Display device and method for manufacturing the same

Abstract

The present invention relates to a display device and a method for preparing the same. The display device comprises a substrate, a patterned first electrode layer, a first encapsulation layer, a dam layer, a light-emitting functional layer and a second electrode layer. The first encapsulation layer is arranged on the substrate, the first encapsulation layer defines a pixel pit, the pixel pit exposes the first electrode layer, the light-emitting functional layer is arranged in the pixel pit defined by the first encapsulation layer, so that the first encapsulation layer can better protect the light-emitting functional layer from water vapor intrusion, the dam layer defines a plurality of deposition areas to avoid bridging of inks of different colors, and the dam layer can be prepared by using a commonly used dam material, so that the dam layer can be quickly prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of display device packaging, and in particular to a display device and a preparation method thereof. Background Art

[0002] Display devices, especially OLEDs (organic light-emitting devices), are sensitive to water vapor and easily fail due to water vapor. Therefore, thin-film encapsulation needs to have strong water and oxygen barrier capabilities (generally required to reach 10 -6 g / cm 2 ·day). Usually, the light-emitting functional layer (including the light-emitting material layer, and may further include the electron transport layer, electron injection layer, hole transport layer, hole injection layer and other functional layers) of the display device is formed in the pixel pit formed by the dam layer. However, the water and oxygen blocking ability of the dam layer is poor, and water and oxygen can easily penetrate the dam layer and invade the light-emitting functional layer, causing device failure. Summary of the invention

[0003] Based on this, it is necessary to provide a display device and a method for preparing the same to improve the water and oxygen blocking capability of the display device.

[0004] A display device, comprising:

[0005] substrate;

[0006] A patterned first electrode layer is disposed on the substrate;

[0007] A first encapsulation layer is disposed on the substrate, the first encapsulation layer is an inorganic encapsulation layer, the first encapsulation layer defines a pixel pit, and the pixel pit exposes the first electrode layer;

[0008] A dam layer, disposed on the first encapsulation layer, the dam layer defines a plurality of deposition areas, each of the deposition areas exposing a plurality of the pixel pits;

[0009] A light-emitting functional layer is disposed in the pixel pit and is located on a side of the first electrode layer away from the substrate;

[0010] The second electrode layer is arranged on the light-emitting functional layer.

[0011] In one of the embodiments, the display device further includes a second encapsulation layer, which is disposed in the deposition area and covers the second electrode layer, and the second encapsulation layers in different deposition areas are independent of each other.

[0012] In one embodiment, the substrate includes a substrate and a TFT driving array arranged on the substrate, the TFT driving array has a source and a drain, the first electrode layer includes a first part and a second part separated from each other, the first part is connected to the light-emitting functional layer and the source, and the second part is connected to the second electrode layer and the drain.

[0013] In one embodiment, the second electrode layer and the dam layer are separated by the second encapsulation layer.

[0014] In one embodiment, the second encapsulation layer is an inorganic encapsulation layer.

[0015] In one of the embodiments, the display device further includes a third encapsulation layer, which is arranged in the deposition area and located on the second encapsulation layer, the third encapsulation layers in different deposition areas are independent of each other, and the third encapsulation layer is a flexible encapsulation layer.

[0016] In one embodiment, the materials of the first encapsulation layer and the second encapsulation layer are independently selected from at least one of silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, titanium dioxide, hafnium dioxide, zinc oxide, magnesium oxide and zirconium oxide.

[0017] In one embodiment, the material of the third encapsulation layer is selected from at least one of silicon carbon nitride, silicon oxycarbide, fluorinated silicon oxycarbon, fluorinated silicon carbon nitride, polydimethylsiloxane, polyparaxylene, polypropylene, polystyrene and polyimide.

[0018] In one embodiment, the material of the dam layer is selected from at least one of polyimide, phenolic resin, polymethyl methacrylate, and PBS.

[0019] In one embodiment, the second encapsulation layer covers the sidewalls of the deposition area to form a deposition pit, and the third encapsulation layer is disposed in the deposition pit.

[0020] In one of the embodiments, the display device further includes a fourth encapsulation layer, the fourth encapsulation layer is disposed on the third encapsulation layer, the fourth encapsulation layers in different deposition areas are independent of each other, and the fourth encapsulation layer is an inorganic encapsulation layer.

[0021] In one embodiment, a groove structure is provided on a side of the dam layer away from the first encapsulation layer for carrying the hydrophobic material.

[0022] In one embodiment, the hydrophobic material is selected from at least one of octadecyltrichlorosilane, octadecylmercaptan, octadecylphosphoric acid, docosyltrichlorosilane, octadecyltrimethoxysilane, dodecyl alcohol, octadecene, polymethyl methacrylate, and polyvinylpyrrolidone.

[0023] 9. The display device according to any one of claims 1 to 8, in one embodiment, the dam layer is a plurality of strip-shaped partition walls, a plurality of the partition walls are arranged in parallel, the partition walls penetrate the display area of ​​the display device, and the deposition area is formed between adjacent partition walls.

[0024] In one embodiment, the thickness of the first encapsulation layer is 0.5 μm to 2 μm.

[0025] In one embodiment, the thickness of the second encapsulation layer is 30 nm to 500 nm.

