An OLED device and a method for manufacturing the same

Abstract

The present invention provides an OLED device and a preparation method thereof, including a substrate and a packaging layer. The substrate is divided into a pixel region and a packaging region. The connection between the substrate and the packaging layer is realized through a sealing medium. A first electrode layer, an organic light-emitting layer, and a second electrode layer are stacked in the pixel region on the substrate, and a buffer layer is provided between the first electrode layer and the substrate. The present invention solves the side etching phenomenon occurring in the dry etching of the auxiliary electrode by providing a buffer layer, and at the same time blocks the metal ions of the glass substrate from infiltrating into the first electrode layer / auxiliary electrode to avoid electrochemical corrosion; by adding an auxiliary electrode, the brightness uniformity of the screen body is improved; at the same time, a pixel definition layer is provided on the first electrode layer and the auxiliary electrode, which is in direct contact with the buffer layer. The materials of the pixel definition layer and the buffer layer are both inorganic compounds, forming a good surrounding structure for the effective pixel region and / or pixels of the OLED, avoiding the release of volatile gas outgas into the pixels, causing pixel shrinkage, and improving the reliability of the OLED screen body.

Description

Technical Field

[0001] The present invention relates to the field of OLED devices, and particularly to an OLED device and a method for manufacturing the same. Background Art

[0002] Organic light-emitting devices (OLED devices) have more advantages compared to other lighting methods (such as candles, halogen lamps, LED lamps). For example, they have no ultraviolet or infrared radiation, soft light, no glare, no stroboscopic effect, rich spectrum, high color rendering quality, etc. And they can be applied in general lighting, automotive lighting, and display fields. Currently, a major bottleneck restricting OLED devices is their service life.

[0003] The structure of traditional OLED devices includes a substrate, an anode, an insulating layer, an organic functional layer, a cathode, and a packaging structure. Among them, the substrate is usually ordinary alkali-free glass (Glass); the anode is usually a transparent conductive oxide (such as indium tin oxide ITO, aluminum-doped zinc oxide AZO); the insulating layer is generally a photoresist resin, and the material is phenolic resin or polymethyl methacrylate; the organic functional layer can also include a hole injection layer (HIL), a hole transport layer (HTL), a light-emitting layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), etc. The packaging layer can be a glass packaging cover, which is bonded to the substrate through UV glue to protect the organic functional layer. The traditional device structure has the following disadvantages:

[0004] (1) Since the substrate is in direct contact with the anode, some ions in the substrate (such as potassium ions, calcium ions, etc.) will penetrate into the anode and cause electrochemical corrosion, which will affect the work function of the anode, increase the power consumption of the OLED, and then reduce the OLED life;

[0005] (2) The adopted photoresist insulating layer, because it is usually an organic resin, when the OLED is lit for a long time, it will cause harmful gases (outgas) to be released from the resin, such as water, carbon dioxide, sulfur compounds, etc. Outgas further reacts chemically with the organic functional layer, affecting the performance of the organic functional layer, and then affecting the OLED life;

[0006] (3) Usually, large-area OLED devices have the phenomenon of uneven brightness. The brightness uniformity can be improved by adding an auxiliary electrode (such as molybdenum-aluminum-molybdenum). However, the industry uses a dry etching method for etching, and it is easy to generate Figure 4 the undercut problem during the dry etching process. The main reason is that during the dry etching process, during the longitudinal etching process of the dry etching gas, the "side etching" occurs on the substrate side. The "undercut" is not expected because it will cause discontinuity and breakage of the subsequent OLED film layers, resulting in packaging failure and abnormal lighting, thus affecting the device service life;

[0007] (4) During the preparation process of OLED, impurities (Particles) are inevitably introduced. Since the device film layer is relatively thin (<500 nm), the introduction of Particles may cause the anode and cathode of the device to come into contact, forming a short-circuit point. The current flows through the short-circuit point, forming a black spot, and the black spot expands, eventually leading to the failure of the entire screen.

[0008] (5) OLED organic materials are vulnerable to water and oxygen erosion. Thin film encapsulation is a good method. However, since thin film encapsulation generally forms an inorganic material such as silicon oxide, silicon nitride or silicon oxynitride by chemical vapor deposition (PECVD), thin film encapsulation usually has a large stress. When the stress is released, it will cause the thin film to wrinkle or break, affecting the thin film encapsulation effect, and then leading to water and oxygen erosion, affecting the lifespan of the OLED device. Summary of the Invention

[0009] Therefore, the technical problem to be solved by the present invention is the problem of poor device lifespan and failure caused by materials or structures in the prior art. For this purpose, the present invention provides an OLED device and its manufacturing method. By adding a buffer layer on the substrate, the metal ions in the glass can be blocked from penetrating into the device. At the same time, the added buffer layer can improve the dry etching undercut problem of the auxiliary electrode thereon, and the Taper angle of the auxiliary electrode is 20-80°, improving the device encapsulation lifespan. In addition, by selecting an inorganic compound as the pixel defining layer, the release of volatile gas outgas into the pixel interior is avoided, preventing pixel shrinkage and improving the reliability of the OLED screen. Moreover, the pixel defining layer provided on the first electrode layer and the auxiliary electrode is in direct contact with the buffer layer, forming a good surrounding structure for the effective pixel region and / or pixels of the OLED, reducing the erosion of impurities or gases introduced during the process on the pixel region. At the same time, the pixel defining layer and / or buffer layer located in the encapsulation region are patterned, and the encapsulation layer on the OLED material is in direct contact with the patterned pixel defining layer and / or buffer layer, further forming a good stress release structure, increasing the interface encapsulation effect, reducing the intrusion of water and oxygen, and improving the encapsulation reliability.

[0010] To achieve the above invention purpose, the present invention adopts the following technical solutions:

[0011] An OLED device, comprising a substrate and an encapsulation layer. Inside the sealed space formed by the substrate and the encapsulation layer, a first electrode layer, an auxiliary electrode and a pixel defining layer are provided.

[0012] A buffer layer is disposed between the first electrode layer / auxiliary electrode and the substrate. A plurality of auxiliary electrodes arranged at intervals are disposed on the buffer layer. The first electrode layer covers the buffer layer and the auxiliary electrodes. The pixel defining layer completely covers the first electrode layer on the auxiliary electrodes and is patterned with an opening exposing at least a part of the first electrode layer. The pixel defining layer and the opening are covered with a continuous organic light-emitting layer and a second electrode layer.

[0013] A plurality of pixel regions arranged in an array and an encapsulation region surrounding all the pixel regions are defined on the substrate. The edge positions of each pixel region are respectively surrounded by the pixel defining layer. The auxiliary electrodes are distributed at the horizontal and / or vertical positions of the pixel regions arranged in an array; the first electrode layer and the auxiliary electrodes in the encapsulation region are etched away, so that the pixel defining layer is in direct contact with the buffer layer.

[0014] A continuous patterned structure is formed on the buffer layer in the encapsulation region, and the encapsulation layer is in direct contact with the patterned structure formed on the buffer layer.

[0015] The patterned structure is a plurality of groove structures and / or dam structures patterned on the buffer layer.

[0016] The first electrode layer on one side or both sides of the auxiliary electrode is etched away, so that the pixel defining layer in this region is in direct contact with the buffer layer.

[0017] The width of the region where the first electrode layer on one side or both sides of each auxiliary electrode is in direct contact with the buffer layer is 1 μm - 1 cm.

