Display panel, manufacturing method thereof and display device

Abstract

The application discloses a display panel, a manufacturing method thereof and a display device. The display panel further comprises a overhanging structure, which is located in a non-opening area and arranged on a pixel definition layer. The light emitting unit comprises a bottom electrode, a light emitting functional layer and a top electrode. The bottom electrode is arranged on the substrate, the light emitting functional layer is arranged on the bottom electrode, and the top electrode is arranged on the light emitting functional layer. The overhanging structure is used to separate the bottom electrodes of two adjacent light emitting units when the bottom electrode is deposited in a whole surface. The overhanging structure comprises a conductive part and a separation part. The separation part is arranged on the separation part, and the radial width of the separation part is greater than the radial width of the conductive part. The application improves the light emitting efficiency of the light emitting unit and the quality of the display panel by arranging the overhanging structure to make the bottom electrode of the light emitting unit deposited in a whole surface.

Description

TECHNICAL FIELD

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

[0002] OLED (Organic Light Emitting Diode) display devices are widely used in various fields due to their lightness, wide viewing angle, fast response, low temperature resistance, high luminous efficiency, and the ability to prepare flexible display screens. As the mass production technology matures, OLED display panels have gradually become mainstream reality panels.

[0003] Existing organic light emitting display panels mainly include two types. One is a normal organic light emitting display panel, wherein the light emitting unit in the normal organic light emitting display panel includes an anode, a light emitting functional layer and a cathode which are sequentially stacked on a substrate. The other is an inverted organic light emitting display panel, which includes a cathode, a light emitting functional layer and an anode which are sequentially stacked on a substrate. In the normal organic light emitting display panel, the active metal in the cathode is easily eroded by water and oxygen, resulting in a decrease in the service life of the display panel. For the inverted organic light emitting display panel, the active metal in the cathode is also easily oxidized or has process residues during the process, resulting in low light emitting efficiency of the inverted organic light emitting display panel. Therefore, there is an urgent need in the art for a solution to the above problems. SUMMARY

[0004] The purpose of the present application is to provide a display panel, a manufacturing method thereof and a display device. By providing an overhanging structure, the bottom electrode in the light emitting unit is deposited by the overhanging structure, without the need for an etching step, thereby reducing the possibility of oxidation or process residues of the active metal in the bottom electrode during the process, improving the light emitting efficiency of the light emitting unit, and improving the quality of the display panel.

[0005] The present application discloses a display panel, which comprises a substrate, a pixel definition layer and a light emitting unit. The pixel definition layer is arranged on the substrate and is provided with a plurality of opening regions. The light emitting unit is arranged on the substrate and is located in the opening regions. The display panel further comprises an overhanging structure, which is located in a non-opening region and is arranged on the pixel definition layer. The light emitting unit comprises a bottom electrode, a light emitting functional layer and a top electrode. The bottom electrode is arranged on the substrate, the light emitting functional layer is arranged on the bottom electrode, and the top electrode is arranged on the light emitting functional layer. The overhanging structure is used to separate the bottom electrodes of two adjacent light emitting units when the bottom electrode is deposited by the whole surface. The overhanging structure comprises a conductive part and a separation part. The separation part is arranged on the conductive part, and the radial width of the separation part is greater than the radial width of the conductive part.

[0006] Optionally, the bottom electrode is a light-transmitting electrode, formed by one or both of magnesium material and silver material; the top electrode is formed by a reflective metal material, and the top electrode is shared by a plurality of the light-emitting units; and a light-emitting direction of the light-emitting unit is from the top electrode to the bottom electrode.

[0007] Optionally, the thickness of the bottom electrode is greater than or equal to 100 angstrom and less than or equal to 300 angstrom; and the overhanging structure is further used to separate the light-emitting functional layer of the adjacent two light-emitting units when the light-emitting functional layer is deposited on the whole surface.

[0008] Optionally, the top electrode is an anode, and the bottom electrode is a cathode; the light-emitting functional layer comprises an electron transport layer, a light-emitting layer and a hole transport layer, the electron transport layer is arranged on the cathode, the light-emitting layer is arranged on the electron transport layer, the hole transport layer is arranged on the light-emitting layer, and the anode is arranged on the hole transport layer.

[0009] Optionally, the display panel further comprises a cathode auxiliary electrode, the cathode auxiliary electrode is formed by a transparent metal oxide material, the cathode auxiliary electrode is arranged below the cathode and is electrically connected with the cathode; and the cathode auxiliary electrodes of the adjacent two light-emitting units are separated by the pixel definition layer.