[0026] A method for preparing a display device comprises the following steps:

[0027] providing a substrate provided with a patterned first electrode layer;

[0028] A first encapsulation layer is formed on the substrate, wherein the first encapsulation layer is an inorganic encapsulation layer, and the first encapsulation layer defines a pixel pit, wherein the pixel pit exposes the first electrode layer;

[0029] Manufacturing a dam layer on the first encapsulation layer, wherein the dam layer defines a plurality of deposition areas, each of the deposition areas exposing a plurality of the pixel pits;

[0030] Manufacturing a light-emitting functional layer in the pixel pit, so that the light-emitting functional layer is located on a side of the first electrode layer away from the substrate;

[0031] A second electrode layer is fabricated on the light-emitting functional layer.

[0032] In one embodiment, the steps are also included:

[0033] A second encapsulation layer is manufactured in the deposition area so that the second encapsulation layer covers the second electrode layer, and the second encapsulation layers in different deposition areas are independent of each other.

[0034] In one embodiment, the steps are also included:

[0035] A third encapsulation layer is manufactured in the deposition area, so that the third encapsulation layer is located on the second encapsulation layer, and the third encapsulation layers in different deposition areas are independent of each other, and the third encapsulation layer is a flexible encapsulation layer.

[0036] In one embodiment, the steps are also included:

[0037] A fourth encapsulation layer is manufactured in the deposition area so that the fourth encapsulation layer is located on the third encapsulation layer. The fourth encapsulation layers in different deposition areas are independent of each other, and the fourth encapsulation layer is an inorganic encapsulation layer.

[0038] In one embodiment, a groove structure is formed on a side of the dam layer away from the first encapsulation layer. Before manufacturing the second encapsulation layer, the preparation method further includes the steps of:

[0039] A hydrophobic material is deposited in the groove structure to form a hydrophobic layer.

[0040] Compared with the existing solutions, the above display device and the preparation method thereof have the following beneficial effects:

[0041] The display device and the preparation method thereof are provided with a first encapsulation layer on the substrate, and the first encapsulation layer is an inorganic encapsulation layer. The first encapsulation layer defines a pixel pit, and the pixel pit exposes the first electrode layer. The light-emitting functional layer is arranged in the pixel pit defined by the first encapsulation layer, so that the first encapsulation layer can better protect the light-emitting functional layer from water vapor intrusion. The dam layer defines multiple deposition areas to avoid bridging of inks of different colors. The dam layer can be prepared by using a commonly used dam material, and the dam layer can be quickly prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic structural diagram of a display device according to an embodiment;

[0043] Figure 2 for Figure 1 A schematic structural diagram of a substrate in the display device shown;

[0044] Figure 3 A schematic diagram of manufacturing a first electrode layer on a substrate;

[0045] Figure 4 for Figure 1 A schematic diagram showing that a first electrode layer is exposed from a first packaging layer in a display device;

[0046] Figure 5 A schematic diagram of manufacturing a first packaging layer on a substrate;

[0047] Figure 6 Schematic diagram of ink film formation in pixel pits;

[0048] Figure 7 A schematic diagram of manufacturing a dam layer on a first packaging layer;

[0049] Figure 8 for Figure 1 The schematic diagram of the distribution of the dam layer in the display device is shown;

[0050] Fig. 9 A schematic diagram of forming a light-emitting functional layer in a pixel pit;

[0051] Fig.10 A schematic diagram of restoring the connection hole in order to remove the light-emitting functional material in the connection hole;

[0052] Fig.11 A schematic diagram of manufacturing a second electrode layer on the light-emitting functional layer;

[0053] Fig.12 Schematic diagram of making a hydrophobic layer on the dam layer;

[0054] Fig.13 A schematic diagram of manufacturing a second encapsulation layer on the second electrode layer;

[0055] Fig.14 A schematic diagram of manufacturing a third packaging layer on the second packaging layer;

[0056] Description of reference numerals:

[0057] 100, display device; 110, substrate; 111, substrate; 112, TFT driving array; 1121, active layer; 1122, gate insulating layer; 1123, gate layer; 1124, intermediate insulating layer; 1125, source; 1126, drain; 113, flat layer; 120, first electrode layer; 121, first part; 122, second part; 130, first encapsulation layer; 131, pixel pit; 132, connecting hole; 140, dam layer; 141, deposition area; 142, groove structure; 150, light-emitting functional layer; 151, light-emitting functional ink; 160, second electrode layer; 170, second encapsulation layer; 171, deposition pit; 180, third encapsulation layer; 190, fourth encapsulation layer; 200, hydrophobic layer. DETAILED DESCRIPTION

[0058] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0059] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0060] In the description of the present invention, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first", "second", etc. may explicitly or implicitly include at least one of the features.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0062] Please refer to Figure 1 As shown, a display device 100 according to an embodiment of the present invention includes a substrate 110 , a patterned first electrode layer 120 , a first encapsulation layer 130 , a dam layer 140 , a light-emitting functional layer 150 and a second electrode layer 160 .

[0063] The patterned first electrode layer 120 is disposed on the substrate 110. The first encapsulation layer 130 is disposed on the substrate 110. Furthermore, the first encapsulation layer 130 defines a pixel pit 131, and the pixel pit 131 exposes the first electrode layer 120. The first encapsulation layer 130 has a pixel pit 131 that exposes the first electrode layer 120. The dam layer 140 is disposed on the first encapsulation layer 130, and the dam layer 140 defines a plurality of deposition areas 141, and each deposition area 141 exposes a plurality of pixel pits 131. The light-emitting functional layer 150 is disposed in the pixel pit 131 on a side of the first electrode layer 120 away from the substrate 110. The second electrode layer 160 is disposed on the light-emitting functional layer 150.