[0018] In the direction perpendicular to the auxiliary electrode, a short-circuit prevention structure layer is patterned on the first electrode layer between two adjacent pixel regions arranged in an array. The short-circuit prevention structure layer is electrically connected to the first electrode layer on the auxiliary electrode and one of the two adjacent pixel regions, and is in an open circuit with the other pixel region; the pixel defining layers on both sides of the short-circuit prevention structure layer are in direct contact with the buffer layer.

[0019] Further, the width of the region where the pixel defining layer is in direct contact with the buffer layer on one side or both sides of each auxiliary electrode is 5 μm - 10 mm.

[0020] One or more combinations among several metals such as titanium (Ti), aluminum (Al), molybdenum (Mo), and copper (Cu).

[0021] The Taper angle formed by the auxiliary electrode is 10 - 90°.

[0022] The etching selectivity of the material with a small etching rate in the auxiliary electrode to the material of the buffer layer is (0.5 - 20);

[0023] The etching selectivity between the material of the pixel defining layer and the material of the buffer layer is (0.5 - 5).

[0024] Further preferably, the etching selectivity between the material of the auxiliary electrode and the material of the buffer layer is (5 - 7).

[0025] The thickness of the buffer layer is 10 nm - 3 μm.

[0026] A planarized auxiliary buffer layer is further provided on the buffer layer between the auxiliary electrodes, and the auxiliary electrodes protrude 0 - 1 μm above the auxiliary buffer layer.

[0027] The materials of the pixel defining layer, the buffer layer and the encapsulation layer are the same or different, and are one or a combination of several of silicon nitride, silicon oxide or silicon oxynitride.

[0028] The encapsulation layer is a thin film encapsulation structure, and a cover plate is further provided thereon. The cover plate is combined with the encapsulation layer through an encapsulation transition layer.

[0029] Alternatively, the encapsulation layer is an encapsulation cover, and the encapsulation cover is combined with the buffer layer in the encapsulation area on the substrate through a UV adhesive.

[0030] Meanwhile, the present invention also provides a method for manufacturing an OLED device, including the following steps:

[0031] S1. Divide a pixel area and an encapsulation area surrounding the pixel area on a substrate, deposit a buffer layer on the substrate, prepare auxiliary electrodes on the buffer layer, and form a plurality of auxiliary electrodes arranged at intervals through etching. The Taper angle of the auxiliary electrodes is 10 - 90°;

[0032] S2. On the basis of step S1, prepare a first electrode layer. The first electrode layer covers the buffer layer and the auxiliary electrodes, and etch away the first electrode layer located between the auxiliary electrodes and the encapsulation area to expose the buffer layer;

[0033] S3. On the basis of step S2, deposit a pixel defining layer. The pixel defining layer covers the first electrode layer and the buffer layer, and etch the pixel defining layer to form an opening. The bottom of the opening is the first electrode layer and the buffer layer;

[0034] S4. On the basis of step S3, fabricate an organic light-emitting layer and a second electrode layer by evaporation. A continuous organic light-emitting layer and a second electrode layer are formed on the pixel defining layer and in the opening;

[0035] S5. On the basis of step S4, fabricate an encapsulation layer. The encapsulation layer covers the entire pixel area, and seals and protects the entire pixel area in the encapsulation area surrounding the pixel area.

[0036] The described step S2 is as follows: On the basis of step S1, a first electrode layer is prepared, and the first electrode layer covers the buffer layer and the auxiliary electrode. The first electrode layer located on one side or both sides of the auxiliary electrode is etched away to expose the buffer layer; an anti-short circuit structure layer is etched and formed.

[0037] In the described step S3, a plurality of patterned groove structures and / or dam structures are formed on the buffer layer located within the encapsulation area; when encapsulating in step S5, the encapsulation layer is in direct contact with the patterned groove structures and / or dam structures on the buffer layer.

[0038] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0039] (1) In the present invention, a buffer layer is added on the glass substrate, which can block metal ions of the glass substrate from infiltrating into the first electrode layer / auxiliary electrode, avoid electrochemical corrosion, and improve the stability of the OLED device.

[0040] (2) Through the added buffer layer structure, side etching during the dry etching or etching process for forming the auxiliary electrode can be avoided, thereby effectively solving the occurrence of the "undercut" phenomenon. The continuity of subsequent organic / metal / encapsulation film layers is improved, and thus the encapsulation reliability and the screen life are enhanced.

[0041] (3) In the present invention, an anti-short circuit structure is introduced through the patterning of the first electrode, so that the device does not fail due to device short circuit during long-term aging (such as long-term lighting).

[0042] (4) In the present invention, an inorganic compound (such as silicon oxide, silicon nitride, silicon oxynitride) is selected as the pixel definition layer to avoid the release of volatile gases (outgas) into the pixel interior, which may cause pixel shrinkage, and improve the reliability of the OLED screen. Moreover, the pixel definition layer provided on the first electrode layer and the auxiliary electrode is in direct contact with the buffer layer, forming a good surrounding structure for the effective pixel area and / or pixels of the OLED, reducing the erosion of impurities or gases introduced during the process to the pixel area, and thus improving the screen life.

[0043] (5) For the OLED device provided by the present invention, a patterned groove structure is made on the buffer layer located within the encapsulation area and / or a dam structure is provided on the buffer layer. The encapsulation layer is in direct contact with the patterned groove structures and / or dam structures on the buffer layer, further forming a good stress release structure, increasing the interface bonding encapsulation effect, reducing the intrusion of water and oxygen, and enhancing the encapsulation reliability and the screen life.

[0044] (6) As a special structure of the present invention, the present invention also adds a silicon nitride (or silicon oxide) structure of an auxiliary buffer layer on the buffer layer 6 between the auxiliary electrodes. The auxiliary buffer layer structure is fabricated and planarized by methods such as dry etching, grinding, and lift-off. The height D of the auxiliary electrode above the auxiliary buffer layer is 0 - 1 μm. This makes the subsequent first electrode layer more planar and helps improve the uniformity of the contact resistance (the resistance of the contact between the auxiliary electrode and the first electrode). BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0046] Figure 1 Schematic diagram of the OLED device of the present invention;

[0047] Figure 2 is Figure 1 A - A' cross-sectional view of;

[0048] Figure 3 Schematic diagram of the structure of the auxiliary electrode of the present invention;

[0049] Figure 4 Schematic diagram of the structure of the auxiliary electrode in the prior art;

[0050] Figure 5 Schematic diagram of the structure of the auxiliary buffer layer provided on the buffer layer;

[0051] Figure 6 Top view after the pixel defining layer is fabricated;

[0052] Figure 7 is Figure 6 C - C' cross-sectional view of;

[0053] Figure 8 is Figure 6 D - D' cross-sectional view of;

[0054] Figure 9 is Figure 8 Partial enlarged view of;

[0055] Figure 10 Schematic diagram of the structure with a cover plate provided by the present invention;

[0056] Figure 11 is Figure 10 Schematic diagram of the first partial structure shown;

[0057] Figure 12 is Figure 10 the second local structure schematic diagram shown;

[0058] Figure 13 is Figure 10 the third local structure schematic diagram shown;

[0059] Figure 14 is Figure 10 the fourth local structure schematic diagram shown.

