Display panel and manufacturing method thereof

Abstract

The application relates to a display panel and a manufacturing method thereof. The display panel comprises a substrate, a first electrode layer, a pixel definition layer, a first functional layer, a light-emitting layer and a second electrode layer. The first functional layer is arranged in a pixel opening. The first functional layer comprises a first subpart and a second subpart connected between the first subpart and the sidewall of the dam. The distance from the side of the second subpart away from the substrate to the substrate is less than or equal to the distance from the side of the first subpart away from the substrate to the substrate. The first functional layer of the display panel of the application does not form a climbing structure at the edge, thereby avoiding the problem of electric leakage caused by the overlapping of the first functional layer and the film layer on the other side of the light-emitting layer at the nail climbing point.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a display panel and a manufacturing method of the display panel. BACKGROUND

[0002] The organic functional layer of an organic light emitting diode (OLED) generally includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and the like. The hole injection layer, the hole transport layer and the light emitting layer can be sequentially formed in the pixel opening by printing. Due to the nature of the material and the limitation of the process, the edges of the hole injection layer, the hole transport layer and the light emitting layer are accumulated on the sidewall of the bank to form a climbing structure. The climbing height of the hole injection layer, the hole transport layer and the light emitting layer is consistent, and the upper layer of film cannot completely cover the edges of the lower layer of film. Therefore, the hole injection layer and the electron transport layer located on the opposite sides of the light emitting layer will be overlapped at the climbing point to form a leakage path, which leads to the performance degradation of the OLED device. SUMMARY

[0003] Embodiments of the present application provide a display panel and a manufacturing method of the display panel to solve the above problems.

[0004] The present application provides a display panel, which comprises:

[0005] a substrate;

[0006] a first electrode layer disposed above the substrate;

[0007] a pixel definition layer disposed above the first electrode layer, the pixel definition layer comprising a plurality of banks and a plurality of pixel openings formed by the banks;

[0008] a first functional layer disposed above the first electrode layer and located in the pixel opening;

[0009] a light emitting layer disposed above the first functional layer and located in the pixel opening, the light emitting layer covering the first functional layer; and

[0010] a second electrode layer disposed above the light emitting layer, the second electrode layer covering the light emitting layer and the pixel definition layer;

[0011] wherein the first functional layer comprises a first subpart and a second subpart connected between the first subpart and the sidewall of the bank, the distance from the second subpart away from the substrate to the substrate is less than or equal to the distance from the first subpart away from the substrate to the substrate.

[0012] In some embodiments, the light-emitting layer comprises a third sub-portion and a fourth sub-portion connected between the third sub-portion and the sidewall of the dam, and a distance from a side of the fourth sub-portion away from the substrate to the substrate is less than or equal to a distance from a side of the third sub-portion away from the substrate to the substrate.

[0013] In some embodiments, the first functional layer is spaced apart from the second electrode layer; and the first functional layer comprises at least one of a hole injection layer and a hole transport layer.

[0014] In some embodiments, the display panel further comprises:

[0015] a second functional layer disposed between the light-emitting layer and the second electrode layer, and the first functional layer is spaced apart from the second functional layer;

[0016] The second functional layer comprises at least one of an electron injection layer and an electron transport layer.

[0017] The present application also provides a manufacturing method of a display panel, comprising:

[0018] forming a first electrode layer above the substrate;

[0019] forming a pixel definition layer above the first electrode layer, the pixel definition layer comprising a plurality of dams and a plurality of pixel openings formed by the dams;

[0020] printing a first ink in the pixel openings;

[0021] printing a first solvent above the dams and above a side of the first ink close to the dams;

[0022] drying the first ink;

[0023] drying the first solvent to form a first functional layer in the pixel openings and above the first electrode layer, the first functional layer comprising a first sub-portion and a second sub-portion connected between the first sub-portion and the sidewall of the dam, and a distance from a side of the second sub-portion away from the substrate to the substrate is less than or equal to a distance from a side of the first sub-portion away from the substrate to the substrate;

[0024] forming a light-emitting layer in the pixel openings and above the first functional layer, the light-emitting layer covering the first functional layer; and

[0025] forming a second electrode layer above the light-emitting layer.

[0026] In some embodiments, the first solvent is immiscible with the first ink, and the first solvent has a density greater than that of the first ink, and a boiling point higher than that of the first ink.

[0027] The temperature for drying the first ink is T1, and the temperature for drying the first solvent is T2, wherein T2>T1.

[0028] In some embodiments, the first functional layer comprises at least one of a hole injection layer and a hole transport layer.