[0010] Optionally, the conductive part is formed by a metal conductive material, the overhanging structure is further used to separate the anodes of the adjacent two light-emitting units when the anode is deposited on the whole surface, and the conductive part is used to connect the anodes of the adjacent two light-emitting units; the radial width of the separation part is less than the radial width of the pixel definition layer; the thickness of the conductive part is greater than or equal to 0.1 um and less than or equal to 1.5 um, and the thickness of the separation part is greater than or equal to 0.03 um and less than or equal to 0.2 um.

[0011] The application discloses a manufacturing method of a display panel, comprising the steps of:

[0012] providing a substrate;

[0013] forming a pixel definition layer on the substrate and patterning the pixel definition layer to form a plurality of opening regions;

[0014] forming an overhanging structure on the pixel definition layer;

[0015] depositing a bottom electrode material on the whole surface, and the overhanging structure is used to separate the bottom electrodes of the adjacent two light-emitting units;

[0016] forming a light-emitting functional layer and a top electrode in the opening regions in sequence to form a plurality of light-emitting units;

[0017] The overhanging structure comprises a conductive part and a partition part, the partition part is arranged on the conductive part, and the radial width of the partition part is greater than the radial width of the conductive part.

[0018] Optionally, the step of forming a pixel definition layer on the substrate and patterning the pixel definition layer to form a plurality of opening regions comprises:

[0019] Depositing a cathode auxiliary electrode material on the substrate, and patterning the cathode auxiliary electrode material to form a cathode auxiliary electrode in the opening region;

[0020] Depositing and patterning a pixel definition layer on the cathode auxiliary electrode, the cathode auxiliary electrodes of two adjacent light emitting units are separated by the pixel definition layer, and a plurality of opening regions are formed, and the cathode auxiliary electrode is exposed from the opening region.

[0021] Optionally, the step of sequentially forming a light emitting functional layer and a top electrode in the opening region to form a plurality of light emitting units comprises:

[0022] The light emitting functional layer material is deposited on the whole surface, and the light emitting functional layers of two adjacent light emitting units are separated by the overhanging structure;

[0023] The anode is deposited on the whole surface to form a plurality of light emitting units;

[0024] The top electrode is an anode, and the bottom electrode is a cathode; the light emitting functional layer comprises an electron transport layer, a light emitting layer and a hole transport layer, the electron transport layer is arranged on the cathode, the light emitting layer is arranged on the electron transport layer, the hole transport layer is arranged on the light emitting layer, and the anode is arranged on the hole transport layer;

[0025] The bottom electrode is formed of magnesium or silver material, and the bottom electrode is a light-transmitting electrode; the top electrode is formed of a reflective metal material, and the top electrode is shared by a plurality of light emitting units; the light emitting direction of the light emitting unit is from the top electrode to the bottom electrode.

[0026] The application further discloses a display device comprising a driving circuit and the display panel.

[0027] The application sets the overhanging structure, when forming the bottom electrode of the light emitting unit, the overhanging structure is used to separate the bottom electrodes of the multiple light emitting units, to form multiple independent and non-connected bottom electrodes. After the bottom electrode process is completed, etching process is not needed, and the light emitting functional layer can be directly formed on the bottom electrode, reducing the influence of etching process on the bottom electrode. Especially when the active metal material is included in the bottom electrode, the problem of oxidation of the active metal and residue in etching is avoided, the film layer interface between the bottom electrode and the light emitting functional layer is improved, the light emitting efficiency of the light emitting unit is improved, and the display effect of the display panel is improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings included are intended to provide a further understanding of the embodiments of the application, and constitute a part of the specification, to illustrate the embodiments of the application, and to explain the principles of the application together with the text description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor under the premise of the drawings. In the drawings:

[0029] Figure 1 is a top view of a display panel of the first embodiment of the application;

[0030] Figure 2 is Figure 1 is a cross-sectional view along the cutting line AA;

[0031] Figure 3 is a schematic view of an inverted organic light emitting display panel of the application;

[0032] Figure 4 is a cross-sectional view of a second display panel of the application;

[0033] Figure 5 is a step schematic view of a manufacturing method of a display panel of the application;

[0034] Figure 6 is a schematic view of a manufacturing process of a display panel of the application;

[0035] Figure 7 is a schematic view of a display device of the application.