[0060] Explanation of reference numerals: 1 - substrate, 2 - first electrode layer, 3 - organic light-emitting layer, 4 - second electrode layer, 5 - cover plate, 6 - buffer layer, 7 - auxiliary electrode, 8 - UV glue, 9 - encapsulation area, 10 - encapsulation layer, 11 - pixel area, 12 - pixel definition layer, 13 - anti-short circuit structure layer, 14 - auxiliary buffer layer, 15 - dam structure, 16 - groove structure, 17 - opening; 18 - encapsulation transition layer. Detailed implementation manners

[0061] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0062] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0063] The present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the present invention to those skilled in the art. The present invention will be defined only by the claims. In the drawings, the dimensions and relative dimensions of layers and regions are exaggerated for clarity. It should be understood that when an element such as a layer, region, or substrate is referred to as being "formed on" or "disposed on" another element "above", the element can be directly disposed on the other element, or there can also be an intermediate element. On the contrary, when an element is referred to as being "directly formed on" or "directly disposed on" another element, there is no intermediate element.

[0064] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0065] As Figure 1 and Figure 2 shown, an OLED device provided by the present invention includes a substrate 1 and a packaging layer 10. A first electrode layer 2, an auxiliary electrode 7, and a pixel defining layer 12 are disposed in a sealed space formed by the substrate 1 and the packaging layer 10. A buffer layer 6 is disposed between the first electrode layer / and the substrate. A plurality of auxiliary electrodes 7 arranged at intervals are disposed on the buffer layer 6. The first electrode layer 2 covers the buffer layer 6 and the auxiliary electrode 7. The pixel defining layer 12 completely covers the first electrode layer 2 on the auxiliary electrode and is patterned with an opening 17 that exposes at least a part of the first electrode layer 2. The shape of the opening 17 is a trapezoidal structure, and the bottom of the trapezoid is the first electrode layer 2. The pixel defining layer 12 and the opening 17 are covered with a continuous organic light emitting layer 3, a second electrode layer 4, and a packaging layer 10.

[0066] On the substrate 1, a plurality of pixel regions 11 and a packaging region surrounding all the pixel regions 11 are defined. The edge positions of each pixel region 11 are respectively surrounded by the pixel defining layer 12. The auxiliary electrodes are distributed at the horizontal and / or vertical positions of the pixel regions arranged in an array; the first electrode layer 2 and the auxiliary electrode 7 located between the auxiliary electrode 7 and the packaging region are etched away, and the pixel defining layer 12 located between the auxiliary electrode 7 and the packaging region is in direct contact with the buffer layer; preferably, the width of the region where the pixel defining layer 12 is in direct contact with the buffer layer 6 is 5 μm - 10 mm.

[0067] As a preferred embodiment, as Figure 6As shown, the first electrode layer 2 located on one or both sides of the auxiliary electrode 7 is etched away, so that the pixel defining layer 12 in this area is in direct contact with the buffer layer; the width of the direct contact area between the first electrode layer 2 located on one or both sides of each auxiliary electrode 7 and the buffer layer 6 is 1 μm - 1 cm. The width of the direct contact area between the pixel defining layer 12 and the buffer layer 6 located on one or both sides of each auxiliary electrode 7 is 5 μm - 10 mm.

[0068] The auxiliary electrode 7 is one or a combination of several metals among titanium (Ti), aluminum (Al), molybdenum (Mo), and copper (Cu). For example, titanium-aluminum-titanium (TiAlTi), aluminum-titanium (AlTi), aluminum-molybdenum (AlMo), molybdenum-aluminum-molybdenum (MoAlMo), molybdenum (Mo), titanium (Ti), copper (Cu), and aluminum (Al) are used. As Figure 3 As shown, the Taper angle of the auxiliary electrode 7 is 10 - 90°, and the Taper angle here refers to the Taper angle of the aluminum layer in the auxiliary electrode 7.

[0069] The etching selectivity between the material with a small etching rate in the auxiliary electrode 7 and the material of the buffer layer 6 is (0.5 - 20), preferably (5 - 7); the Ti material or Mo material in the auxiliary electrode is the material with a small etching rate.

[0070] The etching selectivity between the material of the pixel defining layer 12 and the material of the buffer layer 6 is (0.5 - 5).

[0071] The thickness of the buffer layer 6 is 10 nm - 3 μm, preferably 100 nm.

[0072] An auxiliary buffer layer with planarization is also provided on the buffer layer 6 between the auxiliary electrodes 7, and the auxiliary electrode 7 is 0 - 1 μm higher than the auxiliary buffer layer.

[0073] The materials of the pixel defining layer 12, the buffer layer 6, and the encapsulation layer are the same or different, and are one or a combination of silicon nitride, silicon oxide, or silicon oxynitride.

[0074] The encapsulation layer 10 is a glass encapsulation cover. The glass encapsulation cover 5 is provided with a UV glue 8, and the glass encapsulation cover 5 is bonded to the buffer layer 6 and / or the pixel defining layer 12 on the substrate 1 through the UV glue 8.

[0075] Of course, the encapsulation layer can also adopt a thin film encapsulation method, and the encapsulation layer 10 is fabricated by chemical vapor deposition. The organic light-emitting layer 3, the second electrode layer 4, and the encapsulation layer are sequentially covered from bottom to top on the pixel defining layer 12 and in the opening. At the same time, the encapsulation layer in the encapsulation area is in direct contact with the buffer layer to form a thin film encapsulation; by attaching an encapsulation transition layer, such as UV glue or OCA glue, on the encapsulation layer, and then attaching a cover plate on the encapsulation transition layer for sealing. Here, the cover plate can include glass, copper foil, aluminum foil, etc.

[0076] In order to achieve a better encapsulation effect in the OLED encapsulation area, a continuously arranged patterned structure is formed on the buffer layer 6 located in the encapsulation area, and the encapsulation layer 10 is in direct contact with the patterned structure formed on the buffer layer 6. As Figure 12 , Figure 13 and Figure 14 shown, the patterned structure here is a plurality of recessed structures 16 and / or dam structures 15 patterned on the buffer layer 6. The encapsulation layer covers the patterned structure, and the encapsulation layer 10 is in direct contact with the recessed structures 16 and / or dam structures 15 patterned on the buffer layer 6, further forming a good stress release structure, increasing the interface bonding encapsulation effect, reducing the intrusion of water and oxygen, and improving the encapsulation reliability.

[0077] A method for manufacturing an OLED device, as Figures 1 to 2 shown, includes the following steps:

[0078] S1. Divide the pixel area 11 and the encapsulation area surrounding the pixel area 11 on the substrate 1. Deposit the buffer layer 6 on the pixel area, and prepare the auxiliary electrode 7 on the buffer layer 6. After etching, a plurality of auxiliary electrodes 7 arranged at intervals are formed, and the Taper angle of the auxiliary electrode 7 is 10 - 90°;

[0079] S2. On the basis of step S1, prepare the first electrode layer 2. The first electrode layer 2 covers the buffer layer 6 and the auxiliary electrode 7, and etch away the first electrode layer 2 located between the auxiliary electrode 7 and the encapsulation area 9 to expose the buffer layer 6;

[0080] S3. On the basis of step S2, deposit the pixel defining layer 12. The pixel defining layer 12 covers the first electrode layer 2 and the buffer layer 6, and etch the pixel defining layer 12 to form an opening with a trapezoidal structure, and the bottom of the trapezoidal structure is the first electrode layer 2 and the buffer layer 6;

[0081] S4. On the basis of step S3, fabricate the organic light-emitting material layer 3 and the second electrode layer 4 by evaporation. A continuous organic light-emitting layer 3 and second electrode layer 4 are formed on the pixel defining layer 12 and within the opening;

[0082] S5. On the basis of step S4, fabricate the encapsulation layer 10. The encapsulation layer 10 covers the entire pixel area 11, and seals and protects the entire pixel area 11 in the encapsulation area 9 surrounding the pixel area 11.