[0064] The display device 100 is provided with a first encapsulation layer 130 on a substrate, and the first encapsulation layer 130 is an inorganic encapsulation layer. The first encapsulation layer 130 defines a pixel pit 131, and the pixel pit 131 exposes the first electrode layer 130. The light-emitting functional layer 150 is provided in the pixel pit 131 defined by the first encapsulation layer 130, so that the first encapsulation layer 130 can better protect the light-emitting functional layer 150 from water vapor intrusion. The dam layer 140 defines a plurality of deposition areas 141 to avoid bridging of inks of different colors, and the dam layer 140 can be prepared by using a commonly used dam material, so that the dam layer 140 can be quickly manufactured.

[0065] like Figure 2 As shown, in one example, the substrate 110 includes a substrate 111 , a TFT driving array 112 disposed on the substrate 111 , and a planar layer 113 disposed on an intermediate insulating layer 1124 .

[0066] The substrate 111 is used to carry other layers of the substrate 110, and can also be used to carry OLED, QLED or liquid crystal components, etc. The substrate 111 can be a rigid substrate or a flexible substrate. The rigid substrate can be a ceramic material, various glass materials, etc. The flexible substrate can be PI (polyimide) and its derivatives, PEN (polyethylene naphthalate), PEP (phosphoenolpyruvic acid) and diphenylene ether resin, etc.

[0067] The TFT drive array 112 is a thin film circuit required in a high-definition display screen. The example TFT drive array 112 shown in the figure is a TFT active drive array, which includes an active layer 1121, a gate insulating layer 1122, a gate layer 1123, an intermediate insulating layer 1124, a source electrode 1125, a drain electrode 1126, and TFT devices, capacitor devices, conductive circuits and resistor devices formed by their combination. The function of the TFT drive array 112 is to actively drive the light-emitting functional layer 150 to emit light. Compared with the passive drive method, the TFT active drive array has a more precise single-pixel current and voltage control capability, thereby achieving high-definition display.

[0068] The flat layer 113 mainly plays a flattening role. At the same time, its material properties enable it to be better spread on the uneven surface to form a relatively flat film surface, so that the material thereon can be formed on a relatively flat surface, ensuring the stability of the material thereon and reducing the risk of short circuit and open circuit. The material of the flat layer 113 can be an organic photoresist material such as polyimide (PI), and can be a patterned film layer formed by coating, exposure, and development.

[0069] like Figure 3 As shown, the first electrode layer 120 can be formed by depositing a conductive layer on the flat layer 113, and the first electrode layer 120 is electrically connected to the TFT driving array 112 through a via hole penetrating the flat layer 113. In a liquid crystal display, it serves as part of the upper and lower electrodes that drive the movement of liquid crystals. In an OLED or OLED, it serves as part of the light-emitting device structure and plays a role in injecting holes or electrons.

[0070] like Figure 3 and Figure 4 As shown, the first electrode layer 120 includes a first portion 121 connected to the light-emitting functional layer 150 and a second portion 122 connected to the second electrode layer 160. The first portion 121 and the second portion 122 are separated and insulated from each other and are respectively connected to the source 1125 and the drain 1126 of the TFT driving array 112.

[0071] Optionally, the material of the first electrode layer 120 can be metal oxide conductive materials such as ITO (indium tin oxide) and IZO (indium zinc oxide), organic conductive materials such as PEDOT (3,4-ethylenedioxythiophene monomer), conductive metals such as aluminum, molybdenum, titanium, copper, silver, gold and their alloys, combined stacks, etc.

[0072] In a specific example, the first electrode layer 120 is an ITO / Ag / ITO stack. The Ag coating acts as a reflective layer to focus the light emitted from the light-emitting functional layer 150 to the top. ITO plays a role in matching the work function of the hole injection and transport layers in the display device 100, so that electrons / holes are better injected into the light-emitting layer, which is beneficial to improving the efficiency of the display device 100.

[0073] like Figure 5 As shown, the first encapsulation layer 130 is formed by depositing encapsulation materials on the substrate 110. The first encapsulation layer 130 covers the edge of the first electrode layer 120, and the first encapsulation layer 130 has a pixel pit 131 exposing the first electrode layer 120. More specifically, the pixel pit 131 exposes the first portion 121 of the first electrode layer 120, and the pixel hole is used for the deposition of the light-emitting functional layer 150. The first encapsulation layer 130 also has a connection hole 132 exposing the second portion 122 of the first electrode layer 120, and the connection hole 132 is used for the subsequent second electrode layer 160 to connect with the first electrode layer 120.

[0074] In the traditional device structure, the second electrode layer (usually the cathode) is a full-surface coating of the display area, and its connection with the drive circuit is set at the periphery of the display area, and is connected to the drive circuit through a large area of ​​the cathode overlap area (including vias and exposed electrode structures), and finally forms a loop to light up the device. However, the present invention is to package the device in a separate packaging mode. In this case, if the second electrode layer is deposited on the entire surface, it will not be fully packaged. Therefore, the second electrode layer 160 of the present invention is set in each deposition area 141, rather than deposited on the entire surface, and is connected to the second part 122 of the second electrode layer 160 through the connection hole 132 on the first packaging layer 130, and finally connected to the ground / low-level line in the drive circuit, which can also realize the current path.

[0075] In one example, the first packaging layer 130 is an inorganic packaging layer, which has a harder film quality and greater film stress when bent. It is generally made of inorganic materials and has a strong water and oxygen blocking ability, effectively preventing water vapor from invading the first electrode layer 120 from the dam layer 140 .

[0076] The material of the first encapsulation layer 130 should avoid using materials with strong hydrophobicity. The first encapsulation layer 130 with strong hydrophobicity may hinder the flow of ink in the pixel pits 131, resulting in the ink not being able to flow evenly and thus being evenly filled into the pits formed by the first encapsulation layer 130, resulting in uneven light emission defects.

