Packaging structure, method for manufacturing a packaging structure, and light emitting device

Abstract

The application discloses a packaging structure, a preparation method of the packaging structure and a light-emitting device. The packaging structure comprises one packaging unit or a plurality of stacked packaging units; each packaging unit comprises, in sequence, an inorganic packaging layer, a first transition layer and a buffer layer; the material of the buffer layer comprises an organic polymer, and the organic polymer has a structural formula Si-O-R, wherein R represents a hydrocarbon group; and the material of the first transition layer comprises silicon-containing oxynitride. The packaging structure provided by the application can not only reduce the thickness and improve the bendability of the product, but also ensure the water-oxygen blocking capability of the packaging structure.

Description

Technical Field

[0001] This application relates to the field of display technology, specifically to a packaging structure, a method for preparing the packaging structure, and a light-emitting device. Background Technology

[0002] In the manufacturing process of display screens, as OLED production technology matures, its production cost gradually decreases, making it a technology that can compete with LCD displays. OLED's advantages are becoming increasingly apparent, with its ability to achieve flexible displays being its most significant feature. Flexible display technology replaces the original two-layer glass substrate with a single flexible substrate and a thin-film encapsulation layer to achieve bendable and foldable performance. Because OLEDs are extremely sensitive to moisture and easily fail due to its susceptibility to moisture, the thin-film encapsulation layer needs strong water and oxygen barrier capabilities. Furthermore, as the bending radius of flexible displays becomes smaller, the requirements for the screen become increasingly stringent, necessitating that the thin film in flexible displays be as thin as possible.

[0003] Therefore, there is an urgent need for a packaging structure with excellent water and oxygen barrier capabilities. Summary of the Invention

[0004] The purpose of this application is to provide a packaging structure to address the shortcomings of the prior art.

[0005] This application provides a packaging structure, which includes a packaging unit or multiple stacked packaging units; each packaging unit includes a first inorganic packaging layer, a first transition layer and a buffer layer stacked sequentially.

[0006] The material of the buffer layer includes an organic polymer having the structural formula Si-OR, where R represents a hydrocarbon group; the material of the first transition layer includes silicon nitride.

[0007] Optionally, in some embodiments of this application, in the encapsulation structure, at least one of the encapsulation units further includes a second inorganic encapsulation layer, wherein the second inorganic encapsulation layer is disposed on the side of the buffer layer away from the first transition layer.

[0008] Optionally, in some embodiments of this application, the material of the second inorganic encapsulation layer is selected from at least one of silicon nitride, silicon oxynitride, silicon dioxide, and silicon boron nitride.

[0009] Optionally, in some embodiments of this application, the packaging unit further includes a second transition layer disposed between the second inorganic packaging layer and the buffer layer. The material of the second transition layer includes silicon-containing oxide nitride. The material of the second inorganic packaging layer includes silicon nitride.

[0010] Optionally, in some embodiments of this application, the packaging structure includes a plurality of stacked packaging units, and the packaging structure further includes a third transition layer disposed between two adjacent packaging units. The material of the third transition layer includes silicon oxide nitride.

[0011] Optionally, in some embodiments of this application, the silicon-containing oxide nitride includes silicon oxynitride (SiON).

[0012] Optionally, in some embodiments of this application, the material of the first transition layer is silicon oxynitride.

[0013] Optionally, in some embodiments of this application, the material of the second transition layer is silicon oxynitride.

[0014] Optionally, in some embodiments of this application, the material of the second transition layer is silicon oxynitride.

[0015] Optionally, in some embodiments of this application, the material of the first inorganic encapsulation layer includes silicon nitride. Further, the first inorganic encapsulation layer is a silicon nitride film.

[0016] Optionally, in some embodiments of this application, the material of the buffer layer further includes at least one of oxides and nitrogen oxides.

[0017] Optionally, in some embodiments of this application, the oxide is selected from at least one of silicon dioxide, aluminum oxide, zirconium oxide, and hafnium oxide. The nitrogen oxide includes at least one of silicon oxynitride, aluminum oxynitride, zirconium oxynitride, and hafnium oxynitride. The average particle size of the oxide is 1–15 nm.

