for defining sub-pixel units 50, and one sub-pixel unit 50 is correspondingly disposed within each opening H. Accordingly, the openings H and sub-pixel units 50 are configured in a one-to-one correspondence. In this way, the display panel includes a plurality of sub-pixel units 50, and the substrate 10 drives the plurality of sub-pixel units 50 to emit light, thereby ensuring the display function of the display panel.

[0062] Furthermore, the sub-pixel unit 50 may include an anode, a light-emitting functional layer, and a cathode sequentially disposed in the opening H. The light-emitting functional layer includes a hole injection layer, a hole transport layer, a light-emitting material layer, an electron injection layer, and an electron transport layer sequentially disposed opposite to the anode. In this embodiment, at least one of the hole injection layer, hole transport layer, and light-emitting material layer can be fabricated using inkjet printing. The light-emitting material layers of sub-pixel units 50 of the same color can use the same material. It should be noted that in the relevant top view structural diagrams of this embodiment, the anode, light-emitting functional layer, and cathode film layers are omitted to clearly illustrate the structure of the pixel defining layer 20.

[0063] Furthermore, at least a portion of the plurality of second baffles 40 have first grooves 60, the depth of which is less than or equal to the height of the corresponding second baffle 40. This ensures that all first grooves 60 have equal depth, thereby guaranteeing the spreading efficiency of the solution during subsequent printing. The first grooves 60 are used to contain the solution for fabricating the relevant luminescent functional layer. In one exemplary embodiment, each of the plurality of second baffles 40 has a first groove 60; in another exemplary embodiment, only a portion of the plurality of second baffles 40 has a first groove 60; in another exemplary embodiment, the depth of the first groove 60 can be equal to the height of the corresponding second baffle 40; in another exemplary embodiment, the depth of the first groove 60 can be less than the height of the corresponding second baffle 40. In practical applications, the specific height of the first baffle 30, the specific height of the second baffle 40, and the specific depth of the first groove 60 can be set as needed, and are not limited here.

[0064] In the embodiments of the present invention, it is still combined with Figure 3 As shown, the first retaining wall 30 includes: a plurality of intermediate retaining walls 31 and two edge retaining walls 32 located on opposite sides of the plurality of intermediate retaining walls 31; the height of each of the second retaining walls 40 and each of the edge retaining walls 32 is greater than the height of each of the intermediate retaining walls 31.

[0065] In practical implementation, the first barrier 30 includes multiple intermediate barrier walls 31 and two edge barrier walls 32 located on opposite sides of the multiple intermediate barrier walls 31. The specific number of the multiple intermediate barrier walls 31 can be set according to actual application needs and is not limited here. The height of each second barrier wall 40 and each edge barrier wall 32 is greater than the height of each intermediate barrier wall 31. In this way, the materials of the relevant film layers of the subsequent inkjet-printed sub-pixel units 50 can be effectively isolated by the second barrier walls 40 and each edge barrier wall 32, thereby ensuring the performance of the display panel.

[0066] It should be noted that in the specific manufacturing process, solutions of the same color for sub-pixel units 50 are printed in the same column of openings H in the second direction, while solutions of different colors for sub-pixel units 50 are printed in adjacent columns of openings H in the first direction, thereby achieving color display. Specifically, along the second direction, the solution is printed into the same column of openings H and covers the surface of the intermediate baffle 31, thereby forming a uniform film layer in the same column of openings H. Compared with related technologies, the display panel provided in this embodiment has lower requirements for the alignment accuracy of the inkjet printhead nozzles and openings H during inkjet printing, and the solution printed by each nozzle is uniformly mixed during the flow along the second direction. In this way, the uniformity of the film thickness of each sub-pixel unit 50 will not be affected by the different volumes of solution printed by different nozzles. Moreover, along the first direction, the solutions in adjacent columns are isolated by the higher second baffle 40, and the solutions in adjacent columns will not mix with each other, thereby avoiding the problem of color bleeding and ensuring the display effect.