[0083] As Figures 6 to 9 shown in the structure preparation, other steps are the same as above, and step S2 is: on the basis of step S1, prepare the first electrode layer 2. The first electrode layer 2 covers the buffer layer 6 and the auxiliary electrode 7, and etch away the first electrode layer 2 on one side or both sides of the auxiliary electrode 7 to expose the buffer layer 6; etch to form the anti-short circuit structure layer 13, and the anti-short circuit structure layer 13 is located below the pixel defining layer and is covered by the pixel defining layer.

[0084] The materials and thicknesses used for each layer are as follows:

[0085] Buffer layer: The buffer layer is an inorganic material, such as silicon nitride, silicon oxide, silicon oxynitride. The film deposition method can use chemical vapor deposition (CVD) or atomic layer deposition (ALD). The buffer layer is preferably silicon nitride, with a thickness of 10 nm - 3 μm, preferably 100 nm - 150 nm.

[0086] Auxiliary electrode: The auxiliary electrode is a metal or metal alloy, such as TiAlTi, AlTi, MoAl, MoAlMo, Mo, Ti, Cu, Al. Patterning is carried out using dry etching or wet etching processes; preferably a TiAlTi three-layer structure, with the bottom Ti being 50 - 100 nm, preferably 75 nm, the top Ti being 50 - 100 nm, preferably 50 nm, and Al being 300 - 700 nm, preferably 300 nm; dry etching is carried out using Cl2 and BCl3 (not limited to these two gases), 10 ≤ Taper angle ≤ 90°, preferably 20 - 80°. Among them, the AlTi structure is, from bottom to top, an Al material layer and a Ti material layer, as Figure 3 shown; among them, the MoAlMo structure is, from bottom to top, a Mo material layer, an Al material layer, and a Mo material layer.

[0087] First electrode layer: A transparent conductive metal oxide, such as ITO, AZO, is sputtered by PVD; patterning uses dry etching or wet etching, preferably wet etching, such as etching using hydrochloric acid, nitric acid, acetic acid, etc. or their mixed acids; preferably having a short-circuit prevention patterning structure, that is, through the patterning of the first electrode, pixels can be formed. Refer to the attached Figure 6 .

[0088] Pixel defining layer (or dielectric layer or insulating layer), above the first electrode layer and / or the auxiliary electrode, with a material of silicon oxide, silicon nitride, or silicon oxynitride, using the same process as the buffer layer (such as CVD, ALD), with a thickness of 200 nm - 500 nm, preferably 300 nm, and an etching selectivity ratio with the buffer layer of (0.5 - 5); through the patterning of the first electrode to form "pixels", the pixel defining layer can be in direct contact with the buffer layer, such as H ≥ 0.5 μm in the attached figure. Furthermore, the pixel defining layer forms a good surrounding structure for the effective pixel region and / or pixels of the OLED, avoiding outgas from being released into the pixels, causing pixel shrinkage, improving the reliability of the OLED screen body, and since the materials of the pixel defining layer and the buffer layer are generally the same, the interfacial bonding property is more stable, further improving the packaging reliability of the screen body.

[0089] Organic light-emitting layer 3: including but not limited to hole injection layer (HIL), hole transport layer (HTL), light-emitting layer (EL), electron transport layer (ETL), electron injection layer (EIL), etc.

[0090] The second electrode layer 4, including Al electrode, MgAg electrode, metal oxide electrode (such as ITO), etc. For example, thermally evaporating and sputtering a 200-nm-thick Al layer;

[0091] Encapsulation layer 10: encapsulating the organic light-emitting layer 3, and encapsulating it through the combination of a glass encapsulation cover and UV glue or glass frit in the traditional encapsulation method. For example, using UV glue to encapsulate the substrate and the encapsulation cover to prevent water and oxygen from eroding.

[0092] Of course, in order to improve the encapsulation reliability of the screen body, a thin-film encapsulation method is adopted, such as inorganic layer / organic layer / inorganic layer. The inorganic layer can be deposited by chemical vapor deposition (CVD), and the organic layer can be printed by inkjet printing (IJP). For example, SiO (1μm) / IJP (8μm) / SiO (1μm) is adopted.

[0093] The present invention has the following embodiments:

[0094] Embodiment 1

[0095] As Figure 1 and Figure 2 shown, an OLED device provided by the present invention includes a substrate 1 and an encapsulation layer 10. The substrate 1 is divided into a pixel area 11 and an encapsulation area 9 surrounding the pixel area 11. A UV glue 8 is provided in the encapsulation area 9 to hermetically connect the substrate 1 and the encapsulation layer 10 to form a sealed space. Here, the encapsulation layer is a glass encapsulation cover. A desiccant can be provided on the side of the encapsulation cover close to the substrate 1 to absorb water vapor. Using UV glue as a sealing material layer to encapsulate the substrate and the encapsulation cover can improve the encapsulation reliability of the screen body. The thickness of the buffer layer 6 is 10 nm - 3 μm.

[0096] A buffer layer 6 is provided in the light-emitting area of the substrate 1. A plurality of auxiliary electrodes 7 arranged at intervals are provided on the buffer layer 6. The first electrode layer 2 covers the buffer layer 6 and the auxiliary electrodes 7. The first electrode layer 2 located between the auxiliary electrodes 7 and the encapsulation area is etched away. The width H of the etched-away first electrode layer 2 is 10 μm to expose the buffer layer 6;

[0097] The pixel defining layer 12 completely covers the first electrode layer on the auxiliary electrodes and is patterned with an opening for exposing at least a part of the first electrode layer. The shape of the opening is a trapezoidal structure. The bottom of the trapezoid is the first electrode layer 2. The pixel defining layer and the opening are covered with a continuous organic light-emitting layer 3 and a second electrode layer 4. Since there is no first electrode layer on the buffer layer 6 between the auxiliary electrodes 7 and the encapsulation area 9, the buffer layer 6 in this area is directly in contact with the pixel defining layer 12.

[0098] The width H of the direct contact area between the pixel defining layer 12 and the buffer layer 6 is 10 μm.

[0099] The auxiliary electrode 7 includes an Al material layer and a Ti material layer stacked on top of each other, and the Ti material layer is located above the Al material layer. As Figure 3 shown, the Taper angle of the auxiliary electrode 7 is 20 - 80°. From Figure 3 comparison with Figure 4 it can be seen that adding the SiN buffer layer can effectively improve the Taper angle of AlTi. This is because the etching selectivity between Al and Ti is relatively large, and the etching rate of Al > the etching rate of Ti. Without adding SiN, side etching will occur on the substrate side, resulting in undercutting. At the same time, due to the added buffer layer BufferLayer blocking the penetration of metal ions in the glass substrate into the ITO layer, it avoids the electrochemical corrosion of ITO and improves the stability of the OLED device.

[0100] The etching selectivity ratio between the material of the auxiliary electrode 7 and the material of the buffer layer 6 is (0.5 - 20), preferably (5 - 7);

[0101] The etching selectivity ratio between the material of the pixel defining layer 12 and the material of the buffer layer 6 is (0.5 - 5).

[0102] The etching selectivity ratio means the ratio of the etching rates of different films under the same conditions. That is: the etching rate of film A is E a , and the etching rate of film B under the same conditions is E b , and the etching selectivity ratio at this time is S A / B = E a / E b

[0103] The materials of the pixel defining layer and the buffer layer are the same or different, and are one or a combination of silicon nitride, silicon oxide, or silicon oxynitride.