[0077] Optionally, the material of the first encapsulation layer 130 may be selected from but not limited to at least one of silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, titanium dioxide, hafnium dioxide, zinc oxide, magnesium oxide and zirconium oxide.

[0078] In a specific example, the material of the first encapsulation layer 130 is silicon oxynitride, which mainly plays the role of isolating water and oxygen, and its hydrophilicity can be fine-tuned by controlling its oxygen content.

[0079] The first encapsulation layer 130 may be prepared by, but is not limited to, plasma chemical vapor deposition, atomic layer deposition, ion beam deposition, magnetron sputtering deposition, etc. In a specific example, the first encapsulation layer 130 is prepared by plasma chemical vapor deposition.

[0080] Since the light-emitting functional layer 150 has not been manufactured when the first encapsulation layer 130 is manufactured, the manufacturing process temperature of the first encapsulation layer 130 can be relatively high, and the temperature range of the deposited thin film can be 50° C. to 400° C.

[0081] The hydrophilic and hydrophobic properties of the first encapsulation layer 130 have an influence on the spreading property of the subsequent inkjet ink droplets. Figure 6 As shown, if the hydrophobicity of the first encapsulation layer 130 is too high, the luminescent functional ink 151 in the dam will not flow evenly, thereby reducing the uniformity of the luminescent functional layer 150 and even causing the material of the luminescent functional layer 150 in some pixels to affect device performance.

[0082] The thickness of the first encapsulation layer 130 is greater than the thickness of the light emitting functional layer 150. In one example, the thickness of the first encapsulation layer 130 is 0.5 μm to 2 μm.

[0083] In one example, the first encapsulation layer 130 covers the edge of the first electrode layer 120 , which can avoid the risk of short circuit between the light-emitting functional layer 150 and the electrode layer, and better prevent the first electrode layer 120 from being invaded by water vapor.

[0084] like Figure 7 As shown, the dam layer 140 is formed by depositing a dam material on the first encapsulation layer 130. In one example, the material of the dam layer is selected from at least one of polyimide, phenolic resin, polymethyl methacrylate, and PBS. The above materials can be used to quickly complete the production of the dam layer.

[0085] One of the functions of the dam layer 140 is to separate the printed materials so that OLED materials of different luminous colors can be printed between different dams, and finally a full-color display can be achieved. The dam layer 140 should have a certain hydrophobicity, so that the ink droplets subsequently dripped into the deposition area 141 are confined within the deposition area 141, and will not flow between different deposition areas 141 to form bridges and other defects, which will eventually lead to poor color mixing of the OLED display.

[0086] like Figure 8 As shown, in one example, the dam layer 140 includes a plurality of strip-shaped partition walls, which are arranged in parallel, and a deposition area 141 is formed between adjacent partition walls. This arrangement can change the inkjet method from single printing to linear printing, which can reduce the accuracy of the inkjet device in the linear printing direction, reduce the equipment investment cost while meeting the accuracy requirements.

[0087] like Figure 1 As shown, in one example, a hydrophobic layer 200 is disposed on a side of the dam layer 140 away from the first encapsulation layer 130 .

[0088] During the manufacturing process of the display device 100, the hydrophobic layer 200 located on the dam layer 140 can separate the second encapsulation layer 170 and the fourth encapsulation layer 190 in adjacent pixels to form a mutually independent pixel encapsulation structure, so that the first encapsulation layer 130 is not easily affected by external stress when the display device 100 is bent, thereby reducing the overall stress of the display screen and improving the bending resistance and life of the display device 100.

[0089] The material of the hydrophobic layer 200 may be, but is not limited to, ODTS (octadecyltrichlorosilane), ODT (octadecylmercaptan), ODPA (octadecylphosphoric acid), DTS (docosyltrichlorosilane), ODS (octadecyltrimethoxysilane), dodecyl alcohol, octadecene, PMMA (polymethyl methacrylate), PVP (polyvinylpyrrolidone), etc.

[0090] In one example, the material of the hydrophobic layer 200 is ODTS, the main chain of which is formed by connecting alkane carbon chains, and the tail functional group is an alkyl group (-CH 3 ), has strong hydrophobicity, and can prevent the organic source of atomic layer deposition from being adsorbed on the film layer when the organic source of atomic layer deposition is introduced into the step, which can effectively prevent the growth of atomic layer deposition (ALD) film, and then play a role in the self-assembly patterning of atomic layer deposition.

[0091] like Figure 7 As shown, in one example, a groove 142 is provided on a side of the dam layer 140 away from the first encapsulation layer 130 , and the hydrophobic layer 200 is formed in the groove 142 .

[0092] like Fig. 9 As shown, the light-emitting functional layer 150 is formed by depositing a light-emitting functional material in the pixel pit 131. It should be noted that if the light-emitting functional material is deposited in the connection hole 132, the light-emitting functional material in the connection hole 132 needs to be removed, for example, by etching it with a laser etching device to restore the connection hole 132, such as Fig.10 shown.

[0093] The light-emitting functional layer 150 includes a light-emitting material layer, wherein the light-emitting material may be an organic light-emitting material, a quantum dot light-emitting material, etc. In addition, the light-emitting functional layer 150 may further include a cathode, an anode, a hole injection layer, a hole transport layer, an electron transport layer, etc.

[0094] like Fig.11 As shown, the second electrode layer 160 is formed by depositing a conductive layer on the light-emitting functional layer 150 , and at the same time, the second electrode layer 160 is connected to the second portion 122 of the first electrode layer 120 through the connection hole 132 .