[0029] In some embodiments, the step of forming a light-emitting layer over the first functional layer in the pixel opening comprises:

[0030] printing a second ink over the first functional layer in the pixel opening;

[0031] printing a second solvent over the dam and over the second ink on the side of the dam close to the dam;

[0032] drying the second ink;

[0033] drying the second solvent to form a light-emitting layer over the first functional layer in the pixel opening, the light-emitting layer comprising a third sub-portion and a fourth sub-portion connected between the third sub-portion and the sidewall of the dam, the fourth sub-portion having a distance to the substrate less than or equal to that of the third sub-portion.

[0034] In some embodiments, the second solvent is immiscible with the second ink, and the second solvent has a density greater than that of the second ink, and a boiling point higher than that of the second ink.

[0035] The temperature for drying the second ink is T3, and the temperature for drying the second solvent is T4, wherein T4>T3.

[0036] In some embodiments, the first and second inks are water-soluble inks, the first and second solvents are oily solvents, and the material of the pixel defining layer is a hydrophobic and oleophilic material.

[0037] This application provides a display panel and a method for manufacturing the display panel. The first functional layer of the display panel is formed by first printing first ink into the pixel openings, then printing first solvent above the dam, followed by drying the first ink and the first solvent, to create a first functional layer with a high center and low or flat edges within the pixel openings. During the drying process of the first ink, the solvent in the first ink continuously evaporates. The first solvent located above the dam flows into the pixel openings on both sides. The first solvent above the first ink exerts a force on the first ink, preventing the formation of a sloping structure at the edge where the first functional layer contacts the dam sidewall. The light-emitting layer covers the first functional layer, and the film layer above the first functional layer is spaced apart, thus preventing leakage problems caused by overlapping at the sloping points between the first functional layer and the film layer above the light-emitting layer. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0040] Figure 1 This is a schematic diagram of the structure of a display panel provided by existing technology;

[0041] Figure 2 yes Figure 1 A partially enlarged schematic diagram of point A on a display panel is provided;

[0042] Figure 3 This is a schematic diagram of the structure of a display panel provided in an embodiment of this application;

[0043] Figure 4 This is a schematic diagram of another display panel structure provided in an embodiment of this application;

[0044] Figure 5 This is a schematic diagram showing the state of the first ink and first solvent after printing is completed, according to an embodiment of this application.

[0045] Figure 6 This is a schematic diagram of the drying process of the first ink provided in an embodiment of this application;

[0046] Figure 7 This is a schematic diagram showing the state of the first solvent after drying, provided in an embodiment of this application.

[0047] Figure 8 is a step S1 schematic diagram of a manufacturing method of a display panel provided by an embodiment of the present application;

[0048] Figure 9 is a step S2 schematic diagram of a manufacturing method of a display panel provided by an embodiment of the present application;

[0049] Figure 10 is a step S3 schematic diagram of a manufacturing method of a display panel provided by an embodiment of the present application;

[0050] Figure 11 is a step S4 schematic diagram of a manufacturing method of a display panel provided by an embodiment of the present application;

[0051] Figure 12 is a step S5 schematic diagram of a manufacturing method of a display panel provided by an embodiment of the present application;

[0052] Figure 13 is a step S6 schematic diagram of a manufacturing method of a display panel provided by an embodiment of the present application.

[0053] Legend of reference signs:

[0054] 10, display panel; 101, substrate; 100, first electrode layer; 200, pixel definition layer; 201, dam; 202, pixel opening; 310, first functional layer; 301, first subpart; 302, second subpart; 311, hole injection layer; 312, hole transport layer; 320, light emitting layer; 321, third subpart; 322, fourth subpart; 330, second functional layer; 331, electron transport layer; 400, second electrode layer; 501, first ink; 601, first solvent. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person skilled in the art without any creative effort, fall within the protection scope of the present application.

[0056] Please refer to Figure 1A structural schematic diagram of a display panel provided by the prior art, the display panel comprising a first electrode layer 100 (anode), a pixel definition layer 200, a hole injection layer 311 (HIL), a hole transport layer 312 (HTL), a light-emitting layer 320 (EML), an electron transport layer 331 (ETL), and a second electrode layer 400 (cathode), the hole injection layer 311, the hole transport layer 312, and the light-emitting layer 320 are sequentially formed in the pixel opening by printing, but the edges of the hole injection layer 311, the hole transport layer 312, and the light-emitting layer 320 are accumulated on the sidewall of the bank to form a climbing structure, and the pin climbing height is consistent, which cannot realize that the upper film layer completely covers the edge of the lower film layer, please refer to Figure 2 The hole injection layer 311 and the electron transport layer 331 are overlapped at the pin climbing point (B) to form a leakage path, which causes the performance of the OLED device to decrease.