[0018] Optionally, in some embodiments of this application, the thickness of the buffer layer in the packaging unit is 0.1–20 μm. The thickness of the first transition layer is 2–30 nm. The thickness of the second transition layer is 2–30 nm. The thickness of the third transition layer is 2–30 nm.

[0019] Optionally, in some embodiments of this application, the thickness of the first inorganic encapsulation layer is 50–2000 nm. Further, the thickness of the first inorganic encapsulation layer is 100–1000 nm.

[0020] Accordingly, embodiments of this application provide a method for preparing a packaging structure, comprising the following steps:

[0021] A pre-encapsulation structure is provided, wherein the pre-encapsulation structure includes a pre-encapsulation unit or a plurality of stacked pre-encapsulation units; each pre-encapsulation unit includes a stacked pre-encapsulated first inorganic encapsulation layer and a pre-encapsulated buffer layer, wherein the material of the pre-encapsulated buffer layer includes an organic polymer having the structural formula Si-OR, wherein R represents a hydrocarbon group;

[0022] The packaging structure precursor is subjected to heat treatment to generate a first transition layer between the pre-made buffer layer and the pre-made first inorganic packaging layer, thereby obtaining a packaging unit composed of a stacked structure of the first inorganic packaging layer, the first transition layer, and the buffer layer; wherein, the first transition layer includes silicon oxide nitride.

[0023] Optionally, in some embodiments of this application, before heat treatment of the packaging structure precursor, a prefabricated second inorganic packaging layer is provided on the side of the prefabricated buffer layer of at least one of the prefabricated packaging units away from the prefabricated first inorganic packaging layer.

[0024] The material of the prefabricated second inorganic encapsulation layer is selected from at least one of silicon nitride, silicon oxynitride, silicon dioxide, and silicon boron nitride.

[0025] Optionally, in some embodiments of this application, after heat treatment, a second transition layer is formed between the pre-fabricated second inorganic encapsulation layer and the pre-fabricated buffer layer, resulting in an encapsulation unit composed of a stacked structure of a first inorganic encapsulation layer, a first transition layer, a buffer layer, a second transition layer, and a second inorganic encapsulation layer. The second transition layer comprises silicon-containing oxide nitride. The material of the second inorganic encapsulation layer comprises silicon nitride.

[0026] Optionally, in some embodiments of this application, the packaging structure precursor includes a plurality of stacked pre-fabricated packaging units. The packaging structure precursor is heat-treated to generate a third transition layer between adjacent pre-fabricated packaging units, resulting in a packaging structure composed of a stacked structure of packaging units, a third transition layer, and packaging units. The third transition layer comprises silicon oxide nitride.

[0027] Optionally, in some embodiments of this application, the silicon-containing oxide nitride includes silicon oxynitride (SiON).

[0028] Optionally, in some embodiments of this application, the first transition layer is a silicon oxynitride (SiON) layer. The second transition layer is a silicon oxynitride (SiON) layer. The third transition layer is a silicon oxynitride (SiON) layer.

[0029] Optionally, in some embodiments of this application, the material of the prefabricated first inorganic encapsulation layer includes silicon nitride.

[0030] The organic polymer's Si-OR reacts with the silicon nitride to form the SiON layer.

[0031] The material of the prefabricated buffer layer further includes at least one of oxides and nitrogen oxides; the oxides include at least one of silicon dioxide, aluminum oxide, zirconium oxide, and hafnium oxide; the nitrogen oxides include at least one of silicon oxynitride, aluminum oxynitride, zirconium oxynitride, and hafnium oxynitride. The average particle size of the oxides is 1–15 nm. The average particle size of the nitrogen oxides is 1–15 nm.

[0032] Optionally, in some embodiments of this application, the heat treatment temperature is 80–150°C, and the heat treatment time is 0.5–10 hours.

[0033] Optionally, in some embodiments of this application, a prefabricated first inorganic encapsulation layer is formed in the encapsulation structure precursor; a prefabricated buffer layer is formed on the prefabricated first inorganic encapsulation layer; and a surface pretreatment step is further included before forming the prefabricated first inorganic encapsulation layer on the prefabricated first inorganic encapsulation layer.

[0034] The surface pretreatment includes ozone treatment or plasma treatment. The surface pretreatment time is 0.5-10 minutes.

[0035] Optionally, in some embodiments of this application, the surface pretreatment is a hydroxyl-enhanced surface pretreatment.

