A display panel and a manufacturing method thereof

Abstract

The present application provides a display panel and a manufacturing method thereof, the display panel comprising: a substrate; a plurality of sub-pixels, arranged on the substrate; a pixel defining layer, arranged on the substrate, the pixel defining layer being used to define the positions of the plurality of sub-pixels; an isolation structure, arranged on the pixel defining layer, the isolation structure being used to isolate the plurality of sub-pixels, the isolation structure comprising a first conductive layer, a first insulating layer, a second conductive layer and a second insulating layer stacked in sequence, the cathode layers of two adjacent sub-pixels being connected via the first conductive layer, the first insulating layer being provided with a via hole, the first conductive layer and the second conductive layer being connected via the via hole; a cathode auxiliary layer, arranged on the isolation structure, the cathode auxiliary layer being connected to the second conductive layer. Through the above method, the uniformity of the entire cathode is improved, the cathode area is increased, and the IR Drop caused by the large cathode resistance is reduced, thereby improving the phenomenon of uneven display brightness.

Description

Technical Field

[0001] The present application mainly relates to the field of display technology, and in particular to a display panel and a manufacturing method thereof. Background Art

[0002] OLED (Organic Light-Emitting Diode), or organic light-emitting diode, uses the self-luminous principle of using ITO transparent electrode and metal electrode as the anode and cathode of the device respectively. Under a certain voltage drive, electrons and holes move from the cathode and anode respectively to the organic light-emitting layer and then recombine to emit visible light. It is widely used in various fields because of its advantages such as no need for backlight, large viewing angle, richer colors, and significant energy saving.

[0003] Among the related technologies, in order to achieve high resolution and colorization of passive matrix OLEDs and better solve the problems of low cathode template resolution and low device yield, a cathode isolation column structure was introduced in actual research and the FMM (Fine Metal Mask) process was used for deposition. That is, a metal template is not used in device preparation. Instead, an insulating partition wall is made on the substrate before evaporating the organic film and the metal cathode, ultimately separating the different pixels of the device and realizing a pixel array.

[0004] The above method will result in poor uniformity of the entire cathode surface, resulting in significant IR Drop (resistance drop), and the appearance of uneven brightness. Summary of the invention

[0005] The main purpose of this application is to propose a display panel and a method for manufacturing the same, which can form an auxiliary cathode on top of the cathode in the panel and connect the cathode to the auxiliary cathode, thereby increasing the cathode area and improving the uniformity of the entire cathode, reducing IRDrop, and improving the problem of uneven display brightness.

[0006] To solve the above problems, the present application provides a display panel, which includes the following structure: a substrate; a plurality of sub-pixels, which are arranged on the substrate; a pixel defining layer, which is arranged on the substrate, and the pixel defining layer is used to define the positions of the plurality of sub-pixels; an isolation structure, which is arranged on the pixel defining layer, and the isolation structure is used to isolate the plurality of sub-pixels, and the isolation structure includes a first conductive layer, a first insulating layer, a second conductive layer and a second insulating layer stacked in sequence, the cathode layers of two adjacent sub-pixels are connected through the first conductive layer, the first insulating layer is provided with a via hole, and the first conductive layer and the second conductive layer are connected through the via hole; a cathode auxiliary layer, which is arranged on the isolation structure, and the cathode auxiliary layer is connected to the second conductive layer.

[0007] In one embodiment, the first insulating layer includes a main body and a top portion disposed on the main body, wherein the top portion extends out of the upper surface of the main body to form a first overhang portion; the second insulating layer extends out of the upper surface of the second conductive layer to form a second overhang portion.

[0008] In one embodiment, the via hole passes through the main body and the top.

[0009] In one embodiment, the cathode auxiliary layer covers the upper surface, side surfaces and lower surface of the second overhang portion, the side surfaces of the second conductive layer, and the upper surface and side surfaces of the first overhang portion.

[0010] In one embodiment, an organic layer is further disposed on the side surface of the first overhanging portion, and the cathode auxiliary layer covers the organic layer.

[0011] In one embodiment, the sub-pixel includes an anode layer, a light-emitting layer and a cathode layer stacked in sequence, the light-emitting layer overlaps the upper surface of the pixel defining layer, and the cathode layer extends between the light-emitting layer and the first conductive layer and contacts the upper surface of the pixel defining layer.

