An OLED display panel and a preparation method thereof

Abstract

The application discloses an OLED display panel and a preparation method thereof. The terminal of the application comprises a first metal layer and a second metal layer arranged in a stack, and the edge of the second metal layer protrudes from the edge of the first metal layer. Thus, the terminal of the binding area is designed as an undercut structure, so that the electronic functional layer covering the second metal layer is disconnected from the electronic functional layer covering the array structure layer, the cathode is directly covered on the surface of the side of the second metal layer close to the array structure layer, and the electrical connection between the cathode and the terminal is realized. By adjusting the evaporation angle and using the same mask plate to prepare the electronic functional layer and the cathode, the evaporation process can be reduced, the loop equipment configuration of the mass production line can be reduced, and the investment cost of the mass production line can be reduced without affecting the lapping effect of the cathode and the terminal.

Description

Technical Field

[0001] This invention relates to the field of displays, and more specifically to an OLED display panel and its manufacturing method. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are being heavily developed by major display manufacturers due to their advantages such as simple structure, self-illumination, fast response time, ultra-thinness, and low power consumption. Organic electroluminescent display panels, with their superior characteristics including high contrast, wide color gamut, fast response time, and flexibility, have become the most promising and competitive contender for future displays. Currently, OLED panels are generally manufactured using vacuum evaporation, a process with stringent requirements and high costs. The large-size, high-precision metal mask (FMM) faces unresolved technical challenges, limiting its widespread adoption and application in larger-sized products.

[0003] Currently, inkjet printing technology can rapidly and continuously fabricate red, green, and blue pixel arrays on large-size glass substrates at room temperature and pressure, creating conditions for large-size OLED displays. However, printing technology is still in its early stages, and due to material limitations, not all film layers in OLED devices can be printed. While hole functional layers and luminescent material layers can be printed using display technology, avoiding the difficulties of the vapor deposition FMM process, electronic functional layers and cathode layers still require vapor deposition or SPT film deposition technology for mass production.

[0004] Currently, to ensure proper bonding between the cathode and the terminal (PAD), the industry typically uses a smaller opening in the evaporation mask for the electronic functional layer than the opening in the cathode evaporation mask. This requires two different mask sizes to prepare the electronic functional layer and the cathode separately. Furthermore, current mass production equipment uses two separate evaporation cycle systems to prepare the electronic functional layer and the cathode, resulting in relatively high investment costs for the evaporation equipment. Summary of the Invention

[0005] This invention provides an OLED display panel and its fabrication method, which can solve the technical problem of high equipment investment costs in the evaporation process caused by using two different types of photomasks to prepare the electronic functional layer and cathode separately in the prior art.

[0006] To solve the above problems, the present invention provides an OLED display panel, including a display area and a bonding area, and further including: a substrate; an array structure layer disposed on the substrate; a terminal disposed on a surface of the array structure layer away from the substrate and located in the bonding area, the terminal including a first metal layer and a second metal layer stacked, the second metal layer being disposed on a surface of the first metal layer away from the array structure layer, and an edge of the second metal layer protruding from an edge of the first metal layer; an anode disposed on a surface of the array structure layer away from the substrate and located in the display area; a pixel definition layer disposed on a surface of the anode away from the substrate, extending and covering the array structure layer, and located in the display area, the pixel definition layer having a pixel hole at a position corresponding to the anode; a light-emitting material layer disposed in the pixel hole of the pixel definition layer; an electron functional layer disposed on the light-emitting material layer, extending and covering the pixel definition layer, the array structure layer, and the terminal; wherein, the electron functional layer covering the second metal layer is disconnected from the electron functional layer covering the array structure layer; and a cathode disposed on a surface of the electron functional layer away from the array structure layer and directly covering a surface of the second metal layer close to the array structure layer.

[0007] Further, a thickness of the electron functional layer located in the bonding area is H1, a thickness of the first metal layer is H2, and H1 < H2.