[0104] A method for manufacturing an OLED device, as Figures 6 to 9 shown, includes the following steps:

[0105] S1. Divide the pixel area 11 and the encapsulation area surrounding the pixel area 11 on the substrate 1, deposit the buffer layer 6 on the pixel area, prepare the auxiliary electrode on the buffer layer 6, and form a plurality of spaced-apart auxiliary electrodes 7 through etching. The Taper angle of the auxiliary electrode 7 is 20 - 80°;

[0106] S2. On the basis of step S1, prepare the first electrode layer 2. The first electrode layer 2 covers the buffer layer 6 and the auxiliary electrode 7, and etch away the first electrode layer 2 located between the auxiliary electrode 7 and the encapsulation area to expose the buffer layer 6;

[0107] S3. On the basis of step S2, deposit a pixel defining layer 12, where the pixel defining layer 12 covers the first electrode layer 2 and the buffer layer 6 located between the auxiliary electrode 7 and the encapsulation area. Etch the pixel defining layer 12 to form an opening with a trapezoidal structure, and the bottom of the trapezoidal structure is the first electrode layer 2 and the buffer layer;

[0108] S4. On the basis of step S3, fabricate a light-emitting material layer 2 and a second electrode layer 3 by evaporation. A continuous organic light-emitting layer 3 and a second electrode layer 4 are formed on the pixel defining layer 12 and within the opening;

[0109] S5. On the basis of step S4, fabricate an encapsulation layer 10. Here, the encapsulation layer 10 is a glass encapsulation cover, that is, coat a UV glue on the glass encapsulation cover, and then hermetically connect it to the buffer layer at the encapsulation area position on the substrate, thereby realizing the encapsulation of the entire pixel area, as Figure 2 shown.

[0110] In this embodiment, the materials and thicknesses of each layer are as follows:

[0111] Substrate 1, the material is alkali-free glass;

[0112] Buffer layer 6 (Buffer layer), deposit a layer of silicon nitride with a thickness of 100 nm through a high-temperature CVD process, the process temperature is 350 °C, the adhesion to the substrate is 5B, and the refractive index is 1.8;

[0113] The auxiliary electrode 7 is AlTi, the top titanium is 50 nm, and Al is 300 nm; pattern it by dry etching with Cl2 and BCl3, and the Taper angle is 70°; etching is not limited to dry etching, and wet etching can also be selected. Select a mixed acid solution of H3PO4, CH3COOH, and HNO3 in a certain ratio for etching;

[0114] The first electrode layer 2, sputter indium tin oxide (ITO) by PVD, with a thickness of 150 nm, and pattern it by a wet process (acid etching);

[0115] The pixel defining layer 12, above the first electrode layer, the material is SiN, using the same process as the Buffer, with a thickness of 300 nm, the grid size is 400 μm * 400 μm, and pattern it by dry etching to form the pixel defining layer;

[0116] Organic light-emitting layer 3: including but not limited to a hole injection layer (HIL), a hole transport layer (HTL), a light-emitting layer (EL), an electron transport layer (ETL), an electron injection layer (EIL), etc.;

[0117] The second electrode layer 4 includes an Al electrode, a MgAg electrode, and a metal oxide electrode (such as ITO). For example, sputter a layer of Al with a thickness of 200 nm by thermal evaporation;

[0118] Encapsulation layer 10: Encapsulates the organic light-emitting layer 3, and performs encapsulation through the combination of a glass encapsulation cover by traditional encapsulation and UV glue or glass frit.

[0119] On the basis of Example 1, different materials for the auxiliary electrode 7 and the buffer layer 6 are respectively selected, and the etching selectivity between the material of the pixel definition layer 12 and the material of the buffer layer 6 is preferably 1.

[0120] The effects produced by the etching selectivity between different auxiliary electrodes and buffer layers are shown in the following table:

[0121] Etch selectivity between the auxiliary electrode layer 7 and the buffer layer 6 Taper of Al Side etching of Al <0.5 \ Yes 0.5-20 70 No >20 \ Yes

[0122] As can be seen from the above table, when the etching selectivity between the material of the auxiliary electrode 7 and the material of the buffer layer 6 is small (<0.5), it is easy to cause the buffer layer to be etched away, resulting in Figure 4 the side etching problem, so an inverted trapezoid appears; when the etching selectivity is relatively high (>20), it is difficult to etch away the buffer layer, and side etching is also likely to occur, and then an inverted trapezoid appears. In the present invention, the preferred etching selectivity between the material of the auxiliary electrode 7 and the material of the buffer layer 6 is 5 - 7, which can control the Taper angle of Al within 70° ± 3°. At the same time, the material of the pixel definition layer 12 and the material of the buffer layer 6 are preferably the same or similar, which can well ensure the interface bonding effect, make the subsequent OLED film layer more continuous, have a better encapsulation effect, and improve the service life of the OLED device.

[0123] Example 2

[0124] The basic structure of an OLED device provided by the present invention is the same as that of Example 1, and the difference lies in that: the encapsulation layer in this embodiment adopts a thin-film encapsulation structure, as shown in Figure 10 and Figure 11 shown.

[0125] S1. Divide the pixel area 11 and the encapsulation area surrounding the pixel area 11 on the substrate 1, deposit the buffer layer 6 on the pixel area, prepare the auxiliary electrode on the buffer layer 6, and form a plurality of auxiliary electrodes 7 arranged at intervals through etching. The Taper angle of the auxiliary electrode 7 is 10°;

[0126] S2. On the basis of step S1, prepare the first electrode layer 2, and the first electrode layer 2 covers the buffer layer 6 and the auxiliary electrode 7. Etch away the first electrode layer 2 located between the auxiliary electrode 7 and the encapsulation area to expose the buffer layer 6;

[0127] S3. On the basis of step S2, deposit the pixel definition layer 12. The pixel definition layer 12 covers the first electrode layer 2 and the buffer layer located between the auxiliary electrode 7 and the encapsulation area. Etch the pixel definition layer 12 to form an opening with a trapezoidal structure, and the bottom of the trapezoidal structure is the first electrode layer 2 and the buffer layer;

[0128] S4. On the basis of step S3, the light-emitting material layer 2 and the second electrode layer 3 are fabricated by evaporation, and a continuous organic light-emitting layer 3 and a second electrode layer 4 are formed on the pixel defining layer 12 and within the opening.

[0129] S5. On the basis of step S4, the encapsulation layer 10 is fabricated. Here, the encapsulation layer 10 adopts a thin-film encapsulation method, such as an inorganic layer / organic layer / inorganic layer. The inorganic layer can be deposited by chemical vapor deposition (CVD), and the organic layer is printed by inkjet printing (IJP). For example, SiO(1μm) / IJP(8μm) / SiO(1μm) is used. The encapsulation layer 10 covers the entire pixel area 11, and the entire pixel area 11 is hermetically protected in the encapsulation area 9 surrounding the pixel area 11.

[0130] S6. The encapsulation transition layer 18 is coated on the cover plate 5, and then the cover plate 5 is placed on the encapsulation layer, thereby realizing the encapsulation of the entire pixel area.

[0131] Compared with Embodiment 1, adopting the thin-film encapsulation method can further improve the encapsulation reliability of the screen body.