[0012] In one embodiment, the display panel also includes: a protective layer, which covers the cathode layer, the first conductive layer, the first insulating layer, and the cathode auxiliary layer; a first encapsulation layer, which covers the protective layer and the second insulating layer, and the upper surface of the first encapsulation layer is a flat structure; and a second encapsulation layer, which is arranged on the first encapsulation layer.

[0013] To solve the above problems, the present application also provides a method for manufacturing a display panel, the steps of which include: providing a substrate; forming an anode layer and a pixel defining layer on the substrate; sequentially forming a first conductive layer, a first insulating layer, a second conductive layer and a second insulating layer on the pixel defining layer, the first insulating layer being provided with a via hole, and the first conductive layer and the second conductive layer being connected through the via hole; sequentially forming a light-emitting layer and a cathode layer on the anode layer, and forming a cathode auxiliary layer on the isolation structure, the cathode auxiliary layer being connected to the second conductive layer, the anode layer, the light-emitting layer and the cathode layer forming sub-pixels, and the cathode layers of two adjacent sub-pixels being connected through the first conductive layer.

[0014] In one embodiment, a first conductive layer, a first insulating layer, a second conductive layer and a second insulating layer are sequentially formed on a pixel defining layer, including: a first conductive layer and a first insulating layer are sequentially formed on the pixel defining layer, the first insulating layer comprising a main body and a top portion arranged on the main body, the top portion extending out of an upper surface of the main body to form a first overhang; a via hole penetrating the main body and the top portion is formed on the first insulating layer; a second conductive layer is formed on the first insulating layer, the second conductive layer is connected to the first conductive layer through the via hole; a second insulating layer is formed on the second conductive layer, the second insulating layer extends out of an upper surface of the second conductive layer to form a second overhang.

[0015] In one embodiment, a light-emitting layer and a cathode layer are sequentially formed on the anode layer, and a cathode auxiliary layer is formed on the isolation structure, including: forming a light-emitting layer on the anode layer, and forming an organic layer on the side of the first overhang; forming a cathode layer on the light-emitting layer, and forming a cathode auxiliary layer on the upper surface, side and lower surface of the second overhang, the side of the second conductive layer, and the upper surface and side of the first overhang.

[0016] By using the above display panel and the display panel manufactured using the above manufacturing method, a double suspension structure is added to the suspension structure base, so that the cathode forms an auxiliary cathode on the top suspension structure, so that the bottom cathode and the auxiliary cathode are connected through a metal column, thereby improving the uniformity of the entire cathode, increasing the area of ​​the cathode and thereby reducing the cathode resistance, thereby weakening the IR Drop caused by the large cathode resistance, so as to improve the phenomenon of uneven display brightness. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0018] Figure 1 is a structural schematic diagram of an embodiment of a display panel provided by the present application;

[0019] Figure 2 is a schematic diagram of an intermediate structure of an embodiment of a display panel provided by the present application;

[0020] Figure 3 It is a top view of the positions of the anode, cathode, and auxiliary cathode of the back plate;

[0021] Figure 4 It is a flow chart of an embodiment of a method for manufacturing a display panel provided by the present application;

[0022] Figure 5 yes Figure 4 Schematic diagram of the sub-step flow chart of step S14;

[0023] Figure 6 yes Figure 4 Schematic diagram of the sub-step flow chart of step S16;

[0024] Figure 7a to Figure 7k yes Figure 4 A schematic diagram of the structure corresponding to each step in the display panel manufacturing method provided in;

[0025] Figure 8 It is a structural schematic diagram of an embodiment of a display device provided in the present application.

[0026] Figure numerals: 100, display panel; 10, substrate; 20, sub-pixel; 21, anode layer; 22, light-emitting layer; 23, cathode layer; 30, pixel defining layer; 40, isolation structure; 41, first conductive layer; 42, first insulating layer; 421, main body; 422, top; 43, second conductive layer; 44, second insulating layer; 50, cathode auxiliary layer; 60, protective layer; 70, first encapsulation layer; 80, second encapsulation layer; a, first overhang; b, second overhang; c, organic layer; A, via; 1, anode region; 2, cathode region; 3, auxiliary cathode region; 200, display device. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It will be appreciated that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some but not all structures related to the present application are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present application.