[0008] Further, a thickness of the cathode is H3, and H2 ≤ H1 + H3.

[0009] Further, the electron functional layer includes: an electron transport layer disposed on a surface of the light-emitting material layer away from the anode; and an electron injection layer disposed on a surface of the electron transport layer away from the light-emitting material layer.

[0010] Further, the terminal further includes a third metal layer, the third metal layer being disposed on a side of the second metal layer away from the first metal layer, and an edge of the second metal layer protruding from an edge of the third metal layer.

[0011] Further, the OLED display panel further includes: a packaging layer disposed on a surface of the cathode away from the array structure layer.

[0012] To solve the above problems, the present invention further provides a method for manufacturing an OLED display panel, which includes the following manufacturing steps: providing a substrate, defining a display area and a bonding area on the substrate; manufacturing an array structure layer on the substrate; manufacturing an anode and terminals on the surface of the array structure layer away from the substrate, wherein the terminals are located in the bonding area and the anode is located in the display area; the terminals include a first metal layer and a second metal layer arranged in a stacked manner, the second metal layer is disposed on the surface of the first metal layer away from the array structure layer, wherein the etching amount of the first metal layer is greater than that of the second metal layer, so that the edge of the second metal layer protrudes from the edge of the first metal layer; manufacturing a pixel definition layer on the surface of the anode away from the substrate, the pixel definition layer further extends to cover the array structure layer and is located in the display area, and the pixel definition layer is provided with pixel holes at positions corresponding to the anode; manufacturing a light-emitting material layer in the pixel holes of the pixel definition layer; manufacturing an electron functional layer on the light-emitting material layer, the electron functional layer further extends to cover the pixel definition layer, the array structure layer and the terminals; wherein, the electron functional layer covering the second metal layer is disconnected from the electron functional layer covering the array structure layer; manufacturing a cathode on the surface of the electron functional layer away from the array structure layer, and the cathode directly covers the surface of the second metal layer close to the array structure layer.

[0013] Further, the step of manufacturing an electron functional layer on the light-emitting material layer, and the electron functional layer further extending to cover the pixel definition layer, the array structure layer and the terminals includes: providing a mask plate, through the mask plate, manufacturing an electron functional layer on the light-emitting material layer at an evaporation angle α, and the electron functional layer further extends to cover the pixel definition layer, the array structure layer and the terminals; the thickness of the electron functional layer located in the bonding area is H1, and the thickness of the first metal layer is H2, and H1 < H2.

[0014] Further, the step of manufacturing a cathode on the surface of the electron functional layer away from the array structure layer, and the cathode directly covering the surface of the second metal layer close to the array structure layer includes: through the mask plate, manufacturing a cathode on the surface of the electron functional layer away from the array structure layer at an evaporation angle β, and the cathode directly covers the surface of the second metal layer close to the array structure layer, the thickness of the cathode is H3, and H2 ≤ H1 + H3.

[0015] Further, the evaporation angle α is greater than the evaporation angle β.

[0016] The beneficial effects of this invention are as follows: The terminal of this invention includes a first metal layer and a second metal layer stacked together, with the edge of the second metal layer protruding beyond the edge of the first metal layer; thus, the terminal in the bonding area is designed with an "undercut" structure, thereby disconnecting the electronic functional layer covering the second metal layer from the electronic functional layer covering the array structure layer, facilitating the direct coverage of the cathode on the surface of the second metal layer near the array structure layer, achieving electrical connection between the cathode and the terminal. This invention, by adjusting the evaporation angle and using the same mask to separately prepare the electronic functional layer and the cathode, can reduce the evaporation process, reduce the configuration of loop equipment in the mass production line, and lower the investment cost of the mass production line without affecting the bonding effect between the cathode and the terminal. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the OLED display panel provided by the present invention;

[0019] Figure 2 yes Figure 1 Enlarged view of section A;

[0020] Figure 3 This is a flowchart of the OLED display panel manufacturing method provided by the present invention;

[0021] Figure 4 This is a schematic diagram illustrating the fabrication of an array structure layer, terminals, anode, and pixel definition layer on a substrate according to the present invention.