[0067] In related technologies, after an inkjet printing process is used to drop a solution of organic material for forming the light-emitting functional layer into the opening H, a VCD process is required to form the desired light-emitting functional layer. However, during the drying process, the solution near the edge of the display panel evaporates faster, while the solution in the middle of the display panel dries more slowly. This difference in drying rate between different areas can easily cause uneven film formation. It should be noted that, unless otherwise specified, the edge area of ​​the display panel mentioned in the embodiments of this disclosure is essentially the peripheral area of ​​the display panel, and the middle area of ​​the display panel is essentially the display area of ​​the display panel.

[0068] In this embodiment, at least some of the second barrier walls 40 have first grooves 60. During the manufacturing process, solvent for creating the light-emitting functional layer can be printed simultaneously within the first grooves 60. Compared to related technologies, this increases the amount of solvent in the peripheral area of ​​the display panel, effectively altering the atmosphere around the sub-pixel units 50 located at the edge of the display panel. This ensures that the evaporation rate of the solvent in the display area of ​​the display panel is closer to its evaporation rate in the peripheral area, thereby guaranteeing the uniformity of the thickness of the film layer produced by inkjet printing even in the sub-pixel units 50 at the edge of the display panel.

[0069] In this embodiment of the disclosure, at least one of the two edge retaining walls 32 is provided with a second groove 70, the depth of the second groove 70 is less than or equal to the height of the corresponding edge retaining wall 32, and the second groove 70 is connected to the first groove 60.

[0070] In one exemplary embodiment, only one of the two edge retaining walls 32 may have the second groove 70. Specifically, the depth of the second groove 70 is less than or equal to the height of the corresponding edge retaining wall 32. In one exemplary embodiment, the depth of the second groove 70 may be less than the height of the corresponding edge retaining wall 32, and the second groove 70 may communicate with the first groove 60. In one exemplary embodiment, the depth of the second groove 70 may be equal to the height of the corresponding edge retaining wall 32, and the second groove 70 may communicate with the first groove 60.

[0071] In one exemplary embodiment, such as Figure 5 As shown, each of the two edge retaining walls 32 has a second groove 70.

[0072] In the specific manufacturing process, since the second trench 70 is connected to the first trench 60, the solvent used to create the light-emitting functional layer can be printed simultaneously in both the first trench 60 and the second trench 70. Alternatively, the fluidity of the solution can be used to directly print the second trench 70 while indirectly printing the first trench 60. Compared to related technologies, this further increases the amount of solvent in the peripheral area of ​​the display panel, effectively altering the atmosphere around the sub-pixel units 50 located at the edge of the display panel. In this way, the evaporation rate of the solvent in the display area of ​​the display panel is closer to its evaporation rate in the peripheral area, thus ensuring the uniformity of the film thickness produced by inkjet printing even in the sub-pixel units 50 at the edge of the display panel.

[0073] In this embodiment, the heights of each edge retaining wall 32 and each second retaining wall 40 are equal. In actual manufacturing, the same material can be used to fabricate each edge retaining wall 32 and each second retaining wall 40 in the same layer, thereby simplifying the manufacturing process while ensuring structural stability during subsequent membrane fabrication.

[0074] In this embodiment, the depth of each of the second trenches 70 is equal to the depth of each of the first trenches 60. This ensures consistent solvent spreading and is beneficial for the uniformity of the subsequent film layer.

[0075] In this embodiment of the disclosure, each of the intermediate baffles 31 includes a first hydrophilic material 310, and each of the edge baffles 32 and each of the second baffles 40 includes a hydrophobic material 311.

[0076] In the specific implementation process, combined with Figure 6 and Figure 7 As shown, where, Figure 6 The following is along Figure 3 A schematic diagram of one type of cross-sectional structure in the direction shown in the diagram. Figure 7For along Figure 3 The diagram shows one possible cross-sectional structure along the direction indicated by PP. Specifically, each intermediate baffle 31 includes a first hydrophilic material 310, which has a large surface energy, ensuring complete spreading of the solution within the opening H. This, in turn, ensures the uniformity of solution spreading within the same column of openings H, further guaranteeing the uniformity of film formation in the sub-pixel units 50. Furthermore, each edge baffle 32 and each second baffle 40 includes a hydrophobic material 311. Due to the low surface energy of the hydrophobic material 311, solution overflow is avoided, effectively preventing color bleeding between adjacent columns of sub-pixel units 50 and ensuring the display effect of the display panel.