[0036] Optionally, in some embodiments of this application, the plasma used for plasma processing includes at least one of O2 plasma and N2O plasma.

[0037] Optionally, in some embodiments of this application, the thickness of the buffer layer is 0.1–20 μm. The thickness of the first inorganic encapsulation layer is 50–2000 nm. The organic polymer is obtained by polymerizing polyurethane acrylate and polydimethylsiloxane.

[0038] Accordingly, embodiments of this application also provide a light-emitting device, including a substrate, a light-emitting element, and the above-described encapsulation structure; or, including a substrate, a light-emitting element, and an encapsulation structure prepared by the method described above; wherein the light-emitting element is disposed on the substrate, and the encapsulation structure is disposed on the light-emitting element. Further, the light-emitting element is located between the substrate and the encapsulation structure.

[0039] The beneficial effects of this application are as follows:

[0040] The encapsulation structure of this application incorporates a buffer layer between inorganic encapsulation layers and a transition layer between the inorganic encapsulation layers and the buffer layer. The transition layer in the encapsulation structure possesses excellent water and oxygen barrier properties, enhancing the overall water and oxygen barrier performance of the encapsulation structure and thus improving product performance. Due to the excellent barrier properties of the transition layer, encapsulation can be achieved at a relatively low thickness, reducing the overall thickness of the encapsulation structure; this reduction in thickness further improves the product's bendability. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the packaging structure provided in the embodiments of this application. Figure 1 ;

[0043] Figure 2 This is a schematic diagram of the packaging structure provided in the embodiments of this application. Figure 2 ;

[0044] Figure 3 This is a schematic diagram of the fabrication process of the packaging structure provided in the embodiments of this application. Figure 1 ;

[0045] Figure 4 This is a schematic diagram of the fabrication process of the packaging structure provided in the embodiments of this application. Figure 2 ;

[0046] Figure 5 This is a schematic diagram of the structure of the light-emitting device provided in the embodiments of this application. Detailed Implementation

[0047] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are used only as illustrative purposes and do not impose numerical requirements or establish an order. Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and conciseness and should not be construed as a hard limitation on the scope of the present invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range. Additionally, whenever a numerical range is specified in this document, it means that any referenced number (fraction or integer) within the range is included.

[0048] The inventors of this application discovered during their research that, in order to achieve the effect of blocking water and oxygen, thin-film encapsulation requires the inclusion of a water and oxygen barrier layer. This thin film is typically made of inorganic materials, such as silicon nitride, alumina, and silicon oxynitride, and is prepared using processes like PECVD and ALD, exhibiting ideal water and oxygen barrier capabilities. Furthermore, to achieve even better water and oxygen barrier effects and realize flexible thin-film encapsulation, increasing the resilience of the encapsulation structure, thin-film encapsulation is generally configured as an inorganic water and oxygen barrier layer / organic buffer layer / inorganic water and oxygen barrier layer structure. The buffer layer material can be prepared using processes such as inkjet printing, slot coating, micro-contact printing, plasma-linked chemical vapor deposition, and molecular layer deposition. Materials used in plasma-linked chemical vapor deposition can include HMDSO and HMDSN, which can produce films with properties close to organic polymers, such as SiOC, SiNC, and pp-HMDSO. These materials effectively buffer stress, cover film defects and dust, and increase the pathway for water and oxygen permeation, making a significant contribution to the overall effectiveness of the thin-film encapsulation.

[0049] This application provides a packaging structure, a method for fabricating the packaging structure, and a light-emitting device. These will be described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments.

[0050] This application provides a packaging structure. The packaging structure includes a packaging unit, which includes a first inorganic packaging layer, a first transition layer, and a buffer layer stacked together. The buffer layer is made of an organic polymer having the structural formula Si-OR, where R represents a hydrocarbon group. The first transition layer is made of silicon oxynitride. Further, the silicon oxynitride includes silicon oxynitride (SiON), and even further, the first transition layer is made of silicon oxynitride (SiON).