[0022] Figure 5 Is Figure 4 A schematic diagram of the preparation of a luminescent material layer based on the above;

[0023] Figure 6 Is Figure 5 A schematic diagram of the fabrication of electronic functional layers based on the above;

[0024] Figure 7 This is a schematic diagram of the evaporation angle during the evaporation of electronic functional layers provided in an embodiment of the present invention;

[0025] Figure 8 This is a schematic diagram of the evaporation angle during cathode evaporation provided in an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100. OLED display panel; 101. Display area;

[0028] 102. Binding area;

[0029] 1. Substrate 1; 2. Array structure layer;

[0030] 3. Terminal; 4. Anode;

[0031] 5. Pixel definition layer; 6. Emissive material layer;

[0032] 7. Electronic functional layer; 8. Cathode;

[0033] 9. Encapsulation layer; 10. Buffer layer;

[0034] 11. Leveling layer;

[0035] 21. Active layer; 22. Gate insulating layer;

[0036] 23. Gate layer; 24. Interlayer insulating layer;

[0037] 25. Source; 26. Drain;

[0038] 27. Passivation layer;

[0039] 31. First metal layer; 32. Second metal layer;

[0040] 33. Third metal layer; 51. Pixel hole. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit the present invention. In the present invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0042] This invention provides an OLED display panel and a method for manufacturing the same. The following is a detailed description.

[0043] Example

[0044] like Figure 1As shown, this embodiment discloses an OLED display panel 100. The OLED display panel 100 may include a display area 101 and a bonding area 102 according to its function. The OLED display panel 100 may also include a substrate 1, an array structure layer 2, terminals 3, an anode 4, a pixel definition layer 5, a light-emitting material layer 6, an electronic functional layer 7, a cathode 8, and an encapsulation layer 9 according to its structure.

[0045] The substrate 1 is made of one or more of glass, polyimide, polycarbonate, polyethylene terephthalate, and polyethylene naphthalate, thus giving the substrate 1 good impact resistance and effectively protecting the OLED display panel 100. In this embodiment, the substrate 1 is a glass substrate used to support the various film layers.

[0046] like Figure 1 As shown, a buffer layer 10 is also provided on the substrate 1. The buffer layer 10 mainly serves a buffering function, and its material can be SiOx, SiNx, SiNOx, or a combination of SiNx and SiOx, etc.

[0047] The array structure layer 2 is disposed on the surface of the buffer layer 10 away from the substrate 1. The array structure layer 2 includes: an active layer 21, a gate insulating layer 22, a gate layer 23, an interlayer insulating layer 24, a source 25, a drain 26, and a passivation layer 27.

[0048] The array structure layer 2 also includes a planarization layer 11. The planarization layer 11 can be made of SiOx, SiNx, SiNOx, or a combination of SiNx and SiOx. The planarization layer 11 primarily provides a smooth surface for the fabrication of the film layer thereon.

[0049] Terminal 3 is disposed on the surface of the array structure layer 2 away from the substrate 1, and is located in the bonding area 102. Terminal 3 is mainly used for external drive signals.

[0050] like Figure 1 As shown, in this embodiment, the terminal 3 includes a first metal layer 31, a second metal layer 32, and a third metal layer 33 stacked together. Specifically, the first metal layer 31 is disposed on the surface of the array structure layer 2 away from the substrate 1 and is located in the bonding region 102. The second metal layer 32 is disposed on the surface of the first metal layer 31 away from the array structure layer 2, and the third metal layer 33 is disposed on the side of the second metal layer 32 away from the first metal layer 31. The edge of the second metal layer 32 protrudes beyond the edge of the first metal layer 31; the edge of the second metal layer 32 protrudes beyond the edge of the third metal layer 33.