[0036] Wherein, 100, display panel; 101, opening area; 102, non-opening area; 110, substrate substrate; 120, pixel definition layer; 130, light emitting unit; 131, anode; 132, light emitting functional layer; 1321, electron transport layer; 1322, light emitting layer; 1323, hole transport layer; 1324, electron injection layer; 1325, hole blocking layer; 1326, electron blocking layer; 1327, hole injection layer; 133, cathode; 134, cathode auxiliary electrode; 135, cathode redundancy; 140, overhanging structure; 141, conductive part; 142, partition; 150, drive circuit layer; 200, display device; 210, drive circuit. DETAILED DESCRIPTION

[0037] It should be understood that the terms used herein, the specific structure and functional details disclosed, are only for the purpose of describing specific embodiments, and are representative, but the application can be embodied in many alternative forms, and should not be interpreted as being limited to the embodiments described herein.

[0038] In the description of the present application, the terms "first", "second" are only for the purpose of description, and should not be understood as indicating relative importance, or implying the number of indicated technical features. Therefore, unless otherwise specified, the features limited by "first", "second" can explicitly or implicitly include one or more of the features; "multiple" means two or more. In addition, the terms indicating the orientation or positional relationship such as "up", "down", "left", "right", "vertical", "horizontal", etc. are described based on the orientation or relative positional relationship shown in the drawings, and are only for the purpose of facilitating the simplified description of the present application, and should not be understood as indicating that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be understood as limiting the present application. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] The present application will be described in detail below with reference to the accompanying drawings and optional embodiments.

[0040] Figure 1 is a top view schematic diagram of a display panel of the first embodiment of the present application, Figure 2 is Figure 1 is a schematic diagram of the cross section along the cutting line AA, see Figures 1-2As shown, the display panel 100 disclosed in the present application comprises a substrate 110, a pixel definition layer 120, a light emitting unit 130 and a overhang structure 140. The pixel definition layer 120 is arranged on the substrate 110 and is provided with a plurality of opening regions 101. The light emitting unit 130 is arranged on the substrate 110 and is located in the opening region 101. The overhang structure 140 is located in a non-opening region 102 and is arranged on the pixel definition layer 120. The light emitting unit 130 comprises a bottom electrode, a light emitting functional layer 132 and a top electrode. The bottom electrode is arranged on the substrate 110. The light emitting functional layer 132 is arranged on the bottom electrode. The top electrode is arranged on the light emitting functional layer 132. The overhang structure 140 is used to separate the bottom electrodes of two adjacent light emitting units 130 when the bottom electrode is deposited in a whole surface. The overhang structure 140 comprises a conductive part 141 and a separation part 142. The separation part 142 is arranged on the conductive part 141. The radial width of the separation part 142 is greater than the radial width of the conductive part 141.

[0041] The present application separates the bottom electrodes of a plurality of light emitting units 130 by the overhang structure 140 when the bottom electrode of the light emitting unit 130 is formed. The bottom electrodes are independent and not connected to each other. After the process of the bottom electrode is completed, the light emitting functional layer 132 can be directly formed on the bottom electrode without etching process, which reduces the influence of the etching process on the bottom electrode. Especially when the bottom electrode comprises active metal material, the problem of oxidation of the active metal and residue in the etching process is avoided, the film layer interface between the bottom electrode and the light emitting functional layer 132 is improved, the light emitting efficiency of the light emitting unit 130 is improved, and the display effect of the display panel 100 is improved.

[0042] Specifically, the display panel 100 of the present embodiment is a bottom light emitting display panel 100. The light emitted by the bottom light emitting display panel 100 is emitted from the top electrode to the bottom electrode. The bottom electrode is a light-transmitting electrode formed by magnesium or silver material. The top electrode is formed by reflective metal material. The top electrode is shared by a plurality of light emitting units 130. The light emitting direction of the light emitting unit 130 is from the top electrode to the bottom electrode.

[0043] Specifically, the top electrode of this application is a high-reflectivity opaque electrode, and the bottom electrode is a transparent electrode, enabling light to be emitted from the bottom, thus forming a bottom-emitting display panel 100. The advantage of the bottom-emitting display panel 100 is that the anode 131 does not need to be transparent. Therefore, the anode 131 can be made thick and formed on a single surface. This results in a smaller resistance drop at different locations compared to the single-surface cathode 133 formed with indium tin oxide in the top-emitting display panel 100, leading to more uniform resistance drops and avoiding voltage differences at different locations. Furthermore, after the light-emitting unit 130 completes its manufacturing process, the emitted light does not exit from the encapsulation layer above the light-emitting unit 130. Therefore, there is greater selectivity in the materials and processes of the encapsulation layer, allowing for better encapsulation of the light-emitting unit 130.