[0132] Embodiment 3

[0133] As Figures 6 to 9 shown, the basic structure of an OLED device provided by the present invention is the same as that of Embodiment 2, and the difference lies in:

[0134] A buffer layer 6 is provided in the light-emitting area of the substrate 1. An anti-short circuit structure layer 13 formed by the first electrode layer, several auxiliary electrodes 7 arranged at intervals are provided on the buffer layer 6. The first electrode layer 2 covers the buffer layer 6 and the auxiliary electrodes 7. The first electrode layer 2 located on one side or both sides of the auxiliary electrode 7 is etched away. The width H of the etched-away first electrode layer 2 is 10 μm to expose the buffer layer 6. By introducing the anti-short circuit structure through the patterning of the first electrode, it can be ensured that the device does not fail due to device short circuit during long-term aging (such as long-term lighting).

[0135] As Figure 7 shown, the pixel defining layer 12 completely covers the first electrode layer 2 on the auxiliary electrode and is provided with an opening for exposing at least a part of the first electrode layer 2. The shape of the opening is a trapezoidal structure. The bottom of the trapezoid is the first electrode layer 2. The pixel defining layer 12 and the opening are covered with a continuous organic light-emitting layer 3 and a second electrode layer 4. Since there is no first electrode layer on the buffer layer on one side or both sides of the auxiliary electrode 7, the buffer layer 6 in this area is in direct contact with the pixel defining layer 12.

[0136] Combined Figure 6 and Figure 7, in a direction perpendicular to the auxiliary electrode, a short - circuit prevention structure layer 13 is patterned on the first electrode layer between two adjacent pixel regions arranged in an array. The short - circuit prevention structure layer 13 is electrically connected to the first electrode layer 2 on the auxiliary electrode 7 and one of the two adjacent pixel regions, and forms an open circuit with the other pixel region; the pixel defining layers on both sides of the short - circuit prevention structure layer 13 are in direct contact with the buffer layer 6. The current flow direction in each pixel region is as Figure 6 shown by the arrow direction.

[0137] The width H of the direct - contact area between the pixel defining layer 12 and the buffer layer on one side or both sides of each auxiliary electrode is 10 μm.

[0138] A method for manufacturing an OLED device according to this embodiment, as Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 and Figure 11 shown, includes the following steps:

[0139] S1. Divide the pixel region 11 and the encapsulation region surrounding the pixel region 11 on the substrate 1. Deposit the buffer layer 6 on the pixel region. Prepare the auxiliary electrode on the buffer layer 6, and form a number of auxiliary electrodes 7 arranged at intervals through etching. The Taper angle of the auxiliary electrode 7 is 70°;

[0140] S2. On the basis of step S1, prepare the first electrode layer 2. The first electrode layer 2 covers the buffer layer 6 and the auxiliary electrode 7. Etch and remove the first electrode layer 2 on one side or both sides of the auxiliary electrode 7 to expose the buffer layer 6; etch to form the short - circuit prevention structure layer 13;

[0141] S3. On the basis of step S2, deposit the pixel defining layer 12. The pixel defining layer 12 covers the first electrode layer 2 and the buffer layer between the auxiliary electrode 7 and the encapsulation region 9. Etch the pixel defining layer 12 to form an opening with a trapezoidal structure. The bottom of the trapezoidal structure is the first electrode layer 2 and the buffer layer;

[0142] S4. On the basis of step S3, fabricate the light - emitting material layer 2 and the second electrode layer 3 by evaporation. A continuous organic light - emitting layer 3 and a second electrode layer 4 are formed on the pixel defining layer 12 and within the opening;

[0143] S5. On the basis of step S4, fabricate the encapsulation layer 10. Here, the encapsulation layer 10 adopts a thin - film encapsulation method, such as an inorganic layer / organic layer / inorganic layer. The inorganic layer can be deposited by chemical vapor deposition (CVD) for thin - film deposition, and the organic layer is printed by ink - jet printing (IJP) for thin - film printing. For example, SiO(1μm) / IJP(8μm) / SiO(1μm). The encapsulation layer 10 covers the entire pixel region 11, and seals and protects the entire pixel region 11 in the encapsulation region 9 surrounding the pixel region 11;

[0144] S6. Coat the encapsulation transition layer 18 on the cover plate 5, and then cover the cover plate 5 on the encapsulation layer, so as to realize the encapsulation of the entire pixel area.

[0145] Example 4

[0146] An OLED device provided by the present invention has the same basic structure as that in Example 3. The differences from Example 3 are as follows:

[0147] As Figure 5 shown, the following structure can also be formed on the substrate 1: a patterned auxiliary electrode 7 is formed on the substrate 1, and an auxiliary buffer layer 14SiN (or SiOx) is formed on the buffer layer 6 between the auxiliary electrodes 7 by PECVD. SiN (or SiOx) is planarized by methods such as dry etching, grinding or lift-off. It should be emphasized that the height D of the auxiliary electrode 7 above the auxiliary buffer layer 14 is 0 to 1 μm, which is beneficial to the lap joint of the first electrode layer. Figure 3 Shown is the buffer layer structure provided on the substrate in Examples 1 to 3. In this embodiment, the climbing of the first electrode layer can be avoided. Although the lap joint area of the first electrode layer on the auxiliary electrode in this embodiment is smaller than that in Figure 3 the structure shown in, compared with Examples 1 and 2, the lap joint resistance uniformity in this embodiment will be improved.

[0148] Comparative Example 1

[0149] The substrate 1 is made of non-alkali glass and adopts the conventional Figure 4 substrate structure shown;

[0150] The auxiliary electrode 7 is AlTi, with a top titanium of 50 nm and Al of 300 nm; it is prepared by an etching method Figure 4 to form the structure shown;

[0151] The first electrode layer is formed by PVD sputtering indium tin oxide (ITO) with a thickness of 150 nm;

[0152] The pixel defining layer is above the first electrode layer, made of SiN, and adopts the same process as Buffer, with a thickness of 300 nm and a grid size of 400 μm * 400 μm;

[0153] The organic light-emitting layer includes HIL, HTL, EL, ETL, and EIL;

[0154] The second electrode includes an Al electrode, and a layer of Al with a thickness of 200 nm is sputtered by thermal evaporation;

[0155] The encapsulation layer is a glass encapsulation cover, and the encapsulation area of the substrate and the encapsulation cover are combined by glass encapsulation using UV glue to improve the encapsulation reliability of the screen body.

[0156] The experimental test results are as follows:

[0157] At a brightness of 1000 nits, when the life test is carried out, it can be seen that the device of the present invention can increase the life of the OLED device by 5 times due to the addition of the buffer layer. It shows that adding the buffer layer can significantly improve the reliability of the screen body. The main reasons are as follows:

[0158] Due to the presence of the buffer layer, a more acute Taper angle is formed when dry-etching the first electrode or the auxiliary electrode, that is, due to the setting of the buffer layer, the "undercut" phenomenon of the above-mentioned auxiliary electrode can be well improved, avoiding "side etching", and better modifying the Taper angle of the auxiliary electrode, thereby improving the lap joint of the subsequent organic / metal / encapsulation film layers.

[0159] Furthermore, adding the buffer layer can block metal ions in the glass substrate from penetrating into the first electrode layer / auxiliary electrode, avoiding electrochemical corrosion and improving the stability of the OLED device.

[0160] After testing, the average life of the device in Example 1 of the present invention is 500 h@1000 nit, and the failure rate of the device after 1000 H of long-term aging is 20%;

[0161] The average life of the device in Example 2 is 550 h@1000 nit, and the failure rate of the device after 1000 H of long-term aging is 10%;

[0162] The average life of the device in Example 3 is 560 h@1000 nit, and because of the addition of the anti-short-circuit structure, the device has no failure after 1000 H of long-term aging;

[0163] The average life of the device in Example 4 is 600 h@1000 nit, and because of the addition of the anti-short-circuit structure, the device has no failure after 1000 H of long-term aging;

[0164] The average life of the device in Comparative Example 1 is 100 h@1000 nit.