[0077] In one exemplary embodiment, such as Figure 8 The following is along Figure 3 Another cross-sectional structural diagram in the direction shown in PP. Specifically, each of the edge barriers 32 further includes a second hydrophilic material 320, and the second hydrophilic material 320 is located on the side of the corresponding hydrophobic material 311 near the substrate 10, and the orthographic projection of the hydrophobic material 311 on the substrate 10 completely falls within the area of ​​the orthographic projection of the corresponding second hydrophilic material 320 on the substrate 10. Furthermore, as... Figure 9 The following is along Figure 3 A schematic diagram of one type of cross-sectional structure in the direction shown by QQ, as follows: Figure 10 The following is along Figure 3 A schematic diagram of one type of cross-sectional structure in the direction shown by RR.

[0078] Since the second hydrophilic material 320 in each edge barrier 32 is closer to one side of the substrate 10 than the hydrophobic material 311, and the second hydrophilic material 320 has a larger surface energy, it further ensures that the solution spreads completely within the same column of openings H, thereby ensuring the uniformity of the flow of the solution printed into the same column of openings H, and thus ensuring the uniformity of the film formation of the sub-pixel unit 50. In addition, the orthographic projection of the hydrophobic material 311 on the substrate 10 completely falls within the area of ​​the orthographic projection of the corresponding second hydrophilic material 320 on the substrate 10, thereby ensuring the structural stability of the subsequent film layer fabrication.

[0079] In this embodiment of the disclosure, the emitted light colors of two adjacent sub-pixel units 50 in the second direction are the same, while the emitted light colors of two adjacent sub-pixel units 50 in the first direction are different. For example, the emitted light color of each sub-pixel unit 50 in the current column is red, and the emitted light color of each sub-pixel unit 50 in adjacent columns is green, thereby avoiding color mixing between adjacent sub-pixel units 50 while ensuring the color display of the display panel.

[0080] Based on the same publicly disclosed concept, such as Figure 11 As shown in the embodiments of this disclosure, a display device is also provided, comprising:

[0081] Display panel 100 as described in any of the above items.

[0082] In specific implementation, the display device can be a smartphone, television, flat panel display, computer monitor, billboard, transparent display, theater screen, etc., and is not limited thereto. In addition, since the principle of the display device in solving the problem is similar to that of the display panel 100 described above, the implementation of the display device can refer to the implementation of the display panel 100 described above, and the repeated parts will not be described again.

[0083] Based on the same publicly disclosed concept, such as Figure 12 As shown in the embodiments of this disclosure, a method for manufacturing a display panel is also provided, comprising:

[0084] S101: A pixel defining layer is formed on the substrate. The pixel defining layer includes: a plurality of first barriers extending along a first direction and arranged along a second direction intersecting the first direction, and a plurality of second barriers extending along the second direction and arranged along the first direction; the plurality of first barriers and the plurality of second barriers divide a plurality of openings for defining sub-pixel units, and one sub-pixel unit is correspondingly disposed in one of the openings.

[0085] S102: A light-emitting functional layer for each of the sub-pixel units is formed within the opening;

[0086] The height of each of the second retaining walls and each of the edge retaining walls is greater than the height of each of the intermediate retaining walls; at least some of the second retaining walls have a first groove, the depth of which is less than or equal to the height of the corresponding second retaining wall.

[0087] In the specific implementation process, taking a sub-pixel unit comprising an anode, a light-emitting functional layer, and a cathode sequentially disposed in the opening as an example, the specific implementation process of steps S101 to S102 is as follows:

[0088] First, a substrate for driving the light emission of each sub-pixel unit is fabricated. This substrate may include a substrate base and a driving circuit layer located on the substrate base, wherein the driving circuit layer is used to provide the driving signals required by each sub-pixel unit. After the substrate is fabricated, the anode of each sub-pixel unit is formed on the substrate by methods such as spin coating, deposition, evaporation, and etching. The anode material may be indium tin oxide or other materials, and is not limited thereto.