[0044] Figure 3 This is a schematic diagram of the inverted organic light-emitting display panel of this application, see [link / reference]. Figure 3 As shown, to further improve the luminous efficiency of the bottom-emitting display panel 100, this embodiment can invert the luminous functional layer 132. In this embodiment, the top electrode is the anode 131, the bottom electrode is the cathode 133, and the luminous functional layer 132 includes an electron transport layer 1321, a luminous layer 1322, and a hole transport layer 1323. The electron transport layer 1321 is disposed on the cathode 133, the luminous layer 1322 is disposed on the electron transport layer 1321, the hole transport layer 1323 is disposed on the luminous layer 1322, and the anode 131 is disposed on the hole transport layer 1323. The electron transport layer 1321 is disposed on the side closer to the cathode 133, and the hole transport layer 1323 is disposed on the side closer to the anode 131. This is completely opposite to the luminous functional layer 132 in the luminous unit 130 of the upright organic light-emitting display panel 100. In this embodiment, the electron transport layer 1321 is connected to the cathode 133 via the electron injection layer 1324, and a hole blocking layer 1325 is also disposed between the electron transport layer 1321 and the light-emitting layer 1322. The hole transport layer 1323 is connected to the anode 131 via the hole injection layer 1327, and an electron blocking layer 1321 is also disposed between the hole transport layer 1323 and the light-emitting layer 1322.

[0045] This application employs bottom-emitting technology in the inverted organic light-emitting display panel 100, that is, it uses a light-transmitting cathode 133 and an opaque anode 131 with strong reflective properties, so that light is emitted from the upper anode 131 toward the lower cathode 133, thus achieving bottom-emitting technology.

[0046] Generally speaking, for the inverted bottom light emitting display panel 100, if a higher light emitting efficiency is desired, the work function of the anode 131 is relatively high, and the work function of the cathode 133 is relatively low. When the anode 131 is selected as a reflective electrode and the cathode 133 is selected as a light-transmitting electrode, the work function of the anode 131 is reduced, and the work function of the cathode 133 is increased, which causes the light emitting efficiency of the inverted bottom light emitting display panel 100 to be relatively low.

[0047] Therefore, it is necessary to add a light-transmitting active metal in the cathode 133 to reduce the work function of the cathode 133. For example, the cathode 133 in the present embodiment can use a light-transmitting electrode formed by one or both of magnesium material and silver material as the cathode 133. An indium tin oxide (ITO) material or an indium zinc oxide (IZO) material with a relatively high work function is added in the anode 131, for example, a layer of ITO or IZO material is formed on the anode 131 to increase the work function of the anode 131.

[0048] In the case of adding an active metal in the cathode 133, two aspects need to be considered. The first aspect is to consider the light-transmitting property of the active metal. The transmittance of the metal is related to the crystal lattice structure of the metal. The crystal lattice structure refers to the arrangement of metal atoms in a specific pattern. When the crystal lattice structure of the metal is sufficiently dense and there is not enough space for photons to pass through, the metal will exhibit an opaque characteristic. However, if the thickness of the metal is reduced to a certain extent, photons can pass through the crystal lattice structure of the metal, making the metal light-transmitting. The other aspect is to consider the work function. When considering the light-transmitting property and setting the thickness, the work function also needs to be considered, and the thickness also affects the work function. Generally speaking, when the cathode 133 is formed by an active metal material, for example, magnesium or silver, the thickness of the cathode 133 needs to be smaller than the thickness of the reflective metal layer in the anode 131 to achieve a higher light emitting efficiency. However, when the active metal material used in the cathode 133 is relatively thin, for example, in the range of 100 angstroms to 300 angstroms, the deposition and etching steps in the process are prone to oxidation; in particular, in the etching process, there are also problems such as photoresist residue and etching, which affect the work function of the cathode 133, thereby causing the light emitting efficiency of the inverted bottom light emitting display panel 100 to be relatively low.

[0049] Further, when the thickness of the bottom electrode, i.e. the cathode 133, is greater than or equal to 100 angstrom and less than or equal to 300 angstrom, the cathode 133 can be separated into a plurality of independent and non-communicating cathodes 133 by the blocking effect of the overhang structure 140, so that the cathodes 133 of adjacent light emitting units 130 are completely separated. Even if a part of the cathode redundancy 135 is formed on the overhang structure 140, the part of the cathode redundancy 135 can also be disconnected from the cathode 133 to prevent the problem of current crosstalk. The cathode 133 formed of the active metal material in the embodiment can reduce the work function of the cathode 133 to improve the phenomenon that the hole injection and electron injection are not balanced in the inverted organic light emitting display panel 100, and solve the problem of low light emitting efficiency of the current inverted organic light emitting display panel 100.