[0028] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] At present, in order to better solve the problems of low cathode template resolution and low device yield, a cathode isolation column structure is introduced in actual research to isolate different pixels, so as to solve problems such as short circuit of the organic light-emitting layer between adjacent pixels. In actual design, the opening spacing between pixels is small and the width of the overhang is limited. Therefore, the width of the conductive oxide column is small and the contact resistance is large, resulting in poor uniformity of the entire cathode surface. The resulting IR Drop is obvious, and the display has problems such as uneven brightness.

[0031] See also Figure 1 and Figure 2 , Figure 1 It is a schematic structural diagram of an embodiment of a display panel provided in the present application. Figure 2 1 is a schematic diagram of an intermediate structure of an embodiment of a display panel provided by the present application. The display panel comprises: a substrate 10 , a sub-pixel 20 , a pixel defining layer 30 , an isolation structure 40 , and a cathode auxiliary layer 50 .

[0032] Specifically, a plurality of sub-pixels 20 are arranged on a substrate 10, and the sub-pixels 20 include an anode layer 21, a light-emitting layer 22 and a cathode layer 23 stacked in sequence; a pixel defining layer 30 is arranged on the substrate 10, and the pixel defining layer 30 is used to define the positions of the plurality of sub-pixels 20; an isolation structure 40 is arranged on the pixel defining layer, and the isolation structure 40 is used to isolate the plurality of sub-pixels 20, and the isolation structure 40 includes a first conductive layer 41, a first insulating layer 42, a second conductive layer 43 and a second insulating layer 44 stacked in sequence, and the cathode layers 23 of two adjacent sub-pixels 20 are connected through the first conductive layer 41, and a via A is provided on the first insulating layer 42, and the first conductive layer 41 and the second conductive layer 43 are connected through the via; a cathode auxiliary layer 50 is arranged on the isolation structure 40, and the cathode auxiliary layer 50 is connected to the second conductive layer 43.

[0033] The first conductive layer 41 and the second conductive layer 43 may be made of metal oxide, transition metal oxide or other conductive materials; specifically, the materials of the first conductive layer 41 and the second conductive layer 43 may be the same or different, depending on the actual situation.

[0034] Optionally, in one embodiment, the first insulating layer 42 includes a main body 421 and a top 422 disposed on the main body 421, the top 422 extending out of the upper surface of the main body 421 to form a first overhang a; the second insulating layer 44 extends out of the upper surface of the second conductive layer 43 to form a second overhang b. The main body 421 and the top 422 of the first insulating layer 42 are respectively made of silicon monoxide (SiO), silicon dioxide (SiO2), silicon nitride (SiNx), silicon oxynitride (SiNO) and other materials, and the inverted trapezoidal mushroom shape is formed by using different etching rates of different materials. In one embodiment, the first insulating layer 42 adopts a double-layer structure of silicon monoxide (SiO) and silicon nitride (SiNx) to form a first overhang a above the first conductive layer 41 to constitute a first inverted trapezoidal mushroom-shaped structure; the second insulating layer 44 adopts an inorganic SiNx material to form a second overhang b above the second conductive layer 43 to constitute a second inverted trapezoidal mushroom-shaped structure, and the first inverted trapezoidal structure and the second inverted trapezoidal structure together constitute a double overhang structure.

[0035] Optionally, in one embodiment, the lengths of the first overhang a and the second overhang b are equal, and in another embodiment, the length of the first overhang a is smaller than the length of the second overhang b. By constructing the first overhang a and the second overhang b, the isolation structure 40 presents a mushroom body structure to solve the problem of short circuit of the organic light-emitting layer between adjacent pixels.

[0036] Optionally, in one embodiment, via A passes through the main body 421 and the top 422, and the first insulating layer 42 is etched and punched to achieve subsequent connection of the bottom first conductive layer 41 and the top second conductive layer 43 through via A, and the second conductive layer 43 is connected to the cathode auxiliary layer 50, and the first conductive layer 41 is connected to the cathode layer 23, thereby achieving connection and conduction among the four and forming cathode conduction on the entire surface.

[0037] Optionally, in one embodiment, the cathode auxiliary layer 50 covers the upper surface, side surfaces and lower surface of the second overhang portion b, the side surfaces of the second conductive layer 43 , and the upper surface and side surfaces of the first overhang portion a.