[0051] Specifically, the material of the second metal layer 32 is different from that of the first metal layer 31, and the material of the second metal layer 32 is different from that of the third metal layer 33. The material of the first metal layer 31 can be the same as or different from that of the third metal layer 33. By controlling the etching solution ratio and time during etching, the etching amount of the second metal layer 32 is less than that of the first metal layer 31, causing the outer edge of the second metal layer 32 to protrude beyond the outer edge of the first metal layer 31, and the etching amount of the second metal layer 32 is less than that of the third metal layer 33, causing the outer edge of the second metal layer 32 to protrude beyond the outer edge of the third metal layer 33.

[0052] In summary, by having the edge of the second metal layer 32 protrude beyond the edge of the first metal layer 31, the terminal 3 of the bonding area 102 is designed with an "undercut" structure. This disconnects the electronic functional layer 7 covering the second metal layer 32 from the electronic functional layer 7 covering the array structure layer 2, allowing the cathode 8 to directly cover the surface of the second metal layer 32 near the array structure layer 2, thus achieving electrical connection between the cathode 8 and the terminal 3. By adjusting the evaporation angle and using the same mask to prepare the electronic functional layer 7 and the cathode 8 separately, the evaporation process can be reduced, the configuration of loop equipment in the mass production line can be reduced, and the investment cost of the mass production line can be lowered without affecting the overlap effect between the cathode 8 and the terminal 3.

[0053] In other embodiments, terminal 3 may consist only of a first metal layer 31 and a second metal layer 32 stacked together.

[0054] In this embodiment, the anode 4 is disposed on the surface of the array structure layer 2 away from the substrate 1 and located in the display area 101. The anode 4 includes a first film layer 41, a second film layer 42, and a third film layer 43. Specifically, the first film layer 41 is disposed on the surface of the array structure layer 2 away from the substrate 1 and located in the display area 101. The second film layer 42 is disposed on the surface of the first film layer 41 away from the array structure layer 2, and the third film layer 43 is disposed on the surface of the second film layer 42 away from the first film layer 41. In this embodiment, the material of the first film layer 41 is the same as that of the first metal layer 31, thus allowing the first film layer 41 and the first metal layer 31 to be prepared using the same process, optimizing the preparation process. In this embodiment, the material of the second film layer 42 is the same as that of the second metal layer 32, thus allowing the second film layer 42 and the second metal layer 32 to be prepared using the same process, optimizing the preparation process. In this embodiment, the material of the third film layer 43 is the same as that of the third metal layer 33, so the third film layer 43 and the third metal layer 33 can be prepared in the same process, thus optimizing the preparation process.

[0055] In other embodiments, the material of the first film layer 41 may be different from the material of the first metal layer 31, the material of the second film layer 42 may be different from the material of the second metal layer 32, and the material of the third film layer 43 may be different from the material of the third metal layer 33.

[0056] The pixel definition layer 5 is disposed on the surface of the anode 4 away from the substrate 1 and extends to cover the array structure layer 2 and is located in the display area 101. The pixel definition layer 5 has a pixel hole 51 at the position corresponding to the anode 4, that is, the anode 4 is not covered by the pixel definition layer 5 at the position corresponding to the pixel hole 51 and is exposed to the outside so that the anode 4 can be connected to the subsequent film layer. In order to avoid poor contact at the edge of the anode 4, the bottom size of the pixel hole 51 is smaller than the size of the anode 4, ensuring that the edge of the anode 4 is still covered by the pixel definition layer 5.

[0057] The light-emitting material layer 6 is disposed within the pixel hole 51 of the pixel definition layer 5. In fact, a hole-functional layer (not shown) is also provided between the light-emitting material layer 6 and the anode 4. The hole-functional layer includes a hole injection layer, a hole transport layer, etc.