[0051] Furthermore, the packaging unit also includes a second inorganic packaging layer, which is disposed on the side of the buffer layer away from the first transition layer. It can be imagined that the second inorganic packaging layer is located on the outermost side of the packaging structure. Even further, the material of the second inorganic packaging layer is selected from at least one of silicon nitride, silicon oxynitride, silicon dioxide, and silicon boron nitride. For example, when the material of the second inorganic packaging layer is silicon nitride, a second transition layer can be disposed between the second inorganic packaging layer and the buffer layer. The material of the second transition layer includes silicon-containing oxide nitride. For example, silicon-containing oxide nitride includes silicon oxynitride (SiON); or, for example, the material of the second transition layer is SiON, i.e., the second transition layer is a SiON layer.

[0052] For example, if the packaging structure includes two stacked packaging units, and each packaging unit includes a stacked first inorganic packaging layer, a first transition layer, and a buffer layer, then the packaging structure includes a first inorganic packaging layer, a first transition layer, a buffer layer, a first inorganic packaging layer, a first transition layer, and a buffer layer stacked sequentially.

[0053] In some embodiments, the packaging structure provided in this application includes multiple stacked packaging units, where "multiple packaging units" refers to two or more packaging units; each packaging unit includes a first inorganic packaging layer, a first transition layer, and a buffer layer stacked together. In this case, the outermost layer of the packaging structure is the buffer layer.

[0054] Furthermore, the packaging structure includes multiple stacked packaging units, and also includes a third transition layer disposed between two adjacent packaging units. That is, between the buffer layer of one packaging unit and the first inorganic packaging layer of the other adjacent packaging unit, a third transition layer is disposed. Further, the material of the third transition layer includes silicon oxynitride. For example, silicon oxynitride includes silicon oxynitride (SiON); or, for example, the third transition layer is a SiON layer.

[0055] For example, the packaging structure includes a first packaging unit (a first inorganic packaging layer, a first transition layer, and a buffer layer stacked together) and a second packaging unit (a first inorganic packaging layer, a first transition layer, and a buffer layer stacked together). A third transition layer is also provided between the first packaging unit and the second packaging unit, that is, there may be a third transition layer between the buffer layer of the first packaging unit and the first inorganic packaging layer of the second packaging unit.

[0056] Furthermore, the packaging structure includes multiple stacked packaging units, at least one of which further includes a second inorganic packaging layer, wherein the second inorganic packaging layer is disposed on the side of the buffer layer away from the first transition layer. It is conceivable that if the packaging unit is on the outermost side of the packaging structure, then the second inorganic packaging layer is the outermost side of the entire packaging structure. Even further, the material of the second inorganic packaging layer is selected from, but is not limited to, at least one of silicon nitride, silicon oxynitride, silicon dioxide, and silicon boron nitride. For example, when the material of the second inorganic packaging layer is silicon nitride, a second transition layer can be disposed between the second inorganic packaging layer and the buffer layer. Additionally, it is conceivable that the packaging unit can also be located in the middle of the packaging structure, in which case the second inorganic packaging layer is located on the inner side of the entire packaging structure.

[0057] In this embodiment, the material of the first inorganic encapsulation layer includes silicon nitride. Further, the first inorganic encapsulation layer is a silicon nitride film layer. Further, the silicon nitride film layer is doped with hydrogen atoms; that is, the silicon nitride film layer is a film layer containing H atoms (SiNx:H). The silicon nitride film layer not only serves to isolate water and oxygen, but it can also react with the buffer layer to form a new dense thin film, the SiON layer. If the second inorganic encapsulation layer is also a silicon nitride film layer, then, like the first inorganic encapsulation layer, it can also react with the buffer layer to form a new dense thin film, the SiON layer.

[0058] In this embodiment, the material of the buffer layer includes an organic polymer having a Si-OR structure, where R represents a hydrocarbon group. Further, the material of the buffer layer includes an organosilane; that is, an organic polymer containing a Si-OR structure is an organic polymer. For example, the raw material for the organosilane (an organic polymer containing a Si-OR structure) is obtained by polymerizing polyurethane acrylate (PUA) with polydimethylsiloxane (PDMS). In other words, the raw material for the organic polymer containing a Si-OR structure may include polyurethane acrylate (PUA) and polydimethylsiloxane (PDMS).