[0095] The second electrode layer 160 has the same function as the first electrode layer 120, and serves as an electrical connection. One of the first electrode layer 120 and the second electrode layer 160 serves as an anode, and the other serves as a cathode, and together with the light-emitting functional layer 150, they form a display component. After being connected to the circuit, current flows through the anode, the light-emitting functional layer 150, and the cathode, forming a loop.

[0096] The material of the second electrode layer 160 can be a metal oxide conductive material such as ITO (indium tin oxide), IZO (indium zinc oxide), etc., can be an organic conductive material such as PEDOT (3,4-ethylenedioxythiophene monomer), etc., can also be a conductive metal such as aluminum, molybdenum, titanium, copper, silver, gold, and their alloys, combined stacks, etc. If the display device 100 is a top emission device, the material of the second electrode layer 160 is required to have high transparency, high conductivity, and relatively stable physical and chemical properties within its film thickness range.

[0097] like Fig.12 As shown, in one example, after the second electrode layer 160 is formed and before the second encapsulation layer 170 is formed, the hydrophobic layer 200 is formed on the bank layer 140 .

[0098] like Fig.13 As shown, after the hydrophobic layer 200 is formed, a separate second encapsulation layer 170 can be obtained by depositing an encapsulation material on the entire surface.

[0099] like Figure 1As shown, in one example, the display device 100 also includes a second encapsulation layer 170, which is arranged in the deposition area 141 and connected to the second electrode layer 160, and the second encapsulation layers 170 in different deposition areas 141 are independent of each other, that is, there is no direct connection between the second encapsulation layers 170 in different deposition areas 141.

[0100] The display device 100 of the above example is provided with a first encapsulation layer 130 and a second encapsulation layer 170, wherein the second encapsulation layer 170 is arranged in the deposition area 141 and covers the second electrode layer 160, and the second encapsulation layers 170 located in different deposition areas 141 are independent of each other, so that the second encapsulation layer 170 is not easily affected by external stress when the display device 100 is bent, thereby reducing the overall stress of the display screen and improving the bending resistance and life of the display device 100.

[0101] In one example, the second encapsulation layer 170 is an inorganic encapsulation layer, which has a hard film quality and a large film stress when bent, and is generally made of inorganic materials. The second encapsulation layer 170 needs to have a strong water and oxygen blocking ability and a high visible light transmittance.

[0102] Optionally, the material of the second encapsulation layer 170 may be selected from but not limited to at least one of silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, titanium dioxide, hafnium dioxide, zinc oxide, magnesium oxide and zirconium oxide.

[0103] In a specific example, the first encapsulation layer 130 is a nano-laminated layer of aluminum oxide / zirconium oxide, which mainly serves to isolate water and oxygen.

[0104] The second encapsulation layer 170 may be prepared by, but is not limited to, plasma chemical vapor deposition, atomic layer deposition, ion beam deposition, magnetron sputtering deposition, etc. In a specific example, the first encapsulation layer 130 is prepared by atomic layer deposition.

[0105] Since the second encapsulation layer 170 needs to have a high visible light transmittance, it is preferably thinner on the premise of having a certain water and oxygen blocking ability. In one example, the thickness of the second encapsulation layer 170 is 30 nm to 500 nm.

[0106] like Figure 1 As shown, in one example, there is no direct contact between the second electrode layer 160 and the dam layer 140 , and the two are separated by the second encapsulation layer 170 , thereby preventing water vapor from invading the second electrode layer 160 through the dam layer 140 .

[0107] like Figure 1As shown, in one example, the display device 100 further includes a third encapsulation layer 180, which is disposed in the deposition area 141 and on the second encapsulation layer 170, and the third encapsulation layers 180 in different deposition areas 141 are independent of each other. The third encapsulation layer 180 is a flexible encapsulation layer.

[0108] like Fig.13 and Fig.14 As shown, in one example, the second encapsulation layer 170 also covers the sidewall of the deposition area 141 to form a deposition pit 171, and the third encapsulation layer 180 is disposed in the deposition pit 171. In this way, water vapor is prevented from invading through the sidewall of the dam layer 140, and the water and oxygen barrier performance can be improved.

[0109] The third encapsulation layer 180 is a flexible encapsulation layer with good deformability and can buffer the stress of the upper and lower film layers. Optionally, the material of the third encapsulation layer 180 can be selected from but not limited to at least one of silicon carbonitride, silicon carbide, fluorinated silicon carbon oxide, fluorinated silicon carbon nitride, polydimethylsiloxane, polyparaxylene, polypropylene, polystyrene and polyimide.

[0110] The second encapsulation layer 170, which is an inorganic encapsulation layer, generally has a large internal stress and is not easy to completely cover the foreign matter on the encapsulation surface. The film thickness is prone to be thin and broken at the tip of the foreign matter and the bottom of the step with a negative slope angle. Especially when used in flexible displays, the presence of foreign matter can easily cause these encapsulation films to break, peel off or crack, causing the encapsulation to fail. In the above example, by providing a flexible third encapsulation layer 180, the stress of the upper and lower film layers is buffered, so that the display device 100 can have better reliability and bending resistance. At the same time, the third encapsulation layer 180 can also cover dust and impurities that may fall during the encapsulation process, making the edges and corners of the impurities more rounded, not easy to form channels for water and oxygen to pass through, and has certain water and oxygen barrier properties.