[0165] By comparison, Examples 1 to 4 adopted by the present invention can greatly improve the device life compared with the prior art.

[0166] Example 5

[0167] This embodiment is based on Example 3, and a continuous dam structure surrounding the entire pixel region is provided at the buffer layer located in the encapsulation region, specifically as Figure 12 shown.

[0168] A method for manufacturing an OLED device includes the following steps:

[0169] S1. Divide a pixel region 11 and a packaging region surrounding the pixel region 11 on a substrate 1. Deposit a buffer layer 6 on the pixel region, and prepare an auxiliary electrode 7 on the buffer layer 6. After etching, a number of auxiliary electrodes 7 arranged at intervals are formed, and the Taper angle of the auxiliary electrode 7 is 70°;

[0170] S2. On the basis of step S1, prepare a first electrode layer 2. The first electrode layer 2 covers the buffer layer 6 and the auxiliary electrode 7. Etch and remove the first electrode layer 2 on one side or both sides of the auxiliary electrode 7 to expose the buffer layer 6, and etch to form a short-circuit prevention structure layer 13;

[0171] S3. On the basis of step S2, deposit a pixel defining layer 12. The pixel defining layer 12 covers the first electrode layer 2 and the buffer layer 6 in the packaging region. Etch the pixel defining layer 12 to form an opening with a trapezoidal structure, and form a raised dam structure (DAM) in the packaging region;

[0172] S4. On the basis of step S3, fabricate an organic light-emitting layer 3 and a second electrode layer 4 by evaporation. A continuous organic light-emitting layer 3 and second electrode layer 4 are formed on the pixel defining layer 12 and within the opening.

[0173] S5. On the basis of step S4, fabricate a packaging layer 10 by chemical vapor deposition. A continuous organic light-emitting layer 3, second electrode layer 4 and packaging layer are formed on the pixel defining layer 12 and within the opening. At the same time, the packaging layer in the packaging region is in direct contact with the buffer layer to form a thin-film package;

[0174] S6. By attaching a packaging transition layer, such as UV glue or OCA glue, to step S5, and then attaching a cover plate on the packaging transition layer for sealing. Here, the cover plate can include glass, copper foil, aluminum foil, etc.

[0175] Example 6

[0176] Different from Example 5, in this example, the buffer layer in the packaging region is patterned, specifically as Figure 13 shown. The patterned structure is two groove structures continuously arranged around all pixel regions, and a raised dam structure is also provided on the inner side of the packaging region.

[0177] A method for preparing an OLED device includes the following steps:

[0178] S1. Divide a pixel region 11 and a packaging region surrounding the pixel region 11 on a substrate 1. Deposit a buffer layer 6 on the pixel region, pattern the buffer layer 6 in the packaging region to form two groove structures 16, prepare an auxiliary electrode on the buffer layer 6, and after etching, a number of auxiliary electrodes 7 arranged at intervals are formed, and the Taper angle of the auxiliary electrode 7 is 70°;

[0179] S2. On the basis of step S1, prepare the first electrode layer 2, where the first electrode layer 2 covers the buffer layer 6 and the auxiliary electrode 7, and etch away the first electrode layer 2 on one or both sides of the auxiliary electrode 7 to expose the buffer layer 6; etch to form the short-circuit prevention structure layer 13;

[0180] S3. On the basis of step S2, deposit the pixel definition layer 12, where the pixel definition layer 12 covers the first electrode layer 2 and the buffer layer 6 in the encapsulation area, and etch the pixel definition layer 12 to form an opening with a trapezoidal structure, and form a raised dam structure (DAM) inside the encapsulation area;

[0181] S4. On the basis of step S3, fabricate the light-emitting material layer 2 and the second electrode layer 3 by evaporation, and a continuous organic light-emitting layer 3 and second electrode layer 4 are formed on the pixel definition layer 12 and inside the opening.

[0182] S5. On the basis of step S4, fabricate the thin-film encapsulation layer 10 by chemical vapor deposition, and a continuous organic light-emitting layer 3, second electrode layer 4, and encapsulation layer are formed on the pixel definition layer 12 and inside the opening. At the same time, the encapsulation layer in the encapsulation area is in direct contact with the buffer layer to form a thin-film encapsulation;

[0183] S6. By attaching an encapsulation transition layer, such as UV glue or OCA glue, on the basis of step S5, and then attaching a cover plate on the encapsulation transition layer for sealing. Here, the cover plate can include glass, copper foil, aluminum foil, etc.

[0184] Of course, the patterned structure provided in the encapsulation area is not limited to Figure 12 and Figure 13 the structures shown. It can also be provided with a patterned groove structure only in the encapsulation area, as shown in Figure 14 or not limited to Figure 13 the combination order of the groove structure and the dam structure shown, as well as the number of patterned groove structures and the number of dam structures. This will not be elaborated here.

[0185] Comparative Example 2 (comparative example between Example 5 and Example 6)

[0186] A method for preparing an OLED device, as shown in Figure 10 and Figure 11 includes the following steps:

[0187] S1. Divide the pixel area 11 and the encapsulation area surrounding the pixel area 11 on the substrate 1, deposit the buffer layer 6 on the pixel area, prepare the auxiliary electrode on the buffer layer 6, and etch to form a number of auxiliary electrodes 7 arranged at intervals. The Taper angle of the auxiliary electrode 7 is 70°;

[0188] S2. On the basis of step S1, prepare the first electrode layer 2, where the first electrode layer 2 covers the buffer layer 6 and the auxiliary electrode 7. Etch away the first electrode layer 2 on one or both sides of the auxiliary electrode 7 to expose the buffer layer 6; etch to form the short-circuit prevention structure layer 13;

[0189] S3. On the basis of step S2, deposit the pixel defining layer 12. The pixel defining layer 12 covers the first electrode layer 2 and the buffer layer 6 in the encapsulation area, and etch the pixel defining layer 12 to form an opening with a trapezoidal structure;

[0190] S4. On the basis of step S3, fabricate the light-emitting material layer 2 and the second electrode layer 3 by evaporation. A continuous organic light-emitting layer 3 and the second electrode layer 4 are formed on the pixel defining layer 12 and within the opening.

[0191] S5. On the basis of step S4, fabricate the encapsulation layer 10 by chemical vapor deposition. A continuous organic light-emitting layer 3, the second electrode layer 4, and the encapsulation layer are formed on the pixel defining layer 12 and within the opening. At the same time, the encapsulation layer in the encapsulation area is in direct contact with the buffer layer;

[0192] S6. By attaching an encapsulation transition layer, such as UV glue or OCA glue, on step S5, and then attaching a cover plate on the encapsulation transition layer for thin-film encapsulation and sealing. Here, the cover plate can include glass, copper foil, aluminum foil, etc.

[0193] After testing, the average lifespan of the device in Example 5 of the present invention is 1000h@1000nit, the average lifespan of the device in Example 6 is 1050h@1000nit, while the average lifespan of the device in Comparative Example 2 is 580h@1000nit. Therefore, the lifespan of the device is greatly improved.

[0194] Therefore, it shows that patterning the buffer layer and the pixel defining layer in the encapsulation area can greatly improve the lifespan of the device.