[0058] The electronic functional layer 7 is disposed on the light-emitting material layer 6 and extends to cover the pixel definition layer 5, the array structure layer 2, and the terminal 3. The electronic functional layer 7 includes: an electron transport layer (not shown) disposed on the surface of the light-emitting material layer 6 away from the anode 4; and an electron injection layer (not shown) disposed on the surface of the electron transport layer away from the light-emitting material layer 6.

[0059] Specifically, the electronic functional layer 7 covering the second metal layer 32 is disconnected from the electronic functional layer 7 covering the array structure layer 2. This allows the cathode 8 to directly cover the surface of the second metal layer 32 near the array structure layer 2, achieving electrical connection between the cathode 8 and the terminal 3. By adjusting the evaporation angle and using the same mask to prepare the electronic functional layer 7 and the cathode 8 separately, the evaporation process can be reduced, the configuration of production line loop equipment can be reduced, and the investment cost of the production line can be lowered without affecting the overlap effect between the cathode 8 and the terminal 3.

[0060] The cathode 8 is disposed on the surface of the electronic functional layer 7 away from the array structure layer 2, and directly covers the surface of the second metal layer 32 near the array structure layer 2. The direct coverage of the cathode 8 on the surface of the second metal layer 32 near the array structure layer 2 enables electrical connection between the cathode 8 and the terminal 3.

[0061] like Figure 2 As shown, the thickness of the electronic functional layer 7 located in the bonding area 102 is H1, and the thickness of the first metal layer 31 is H2, where H1 < H2. This can ensure that the electronic functional layer 7 covering the second metal layer 32 is disconnected from the electronic functional layer 7 covering the flat layer 11. It is convenient for the cathode 8 to directly cover the surface of the second metal layer 32 on the side close to the array structure layer 2, realizing the electrical connection between the cathode 8 and the terminal 3.

[0062] As Figure 2 shown, the thickness of the cathode 8 is H3, where H2 ≤ H1 + H3. This can ensure that the cathode 8 directly covers the surface of the second metal layer 32 on the side close to the array structure layer 2, realizing the electrical connection between the cathode 8 and the terminal 3.

[0063] Among them, the encapsulation layer 9 is provided on the surface of the cathode 8 on the side away from the array structure layer 2. Specifically, the encapsulation layer 9 may include a first inorganic encapsulation layer (not shown in the figure), an organic encapsulation layer (not shown in the figure), and a second inorganic encapsulation layer (not shown in the figure). The encapsulation layer 9 is mainly used to protect each metal film layer it covers, avoiding the technical problem that the life of the metal film layer is reduced due to the intrusion of external moisture. Among them, the encapsulation layer 9 is a transparent material, thereby reducing the light loss of the light-emitting material layer 6.

[0064] As Figure 3As shown, this embodiment also provides a method for fabricating an OLED display panel as described in this embodiment. The method for fabricating an OLED display panel includes the following fabrication steps: S1, providing a substrate 1, defining a display area 101 and a bonding area 102 on the substrate 1; S2, fabricating an array structure layer 2 on the substrate 1; S3, fabricating an anode 4 and a terminal 3 on the surface of the array structure layer 2 away from the substrate 1, wherein the terminal 3 is located in the bonding area 102, and the anode 4 is located in the display area 101; the terminal 3 includes a first metal layer 31 and a second metal layer 32 stacked together, the second metal layer 32 being disposed on the surface of the first metal layer 31 away from the array structure layer 2, wherein the etching amount of the first metal layer 31 is greater than the etching amount of the second metal layer 32, such that the edge of the second metal layer 32 protrudes beyond the edge of the first metal layer 31; S4, on the surface of the anode 4 away from the substrate 1... A pixel definition layer 5 is prepared on one side of the surface, the pixel definition layer 5 also extends and covers the array structure layer 2 and is located in the display area 101, the pixel definition layer 5 has a pixel hole 51 at the position corresponding to the anode 4; S5, a light-emitting material layer 6 is prepared in the pixel hole 51 of the pixel definition layer 5; S6, an electronic functional layer 7 is prepared on the light-emitting material layer 6, the electronic functional layer 7 also extends and covers the pixel definition layer 5, the array structure layer 2 and the terminal 3; wherein, the electronic functional layer 7 covering the second metal layer 32 is disconnected from the electronic functional layer 7 covering the array structure layer 2; S7, a cathode 8 is prepared on the surface of the electronic functional layer 7 away from the array structure layer 2, the cathode 8 directly covers the surface of the second metal layer 32 close to the array structure layer 2.