[0089] After the anode is fabricated, a pixel defining layer is formed on the anode. The pixel defining layer includes a plurality of first barriers extending along a first direction and arranged along a second direction intersecting the first direction, and a plurality of second barriers extending along the second direction and arranged along the first direction. The plurality of first barriers and the plurality of second barriers divide a plurality of openings for defining sub-pixel units, and a sub-pixel unit is disposed in each opening.

[0090] In the specific implementation process, at least some of the multiple second retaining walls are provided with first grooves, and the depth of the first grooves is less than or equal to the height of the corresponding second retaining wall.

[0091] After the pixel defining layer is fabricated, corresponding sub-pixel units are fabricated within the openings of this pixel defining layer. In one exemplary embodiment, the sub-pixel units are OLED devices. Solutions of each sub-pixel unit can be printed on the side of the anode and pixel defining layer away from the substrate using an inkjet printing process. The solutions are then dried to form the desired light-emitting functional layer. A cathode is then formed on the side of the light-emitting functional layer away from the anode using a process such as vapor deposition, thereby fabricating each sub-pixel unit. Other film layers of the display panel can then be fabricated using related technologies, which will not be detailed here. It should be noted that other film layers in the display panel not mentioned can be implemented using related technologies, which will not be detailed here.

[0092] In the specific manufacturing process, solutions of the same color for sub-pixel units can be printed along the second direction to the same column of openings, while solutions of different colors for sub-pixel units can be printed along the first direction to adjacent columns of openings, thus achieving color display. Since the solutions printed within the same column of openings can flow together, a uniform film layer is formed. Compared to related technologies, inkjet printing requires lower alignment precision between the nozzles and openings of the inkjet printhead, and the solutions printed by each nozzle are uniformly mixed during flow along the second direction, ensuring that the film thickness uniformity of sub-pixel units within the corresponding area is not affected by the different volumes of solutions printed by different nozzles. Furthermore, along the first direction, the solutions in adjacent columns are blocked by a second barrier, preventing them from mixing and thus avoiding color bleeding.

[0093] Furthermore, in related technologies, during the solution drying process, the solution drying rate is faster in the edge area of ​​the display panel and slower in the middle area of ​​the display panel. The difference in the solution drying rate in different areas can easily cause uneven film formation.

[0094] In this embodiment, at least some of the second barrier walls have first grooves. This allows the solvent used to create the light-emitting functional layer to be printed simultaneously within the first grooves during inkjet printing. Compared to related technologies, this increases the amount of solvent in the peripheral area of ​​the display panel, effectively altering the atmosphere around the sub-pixel units located at the edge of the display panel. Consequently, during drying, the evaporation rate of the solvent in the display area of ​​the display panel is closer to its evaporation rate in the peripheral area, ensuring uniform thickness of the film layer produced by inkjet printing even for sub-pixel units at the edge of the display panel.

[0095] In the embodiments disclosed herein, such as Figure 13 As shown, the first barrier wall includes a plurality of intermediate barrier walls and two edge barrier walls located on opposite sides of the plurality of intermediate barrier walls. Step S101: Forming a pixel defining layer on the substrate includes:

[0096] S201: A first hydrophilic material layer is formed on the substrate;

[0097] S202: Pattern the first hydrophilic material layer to form the plurality of intermediate baffles;

[0098] S203: A whole layer of hydrophobic material is formed on the side of the plurality of intermediate baffles away from the substrate;

[0099] S204: The entire hydrophobic material layer is patterned to form the two edge barriers and the plurality of second barriers;

[0100] S205: A first trench is opened in at least a portion of the plurality of second retaining walls.

[0101] In the specific implementation process, the first baffle wall includes multiple intermediate baffle walls and two edge baffle walls located on opposite sides of the multiple intermediate baffle walls; the height of each second baffle wall and each edge baffle wall is greater than the height of each intermediate baffle wall; in addition, since the height of each second baffle wall and each edge baffle wall is greater than the height of each intermediate baffle wall, during the inkjet printing of the light-emitting functional layer along the second direction, the solution can flow along the second direction to adjacent openings in the same column, thereby forming the same film layer; at the same time, due to the isolation of the higher second baffle walls, the solution cannot flow between the openings in adjacent columns, thereby avoiding the problem of color mixing.