[0057] To solve the above problems, the present application provides a display panel 10, which can be an organic light-emitting diode (OLED) display panel 10. Please refer to Figure 3 The display panel 10 comprises a substrate 101, a first electrode layer 100, a pixel definition layer 200, a first functional layer 310, a light-emitting layer 320, and a second electrode layer 400. Among them, the first electrode layer 100 is arranged above the substrate 101; the pixel definition layer 200 is arranged above the first electrode layer 100, the pixel definition layer 200 comprises a plurality of banks 201 and a plurality of pixel openings 202 formed by the banks 201; the first functional layer 310 is arranged above the first electrode layer 100 and located in the pixel opening 202; the light-emitting layer 320 is arranged above the first functional layer 310 and located in the pixel opening 202, the light-emitting layer 320 covers the first functional layer 310; the second electrode layer 400 is arranged above the light-emitting layer 320. Among them, the first functional layer 310 comprises a first sub-part 301 and a second sub-part 302 connected between the first sub-part 301 and the sidewall of the bank 201, the distance b2 from the side of the second sub-part 302 away from the substrate 101 to the substrate 101 is less than or equal to the distance b1 from the side of the first sub-part 301 away from the substrate 101 to the substrate 101.

[0058] In the present application, the first functional layer 310 is formed in the pixel opening 202, and the first functional layer 310 has a middle-high edge-low or flat shape, that is, the height of the edge of the first functional layer 310 in contact with the sidewall of the dam 201 in the direction perpendicular to the substrate 101 is less than or equal to the height of the middle of the first functional layer 310 in the direction perpendicular to the substrate 101, so that the edge of the first functional layer 310 of the present application does not form a climbing structure on the sidewall of the dam 202, and thus the problem of electric leakage caused by the first functional layer 310 and the film layer above the light-emitting layer 320 being overlapped at a nail climbing point does not occur.

[0059] In some embodiments, the light-emitting layer 320 includes a third sub-portion 321 and a fourth sub-portion 322 connected between the third sub-portion 321 and the sidewall of the pixel opening 202, and the distance d4 from one side of the fourth sub-portion 322 away from the substrate 101 to the substrate 101 is less than or equal to the distance d3 from one side of the third sub-portion 321 away from the substrate 101 to the substrate 101. Similar to the first functional layer 310, the light-emitting layer 320 is formed in the pixel opening 202 and also has a middle-high edge-low or flat shape, and the edge of the light-emitting layer 320 does not form a climbing structure on the sidewall of the dam 202, and can completely cover the first functional layer 310, so that the first functional layer 310 and the film layer above the light-emitting layer 320 are arranged in a spaced manner, for example, the first functional layer 310 and the second electrode layer 400 are arranged in a spaced manner, and the light-emitting layer 320 is arranged between the first functional layer 310 and the second electrode layer 400 at the sidewall of the dam 201, so that the problem of electric leakage caused by the first functional layer 310 and the second electrode layer 400 being in contact can be avoided.

[0060] In the present application, one of the first electrode layer 100 and the second electrode layer 400 is an anode, and the other is a cathode. The first functional layer 310 includes at least one of a hole injection layer 311, a hole transport layer 312, an electron injection layer, and an electron transport layer 331.

[0061] In some embodiments, the first electrode layer 100 can be an anode, the second electrode layer 400 can be a cathode, and the first functional layer 310 can be at least one of a hole injection layer 311 and a hole transport layer 312.

[0062] Please refer to Figure 4When the first functional layer 310 comprises the hole injection layer 311 and the hole transport layer 312, the hole injection layer 311 is located between the hole transport layer 312 and the first electrode layer 100, and the hole injection layer 311 and the hole transport layer 312 both have the structural features of the first functional layer 310 as described above, i.e. have the form of high in the middle and low at the edges or the form of flat.

[0063] Specifically, the hole injection layer 311 comprises a first sub-part a and a second sub-part a connected between the first sub-part a and the sidewall of the dam 201, and the distance from the side of the second sub-part a away from the substrate 101 to the substrate 101 is less than or equal to the distance from the side of the first sub-part a away from the substrate 101 to the substrate 101. The hole transport layer 312 comprises a first sub-part b and a second sub-part b connected between the first sub-part b and the sidewall of the dam 201, and the distance from the side of the second sub-part b away from the substrate 101 to the substrate 101 is less than or equal to the distance from the side of the first sub-part b away from the substrate 101 to the substrate 101.

[0064] In some embodiments, referring to Figure 3 , the display panel 10 further comprises a second functional layer 330, which is arranged between the light-emitting layer 320 and the second electrode layer 400, and the first functional layer 310 and the second functional layer 330 are arranged apart from each other. The second functional layer 330 comprises at least one of an electron injection layer and an electron transport layer 331.