[0111] The preparation method of the third encapsulation layer 180 can be inkjet printing, nano transfer printing, etc. In a specific example, the third encapsulation layer 180 is prepared by inkjet printing. Using inkjet printing, ink is dripped into the deposition pit 171 formed in the second encapsulation layer 170, and its thickness is controlled to be equivalent to the height of the dam layer 140, so that the surface of the display screen is basically flat after the third encapsulation layer 180 is completed. The thickness of the third encapsulation layer 180 should be set in accordance with the height of the dam layer 140, so that the upper surface of the third encapsulation layer 180 is basically flat with the upper surface of the dam layer 140, or slightly higher than the upper surface of the dam layer 140.

[0112] Compared with the buffer layer in the traditional device packaging (whole surface coating, 8-12 μm), the third packaging layer 180 is discrete and can be thinner, about 1-6 μm, so that the display device 100 has reliable anti-bending performance.

[0113] like Figure 1 As shown, in one example, the display device 100 further includes a fourth encapsulation layer 190, which is disposed on the third encapsulation layer 180, and the fourth encapsulation layers 190 of different deposition areas 141 are independent of each other. The fourth encapsulation layer 190 is an inorganic encapsulation layer, which can generally be made of inorganic materials. The second encapsulation layer 170 needs to have a strong water and oxygen blocking ability and a high visible light transmittance.

[0114] Optionally, the material of the fourth encapsulation layer 190 may be selected from but not limited to at least one of silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, titanium dioxide, hafnium dioxide, zinc oxide, magnesium oxide and zirconium oxide.

[0115] It should be noted that the first encapsulation layer 130 , the second encapsulation layer 170 and the fourth encapsulation layer 190 are inorganic encapsulation layers, and their materials may be the same or different.

[0116] In the specific example shown in the figure, the second encapsulation layer 170 cooperates with the fourth encapsulation layer 190 to completely wrap the third encapsulation layer 180 therein. In this way, the second encapsulation layer 170 with relatively low water and oxygen barrier performance is completely wrapped, which can improve the water and oxygen barrier performance.

[0117] The display device 100 can be applied to flat panel displays, TV displays, electronic paper, logic and storage circuits, flexible displays and other fields, such as mobile phones, TVs, tablet computers, monitors, VR / AR devices, computers, car displays or any other products or components with display functions.

[0118] Furthermore, the present invention also provides a method for preparing the display device 100 of any of the above examples, comprising the following steps:

[0119] Providing a substrate 110 provided with a patterned first electrode layer 120;

[0120] A first encapsulation layer 130 is formed on the substrate 110 . The first encapsulation layer 130 is an inorganic encapsulation layer. The first encapsulation layer 130 defines a pixel pit 131 . The pixel pit 131 exposes the first electrode layer 120 .

[0121] A dam layer 140 is formed on the first encapsulation layer 130 , wherein the dam layer 140 defines a plurality of deposition areas 141 , and each deposition area 141 exposes a plurality of pixel pits 131 ;

[0122] A light-emitting functional layer 150 is formed in the pixel pit 131 , so that the light-emitting functional layer 150 is located on a side of the first electrode layer 120 away from the substrate 110 ;

[0123] The second electrode layer 160 is formed on the light emitting functional layer 150 .

[0124] In one example, the method for preparing the display device 100 further includes the following steps:

[0125] The second encapsulation layer 170 is manufactured in the deposition area 141 so that the second encapsulation layer 170 covers the second electrode layer 160 , and the second encapsulation layers 170 in different deposition areas 141 are independent of each other.

[0126] A specific example of a display device 100 and a method for manufacturing the same are provided below to further illustrate the present invention. However, the present invention is not limited to the following specific examples. It should be understood that the appended claims summarize the scope of the present invention. Under the guidance of the concept of the present invention, those skilled in the art should realize that certain changes made to the various embodiments of the present invention will be covered by the spirit and scope of the claims of the present invention.

[0127] A method for preparing a display device 100 (OLED device) according to a specific example includes the following steps:

[0128] Step S1, such as Figure 2 As shown, a substrate 110 is manufactured.

[0129] An active layer 1121 , a gate insulating layer 1122 , a gate layer 1123 , an intermediate insulating layer 1124 , a source electrode 1125 and a drain electrode 1126 are sequentially deposited on the substrate 111 to obtain a TFT driving array 112 , on which a flat layer 113 is fabricated to obtain a substrate 110 with a flat surface.

[0130] Step S2, such as Figure 3 As shown, a first electrode layer 120 is formed on the planar layer 113 .

[0131] After depositing the ITO / Ag / ITO metal film by magnetron sputtering, it is patterned. The difference from the general electrode layer is that the patterned first electrode layer 120 is divided into two parts, namely, the first part 121 that will directly contact the OLED device, and the second part 122 that contacts the second electrode layer 160. The two parts are separated and insulated from each other in the first electrode layer 120, and are respectively connected to the source 1125 and the drain 1126 of the TFT driving array 112.

[0132] Step S3, such as Figure 5 As shown, the first encapsulation layer 130 is manufactured on the substrate 110 on which the first electrode layer 120 is formed.

[0133] The first encapsulation layer 130 is prepared by evaporation, magnetron sputtering, plasma chemical vapor deposition (PECVD), atomic layer deposition or molecular layer deposition. One preferred solution is to use PECVD to deposit the SION film. By controlling the gas flow rate during PECVD deposition, the oxygen content of the SION film can be more conveniently controlled, thereby fine-tuning the hydrophilicity of the first encapsulation layer 130.

[0134] Step S4, such as Figure 7 As shown, a dam layer 140 is formed on the first encapsulation layer 130 .