[0102] Specifically, the implementation process of steps S201 to S205 is as follows:

[0103] First, a full-length first hydrophilic material layer is formed on the substrate; this can be achieved by spin coating, deposition, vapor deposition, or other methods. Then, the first hydrophilic material layer is patterned to form multiple intermediate barriers. Next, a full-length hydrophobic material layer is formed on the side of the multiple intermediate barriers facing away from the substrate, using spin coating, deposition, vapor deposition, or other methods. Then, the full-length hydrophobic material layer is patterned to form two edge barriers and multiple second barriers. Finally, an etching process is used to create first trenches in at least some of the multiple second barriers.

[0104] In this embodiment of the disclosure, after step S204: patterning the entire hydrophobic material layer to form the two edge barriers and the plurality of second barriers, the method further includes:

[0105] A second groove is formed in at least one of the two edge retaining walls. The depth of the second groove is less than or equal to the height of the corresponding edge retaining wall, and the second groove communicates with the first groove.

[0106] In one exemplary embodiment, after patterning the entire hydrophobic material layer to form two edge barriers and multiple second barriers, an etching process can be used to create a second trench in at least one of the two edge barriers. Since the second trench is connected to the first trench, the solvent used to create the light-emitting functional layer can be printed simultaneously in both the first and second trenches. Compared to related technologies, this further increases the amount of solvent in the peripheral area of ​​the display panel, effectively altering the atmosphere around the sub-pixel units located at the edges of the display panel. In this way, the evaporation rate of the solvent in the display area of ​​the display panel is closer to the evaporation rate in its peripheral area, thereby ensuring the uniformity of the thickness of the film layer produced by inkjet printing even in the sub-pixel units at the edges of the display panel.

[0107] In the embodiments disclosed herein, the printing of the light-emitting functional layer can be implemented in two ways, but is not limited to these two ways.

[0108] In one exemplary embodiment, such as Figure 14 As shown, the light-emitting functional layer includes a hole injection layer or a hole transport layer. The hole injection layer or the hole transport layer is formed within the opening, comprising:

[0109] S301: Using inkjet printing technology, a first solution containing only a first solvent is printed in the groove of the light-emitting functional layer, and a second solution of the light-emitting functional layer is printed in the opening. The second solution includes a first solute and a second solvent. The first solute includes an organic functional material. The saturated vapor pressure of the second solvent in the opening corresponding to the sub-pixel unit of different colors is equal to the saturated vapor pressure of the first solvent.

[0110] S302: The first solution and the second solution are dried to form the light-emitting functional layer.

[0111] In the specific implementation process, steps S301 to S302 are implemented as follows:

[0112] In the process of fabricating a hole injection layer using inkjet printing, a first solution comprising only a first solvent is printed in the first trench, and a second solution for the hole injection layer is printed in the opening. This second solution comprises a first solute and a second solvent. The first solute includes an organic functional material for forming the hole injection layer, which dissolves in the second solvent to form the second solution, i.e., the inkjet printing ink used to fabricate the hole injection layer. Then, the first and second solutions are dried to form the light-emitting functional layer. Since the saturated vapor pressure of the second solvent in the opening corresponding to different color sub-pixel units is equal to the saturated vapor pressure of the first solvent, the evaporation rate of the first solvent in the first trench is close to the evaporation rate of the second solution in the opening, thus ensuring the uniformity of the thickness of the film layer fabricated by the drying process. It should be noted that the specific implementation process of fabricating a hole transport layer using inkjet printing can be referred to the implementation process of fabricating a hole injection layer using inkjet printing, and will not be detailed here.