[0050] Specifically, the anode 131 is formed by depositing a reflective metal material all over, and the plurality of light emitting units 130 share the anode 131. In order to match the work function of the cathode 133 and the light emitting functional layer 132, the anode 131 in the embodiment can first form a thin layer of indium tin oxide material with a thickness of about 0.01 mm to 0.1 mm by sputtering process, and then vacuum evaporate a reflective metal material with high reflectivity, which can be silver material in general, and the thickness of the reflective metal material of the anode 131 is much thicker than the active metal material in the cathode 133.

[0051] It is worth mentioning that the display panel 100 in the embodiment can also be a top light emitting display panel 100, i.e. the bottom electrode is formed of a light-proof high-reflective electrode, and the top electrode is formed of a light-transmitting electrode, for example, the bottom electrode is the anode 131, and the top electrode is the cathode 133. The bottom electrode is directly formed in a pattern by the overhang structure 140, and does not need to be formed before the pixel definition layer 120. That is, the scheme of forming the bottom electrode by the overhang structure 140 is also applicable to the top light emitting display panel 100, and also belongs to the protection scope of the present application.

[0052] Figure 4 is a cross-sectional schematic view of a second display panel of the present application, referring to Figure 4 Specifically, the inverted bottom light emitting display panel 100 in the embodiment further comprises a cathode auxiliary electrode 134 formed of a transparent metal oxide material, such as ITO material or IZO material. The cathode auxiliary electrode 134 is arranged below the cathode 133 and electrically connected with the cathode 133, and the cathode auxiliary electrodes 134 of adjacent two light emitting units 130 are separated by the pixel definition layer 120.

[0053] In order to further improve the light emitting efficiency of the inverted bottom light emitting unit 130, a cathode auxiliary electrode 134 is arranged below the cathode 133 in the embodiment. The transparent metal oxide material of the cathode auxiliary electrode 134 includes indium tin oxide material (ITO) or indium zinc oxide material (IZO) formed. The light transmittance of such material is greater than 90% of the metal material. The cathode auxiliary electrode 134 is connected to the pixel active switch in the driving circuit layer 150 through a via hole. It can be understood that the driving circuit layer 150 is also arranged on the substrate 110. The driving circuit layer 150 generally includes the pixel driving circuit of the light emitting unit 130, such as the pixel active switch, the data driving line, the scan control line, etc. The cathode 133 of each light emitting unit 130 is connected to the pixel active switch through the cathode auxiliary electrode 134, and the voltage of the cathode 133 is controlled through the pixel active switch.

[0054] Specifically, the cathode auxiliary electrodes 134 of two adjacent light emitting units 130 are separated by the pixel definition layer 120. Considering that the cathode auxiliary electrode 134 needs to be directly connected to the cathode 133 of each light emitting unit 130, the cathode auxiliary electrodes 134 of adjacent light emitting units 130 also need to be arranged at intervals to avoid electrical crosstalk problems.

[0055] Specifically, the overhanging structure 140 is also used to separate the light emitting functional layer 132 of two adjacent light emitting units 130 when the light emitting functional layer 132 is deposited on the whole surface.

[0056] In this application, after the evaporation of the cathode 133 is completed, the evaporation of the light emitting functional layer 132 can be continued in a vacuum environment, and the evaporation of the electron transport layer 1321, the light emitting layer 1322 and the hole transport layer 1323 is completed in turn, so that each opening area 101 forms the electron transport layer 1321, the light emitting layer 1322 and the hole transport layer 1323 which are not connected to each other.

[0057] Of course, in the embodiment, the material of the light emitting functional layer 132 is not completely the same when there are different colors of light emitting functional layers 132. Therefore, mask evaporation can also be used so that different opening areas 101 can form different light emitting functional layers 132.

[0058] Specifically, the overhanging structure 140 is further improved in the embodiment, which includes that the conductive part 141 is formed by metal conductive material, and the overhanging structure 140 is also used to separate the anode 131 of two adjacent light emitting units 130 when the anode 131 is deposited on the whole surface. The conductive part 141 is used to connect the anodes 131 of two adjacent light emitting units 130.

[0059] In the embodiment, when the anode 131 layer is thin and cannot cover the overhanging structure 140 during the formation of the anode 131, the anode 131 material will also be blocked by the overhanging structure 140 in each opening area 101, that is, a plurality of independent and non-connected anodes 131 are formed. However, under the driving of the light emitting unit 130 in the embodiment, different driving voltages do not need to be set for the anodes 131 of the plurality of light emitting units 130. Therefore, the anodes 131 of the plurality of light emitting units 130 are directly connected through the conductive part 141, so that the anode 131 forms a full-area electrode, and the same driving voltage is used to drive the light emitting unit 130, and different driving voltages are provided at the cathode 133 end to realize different display effects of different light emitting units 130.