[0065] Specifically, referring to Figure 4 , the second functional layer 330 can be the electron transport layer 331. The hole injection layer 311 and the electron transport layer 331 are arranged apart from each other, and at the sidewall of the dam 201, the light-emitting layer 320 is arranged between the hole injection layer 311 and the electron transport layer 331, so that the problem of electric leakage caused by the contact between the hole injection layer 311 and the electron transport layer 331 can be avoided.

[0066] The present application provides a manufacturing method of a display panel 10, which comprises:

[0067] forming a first electrode layer 100 above a substrate 101;

[0068] forming a pixel definition layer 200 above the first electrode layer 100, the pixel definition layer 200 comprising a plurality of dams 201 and a plurality of pixel openings 202 formed by the dams 201;

[0069] forming a first functional layer 310 in the pixel opening 202 and above the first electrode layer 100, the first functional layer 310 comprising a first sub-portion 301 and a second sub-portion 302 connected between the first sub-portion 301 and the sidewall of the dam 201, the second sub-portion 302 being away from the substrate 101 by a distance less than or equal to the distance between the first sub-portion 301 and the substrate 101;

[0070] forming a light emitting layer 320 in the pixel opening 202 and above the first functional layer 310, the light emitting layer 320 covering the first functional layer 310; and

[0071] forming a second electrode layer 400 above the light emitting layer 320;

[0072] wherein the step of forming the first functional layer 310 in the pixel opening 202 and above the first electrode layer 100 comprises:

[0073] printing a first ink 501 in the pixel opening 202;

[0074] printing a first solvent 601 above the dam 201 and above the first ink 501 near the dam 201;

[0075] drying the first ink 501;

[0076] drying the first solvent 601 to form the first functional layer 310 in the pixel opening 202 and above the first electrode layer 100.

[0077] Further, the first solvent 601 is not soluble with the first ink 501, and the density of the first solvent 601 is greater than the density of the first ink 501, so that the first solvent 601 can float above the first ink 501.

[0078] Further, the boiling point of the first solvent 601 is higher than the boiling point of the first ink 501; the drying temperature of the first ink 501 is T1, and the drying temperature of the first solvent 601 is T2, where T2>T1. By making the boiling point of the first solvent 601 higher than the boiling point of the first ink 501, the first solvent 601 and the first ink 501 can be dried in stages. First, the first ink 501 is dried at a lower temperature T1, so that the solvent in the first ink 501 evaporates first, and the first solvent 601 does not evaporate at T1, which does not affect the first solvent 601. Then, the first solvent 601 is dried at a higher temperature T2, which further evaporates the first solvent 601 completely, and finally forms a flat first functional layer 310 in the pixel opening 202. By using different temperatures and drying in stages, the process is facilitated, which is conducive to controlling the flatness and stability of the first functional layer 310.

[0079] In this application, the above method can form the first functional layer 310 with a shape of high in the middle and low at the edges or a flat shape. The edges of the first functional layer 310 do not accumulate on the sidewalls of the dam 201 to form a climbing structure. The light-emitting layer 320 can better cover the edges of the first functional layer 310, so there is no problem of electrical leakage caused by the first functional layer 310 and the film layer above the light-emitting layer 320 being connected at a climbing point. Therefore, the performance of the display panel 10 can be effectively improved.

[0080] Please refer to Figure 5 , Figure 5 FIG. 2 is a schematic diagram of the state after printing the first ink 501 and the first solvent 601. The first ink 501 is printed into the corresponding pixel opening 202 by inkjet printing, and the first ink 501 can fill the corresponding pixel opening 202. The first solvent 601 is printed onto the dam 201 above the adjacent pixel openings 202 and above the side of the first ink 501 close to the dam 201 by inkjet printing. The first solvent 601 is located between the first ink 501 of adjacent pixels, and the edge of the first solvent 601 is in contact with the edge of the adjacent first ink 501.

[0081] Please refer to Figure 6 , Figure 6As shown in FIG. 6, a schematic diagram of a drying process of the first ink 501 is shown. During the drying process of the first ink 501, the volume of the first ink 501 in the pixel opening 202 is reduced due to the evaporation of the solvent in the first ink 501. The first solvent 601 above the dam 201 flows into the pixel openings 202 on both sides. Since the first solvent 601 is not soluble in the first ink 501 and the density of the first solvent 601 is greater than that of the first ink 501, the first solvent 601 floating on the first ink 501 exerts a force on the surface of the first ink 501. Due to the surface tension of the liquid, the surface of the first ink 501 is convex, i.e., the middle part is high and the edge is low. The first solvent 601 first gathers in the low-lying area between the first ink 501 and the dam 201, and then exerts a force on the edge of the first ink 501, thereby avoiding the accumulation of the first ink 501 on the edge during the drying process. During the continuous drying process of the first ink 501, the volume of the first ink 501 is gradually reduced, and the arc surface of the first ink 501 gradually tends to be flat. The first solvent 601 finally completely covers the surface of the first ink 501, and exerts a force on the entire surface of the first ink 501, so that the first ink 501 tends to be flat during the subsequent drying process. Therefore, the first functional layer 310 formed after the first ink 501 is dried has a shape of the middle part being high and the edge being low or a flat shape, and the edge does not climb.