[0038] Optionally, in one embodiment, an organic layer c is further disposed on the side surface of the first overhanging portion a, and the cathode auxiliary layer 50 covers the organic layer c.

[0039] In the process of evaporation deposition, due to the existence of the extended overhanging portion in the isolation structure 40, the cathode layer 23 and the light-emitting layer 22 will be broken at the extended overhanging portion during the formation process, so as to form the cathode auxiliary layer 50 and the organic layer c on the overhanging portion. Specifically, in one embodiment, by changing the evaporation deposition angle of the cathode layer 23 and the light-emitting layer 22, the cathode auxiliary layer 50 and the organic layer c are formed, wherein the organic layer c covers the upper surface and part of the side of the first overhanging portion a in the first insulating layer 42; the cathode auxiliary layer 50 covers the upper surface and side of the first overhanging portion a in the first insulating layer 42 and the upper surface and side of the second overhanging portion b in the second insulating layer 44, covers the surface of the organic layer c, and deposits and covers the side of the second conductive layer 43, contacts and connects with the second conductive layer 43, and realizes the conduction between the cathode auxiliary layer 50 and the second conductive layer 43.

[0040] Optionally, in one embodiment, the sub-pixel 20 includes an anode layer 21, a light-emitting layer 22, and a cathode layer 23 stacked in sequence, the light-emitting layer 22 overlaps the upper surface of the pixel-defining layer 30, and the cathode layer 23 extends between the light-emitting layer 22 and the first conductive layer 41 and contacts the upper surface of the pixel-defining layer 30. Due to the first overhang a and the second overhang b, during the deposition of the cathode layer 23 and the light-emitting layer 22, the cathode layer 23 covers the upper surface and side surface of the light-emitting layer 22 and contacts the first conductive layer 41, thereby achieving conduction between the cathode layer 23 and the first conductive layer 41, and the light-emitting layer 22 is separated from the first conductive layer 41 by the cathode layer 23, preventing the light-emitting layer 22 from being conductive to the first conductive layer 41, so as to prevent the problem of short circuit of the organic light-emitting layer between adjacent sub-pixels.

[0041] There are multiple sub-pixels 20 that are spaced apart between the isolation structures 40 , and the material of the anode layer 21 includes but is not limited to chromium, titanium, gold, silver, copper, aluminum, ITO, combinations thereof or other suitable conductive materials and combinations thereof.

[0042] The light emitting layer 22 is used to emit red light, blue light or green light when powered on. The light emitting layer 22 may include one or more of a HIL (Hole Injection Layer), a HTL (Hole Transfer Layer), an EML (Emitting Layer) and an ETL (Electron Transfer Layer).

[0043] The two ends of the cathode layer 23 are in contact with the first conductive layer 41 in the isolation structure 40, so that the cathode layers 23 of adjacent sub-pixels are connected together through the first conductive layer 41 to achieve cathode connection and conduction of the entire surface, wherein the material of the cathode layer 23 includes but is not limited to chromium, titanium, gold, silver, copper, aluminum, ITO, combinations thereof or other suitable conductive materials and combinations thereof. The material of the cathode layer 23 may be the same as or different from that of the anode layer 21, and is specifically set according to actual conditions.

[0044] Specifically, in one embodiment, the cathode auxiliary layer 50 is as follows: Figure 3 As shown, Figure 3 This is a top view of the positions of the anode, cathode, and auxiliary cathode of the backplane. The middle position is the anode area 1, and the open cathode area 2 is connected to form a whole surface through the conductive layer of the overhanging structure around the anode. The auxiliary cathode area 3 on the top of the overhanging structure forms a ring-shaped full-surface conductive layer around each opening, and the connection surface of the entire auxiliary cathode is realized by overlapping with the top conductive layer, thereby improving the reliability of the entire surface overlap.

[0045] Optionally, in one embodiment, if Figure 1 As shown, the display panel also includes: a protective layer 60, a first encapsulation layer 70 and a second encapsulation layer 80, the protective layer 60 covers the cathode layer 23, the first conductive layer 41, the first insulating layer 42, and the cathode auxiliary layer 50; the first encapsulation layer 70 covers the protective layer 60 and the second insulating layer 44, and the upper surface of the first encapsulation layer 70 is a flat structure; the second encapsulation layer 80 is arranged on the first encapsulation layer 70.