[0113] In one exemplary embodiment, the light-emitting functional layer includes a light-emitting material layer, wherein the light-emitting material layer forming each of the sub-pixel units within the opening includes:

[0114] Using an inkjet printing process, a third solution comprising only a third solvent is printed in the first trench of the luminescent material layer, and a fourth solution of the luminescent material layer is printed in the opening. The fourth solution comprises a second solute and a fourth solvent. The second solute comprises an organic material for forming the luminescent material layer. The average saturated vapor pressure of the fourth solvent in the opening corresponding to different color sub-pixel units is equal to the saturated vapor pressure of the third solvent.

[0115] In the specific implementation process, during the fabrication of the luminescent material layer using inkjet printing, a third solution comprising only a third solvent can be printed in the first trench, and a fourth solution of the luminescent material layer can be printed in the opening. The fourth solution comprises a second solute and a fourth solvent. The second solute includes an organic material used to form the luminescent material layer, which dissolves in the fourth solvent to form the fourth solution, i.e., the inkjet printing ink used to fabricate the luminescent material layer. Furthermore, the average saturated vapor pressure of the fourth solvent in the opening corresponding to different color sub-pixel units is equal to the saturated vapor pressure of the third solvent. Taking a display panel comprising red, green, and blue sub-pixel units as an example, if the saturated vapor pressure of the fourth solvent in the opening corresponding to the red sub-pixel unit is 'a', the saturated vapor pressure of the fourth solvent in the opening corresponding to the green sub-pixel unit is 'b', and the saturated vapor pressure of the fourth solvent in the opening corresponding to the blue sub-pixel unit is 'c', then a third solvent with a saturated vapor pressure of 'd' can be used to print into the first trench, where 'd' is (a+b+c) / 3.

[0116] It should be noted that in the actual manufacturing process of low pixel density (Pixels Per Inch, PPI) display panels, the distance between two adjacent sub-pixel units along the first direction is often relatively large, for example, greater than or equal to 25μm. When using inkjet printing to fabricate the light-emitting functional layer, a smaller distance can be used. Figure 3 The display panel shown is printed with only the first groove.

[0117] In the actual manufacturing process of high PPI display panels, the distance between two adjacent sub-pixel units along the first direction is often small, for example, less than 25μm. When using inkjet printing to fabricate the light-emitting functional layer, printing the first trench separately is relatively difficult, so a method can be used... Figure 5 The display panel shown prints the second groove. Since the first groove and the second groove are connected, the fluidity of the solution can be used to indirectly print the first groove. In this way, the printing effect is guaranteed while ensuring the uniformity of the film layer.

[0118] Although preferred embodiments of this disclosure have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this disclosure.

[0119] Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include such modifications and variations.

Claims

1. A display panel, wherein, The display panel comprises: a substrate and a pixel defining layer on the substrate; the pixel defining layer comprises: a plurality of first barriers extending along a first direction and arranged along a second direction intersecting the first direction, and a plurality of second barriers extending along the second direction and arranged along the first direction; the plurality of first barriers and the plurality of second barriers divide a plurality of openings for defining sub-pixel units, and one of the sub-pixel units is arranged in one of the openings; wherein at least some of the plurality of second barriers are provided with a first groove, the depth of the first groove is less than or equal to the height of the corresponding second barrier; the first groove is continuous and has no partition structure along the second direction, and the first barrier comprises a plurality of intermediate barriers and two edge barriers located on opposite sides of the plurality of intermediate barriers; the height of each of the second barriers and each of the edge barriers is greater than the height of each of the intermediate barriers; the sub-pixel units in the same column of the openings along the second direction are of the same color, and the sub-pixel units in adjacent two columns of the openings are of different colors; each of the intermediate barriers comprises a first lyophilic material, and each of the edge barriers and each of the second barriers comprises a lyophobic material; each of the edge barriers further comprises a second lyophilic material, and the second lyophilic material is located on the side of the corresponding lyophobic material close to the substrate, and the orthogonal projection of the lyophobic material on the substrate falls within the area of the orthogonal projection of the corresponding second lyophilic material on the substrate.

2. The display panel of claim 1, wherein, At least one of the two edge barriers is provided with a second groove, the depth of the second groove is less than or equal to the height of the corresponding edge barrier, and the second groove is in communication with the first groove.