[0135] A thin film layer is formed on the first encapsulation layer 130 using methods such as spin coating or slit coating, and a patterned dam layer 140 is obtained through steps such as exposure, development, and curing. The dam layer 140 has a deposition area 141, and the deposition area 141 is connected to the pixel pit 131 of the first encapsulation layer 130, exposing the first electrode layer 120. A groove 142 is formed on the top of the dam layer 140 (i.e., on the side away from the substrate 110). The groove 142 can be obtained using a "half-mask" patterning method. Unlike a general exposure mask, the mask used in this case has a light transmittance of 20% at the groove 142 during exposure, a light transmittance of 100% on the inner side of the dam, and 0% for the rest. Since the amount of light irradiated at the groove 142 is small, only a small amount of material of the dam layer 140 on the top reacts with the light and is removed after development, ultimately forming a film such as Figure 7 Pattern. Figure 8 As shown, in this example, the dam layer 140 is a linear structure that runs through the entire display area.

[0136] Step S5, such as Fig. 9 As shown, ink containing OLED materials is sprayed in the space between the dam layers 140. For linear dams, the dripping ink drops will connect to each other in the dams to form strips. After curing, most of the materials will gather in the pixel pits 131 of the first encapsulation layer 130 to form a light-emitting functional layer 150.

[0137] Step S6, as Fig.10 As shown, the OLED film on the second portion 122 of the first electrode layer 120 is removed.

[0138] The OLED film on the second portion 122 of the first electrode layer 120 is irradiated by laser ablation. After appropriate laser wavelength, energy and frequency are selected, the OLED film will be vaporized after irradiation, thereby exposing the second portion 122 of the first electrode layer 120.

[0139] Step S7, Fig.11 As shown, the second electrode layer 160 is formed between the bank layers 140 .

[0140] The second electrode layer 160 is formed between the dam layer 140 by using a patterned deposition coating method such as inkjet printing or selected atomic layer deposition. The second electrode layer 160 is connected to the light-emitting functional layer 150 and the grounding / negative potential circuit in the TFT driving array 112. During the lighting process of the OLED, generally, the current flows from the high-level circuit in the TFT circuit into the first part 121 of the first electrode layer 120 and supplies power to the light-emitting functional layer 150, and the current flows out to the second part 122 of the first electrode layer 120 through the second electrode layer 160, and finally connects to the low-level circuit in the TFT driving array 112 to form a loop.

[0141] Step S8, Fig.12 As shown, a hydrophobic layer 200 is formed in the groove 142 on the top of the bank layer 140 .

[0142] By using inkjet printing or micro-contact printing technology, a surface modification film with a thickness of 1-10 nm is deposited in the groove 142 on the top of the bank layer 140 between two pixels.

[0143] Step S9, as Fig.13 As shown, a patterned second encapsulation layer 170 is formed on the second electrode layer 160 .

[0144] The second encapsulation film layer is made on the substrate 110 by coating means such as magnetron sputtering, evaporation, chemical vapor deposition, atomic layer deposition or molecular layer deposition. A preferred solution is to use atomic layer deposition to prepare a nano-laminated film of AlOx / ZrOx, wherein the nano-laminated film is an alternating laminate of AlOx and ZrOx, the thickness of a single film can be 0.5 to 50 nm, and the total thickness of the laminate can range from 30 to 500 nm. The number of laminated layers can be 2 to 5000 layers. Due to the presence of the hydrophobic layer 200 on the dam layer 140, the second encapsulation layers 170 of adjacent pixels are separated from each other.

[0145] Step S10, as Fig.14 As shown, the third encapsulation layer 180 is formed on the second encapsulation layer 170 .

[0146] By using an inkjet printing process, a discrete third encapsulation layer 180 is formed on the second encapsulation layer 170 and only between the dams of the dam layer 140. First, a large amount of ink is precisely dropped to form a liquid film with good fluidity on the surface, and then the liquid film is cured by ultraviolet curing or thermal curing to obtain the third encapsulation layer 180.

[0147] The upper surface of the third encapsulation layer 180 is substantially flush with the upper surface of the dam layer 140, or slightly higher than the upper surface of the dam layer 140, providing a flat deposition surface for the fourth encapsulation film layer to be deposited, thereby improving the encapsulation effect of the fourth encapsulation layer 190. Thinning the third encapsulation film layer is beneficial to reducing the failure probability of the entire display screen after bending, curling and twisting.

[0148] Step S11, forming a fourth encapsulation layer 190 on the third encapsulation layer 180, and obtaining Figure 1 A display device 100 is shown.

[0149] The fourth encapsulation layer 190 is coated on the third encapsulation layer 180 by means of coating methods such as magnetron sputtering, evaporation, chemical vapor deposition, atomic layer deposition, molecular layer deposition, etc. Due to the presence of the hydrophobic layer 200 on the dam layer 140, the fourth encapsulation layers 190 of adjacent pixels are separated from each other.

[0150] The display device 100 and the preparation method thereof are provided with a first encapsulation layer 130 and a second encapsulation layer 170, wherein the second encapsulation layer 170 is provided in the second opening and covers the second electrode layer 160, and the second encapsulation layers 170 located in different second openings are independent of each other, so that the second encapsulation layer 170 is not easily affected by external stress when the display device 100 is bent, reducing the overall stress of the display screen, and improving the bending resistance and life of the display device 100. The first encapsulation layer 130 covers the edge of the first electrode layer 120, which can prevent water vapor from penetrating the dam layer 140 and invading the first electrode layer 120, and can improve the water and oxygen barrier performance.