[0082] Please refer to Figure 7 , Figure 7 As shown in FIG. 7, a schematic diagram of a state after the first solvent 601 is dried is shown. After the first solvent 601 is dried, the first solvent 601 is completely evaporated, and only the first functional layer 310 is left in the pixel opening 202. Since the first solvent 601 has no actual function, it can be removed by further drying. Therefore, the first solvent 601 does not affect the structure of the display panel 10.

[0083] In some embodiments, the first ink 501 can be water-soluble ink, and the first solvent 601 can be an oily solvent.

[0084] The first ink 501 can include a first functional material and a first ink 501 solvent. The first functional material includes at least one of a hole injection material and a hole transport material. The first ink 501 solvent includes at least one of water or a water-soluble solvent, and the boiling point of the first ink 501 solvent is lower than that of the first solvent 601.

[0085] The first ink 501 is selected to be water-soluble ink, and the first solvent 601 is selected to be oil-based solvent, so that the first solvent 601 and the first ink 501 are not soluble.

[0086] Further, the material of the pixel definition layer 200 can be hydrophobic and oleophilic material. When the first ink 501 is water-soluble ink and the first solvent 601 is oil-based solvent, the pixel definition layer 200 is hydrophobic and oleophilic material, which can avoid the formation of climbing structure on the sidewall of the dam 201 caused by ink accumulation, and is beneficial to the flow of the first solvent 601 into the pixel opening 202. Moreover, the dam 201 structure formed by the hydrophobic and oleophilic material can avoid the problem of color mixing of the first ink 501 of adjacent two pixel openings 202 on the top surface of the dam 201 during ink printing.

[0087] In some embodiments, the pixel definition layer 200 is made of fluorine-free material to avoid the risk of fluorine-containing resin ban in the later stage. The material of the pixel definition layer 200 can be at least one of modified polyimide (PI), modified polyacrylate (PAA), modified polystyrene (PS), siloxane polymer and amide polymer. The modified polyimide can be modified by silane, modified polymer and other additives to enhance its hydrophobicity. The modified polystyrene can be modified by grafting copolymerization of other monomers, introduction of functional groups (carboxyl, amino, etc.) and the like to enhance its hydrophobicity. The siloxane polymer can be, for example, epoxy siloxane. The amide polymer can be, for example, polybutylene terephthalate (PBAT), but is not limited thereto.

[0088] In some embodiments, the step of forming a light-emitting layer 320 in the pixel opening 202 and above the first functional layer 310 comprises:

[0089] printing a second ink in the pixel opening 202 and above the first functional layer 310;

[0090] printing a second solvent above the dam 201 and above the side of the second ink close to the dam 201;

[0091] drying the second ink;

[0092] The second solvent is dried to form a light-emitting layer 320 in the pixel opening 202 and above the first functional layer 310, the light-emitting layer 320 including a third sub-portion 321 and a fourth sub-portion 322 connected between the third sub-portion 321 and the sidewall of the pixel opening 202, the fourth sub-portion 322 being away from the substrate 101 by a distance less than or equal to the distance from the third sub-portion 321 to the substrate 101.

[0093] Further, the second solvent is not soluble with the second ink, and the density of the second solvent is greater than the density of the second ink.

[0094] Further, the boiling point of the second solvent is higher than the boiling point of the second ink, the drying temperature of the second ink is T3, and the drying temperature of the second solvent is T4, where T4>T3.

[0095] Further, the second ink is water-soluble ink, and the second solvent is an oily solvent. The second ink includes an organic light-emitting material and a second ink solvent, and the second ink solvent includes at least one of water or a water-soluble solvent. The boiling point of the second ink solvent is lower than the boiling point of the second solvent.

[0096] In the present embodiment, the above method can be used to form the light-emitting layer 320 with a high middle and low edge shape or a flat shape. The edge of the light-emitting layer 320 does not form a climbing structure, and the light-emitting layer 320 better covers the first functional layer 310, avoiding the edge of the first functional layer 310 contacting the film layer above the light-emitting layer 320 causing a leakage problem. The specific forming process and principle of the light-emitting layer 320 are similar to those of the first functional layer 310 described above, which will not be described here.