[0059] In this embodiment, the transition layer is made of SiON. That is, the first, second, and third transition layers are all made of SiON. The terms "first," "second," and "third" are used only as designations. It can be understood that the transition layer (SiON layer) is disposed between the inorganic encapsulation layer (silicon nitride film layer) and the buffer layer, and the two opposite surfaces of the transition layer are bonded to the adjacent inorganic encapsulation layer (silicon nitride film layer) and the buffer layer, respectively. The SiON layer in the encapsulation structure of this application has excellent barrier properties, and when combined with the inorganic encapsulation layer, it greatly enhances the water and oxygen barrier properties of the encapsulation structure.

[0060] In this embodiment, the material of the buffer layer further includes at least one of oxides and oxynitrides. That is, the material of the buffer layer includes an organic polymer doped with oxides and / or oxynitrides. Further, the oxide is selected from at least one of silicon dioxide, aluminum oxide, zirconium oxide, and hafnium oxide. The oxynitride includes at least one of silicon oxynitride, aluminum oxynitride, zirconium oxynitride, and hafnium oxynitride. For example, the oxide includes silicon dioxide, which, because it has both silicon and oxygen atoms as in the Si-OR structure of organosilanes, can help improve the performance of the buffer layer by doping it with silicon dioxide. Even further, the average particle size of the oxide or oxynitride is 1–15 nm. For example, the average particle size of the oxide can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, or 15 nm. For example, the average particle size of nitrogen oxides can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm or 15 nm.

[0061] In this embodiment of the application, the thickness of each buffer layer in the encapsulation unit is independently 0.1 to 20 μm. For example, the thickness of each buffer layer can be 0.1 μm, 0.5 μm, 1 μm, 2 μm, 5 μm, 10 μm, 15 μm, 18 μm or 20 μm.

[0062] In this embodiment of the application, the thickness of the inorganic encapsulation layer in the packaging structure can be independently ranging from 50 to 2000 nm. For example, the thickness of the inorganic encapsulation layer can be 50 nm, 60 nm, 80 nm, 100 nm, 150 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm, 1600 nm, 1700 nm, 1800 nm, 1900 nm, or 2000 nm. The inorganic encapsulation layer here can be either a first inorganic encapsulation layer or a second inorganic encapsulation layer.

[0063] In this embodiment, the formation of the SiON layer between layers effectively improves the encapsulation capability of the packaging structure, and ensures the encapsulation effect even when the SiNx film layer of the packaging structure is relatively thin. Therefore, the SiON layer in this application also helps to reduce the thickness of the packaging structure. Furthermore, the thickness of the transition layer is 2–30 nm; for example, the thickness of the transition layer can be 2 nm, 3 nm, 4 nm, 5 nm, 8 nm, 10 nm, 15 nm, 20 nm, 22 nm, 25 nm, 28 nm, or 30 nm. It is conceivable that the transition layer here can be a first transition layer, a second transition layer, or a third transition layer.

[0064] In this embodiment, the visible light transmittance of the buffer layer is greater than 85%. For example, the visible light transmittance of the buffer layer can be 85.5%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 95%, 96%, 97%, 98%, or 99%.

[0065] In this embodiment, the buffer layer is a relatively soft film with almost zero stress and high visible light transmittance. Furthermore, the buffer layer can also encapsulate dust and particles that may fall during the encapsulation process, making the edges of the particles more rounded, less likely to form channels for water and oxygen to pass through, and providing a certain degree of water and oxygen blocking performance.

[0066] In one specific embodiment, please refer to Figure 1 In the encapsulation structure 100, the inorganic encapsulation layer may include a first inorganic encapsulation layer 130a, a first buffer layer 150a, and a second inorganic encapsulation layer 130b stacked together. Further, the first buffer layer 150a is disposed between the first inorganic encapsulation layer 130a and the second inorganic encapsulation layer 130b, and a first transition layer 140a is formed between the first buffer layer 150a and the first inorganic encapsulation layer 130a; a second transition layer 140b is formed between the first buffer layer 150a and the second inorganic encapsulation layer 130b. The material of the first buffer layer includes an organic polymer containing a Si-OR structure, wherein R represents a hydrocarbon group. The material of the first inorganic encapsulation layer 130a includes silicon nitride; the material of the second inorganic encapsulation layer 130b includes silicon nitride.