[0060] Specifically, the thickness of the conductive part 141 is greater than or equal to 0.1 um and less than or equal to 1.5 um, and the thickness of the blocking part 142 is greater than or equal to 0.03 um and less than or equal to 0.2 um.

[0061] When the thickness of the conductive part 141 is thin, the conductive part 141 cannot block the cathode 133; and when the thickness of the conductive part 141 is thick, on the one hand, the conductive part 141 is prone to falling off, and on the other hand, the conductive part 141 is not easy to etch. Therefore, in the embodiment, the thickness of the conductive part 141 is greater than or equal to 0.1 um and less than or equal to 1.5 um. The material of the conductive part 141 can be aluminum, molybdenum, and silver material or alloy material of the above-mentioned metals, and the blocking part 142 is insulating material or metal material, the insulating material includes silicon oxide, silicon nitride, and silicon oxynitride, and the metal material includes titanium and metal oxide material (ITO or IZO). The thickness is generally between 0.03 um and 0.2 um.

[0062] Specifically, in the process of the overhanging structure 140, the conductive part material and the blocking part material are deposited on the whole surface in sequence. First, the blocking part material is etched away by a dry etching process, and the remaining part of the blocking part material on the pixel definition layer 120 forms the blocking part. Then, the conductive part is etched by a wet etching process using the blocking part as a protective layer. Since the wet etching process is isotropic, the lower part of the conductive part 141 will be side-etched, so that the width of the conductive part 141 is smaller than the width of the blocking part 142. This structure is also called a roof structure.

[0063] The radial width of the blocking part 142 is smaller than the radial width of the pixel definition layer 120, and the width between the blocking part 142 and the conductive part 141 needs to be adjusted according to the evaporation angle and the thickness of each film layer.

[0064] It is worth mentioning that when considering the use of metal conductive material for the conductive part 141, it is also necessary to consider that the cathode 133 and the light emitting functional layer 132 cannot be in contact with the conductive part 141 to prevent the problem of electrical interference. In practice, the evaporation angle of the above-mentioned material during evaporation can be changed so that during evaporation, especially the cathode 133 and the light emitting functional layer 132 will not contact the conductive part 141. When evaporating the anode 131, the evaporation angle of the anode 131 can be increased so that the anode 131 is connected to the conductive part 141 and conducts electricity. For the anode 131, the thickness of the anode 131 can also be increased to exceed the height of the overhanging structure 140, so as to completely cover the overhanging structure 140, thereby forming a whole anode 131. Of course, in addition to the above-mentioned method of changing the evaporation angle, the width difference between the conductive part 141 and the partition part 142 can also be increased so that the cathode 133 and the light emitting functional layer 132 are not connected to the conductive part 141.

[0065] In another embodiment, in order to prevent the conductive part 141 in the overhanging structure 140 from contacting the cathode 133 or the light emitting functional layer 132, the embodiment can also use an insulating material to replace the conductive part, so that the overhanging structure is more insulating.

[0066] Figure 5 is a schematic diagram of the manufacturing method of the display panel of the present application, Figure 6 is a schematic diagram of the manufacturing process of the display panel of the present application, as shown in Figures 5-6 The present application also discloses a manufacturing method of a display panel, comprising the steps of:

[0067] S110: providing a substrate;

[0068] S120: forming a pixel definition layer on the substrate and patterning the pixel definition layer to form a plurality of opening regions;

[0069] S130: forming an overhanging structure on the pixel definition layer;

[0070] S140: depositing a bottom electrode material on the whole surface, and the overhanging structure is used to separate the bottom electrodes of two adjacent light emitting units;

[0071] S150: sequentially forming a light emitting functional layer and a top electrode in the opening regions to form a plurality of light emitting units.

[0072] The overhanging structure 140 comprises a conductive part 141 and a partition part 142, the partition part 142 is arranged on the conductive part 141, and the radial width of the partition part 142 is greater than the radial width of the conductive part 141.

[0073] Before S120, further comprising: forming a driving circuit layer on the substrate, the driving circuit layer comprising a plurality of thin film transistors and driving lines, the thin film transistors and the driving lines forming a driving circuit for driving the plurality of light emitting units to emit light.

[0074] In the embodiment, the overhanging structure 140 is arranged to separate the bottom electrodes between the plurality of light emitting units 130 when forming the bottom electrodes of the light emitting units 130, so that the bottom electrodes are formed independently and are not connected to each other. After the process of forming the bottom electrodes is completed, the light emitting functional layer 132 can be formed directly on the bottom electrodes without using etching process, so that the influence of etching process on the bottom electrodes is reduced. In particular, when the bottom electrodes comprise active metal material, the problems of oxidation of the active metal and residue in etching are avoided, the interface between the bottom electrodes and the light emitting functional layer 132 is improved, the light emitting efficiency of the light emitting units 130 is improved, and the display effect of the display panel 100 is improved.