[0097] It should be noted that the colors of the light-emitting layers 320 located in different pixel openings can be the same or different, and the light-emitting layers 320 in different pixel openings can emit any one of red light, green light, or blue light.

[0098] In some embodiments, the first solvent 601 and the second solvent are the same or different in material. When the first solvent 601 and the second solvent are the same in material, the boiling points of the first solvent 601 and the second solvent are the same and greater than the boiling point of the one with a greater boiling point among the first ink 501 and the second ink. When the first solvent 601 and the second solvent are different in material, the boiling points of the first solvent 601 and the second solvent are different, the boiling point of the first solvent 601 is higher than the boiling point of the first ink 501, and the boiling point of the second solvent is higher than the boiling point of the second ink.

[0099] In the present application, one of the first electrode layer 100 and the second electrode layer 400 is an anode, and the other is a cathode. The first functional layer 310 includes at least one of a hole injection layer 311, a hole transport layer 312, an electron injection layer, and an electron transport layer 331. Taking the first electrode layer 100 as an anode and the second electrode layer 400 as a cathode as an example, the first functional layer 310 can be at least one of the hole injection layer 311 and the hole transport layer 312.

[0100] In some embodiments, the method further includes, before forming the second electrode layer 400 above the light-emitting layer 320:

[0101] forming a second functional layer 330 above the light-emitting layer 320;

[0102] wherein the second functional layer 330 includes at least one of an electron injection layer and an electron transport layer 331.

[0103] In the present embodiment, the second functional layer 330 can be formed by printing a third ink directly above the light-emitting layer 320 and drying, or by evaporation, without limitation. Since the first functional layer 310 and the light-emitting layer 320 are formed flat within the pixel opening 202, and the light-emitting layer 320 completely covers the edges of the first functional layer 310, the first functional layer 310 and the second functional layer 330 above the light-emitting layer 320 can be effectively prevented from contacting, and the problem of electrical leakage can be avoided. Therefore, the second functional layer 330 can no longer need a solvent such as the first solvent 601 or the second solvent to assist the third ink in forming the second functional layer 330, and the second functional layer 330 can be formed by conventional inkjet printing or evaporation, thereby simplifying the process. The third ink can include a second functional material and a third ink solvent. The second functional material includes at least one of an electron injection material and an electron transport material. The first ink 501 solvent includes at least one of water or a water-soluble solvent.

[0104] Of course, in other embodiments, the second functional layer 330 can also be formed by the same method as the first functional layer 310, and the manufacturing method and principle are the same as those of the first functional layer 310, which will not be described here.

[0105] Specifically, the manufacturing method of the display panel 10 includes the following steps:

[0106] S1, please refer to Figure 8 forming a first electrode layer 100 above the substrate 101.

[0107] Specifically, a first electrode material can be first deposited over the substrate 101 by a deposition process, and then patterned to form the first electrode layer 100.

[0108] The substrate 101 can be an array substrate including a substrate and a driving circuit layer over the substrate. The substrate can be a rigid substrate such as glass or a flexible substrate such as polyimide (PI). The driving circuit layer includes thin film transistors, signal lines, etc. The structure of the array substrate can refer to the prior art, which is not specifically limited here.

[0109] The first electrode layer 100 is an anode, and the material of the first electrode layer 100 includes at least one of a metal oxide such as indium tin oxide (ITO) or a metal such as Ag, Mg, Al, etc., but is not limited thereto.

[0110] S2, please refer to Figure 9 A pixel definition layer 200 is formed over the first electrode layer 100, the pixel definition layer 200 includes a plurality of dams 201 and a plurality of pixel openings 202 formed by the dams 201, and the pixel openings 202 expose at least part of the first electrode layer 100.

[0111] Specifically, a pixel definition layer 200 material can be first deposited over the substrate 101 and the first electrode layer 100 by a deposition process, and then patterned to form the pixel definition layer 200.

[0112] The material of the pixel definition layer 200 is a hydrophobic and oleophilic material, and the material of the pixel definition layer 200 does not contain fluorine. The material of the pixel definition layer 200 includes at least one of modified polyimide, modified polyacrylate, modified polystyrene, siloxane polymer and amide polymer.

[0113] S3, please refer to Figure 10 A hole injection layer 311 is formed in the pixel opening 202 and over the first electrode layer 100.

[0114] Step S3 specifically includes the steps of:

[0115] S31, printing a first ink a in the pixel opening 202, the first ink a including a hole injection material;

[0116] S32, printing a first solvent a over the dam 201 and over the first ink a close to the dam 201 side;

[0117] S33, drying the first ink a;

[0118] S34, drying the first solvent a to form the hole injection layer 311 in the pixel opening 202 and above the first electrode layer 100;

[0119] The first solvent a is insoluble with the first ink a, and the density of the first solvent a is greater than the density of the first ink a.