[0046] Among them, after a single sub-pixel is formed through a single etching, the monochrome OLED material and the cathode are encapsulated and protected by an inorganic packaging method to form an etching protection layer, and then other light-emitting layers and cathodes are prepared one by one. After the three-color light-emitting layers and cathodes are prepared, they are packaged as a whole using organic and inorganic packaging. In one embodiment, the protective layer 60 is encapsulated inorganically, the first encapsulation layer 70 is encapsulated organically, and the second encapsulation layer 80 is encapsulated inorganically.

[0047] Optionally, in one embodiment, the protective layer 60, the first encapsulation layer 70 and the second encapsulation layer 80 may be made of any encapsulation material, such as inorganic encapsulation, organic encapsulation and inorganic-organic composite encapsulation, wherein the inorganic-organic composite encapsulation material has the advantages of good water and oxygen barrier properties of inorganic encapsulation materials and good film-forming properties of organic encapsulation materials.

[0048] The present application also provides a method for manufacturing a display panel 100 to solve the above problem. The manufacturing method specifically includes the following steps:

[0049] See also Figure 4 and Figure 7a to Figure 7k , Figure 4 It is a flow chart of an embodiment of a method for manufacturing a display panel provided in the present application. Figure 7a to Figure 7k yes Figure 4 A structural schematic diagram corresponding to each step in the display panel manufacturing method provided in .

[0050] Step S10: providing a substrate.

[0051] Specifically, the substrate 10 plays a supporting role in the entire display panel and is used to carry various components and materials.

[0052] Optionally, in one embodiment, the substrate 10 includes a substrate (not shown) and a driving circuit (not shown), and the display panel 100 is an active OLED; in another embodiment, the substrate only includes a substrate but does not include a driving circuit, and the display panel 100 is a passive OLED.

[0053] Specifically, in one embodiment, the material of the substrate is a glass substrate, which is generally used as a carrier; in another embodiment, the material of the substrate is a flexible substrate, wherein the flexible substrate uses a flexible PI (polyimide) film as a substrate.

[0054] The driving circuit mentioned above can be divided into a pixel driving circuit and a peripheral driving circuit. The pixel driving circuit mainly provides the conditions for the continuous lighting of the panel, while the peripheral circuit provides accurate input signals for the matrix circuit of the panel, for example, providing a scanning signal (row driving signal) for row-by-row selection for the active matrix circuit, and providing a data signal (column driving signal) with display information for each OLED pixel of the selected row. Therefore, the pixel driving circuit and the peripheral driving circuit complement each other and work closely together to complete the normal operation of driving the active OLED display screen.

[0055] Step S12: forming an anode layer and a pixel defining layer on the substrate.

[0056] Specifically, Figure 7a As shown, a corresponding required metal layer is formed on the substrate as the anode layer material, wherein the material of the metal layer includes but is not limited to chromium, titanium, gold, silver, copper, aluminum, ITO, combinations thereof or other suitable conductive materials and combinations thereof.

[0057] Optionally, in one embodiment, if Figure 7aAs shown, by coating a first layer of photoresist on the metal layer and patterning the photoresist, the corresponding required structure is retained to form the required anode layer 21 on the substrate; a pixel defining layer 30 is prepared on the anode layer 21 after etching, which is used to separate the anode layer 21 of the adjacent sub-pixels 20. Similarly, a second layer of photoresist is coated on the pixel defining layer 30 and patterned to retain the corresponding required structure to form the pixel defining layer 30; in one embodiment, the height of the pixel defining layer 30 perpendicular to the substrate direction is higher than the anode layer 21. The pixel defining layer 30 is made of organic materials including but not limited to polyimide, and the inorganic materials of the pixel defining layer 30 are including but not limited to silicon oxide (SiO2), silicon nitride (Si3N4), silicon oxynitride (Si2N2O), magnesium fluoride (MgF2) or a combination thereof. In another embodiment, a PDL material is used as the material of the pixel defining layer 30. PDL is a pixel definition material used to define each sub-pixel so that the colors between the light-emitting layers therein do not interfere with each other.

[0058] The etching method includes wet etching or dry etching, wherein dry etching includes laser etching or plasma etching, and wet etching includes chemical etching.