[0067] In one specific embodiment, please refer to Figure 2The encapsulation structure 100 includes a first inorganic encapsulation layer 130a, a first buffer layer 150a, a second inorganic encapsulation layer 130b, and a second buffer layer 150b stacked together. In this case, the encapsulation structure 100 includes two buffer layers, namely the first buffer layer 150a and the second buffer layer 150b. The second buffer layer 150b is disposed on the side of the second inorganic encapsulation layer 130b opposite to the first buffer layer 150a. The material of the second inorganic encapsulation layer 130b is silicon nitride. It is conceivable that the second buffer layer 150b is disposed on the side of the second inorganic encapsulation layer 130b opposite to either the first inorganic encapsulation layer 130a or the first buffer layer 150a. A first transition layer 140a is formed between the first buffer layer 150a and the first inorganic encapsulation layer 130a; a second transition layer 140b is formed between the first buffer layer 150a and the second inorganic encapsulation layer 130b; and a third transition layer 140c is formed between the second buffer layer 150b and the second inorganic encapsulation layer 130b. It can be observed that the encapsulation structure has three transition layers: the first transition layer 140a, the second transition layer 140b, and the third transition layer 140c. Furthermore, the third transition layer 140c is the same as the first transition layer 140a and the second transition layer 140b, being a SiON layer, and exhibits excellent density and barrier properties. It can be imagined that the encapsulation structure at this time includes a first inorganic encapsulation layer 130a, a first transition layer 140a, a first buffer layer 150a, a second transition layer 140b, a second inorganic encapsulation layer 130b, a third transition layer 140c, and a second buffer layer 150b stacked sequentially. This is equivalent to the encapsulation structure including two stacked encapsulation units (inorganic encapsulation layer / transition layer / buffer layer), with a transition layer between the stacked encapsulation units. The terms "first," "second," and "third," etc., used in this embodiment are for illustrative purposes only.

[0068] In one embodiment, in the above Figure 2Based on the illustrated encapsulation structure, the encapsulation structure may further include a third inorganic encapsulation layer (not shown in the figure), disposed on the side of the second buffer layer opposite to the second inorganic encapsulation layer. It can be imagined that the encapsulation structure at this time includes three inorganic encapsulation layers: a first inorganic encapsulation layer, a second inorganic encapsulation layer, and a third inorganic encapsulation layer. It can be imagined that the third inorganic encapsulation layer is disposed on the second buffer layer, that is, on the side of the second buffer layer opposite to the second inorganic encapsulation layer. Furthermore, a fourth transition layer is formed between the third inorganic encapsulation layer and the second buffer layer. At this time, the encapsulation structure has four transition layers: a first transition layer, a second transition layer, a third transition layer, and a fourth transition layer, all of which are SiON layers. Furthermore, the material of the third inorganic encapsulation layer includes silicon nitride. The first inorganic encapsulation layer, the second inorganic encapsulation layer, and the third inorganic encapsulation layer are all silicon nitride (SiNx) film layers. In this embodiment, the terms first, second, and third are used merely as designations and do not impose numerical requirements or establish an order. For example, the first buffer layer and the second buffer layer are both buffer layers; the first inorganic encapsulation layer, the second inorganic encapsulation layer, and the third inorganic encapsulation layer are all inorganic encapsulation layers.

[0069] In this embodiment, the encapsulation structure is based on an inorganic encapsulation layer, a transition layer, and a buffer layer, which are repeatedly stacked. The number of inorganic encapsulation layers can be flexibly varied according to different applications and requirements. Similarly, the number of buffer layers can be flexibly varied according to different application requirements. The inorganic encapsulation layer has an ideal ability to block water and oxygen; in addition, it also has high visible light transmittance.

[0070] For example, the packaging structure of this application may include a three-layer stack (e.g., inorganic packaging layer / buffer layer / inorganic packaging layer), a four-layer stack (inorganic packaging layer / buffer layer / inorganic packaging layer / buffer layer), or a five-layer stack (inorganic packaging layer / buffer layer / inorganic packaging layer / buffer layer / inorganic packaging layer), and so on, with the number of layers determined according to requirements. Furthermore, if the inorganic packaging layers are all made of silicon nitride (SiNx) and the buffer layers are all made of organic polymers, then there is a transition layer between each inorganic packaging layer and the adjacent buffer layer; even further, the transition layer may be a SiON layer.