[0120] The first ink a is water-soluble ink, and the first solvent a is oily solvent.

[0121] The boiling point of the first solvent a is higher than the boiling point of the first ink a.

[0122] The drying temperature of the first ink a is T1a, and the drying temperature of the first solvent a is T2a, wherein T2a>T1a.

[0123] S4, please refer to Figure 11 The hole transport layer 312 is formed in the pixel opening 202 and above the hole injection layer 311.

[0124] The step S4 specifically includes the following steps:

[0125] S41, printing the first ink b in the pixel opening 202, the first ink b comprising hole transport material;

[0126] S42, printing the first solvent b above the dam 201 and above the side of the first ink b close to the dam 201;

[0127] S43, drying the first ink b;

[0128] S44, drying the first solvent b to form the hole transport layer 312 in the pixel opening 202 and above the hole injection layer 311;

[0129] The first solvent b is insoluble with the first ink b, and the density of the first solvent b is greater than the density of the first ink b.

[0130] The first ink b is water-soluble ink, and the first solvent b is oily solvent.

[0131] The boiling point of the first solvent b is higher than the boiling point of the first ink b.

[0132] The drying temperature of the first ink b is T1b, and the drying temperature of the first solvent b is T2b, wherein T2b>T1b.

[0133] S5, please refer to Figure 12A light emitting layer 320 is formed in the pixel opening 202 and above the hole transport layer 312.

[0134] Step S5 specifically includes steps of:

[0135] S51, printing a second ink in the pixel opening 202 and above the hole transport layer 312, the second ink including an organic light emitting material;

[0136] S52, printing a second solvent above the dam 201 and above the second ink close to the dam 201;

[0137] S53, drying the second ink;

[0138] S54, drying the second solvent, forming the light emitting layer 320 in the pixel opening 202 and above the hole transport layer 312;

[0139] The second solvent is not soluble with the second ink, and the density of the second solvent is greater than that of the second ink; the second ink is water-soluble ink, and the second solvent is oily solvent.

[0140] The boiling point of the second solvent is higher than that of the second ink; the temperature for drying the second ink is T3, and the temperature for drying the second solvent is T4, where T4>T3.

[0141] S6, please refer to Figure 13 An electron transport layer 331 is formed above the light emitting layer 320, covering the light emitting layer 320 and the pixel definition layer 200.

[0142] Specifically, a third ink is printed above the light emitting layer 320 and the pixel definition layer 200, and dried to form the electron transport layer 331, where the third ink includes an electron transport material.

[0143] S7, please refer to Figure 4 A second electrode layer 400 is formed above the electron transport layer 331, covering the electron transport layer 331.

[0144] The second electrode layer 400 is a cathode, and the material of the second electrode layer 400 includes metal, such as Al, Mg, etc., but is not limited thereto.

[0145] In the above steps S3, S4 and S5, the boiling points of the first solvent a, the first solvent b and the second solvent can be the same or different. When the boiling points of the first solvent a, the first solvent b and the second solvent are the same, the drying temperatures T2a, T2b and T4 can be the same, and can be specifically set according to the materials of the inks and the materials of the solvents.

[0146] Further, after forming the second electrode layer 400, the method further comprises:

[0147] A packaging layer is formed above the second electrode layer 400, covering the second electrode layer 400, the pixel definition layer 200 and the substrate 101, to protect the light-emitting device. The packaging layer can be manufactured by referring to the prior art, which is not limited in the present application.

[0148] In the present embodiment, since the hole injection layer 311, the hole transport layer 312 and the light-emitting layer 320 are all formed in the pixel opening 202 and have the shape of high in the middle and low at the edge or the shape of flat, the hole transport layer 312 and the light-emitting layer 320 completely cover the hole injection layer 311, avoiding the contact between the edge of the hole injection layer 311 and the electron transport layer 331, thereby avoiding the electric leakage problem caused by the lap joint of the pin climbing point.

[0149] In summary, the present application provides a display panel and a manufacturing method thereof. In the display panel of the present application, the first functional layer is formed by first printing the first ink into the pixel opening, second printing the first solvent above the dam, then drying the first ink, and drying the first solvent, to form the first functional layer having the shape of high in the middle and low at the edge or the shape of flat in the pixel opening. In the process of drying the first ink, the solvent in the first ink evaporates continuously, and the first solvent above the dam flows into the pixel openings on the two adjacent sides. The first solvent above the first ink exerts a force on the first ink, to avoid the formation of the climbing structure at the edge where the first functional layer contacts the sidewall of the dam. The light-emitting layer covers the first functional layer, so that the first functional layer is spaced apart from the film layer above the light-emitting layer, and thus the electric leakage problem caused by the lap joint of the pin climbing point does not occur.