[0195] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. An OLED device, comprising a substrate (1) and a packaging layer (10). A plurality of pixel regions (11) distributed in an array and a packaging region (9) surrounding all the pixel regions (11) are defined on the substrate (1). A first electrode layer (2), an auxiliary electrode (7) and a pixel defining layer (12) are disposed in the enclosed space formed by the substrate (1) and the packaging layer (10), characterized in that, A buffer layer (6) is provided between the first electrode layer (2) / auxiliary electrode (7) and the substrate (1). A plurality of spaced-apart auxiliary electrodes (7) are provided on the buffer layer (6). The first electrode layer (2) covers the buffer layer (6) and the auxiliary electrodes (7). The pixel definition layer (12) completely covers the first electrode layer (2) on the auxiliary electrodes (7) and is patterned with an opening exposing at least a part of the first electrode layer (2). The pixel definition layer (12) covers the first electrode layer (2) and the buffer layer (6). The bottom of the opening is the first electrode layer (2) and the buffer layer (6). The pixel definition layer (12) and the continuous organic light-emitting layer (3) and the second electrode layer (4) are covered in the opening; The materials of the pixel definition layer (12), the buffer layer (6) and the encapsulation layer (10) are the same or different, and are one or a combination of silicon nitride, silicon oxide or silicon oxynitride; The first electrode layer (2) located between the auxiliary electrode (7) and the encapsulation area (9) is etched away to expose the buffer layer (6), so that the pixel definition layer (12) located between the auxiliary electrode (7) and the encapsulation area (9) is in direct contact with the buffer layer (6).

2. The OLED device according to claim 1, wherein The edge positions of each pixel area (11) are respectively surrounded by the pixel definition layer (12). The auxiliary electrodes (7) are distributed at the horizontal and / or vertical positions of the pixel areas arranged in an array; the first electrode layer (2) and the auxiliary electrodes (7) in the encapsulation area (9) are etched away, so that the pixel definition layer (12) is in direct contact with the buffer layer (6).

3. The OLED device according to claim 1 or 2, characterized in that, A continuously provided patterned structure is formed on the buffer layer (6) located in the encapsulation area. The encapsulation layer (10) is in direct contact with the patterned structure formed on the buffer layer (6).

4. The OLED device according to claim 3, wherein, The patterned structure is a plurality of groove structures (16) and / or dam structures (15) patterned on the buffer layer (6).

5. The OLED device according to claim 4, wherein The first electrode layer (2) on one or both sides of the auxiliary electrode (7) is etched away, so that the pixel definition layer (12) covering both sides of the auxiliary electrode (7) is in direct contact with the buffer layer (6).

6. The OLED device according to claim 5, wherein The width of the direct contact area between the first electrode layer (2) and the buffer layer (6) on one or both sides of each auxiliary electrode (7) is 1 μm - 1 cm.

7. The OLED device according to claim 6, wherein In the direction perpendicular to the auxiliary electrode (7), between two adjacent pixel areas (11) arranged in an array, the first electrode layer (2) is patterned with a short-circuit prevention structure layer (13). The short-circuit prevention structure layer (13) is electrically connected to the first electrode layer (2) on the auxiliary electrode (7) and one of the two adjacent pixel areas (11), and forms an open circuit with the other pixel area (11); the pixel definition layer (12) on both sides of the short-circuit prevention structure layer (13) is in direct contact with the buffer layer (6).

8. The OLED device according to claim 7, wherein The width of the direct contact area between the pixel defining layer (12) and the buffer layer (6) located on one or both sides of each auxiliary electrode (7) is 5 μm - 10 mm.

9. The OLED device according to claim 1, wherein The auxiliary electrode (7) is one or a combination of several metals among titanium (Ti), aluminum (Al), molybdenum (Mo), and copper (Cu).

10. The OLED device according to claim 1, wherein The inclination angle formed by the auxiliary electrode (7) is 10 - 90 °.

11. The OLED device according to claim 1, wherein The etching selectivity between the material with a low etching rate in the auxiliary electrode (7) and the material of the buffer layer (6) is 0.5 - 20; The etching selectivity between the material of the pixel defining layer (12) and the material of the buffer layer (6) is 0.5 - 5.

12. The OLED device according to claim 11, wherein The etching selectivity between the material of the auxiliary electrode (7) and the material of the buffer layer (6) is 5 - 7.

13. The OLED device according to claim 1, wherein The thickness of the buffer layer (6) is 10 nm - 3 μm.

14. The OLED device according to claim 12, wherein, An auxiliary buffer layer (14) is further provided on the buffer layer (6) located between the auxiliary electrodes (7), and the auxiliary electrode (7) protrudes 0 - 1 μm above the auxiliary buffer layer (14).

15. The OLED device according to claim 1, characterized in that, The encapsulation layer (10) is a thin film encapsulation structure, and a cover plate (5) is further provided thereon. The cover plate (5) is combined with the encapsulation layer (10) through an encapsulation transition layer (18).

16. The OLED device according to claim 1, wherein, The encapsulation layer (10) is an encapsulation cover, and the encapsulation cover is combined with the buffer layer (6) in the encapsulation area on the substrate (1) through a UV adhesive (8).

17. A method for preparing an OLED device, characterized in that, Including the following steps: S1. Divide a pixel area (11) and an encapsulation area (9) surrounding the pixel area (11) on the substrate (1). Deposit a buffer layer (6) on the substrate (1), prepare an auxiliary electrode (7) on the buffer layer (6), and form a plurality of auxiliary electrodes (7) arranged at intervals through etching. The inclination angle of the auxiliary electrode (7) is 10 - 90°; S2. On the basis of step S1, prepare a first electrode layer (2). The first electrode layer (2) covers the buffer layer (6) and the auxiliary electrode (7), and etch away the first electrode layer (2) located between the auxiliary electrode (7) and the encapsulation area (9) to expose the buffer layer (6); S3. On the basis of step S2, deposit a pixel defining layer (12). The pixel defining layer (12) covers the first electrode layer (2) and the buffer layer (6), and etch the pixel defining layer (12) to form an opening. The bottom of the opening is the first electrode layer (2) and the buffer layer (6); The pixel defining layer (12) completely covers the first electrode layer (2) on the auxiliary electrode (7) and is patterned with an opening exposing at least a part of the first electrode layer (2); The materials of the pixel defining layer (12), the buffer layer (6), and the encapsulation layer (10) are the same or different, and are one or a combination of silicon nitride, silicon oxide, or silicon oxynitride; S4. On the basis of step S3, fabricate an organic light emitting layer (3) and a second electrode layer (4) by evaporation. A continuous organic light emitting layer (3) and a second electrode layer (4) are formed on the pixel defining layer (12) and in the opening; S5. On the basis of step S4, an encapsulation layer (10) is fabricated, and the encapsulation layer (10) covers the entire pixel region (11), and the entire pixel region (11) is hermetically protected in the encapsulation region (9) surrounding the pixel region (11).

18. The manufacturing method of the OLED device according to claim 17, wherein, The said step S2 is: on the basis of step S1, a first electrode layer (2) is prepared, and the first electrode layer (2) covers the buffer layer (6) and the auxiliary electrode (7). The first electrode layer (2) located on one side or both sides of the auxiliary electrode (7) is etched away to expose the buffer layer (6); an anti-short circuit structure layer (13) is etched and formed.

19. The method for manufacturing the OLED device according to claim 17, wherein In the said step S3, a plurality of patterned groove structures (16) and / or dam structures (15) are formed on the buffer layer (6) within the encapsulation region (9); during encapsulation in step S5, the encapsulation layer (10) is in direct contact with the patterned groove structures (16) and / or dam structures (15) on the buffer layer (6).

Images