[0071] In this embodiment, the transition layer in the encapsulation structure is not deposited initially, but rather formed between SiNx and the organic polymer through post-processing. Specifically, a hydrolysis-condensation reaction occurs between SiNx and the Si-OR structure in the organic polymer, thereby forming a dense thin film layer, namely a SiON layer, between SiNx and the organic polymer. The formation of the SiON layer between the layers effectively improves the encapsulation capability of the encapsulation structure, ensuring the encapsulation effect even if the SiNx film layer is relatively thin. Therefore, this application can help reduce the thickness of the encapsulation structure.

[0072] This application also provides a method for preparing a packaging structure, including the following steps:

[0073] A packaging structure precursor is provided, wherein the packaging structure precursor includes a pre-fabricated packaging unit or a stack of pre-fabricated packaging units; each pre-fabricated packaging unit includes a stacked pre-fabricated first inorganic packaging layer and a pre-fabricated buffer layer, the material of the pre-fabricated buffer layer including an organic polymer having the structural formula Si-OR, wherein R represents a hydrocarbon group;

[0074] The packaging structure precursor is heat-treated to generate a first transition layer between the pre-fabricated buffer layer and the pre-fabricated first inorganic packaging layer, resulting in a packaging unit composed of a stacked structure of the first inorganic packaging layer, the first transition layer, and the buffer layer; wherein the first transition layer comprises silicon oxynitride. Further, the silicon oxynitride comprises silicon oxynitride (SiON), and even further, the material of the first transition layer is SiON.

[0075] Furthermore, a first transition layer is generated in the contact area between the prefabricated buffer layer and the prefabricated first inorganic encapsulation layer.

[0076] In some embodiments, prior to heat treatment of the packaging structure precursor, a prefabricated second inorganic packaging layer is provided on the side of the prefabricated buffer layer of at least one prefabricated packaging unit away from the prefabricated first inorganic packaging layer. Further, the material of the prefabricated second inorganic packaging layer is selected from at least one of silicon nitride, silicon oxynitride, silicon dioxide, and silicon boron nitride.

[0077] In some embodiments, after heat treatment, a second transition layer is formed between the pre-fabricated second inorganic encapsulation layer and the pre-fabricated buffer layer, resulting in an encapsulation unit composed of a stacked structure of a first inorganic encapsulation layer, a first transition layer, a buffer layer, a second transition layer, and a second inorganic encapsulation layer; wherein, the second transition layer comprises silicon oxynitride. Further, the silicon oxynitride comprises silicon oxynitride (SiON), and even further, the material of the second transition layer is a SiON layer. It is conceivable that the material of the pre-fabricated second inorganic encapsulation layer in this case includes silicon nitride.

[0078] In this embodiment, the principle of generating a transition layer between the prefabricated second inorganic encapsulation layer and the prefabricated buffer layer is the same as the principle of generating a transition layer between the prefabricated first inorganic encapsulation layer and the prefabricated buffer layer, that is, silicon nitride and organic polymer form SiON under heat treatment conditions.

[0079] In some embodiments, the packaging structure precursor includes a plurality of stacked pre-fabricated packaging units. The packaging structure precursor is heat-treated to generate a third transition layer between two adjacent pre-fabricated packaging units, resulting in a packaging structure composed of a stacked structure of packaging units, a third transition layer, and packaging units. The third transition layer comprises silicon oxynitride. Further, the silicon oxynitride comprises silicon oxynitride (SiON), and even further, the material of the second transition layer is a SiON layer.

[0080] In some embodiments, the prefabricated first inorganic encapsulation layer and prefabricated buffer layer in the pre-encapsulation structure of the preparation method may refer to the aforementioned encapsulation structure. Therefore, in the pre-encapsulation unit, the outermost layer may be a prefabricated second inorganic encapsulation layer or a prefabricated buffer layer. In the pre-encapsulation structure, after heat treatment, a transition layer (such as a SiON layer) may be formed between the prefabricated buffer layer and the prefabricated first inorganic encapsulation layer (or second inorganic encapsulation layer).

[0081] Furthermore, the preparation of the prefabricated buffer layer includes the following steps: forming a flowable liquid film on the prefabricated inorganic encapsulation layer using a buffer layer material, and then curing it to obtain the prefabricated buffer layer; wherein, the curing is UV curing and / or thermal curing.

[0082] In some embodiments, the material for the pre-formed first inorganic encapsulation layer includes silicon nitride. An organic polymer with Si-OR reacts with silicon nitride to form a SiON layer.