[0059] Step S14: forming a first conductive layer, a first insulating layer, a second conductive layer and a second insulating layer in sequence on the pixel defining layer, wherein the first insulating layer is provided with a via hole, and the first conductive layer and the second conductive layer are connected through the via hole.

[0060] See also Figure 5 , Figure 5 yes Figure 4 Schematic diagram of the sub-step flow chart of step S14.

[0061] The sub-steps of step S14 specifically include the following steps:

[0062] Step S140: forming a first conductive layer and a first insulating layer in sequence on the pixel defining layer, the first insulating layer comprising a main body and a top portion disposed on the main body, the top portion extending out of an upper surface of the main body to form a first overhanging portion.

[0063] Optionally, in one embodiment, if Figure 7b As shown, a conductive layer is deposited on the pixel defining layer 30 by physical vapor deposition, chemical vapor deposition or vacuum sputtering, and a third layer of photoresist is coated on the conductive layer and patterned to retain the first conductive layer 41 structure on the pixel defining layer, wherein the material of the first conductive layer 41 is made of metal oxide or transition metal oxide or other conductive materials, such as metal molybdenum (MO), aluminum nitride (AlN) and other materials.

[0064] Optionally, in one embodiment, if Figure 7cAs shown, a first insulating layer 42 is prepared above the first conductive layer 41, and a first overhang a is formed on the first insulating layer 42 by utilizing the different etching rates of different materials to form an overhang structure. The material of the first insulating layer 42 may be a non-conductive organic material, and the non-conductive organic material may include a negative photosensitive organic material. For example, the negative photosensitive organic material includes but is not limited to a negative photoresist.

[0065] Optionally, in one embodiment, the first overhang structure formed by the first insulating layer 42 can be formed by polymerizing and crosslinking the portion of the negative photoresist that is illuminated during the exposure process, while the portion that is not illuminated does not undergo crosslinking polymerization. The surface of the negative photoresist is more easily polymerized and crosslinked, and the light intensity of the portion of the negative photoresist that is far from the surface gradually weakens. From the surface to the direction away from the surface, the degree of polymerization and crosslinking of the negative photoresist gradually weakens. In the development process, the negative photoresist that has not undergone crosslinking polymerization will be washed away to obtain an overhang structure with an inverted trapezoidal structure.

[0066] Step S142: forming a via hole penetrating the main body and the top on the first insulating layer.

[0067] Optionally, in one embodiment, if Figure 7d As shown, vias A can be formed on the first insulating layer 42 by etching or the like, and the subsequent second conductive layer 43 is connected to the first conductive layer 41 through the vias A, thereby increasing the number of overlapping interfaces between the cathode and the auxiliary cathode and improving the reliability of the overlapping interfaces.

[0068] Step S144: forming a second conductive layer on the first insulating layer, wherein the second conductive layer is connected to the first conductive layer through vias.

[0069] Optionally, in one embodiment, if Figure 7e As shown, a conductive layer is deposited on the first insulating layer 42 forming the via hole A by physical vapor deposition, chemical vapor deposition or vacuum sputtering to form a second conductive layer 43, and the second conductive layer 43 is overlapped with the bottom first conductive layer 41 through the via hole A. In one embodiment, considering the slope angle of cathode evaporation deposition, the width of the second conductive layer 43 in the cross section should be less than or equal to the first conductive layer 41.

[0070] Step S146: forming a second insulating layer on the second conductive layer, wherein the second insulating layer extends out of the upper surface of the second conductive layer to form a second overhanging portion.

[0071] Optionally, in one embodiment, if Figure 7fAs shown, a second insulating layer 44 is formed on the second conductive layer 43 by deposition or the like, wherein the second insulating layer 44 is formed in the same manner as the first insulating layer 42, which will not be described in detail herein. In one embodiment, the length of the second overhanging portion b of the second insulating layer 44 is equal to the length of the first overhanging portion a of the first insulating layer 42.

[0072] Step S16: forming a light-emitting layer and a cathode layer in sequence on the anode layer, and forming a cathode auxiliary layer on the isolation structure, the cathode auxiliary layer is connected to the second conductive layer, the anode layer, the light-emitting layer and the cathode layer form a sub-pixel, and the cathode layers of two adjacent sub-pixels are connected through the first conductive layer.