[0075] Specifically, the bottom electrode in the embodiment is a cathode 133, and is a light-transmitting electrode. The top electrode is an anode 131, and is a high-reflectivity light-non-transmitting electrode. The light emitting functional layer 132 comprises an electron transport layer 1321, a light emitting layer 1322 and a hole transport layer 1323, the electron transport layer 1321 is arranged on the cathode 133, the light emitting layer 1322 is arranged on the electron transport layer 1321, the hole transport layer 1323 is arranged on the light emitting layer 1322, and the anode 131 is arranged on the hole transport layer 1323. The electron transport layer 1321 is arranged on the side close to the cathode 133, and the hole transport layer 1323 is arranged on the side close to the anode 131. The display panel 100 of the present application is an inverted bottom-emitting display panel 100. The bottom electrode is formed by using magnesium or silver material, and the bottom electrode is a light-transmitting electrode. The top electrode is formed by using reflective metal material, and the top electrode is shared by the plurality of light emitting units 130. The light emitting direction of the light emitting units 130 is from the top electrode to the bottom electrode.

[0076] The present application avoids the problems of oxidation of the active metal material in the cathode 133 in the subsequent etching process of the cathode 133 pattern, and also avoids the influence of residue of etching material in the etching process. It is worth mentioning that the cathode 133 is formed by using the overhanging structure 140 in the present application, so that the active metal can be used as the cathode 133, which can avoid the oxidation of the active metal in the cathode 133, and can also reduce the work function of the cathode 133 to improve the imbalance between hole injection and electron injection in the inverted organic light emitting display panel 100, so that the problem of low light emitting efficiency of the inverted organic light emitting display panel 100 is solved.

[0077] In the step of S120, the step of:

[0078] S121: depositing a cathode auxiliary electrode material on the substrate, and patterning to form a cathode auxiliary electrode in the opening region;

[0079] S122: depositing and patterning a pixel definition layer on the cathode auxiliary electrode, the cathode auxiliary electrodes of two adjacent light emitting units are separated by the pixel definition layer, and a plurality of opening regions are formed, and the cathode auxiliary electrode is exposed from the opening region.

[0080] In this embodiment, after the process of the driving circuit layer 150 is completed, the cathode auxiliary electrode 134 is formed on the driving circuit layer 150, and at the via position of the driving circuit layer 150, the cathode auxiliary electrode 134 in each opening region 101 is connected to the output end of a thin film transistor, so as to realize the driving voltage of the cathode 133 controlled by the thin film transistor.

[0081] In the step of S130, the step of:

[0082] S131: sequentially depositing a whole surface of a conductive part material and a partition part material;

[0083] S132: removing the partition part material in the opening region by a patterning process, and forming a partition part in the non-opening region;

[0084] S133: taking the partition part as a protection layer, etching the conductive part, so that the width of the conductive part is smaller than the width of the partition part to form a overhanging structure.

[0085] Sequentially depositing a whole surface of a conductive part material and a partition part material, taking the partition part as a protection layer, and etching the conductive part by a wet etching process. Since the wet etching process is isotropic, the lower part of the conductive part 141 will be side etched, so that the width of the conductive part 141 is smaller than the width of the partition part 142. The etching of the partition part material can be selected as a dry etching process.

[0086] In the step of S150, the step of:

[0087] S151: depositing the light emitting functional layer material on the whole surface, and separating the light emitting functional layers of two adjacent light emitting units by the overhanging structure;

[0088] S152: depositing the anode on the whole surface to form a plurality of light emitting units.

[0089] In the present solution, the light emitting functional layer 132 of the two adjacent light emitting units 130 is separated by the overhanging structure 140, so that the light emitting functional layer 132 of the adjacent light emitting units 130 is not directly connected, and the separation of the light emitting functional layer 132 material is realized by the thickness of the separation part 142 and the conductive part 141 of the overhanging structure 140. Specifically, the light emitting functional layer 132 can be selectively separated by changing the thickness of the separation part 142 and the conductive part 141, for example, to one of the electron transport layer 1321, the light emitting layer 1322, and the hole transport layer 1323.