[0065] like Figure 4 As shown, terminal 3 further includes a stacked third metal layer 33. The third metal layer 33 is disposed on the surface of the second metal layer 32 on the side away from the array structure layer 2, wherein the etching amount of the third metal layer 33 is greater than the etching amount of the second metal layer 32, such that the edge of the second metal layer 32 protrudes beyond the edge of the third metal layer 33.

[0066] like Figure 5 As shown, luminescent material is printed only on the anode 4 within the pixel hole 51 of the pixel definition layer 5 to form the luminescent material layer 6.

[0067] like Figure 2 , Figure 6 , Figure 7As shown, in S6, a mask plate is provided. Through the mask plate, an electron functional layer 7 is formed on the light-emitting material layer 6 at an evaporation angle α. The electron functional layer 7 also extends to cover the pixel definition layer 5, the array structure layer 2, and the terminal 3. The thickness of the electron functional layer 7 in the bonding area 102 is H1, and the thickness of the first metal layer 31 is H2, where H1 < H2. This can ensure that the electron functional layer 7 covering the second metal layer 32 is disconnected from the electron functional layer 7 covering the planar layer 11. Facilitate the cathode 8 to directly cover the surface of the second metal layer 32 on the side close to the array structure layer 2, realizing the electrical connection between the cathode 8 and the terminal 3.

[0068] As Figure 2 , Figure 6 , Figure 8 shown, in S7, through the mask plate, a cathode 8 is formed on the surface of the electron functional layer 7 on the side away from the array structure layer 2 at an evaporation angle β. The cathode 8 directly covers the surface of the second metal layer 32 on the side close to the array structure layer 2. The thickness of the cathode 8 is H3, where H2 ≤ H1 + H3. The evaporation angle α is greater than the evaporation angle β. This can ensure that the cathode 8 directly covers the surface of the second metal layer 32 on the side close to the array structure layer 2, realizing the electrical connection between the cathode 8 and the terminal 3.

[0069] In summary, by adjusting the evaporation angle and using the same mask plate to form the electron functional layer 7 and the cathode 8 respectively, the present invention can reduce the evaporation process, reduce the configuration of loop equipment on the mass production line, and lower the investment cost of the mass production line without affecting the overlapping effect between the cathode 8 and the terminal 3.

[0070] The above has introduced in detail an OLED display panel and its manufacturing method provided by the embodiments of the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. An OLED display panel, comprising a display area and a bonding area, characterized in that, Also includes: substrate; An array structure layer is disposed on the substrate; A terminal is disposed on the surface of the array structure layer away from the substrate and located in the bonding area. The terminal is used to connect an external driving signal. The terminal includes a first metal layer and a second metal layer stacked together. The second metal layer is disposed on the surface of the first metal layer away from the array structure layer. The edge of the second metal layer protrudes from the edge of the first metal layer. An undercut structure is formed on the side of the terminal near the display area. The anode is disposed on the surface of the array structure layer on the side away from the substrate and is located in the display area; A pixel definition layer is disposed on the surface of the anode on the side away from the substrate, and extends to cover the array structure layer and is located in the display area. The pixel definition layer has pixel holes at positions corresponding to the anode. A light-emitting material layer is disposed within the pixel hole of the pixel definition layer; An electronic functional layer is disposed on the light-emitting material layer and extends to cover the pixel definition layer, the array structure layer, and the terminal; wherein the electronic functional layer covering the second metal layer is disconnected from the electronic functional layer covering the array structure layer; as well as The cathode is disposed on the surface of the electronic functional layer away from the array structure layer, and directly covers the surface of the second metal layer near the array structure layer. The cathode is continuously disposed at the undercut structure and electrically connected to the terminal.