[0073] See also Figure 6 , Figure 6 yes Figure 4 Schematic diagram of the sub-step flow chart of step S16.

[0074] The sub-steps of step S16 specifically include the following steps:

[0075] Step S160: forming a light-emitting layer on the anode layer, and forming an organic layer on the side of the first overhanging portion.

[0076] Specifically, since the colors of light emitted by different sub-pixels 20 are different, the materials of the light-emitting layers 22 in different sub-pixels 20 are different, and sub-pixels 20 emitting light of different colors need to be prepared in different steps. The light-emitting layer 22 includes but is not limited to a red light-emitting layer (not shown), a green light-emitting layer (not shown), and a blue light-emitting layer (not shown). The order of forming the red light-emitting layer, the green light-emitting layer, and the blue light-emitting layer is set according to the actual situation. For example, the red light-emitting layer is formed first, then the green light-emitting layer is formed, and finally the blue light-emitting layer is formed.

[0077] Optionally, in one embodiment, if Figure 7g As shown, the light-emitting layer 22 is formed by evaporation deposition, but due to the first overhang a and the second overhang b of the protruding parts of the overhang structure, the light-emitting layer breaks at the protruding parts, so that the light-emitting layer at the lower fracture surface overlaps the pixel defining layer 30, but is not in contact with the first conductive layer 41, and the organic layer c is formed at the first overhang a of the first insulating layer 42 at the upper fracture surface.

[0078] Step S162: forming a cathode layer on the light-emitting layer, and forming a cathode auxiliary layer on the upper surface, side surface and lower surface of the second overhang, the side surface of the second conductive layer, and the upper surface and side surface of the first overhang.

[0079] Optionally, in one embodiment, if Figure 7hAs shown, a cathode layer 23 and a cathode auxiliary layer 50 are formed on the light-emitting layer 22 by evaporation deposition. The reason for the formation of the light-emitting layer 22 is the same as that of the first overhang a and the second overhang b of the overhang structure, resulting in a film break in the cathode at the protruding part. In one embodiment, by changing the evaporation angle, the cathode wraps the light-emitting layer 22 at the lower break, so that the light-emitting layer 22 is isolated from the first conductive layer 41, and the cathode layer 23 is directly connected to the first conductive layer 41, so that the cathode layers 23 of different sub-pixels 20 are connected through the first conductive layer 41 to form a mesh connection of cathodes between different sub-pixels, wherein the first conductive layer 41 is higher than the cathode layer 23 in the direction perpendicular to the substrate. The cathode at the upper break is deposited along the double overhang structure constructed by the first insulating layer 42 and the second insulating layer 44 to form a cathode auxiliary layer 50 on the upper surface, side and lower surface of the second overhang portion b, the side of the second conductive layer 43, and the upper surface and side of the first overhang portion a, and the cathode auxiliary layer 50 is overlapped and connected with the side of the second conductive layer 43, thereby achieving overall conduction between the cathode auxiliary layer 50 and the second conductive layer 43, the first conductive layer 41 and the cathode layer 23, increasing the reliability of the cathode connection, effectively reducing the overall surface resistance of the cathode, and thus improving the overall surface uniformity of the cathode.

[0080] Optionally, in one embodiment, the above-mentioned preparation method further comprises packaging the display panel, such as Figure 7i As shown, firstly, the monochrome OLED material and the cathode are encapsulated and protected, and then other light-emitting layers and cathodes are prepared one by one, such as Figure 7j and Figure 7k As shown, after the three-color organic light-emitting layers and the cathode are patterned, they are packaged as a whole by combining organic packaging and inorganic packaging, wherein the protective layer 60 is packaged inorganically, the first packaging layer 70 is packaged organically, and the second packaging layer 80 is packaged inorganically.

[0081] The present application provides a display panel. By using the above display panel and the display panel manufactured by the above manufacturing method, a double suspension structure is added to the suspension structure base, so that the cathode forms a mesh auxiliary cathode on the top suspension structure, so that the bottom cathode and the auxiliary cathode are connected through a metal column, thereby improving the uniformity of the entire cathode, increasing the area of ​​the cathode and thus reducing the cathode resistance, thereby reducing the IR Drop caused by the large cathode resistance, so as to improve the phenomenon of uneven display brightness.