3. The display panel of claim 2, wherein, The height of each of the edge barriers and each of the second barriers is equal.

4. The display panel of claim 3, wherein, The depth of each of the second grooves and the depth of each of the first grooves are equal.

5. The display panel of claim 1, wherein, The colors of the emitted light of two adjacent sub-pixel units in the second direction are the same, and the colors of the emitted light of two adjacent sub-pixel units in the first direction are different.

6. The display panel of claim 5, wherein, The sub-pixel unit comprises, in sequence, an anode, a light-emitting functional layer, and a cathode arranged in the opening.

7. A display device, wherein, The display panel comprises: The display panel of any one of claims 1-6.

8. A manufacturing method of a display panel, wherein, The display panel comprises: forming a pixel defining layer on a substrate, the pixel defining layer comprising: a plurality of first barriers extending along a first direction and arranged along a second direction intersecting the first direction, and a plurality of second barriers extending along the second direction and arranged along the first direction; the plurality of first barriers and the plurality of second barriers divide a plurality of openings for defining sub-pixel units, and one of the sub-pixel units is arranged in one of the openings; forming a light-emitting functional layer of each of the sub-pixel units in the opening; The first groove is continuous and has no partition structure along the second direction, and the first barrier wall includes a plurality of intermediate barrier walls and two edge barrier walls located on opposite sides of the plurality of intermediate barrier walls; the height of each second barrier wall and each edge barrier wall is greater than the height of each intermediate barrier wall; the sub-pixel units in the same column of openings along the second direction are of the same color, and the sub-pixel units in adjacent two columns of openings are of different colors; each intermediate barrier wall includes a first lyophilic material, and each edge barrier wall and each second barrier wall include a lyophobic material; each edge barrier wall further includes a second lyophilic material, and the second lyophilic material is located on the side of the corresponding lyophobic material close to the substrate, and the orthogonal projection of the lyophobic material on the substrate completely falls within the area range of the orthogonal projection of the corresponding second lyophilic material on the substrate.

9. The method of claim 8, wherein, Forming a pixel definition layer on the substrate, comprising: forming a whole layer of first lyophilic material layer on the substrate; performing a patterning process on the first lyophilic material layer to form the plurality of intermediate barrier walls; forming a whole layer of lyophobic material layer on the side of the plurality of intermediate barrier walls away from the substrate; performing a patterning process on the whole layer of lyophobic material layer to form the two edge barrier walls and the plurality of second barrier walls; forming a first groove in at least part of the plurality of second barrier walls.

10. The method of claim 9, wherein, After performing the patterning process on the whole layer of lyophobic material layer to form the two edge barrier walls and the plurality of second barrier walls, the method further comprises: forming a second groove in at least one of the two edge barrier walls, the depth of the second groove being less than or equal to the height of the corresponding edge barrier wall, and the second groove being in communication with the first groove.

11. The method of claim 8, wherein, The light-emitting functional layer includes a hole injection layer or a hole transport layer, and the hole injection layer or the hole transport layer is formed in the openings, comprising: using an inkjet printing process to print a first solution of the light-emitting functional layer including only a first solvent in the first groove, and to print a second solution of the light-emitting functional layer in the openings, wherein the second solution includes a first solute and a second solvent, the first solute includes an organic functional material, and the saturated vapor pressure of the second solvent in the openings corresponding to different color sub-pixel units is equal to the saturated vapor pressure of the first solvent; performing a drying process on the first solution and the second solution to form the light-emitting functional layer.

12. The method of claim 8, wherein, The light-emitting functional layer includes a light-emitting material layer, and the light-emitting material layer of each sub-pixel unit is formed in the openings, comprising: The inkjet printing process is used to print the third solution of the luminescent material layer only including the third solvent in the first groove, and to print the fourth solution of the luminescent material layer in the opening, wherein the fourth solution includes the second solute and the fourth solvent, and the second solute includes the organic material used to form the luminescent material layer, and the average value of the saturated vapor pressure of the fourth solvent in the opening corresponding to the sub-pixel units of different colors is equal to the saturated vapor pressure of the third solvent.

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