2. The OLED display panel according to claim 1, characterized in that, The thickness of the electronic functional layer located in the bonding region is H1, and the thickness of the first metal layer is H2. <H2。 3. The OLED display panel according to claim 2, characterized in that, The thickness of the cathode is H3, where H2 ≤ H1 + H3.

4. The OLED display panel according to claim 1, characterized in that, The electronic functional layer includes: An electron transport layer is disposed on the surface of the luminescent material layer on the side away from the anode; and An electron injection layer is disposed on the surface of the electron transport layer on the side away from the luminescent material layer.

5. The OLED display panel according to claim 1, characterized in that, The terminal further includes a third metal layer disposed on the side of the second metal layer away from the first metal layer, and the edge of the second metal layer protrudes beyond the edge of the third metal layer.

6. The OLED display panel according to claim 1, characterized in that, Also includes: An encapsulation layer is disposed on the surface of the cathode on the side away from the array structure layer.

7. A method for manufacturing an OLED display panel, characterized in that, The preparation steps include the following: A substrate is provided, on which a display area and a bonding area are defined; An array structure layer is fabricated on the substrate; An anode and a terminal are fabricated on the surface of the array structure layer away from the substrate. The terminal is located in the bonding area and is used to connect an external driving signal. The anode is located in the display area. The terminal includes a first metal layer and a second metal layer stacked together. The second metal layer is disposed on the surface of the first metal layer away from the array structure layer. The etching amount of the first metal layer is greater than that of the second metal layer, such that the edge of the second metal layer protrudes beyond the edge of the first metal layer. An undercut structure is formed on the side of the terminal near the display area. A pixel definition layer is fabricated on the surface of the anode away from the substrate. The pixel definition layer also extends and covers the array structure layer and is located in the display area. The pixel definition layer has a pixel hole at a position corresponding to the anode. A light-emitting material layer is prepared within the pixel hole of the pixel definition layer; An electronic functional layer is fabricated on the light-emitting material layer, and the electronic functional layer further extends and covers the pixel definition layer, the array structure layer, and the terminal; wherein the electronic functional layer covering the second metal layer is disconnected from the electronic functional layer covering the array structure layer; A cathode is fabricated on the surface of the electronic functional layer away from the array structure layer. The cathode directly covers the surface of the second metal layer near the array structure layer. The cathode is continuously disposed at the undercut structure and electrically connected to the terminal.

8. The method for preparing an OLED display panel according to claim 7, characterized in that, The step of fabricating an electronic functional layer on the luminescent material layer, wherein the electronic functional layer further extends and covers the pixel definition layer, the array structure layer, and the terminal, includes: A mask is provided, and an electronic functional layer is prepared on the light-emitting material layer by means of the mask at a deposition angle α. The electronic functional layer also extends and covers the pixel definition layer, the array structure layer and the terminal. The thickness of the electronic functional layer located in the bonding region is H1, and the thickness of the first metal layer is H2. <H2。 9. The method for preparing an OLED display panel according to claim 8, characterized in that, The step of fabricating a cathode on the surface of the electronic functional layer away from the array structure layer, wherein the cathode directly covers the surface of the second metal layer near the array structure layer, includes: A cathode is fabricated on the surface of the electronic functional layer away from the array structure layer using the mask at a deposition angle β. The cathode directly covers the surface of the second metal layer near the array structure layer. The thickness of the cathode is H3, where H2 ≤ H1 + H3.

10. The method for preparing an OLED display panel according to claim 9, characterized in that, The evaporation angle α is greater than the evaporation angle β.

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