[0082] See also Figure 8 , Figure 81 is a schematic diagram of a display device according to an embodiment of the present application. The display device 200 includes any display panel 100 described in the above embodiments or a display panel 100 manufactured by the above manufacturing method, so that the display panel 100 provides a stable picture output for the display device 200.

[0083] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A display panel, characterized in that: include: substrate; A plurality of sub-pixels are disposed on the substrate; A pixel defining layer, disposed on the substrate, and used to define positions of a plurality of sub-pixels; an isolation structure, disposed on the pixel defining layer, the isolation structure being used to isolate the plurality of sub-pixels, the isolation structure comprising a first conductive layer, a first insulating layer, a second conductive layer, and a second insulating layer stacked in sequence, the cathode layers of two adjacent sub-pixels being connected via the first conductive layer, the first insulating layer being provided with a via hole, and the first conductive layer and the second conductive layer being connected via the via hole; a cathode auxiliary layer, disposed on the isolation structure, the cathode auxiliary layer being connected to the second conductive layer; Wherein, the first insulating layer includes a main body and a top portion disposed on the main body, and the top portion extends out of the upper surface of the main body to form a first overhanging portion; The second insulating layer extends out of the upper surface of the second conductive layer to form a second overhanging portion.

2. The display panel according to claim 1, characterized in that: The via hole passes through the main body and the top.

3. The display panel according to claim 1, characterized in that: The cathode auxiliary layer covers the upper surface, side surfaces, and lower surface of the second overhang portion, the side surfaces of the second conductive layer, and the upper surface and side surfaces of the first overhang portion.

4. The display panel according to claim 3, characterized in that: An organic layer is also disposed on the side surface of the first overhanging portion, and the cathode auxiliary layer covers the organic layer.

5. The display panel according to claim 1, characterized in that: The sub-pixel includes an anode layer, a light-emitting layer and a cathode layer stacked in sequence, the light-emitting layer overlaps the upper surface of the pixel defining layer, and the cathode layer extends between the light-emitting layer and the first conductive layer and contacts the upper surface of the pixel defining layer.

6. The display panel according to claim 5, characterized in that: The display panel further includes: a protective layer, the protective layer covering the cathode layer, the first conductive layer, the first insulating layer, and the cathode auxiliary layer; A first encapsulation layer, the first encapsulation layer covers the protection layer and the second insulating layer, and the upper surface of the first encapsulation layer is a flat structure; The second packaging layer is disposed on the first packaging layer.

7. A method for manufacturing a display panel, characterized in that: include: providing a substrate; forming an anode layer and a pixel defining layer on the substrate; forming a first conductive layer, a first insulating layer, a second conductive layer and a second insulating layer in sequence on the pixel defining layer, wherein the first insulating layer is provided with a via hole, and the first conductive layer and the second conductive layer are connected through the via hole; A light-emitting layer and a cathode layer are sequentially formed on the anode layer, and a cathode auxiliary layer is formed on the second insulating layer, wherein the cathode auxiliary layer is connected to the second conductive layer, the anode layer, the light-emitting layer and the cathode layer form a sub-pixel, and the cathode layers of two adjacent sub-pixels are connected through the first conductive layer; Wherein, the first conductive layer, the first insulating layer, the second conductive layer and the second insulating layer are sequentially formed on the pixel defining layer, comprising: A first conductive layer and a first insulating layer are sequentially formed on the pixel defining layer, wherein the first insulating layer includes a main body and a top portion disposed on the main body, wherein the top portion extends out of an upper surface of the main body to form a first overhanging portion; forming a via hole penetrating the main body and the top on the first insulating layer; forming a second conductive layer on the first insulating layer, wherein the second conductive layer is connected to the first conductive layer through the via hole; A second insulating layer is formed on the second conductive layer, wherein the second insulating layer extends out of an upper surface of the second conductive layer to form a second overhanging portion.

8. The method for manufacturing a display panel according to claim 7, characterized in that: The step of sequentially forming a light emitting layer and a cathode layer on the anode layer, and forming a cathode auxiliary layer on the second insulating layer comprises: forming a light-emitting layer on the anode layer and forming an organic layer on the side of the first overhanging portion; A cathode layer is formed on the light emitting layer, and a cathode auxiliary layer is formed on the upper surface, side surface and lower surface of the second overhang, the side surface of the second conductive layer, and the upper surface and side surface of the first overhang.

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