[0150] In the description of the present application, the terms "first", "second" are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0151] In the above embodiments, the description of each embodiment is focused on, and the part not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0152] The embodiments, implementation manners and related technical features of the present application can be combined or replaced with each other without conflict.

[0153] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification made to the above embodiment without departing from the technical solution content of the present application and in accordance with the technical essence of the present application still belongs to the scope of the technical solution of the present application.

Claims

1. A method for manufacturing a display panel, characterized in that, include: A first electrode layer is formed on top of the substrate; A pixel definition layer is formed above the first electrode layer. The pixel definition layer includes multiple dams and multiple pixel openings enclosed by the dams. The material of the pixel definition layer is a hydrophobic and oleophilic material. Print the first ink within the pixel opening; The first solvent is printed above the dam and above the side of the first ink closest to the dam; The first ink is dried; The first solvent is dried to form a first functional layer within the pixel opening and above the first electrode layer. The first functional layer includes a first sub-part and a second sub-part connected between the first sub-part and the sidewall of the dam. The distance from the side of the second sub-part away from the substrate to the substrate is less than or equal to the distance from the side of the first sub-part away from the substrate to the substrate. The first solvent is immiscible with the first ink, and the density of the first solvent is greater than the density of the first ink. The boiling point of the first solvent is higher than the boiling point of the first ink. The drying temperature of the first ink is T1, and the drying temperature of the first solvent is T2, where T2 > T1. The first functional layer includes a hole injection layer and a hole transport layer, with the hole injection layer located between the first electrode layer and the hole transport layer. A light-emitting layer is formed within the pixel opening and above the first functional layer, the light-emitting layer covering the first functional layer; and A second electrode layer is formed above the light-emitting layer.

2. The method for manufacturing a display panel according to claim 1, characterized in that, The step of forming a light-emitting layer within the pixel opening and above the first functional layer includes: Print a second ink within the pixel opening and above the first functional layer; A second solvent is printed above the dam and above the side of the second ink closest to the dam; The second ink is dried; The second solvent is dried to form a light-emitting layer within the pixel opening and above the first functional layer. The light-emitting layer includes a third sub-part and a fourth sub-part connecting the third sub-part and the sidewall of the dam. The distance from the side of the fourth sub-part away from the substrate to the substrate is less than or equal to the distance from the side of the third sub-part away from the substrate to the substrate.

3. The method for manufacturing a display panel according to claim 2, characterized in that, The second solvent is immiscible with the second ink, and the density of the second solvent is greater than the density of the second ink, and the boiling point of the second solvent is higher than the boiling point of the second ink. The drying temperature for the second ink is T3, and the drying temperature for the second solvent is T4, wherein T4 > T3.

4. The method for manufacturing a display panel according to claim 2, characterized in that, The first ink and the second ink are water-soluble inks, and the first solvent and the second solvent are oil-based solvents.

5. A display panel manufactured by the method according to any one of claims 1 to 4, characterized in that, include: substrate; A first electrode layer is disposed above the substrate; A pixel definition layer is disposed above the first electrode layer, and the pixel definition layer includes a plurality of dams and a plurality of pixel openings formed by the dams; The pixel definition layer is made of a hydrophobic and oleophilic material; A first functional layer is disposed above the first electrode layer and located within the pixel opening; the first functional layer includes a hole injection layer and a hole transport layer, wherein the hole injection layer is located between the first electrode layer and the hole transport layer; A light-emitting layer is disposed above the first functional layer and located within the pixel opening, the light-emitting layer covering the first functional layer; as well as A second electrode layer is disposed above the light-emitting layer, and the second electrode layer covers the light-emitting layer and the pixel definition layer; Each of the first functional layers includes a first sub-part and a second sub-part connected between the first sub-part and the sidewall of the dam, wherein the distance from the side of the second sub-part away from the substrate to the substrate is less than or equal to the distance from the side of the first sub-part away from the substrate to the substrate.

6. The display panel according to claim 5, characterized in that, The light-emitting layer includes a third sub-part and a fourth sub-part connected between the third sub-part and the sidewall of the dam, wherein the distance from the side of the fourth sub-part away from the substrate to the substrate is less than or equal to the distance from the side of the third sub-part away from the substrate to the substrate.

7. The display panel according to claim 5, characterized in that, The display panel also includes: A second functional layer is disposed between the light-emitting layer and the second electrode layer, and the first functional layer and the second functional layer are disposed at an interval. The second functional layer includes at least one of an electron injection layer and an electron transport layer.

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