[0151] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0152] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A display device, characterized in that: include: substrate; A patterned first electrode layer is disposed on the substrate; A first encapsulation layer is disposed on the substrate, the first encapsulation layer is an inorganic encapsulation layer, the first encapsulation layer defines a pixel pit, and the pixel pit exposes the first electrode layer; a dam layer, disposed on the first encapsulation layer, the dam layer defining a plurality of deposition areas, each of the deposition areas exposing a plurality of the pixel pits, and a groove structure being disposed on a side of the dam layer away from the first encapsulation layer for carrying a hydrophobic material; A light-emitting functional layer is disposed in the pixel pit and is located on a side of the first electrode layer away from the substrate; A second electrode layer is arranged on the light-emitting functional layer; The second encapsulation layer is arranged in the deposition area and covers the second electrode layer. The second encapsulation layers in different deposition areas are independent of each other. The second electrode layer is separated from the dam layer by the second encapsulation layer. The second encapsulation layer is an inorganic encapsulation layer.

2. The display device according to claim 1, characterized in that The substrate includes a substrate and a TFT driving array arranged on the substrate, the TFT driving array has a source and a drain, the first electrode layer includes a first part and a second part separated from each other, the first part is connected to the light-emitting functional layer and the source, and the second part is connected to the second electrode layer and the drain.

3. The display device according to claim 1, characterized in that The display device further includes a third encapsulation layer, which is disposed in the deposition area and located on the second encapsulation layer. The third encapsulation layers in different deposition areas are independent of each other, and the third encapsulation layer is a flexible encapsulation layer.

4. The display device according to claim 3, characterized in that The materials of the first encapsulation layer and the second encapsulation layer are independently selected from at least one of silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, titanium dioxide, hafnium dioxide, zinc oxide, magnesium oxide and zirconium oxide; and / or The material of the third encapsulation layer is selected from at least one of silicon carbonitride, silicon oxycarbide, fluorinated silicon oxycarbon, fluorinated silicon carbon nitride, polydimethylsiloxane, polyparaxylene, polypropylene, polystyrene and polyimide; and / or The material of the dam layer is selected from at least one of polyimide, phenolic resin, polymethyl methacrylate, and PBS.

5. The display device according to claim 3, characterized in that The second encapsulation layer covers the sidewall of the deposition area to form a deposition pit, and the third encapsulation layer is disposed in the deposition pit.

6. The display device according to claim 5, characterized in that The display device further includes a fourth encapsulation layer, which is disposed on the third encapsulation layer. The fourth encapsulation layers in different deposition areas are independent of each other, and the fourth encapsulation layer is an inorganic encapsulation layer.

7. The display device according to claim 6, characterized in that The hydrophobic material is selected from at least one of octadecyltrichlorosilane, octadecylmercaptan, octadecylphosphoric acid, docosyltrichlorosilane, octadecyltrimethoxysilane, dodecyl alcohol, octadecene, polymethyl methacrylate, and polyvinylpyrrolidone.

8. The display device according to any one of claims 1 to 7, characterized in that: The dam layer is a plurality of strip-shaped partition walls, and the plurality of partition walls are arranged in parallel. The partition walls penetrate the display area of ​​the display device, and the deposition area is formed between adjacent partition walls.

9. The display device according to any one of claims 1 to 7, characterized in that: The thickness of the first encapsulation layer is 0.5 μm to 2 μm; and / or The thickness of the second encapsulation layer is 30nm-500nm.

10. A method for preparing a display device, characterized in that: The following steps are involved: providing a substrate provided with a patterned first electrode layer; A first encapsulation layer is formed on the substrate, wherein the first encapsulation layer is an inorganic encapsulation layer, and the first encapsulation layer defines a pixel pit, wherein the pixel pit exposes the first electrode layer; A dam layer is formed on the first encapsulation layer, wherein the dam layer defines a plurality of deposition areas, each of the deposition areas exposes a plurality of the pixel pits, and a groove structure is formed on a side of the dam layer away from the first encapsulation layer; Manufacturing a light-emitting functional layer in the pixel pit, so that the light-emitting functional layer is located on a side of the first electrode layer away from the substrate; Fabricating a second electrode layer on the light-emitting functional layer; Making a second encapsulation layer in the deposition area, so that the second encapsulation layer covers the second electrode layer, the second encapsulation layers in different deposition areas are independent of each other, the second electrode layer and the dam layer are separated by the second encapsulation layer, and the second encapsulation layer is an inorganic encapsulation layer; Before manufacturing the second encapsulation layer, the preparation method further comprises the steps of: A hydrophobic material is deposited in the groove structure to form a hydrophobic layer.

11. The method for manufacturing a display device according to claim 10, characterized in that: Also includes the steps: A third encapsulation layer is manufactured in the deposition area, so that the third encapsulation layer is located on the second encapsulation layer, and the third encapsulation layers in different deposition areas are independent of each other, and the third encapsulation layer is a flexible encapsulation layer.

12. The method for manufacturing a display device according to claim 11, characterized in that: Also includes the steps: A fourth encapsulation layer is manufactured in the deposition area so that the fourth encapsulation layer is located on the third encapsulation layer. The fourth encapsulation layers in different deposition areas are independent of each other, and the fourth encapsulation layer is an inorganic encapsulation layer.

13. The method for preparing a display device according to claim 11 or 12, characterized in that: The material of the third encapsulation layer is selected from at least one of silicon carbon nitride, silicon oxycarbide, fluorinated silicon oxycarbon, fluorinated silicon carbon nitride, polydimethylsiloxane, polyparaxylene, polypropylene, polystyrene and polyimide.

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