[0090] It is worth mentioning that another important factor is that the greater the thickness of the conductive part 141, the stronger the separation ability of the overhanging structure 140, which leads to the separation of the anode 131 when the anode 131 is formed. Therefore, the thickness of the conductive part 141 is greater than or equal to 0.1 um and less than or equal to 1.5 um, and the thickness of the separation part 142 is greater than or equal to 0.03 um and less than or equal to 0.2 um.

[0091] Of course, in order to make the overhanging structure 140 have good separation effect, the subsequent anode 131 can be connected by the conductive part 141 in the overhanging structure 140 even if it is separated by the overhanging structure 140. The conductive part 141 can be formed of a metal material, and the separation part 142 can be formed of an insulating material. When the anode 131 is separated by the overhanging structure 140, the anode 131 is directly lapped on the conductive part 141 by adjusting the evaporation angle of the anode 131, and the conductive part 141 is connected to form a whole anode 131.

[0092] Figure 7 is a schematic view of the display device of the present application, referring to Figure 7 The display device 200 disclosed by the present application comprises a driving circuit 210 and the display panel 100 of any one of the above embodiments, wherein the driving circuit 210 is used to drive the display panel 100 to display.

[0093] It should be noted that the inventive concept of the present application can form a very large number of embodiments, but the length of the application file is limited and cannot be listed one by one, so that the above described embodiments or technical features can be combined to form new embodiments without conflict. The combination of each embodiment or technical feature will enhance the original technical effect.

[0094] The above are further detailed descriptions of the present application in connection with specific optional embodiments. The present application is not limited to these descriptions. For ordinary skilled people in the art, some simple deductions or replacements made without departing from the spirit of the present application should be considered as falling within the scope of protection of the present application.

Claims

1. A method for manufacturing a display panel, characterized in that, The method comprises the steps of: providing a substrate; forming a pixel definition layer on the substrate and patterning the pixel definition layer to form a plurality of opening regions; forming a overhang structure on the pixel definition layer; depositing a bottom electrode material on the entire surface, the overhang structure being used to separate the bottom electrodes of adjacent two light emitting units; forming a light emitting functional layer and a top electrode in the opening regions in sequence to form a plurality of light emitting units; wherein the overhang structure comprises a conductive part and a separation part, the separation part being arranged on the conductive part, and the radial width of the separation part is greater than the radial width of the conductive part; the step of forming a pixel definition layer on the substrate and patterning the pixel definition layer to form a plurality of opening regions comprises: depositing a cathode auxiliary electrode material on the substrate, and patterning the cathode auxiliary electrode material to form a cathode auxiliary electrode in the opening regions; depositing and patterning a pixel definition layer on the cathode auxiliary electrode, the cathode auxiliary electrodes of adjacent two light emitting units being separated by the pixel definition layer, and a plurality of opening regions are formed, the cathode auxiliary electrodes being exposed from the opening regions; the step of forming a light emitting functional layer and a top electrode in the opening regions in sequence to form a plurality of light emitting units comprises: depositing the light emitting functional layer material on the entire surface, and separating the light emitting functional layers of adjacent two light emitting units by the overhang structure; depositing the top electrode on the entire surface to form a plurality of light emitting units; wherein the top electrode is an anode, the bottom electrode is a cathode, the light emitting functional layer comprises an electron transport layer, a light emitting layer and a hole transport layer, the electron transport layer is arranged on the cathode, the light emitting layer is arranged on the electron transport layer, the hole transport layer is arranged on the light emitting layer, and the anode is arranged on the hole transport layer; the light emitted by the light emitting unit is emitted from one side of the substrate.

2. The method according to claim 1, wherein: the cathode is formed by one or both of magnesium material and silver material, the cathode is a light-transmitting electrode, the anode is formed by a reflective metal material, and a plurality of light emitting units share the anode.

3. The manufacturing method of a display panel according to claim 1, wherein The thickness of the bottom electrode is greater than or equal to 100 angstrom and less than or equal to 300 angstrom.

4. The manufacturing method of a display panel according to claim 1, wherein The display panel further comprises a cathode auxiliary electrode, the cathode auxiliary electrode is formed by a transparent metal oxide material, the cathode auxiliary electrode is arranged below the cathode and is electrically connected to the cathode.

5. The method of manufacturing a display panel according to claim 1, wherein The conductive part is formed by a metal conductive material, the overhang structure is also used to separate the anodes of adjacent two light emitting units when the anode is deposited on the entire surface, and the conductive part is used to connect the anodes of adjacent two light emitting units. The radial width of the separation part is less than the radial width of the pixel definition layer. The thickness of the conductive part is greater than or equal to 0.1 um and less than or equal to 1.5 um, the thickness of the separation part is greater than or equal to 0.03 um and less than or equal to 0.2 um.

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