[0083] In this embodiment, the organic polymer has the structural formula Si-OR, where R represents a hydrocarbon group, such as the group remaining after a saturated alkane loses one H atom, for example, ethane (CH3CH3) loses one H atom to become -CH2CH3, becoming an ethyl group. The inorganic encapsulation layer is a silicon nitride film layer (SiNx:H). It can be imagined that the transition layer, obtained by reacting the organic polymer containing the Si-OR structure with the silicon nitride film layer, provides excellent barrier properties. Combined with the inorganic encapsulation layer, this significantly enhances the water and oxygen barrier properties of the encapsulation structure. The buffer layer has a softer film with lower stress and better planarization properties, thereby effectively improving the barrier capability of the inorganic encapsulation layer.

[0084] Furthermore, the material of the pre-fabricated buffer layer also includes at least one of oxides and oxynitrides. The oxides include at least one of silicon dioxide, aluminum oxide, zirconium oxide, and hafnium oxide; the oxynitrides include at least one of silicon oxynitride, aluminum oxynitride, zirconium oxynitride, and hafnium oxynitride. Furthermore, the average particle size of the oxides is 1–15 nm, for example, 1–10 nm, 3–15 nm, 3–10 nm, etc. Furthermore, the average particle size of the oxynitrides is 1–15 nm, for example, 1–10 nm, 3–15 nm, 3–10 nm, etc.

[0085] In some embodiments, a prefabricated first inorganic encapsulation layer is formed in the encapsulation structure precursor; a prefabricated buffer layer is formed on the prefabricated first inorganic encapsulation layer; and a hydroxyl-enriched surface pretreatment step is included before forming the prefabricated buffer layer on the prefabricated first inorganic encapsulation layer; the hydroxyl-enriched surface pretreatment includes ozone treatment or plasma treatment. The duration of the hydroxyl-enriched surface pretreatment is 0.5-10 minutes. Further, the plasma used for the plasma treatment can be an oxygen-containing plasma, for example, an oxygen-containing plasma including at least one of O2 plasma and N2O plasma.

[0086] Specifically, in order to form a thicker intermediate dense SiON layer, oxygen-containing plasma or O3 pretreatment can be performed on the surface of the SiNx:H film before forming the organic buffer and induction layer. This allows more -OH bonds to form on the surface of the SiNx:H film, increasing the degree of hydrolysis and condensation reaction between the film and the organic buffer and induction layer, and making it easier to form the SiON layer.

[0087] In some embodiments, the heat treatment temperature is 80–150°C. The heat treatment time is 0.5–10 hours. For example, the heat treatment temperature is 80°C, 90°C, 100°C, 120°C, 140°C, or 150°C; the heat treatment time can be 0.5 hours, 1 hour, 2 hours, 4 hours, 5 hours, 6 hours, 8 hours, 9 hours, or 10 hours. For example, the heat treatment temperature is 120°C, and the time is 5 hours.

[0088] In some embodiments, the thickness of the buffer layer is 0.1–20 μm. The thickness of the first inorganic encapsulation layer is 50–2000 nm. The organic polymer is obtained by polymerizing polyurethane acrylate with polydimethylsiloxane.

[0089] In one specific embodiment, see Figure 3 As shown, the method for fabricating the encapsulation structure includes the following steps:

[0090] A pre-encapsulation structure is provided, wherein the pre-encapsulation structure includes a pre-encapsulation unit, the pre-encapsulation unit includes a stacked pre-encapsulated first inorganic encapsulation layer 130a' and a pre-encapsulated first buffer layer 150a', the material of the pre-encapsulated buffer layer includes an organic polymer having the structural formula Si-OR, wherein R represents a hydrocarbon group;

[0091] The packaging structure precursor is heat-treated to generate a first transition layer between the pre-made buffer layer and the pre-made first inorganic packaging layer, resulting in a packaging unit composed of a stacked structure of the first inorganic packaging layer 130a, the first transition layer 140a, and the first buffer layer 150a; wherein, the first transition layer is a SiON layer.

[0092] For further information, please refer to [link / reference]. Figure 3A substrate 110 with a light-emitting element 120 is provided, and a pre-fabrication of an encapsulation structure is performed thereon, including:

[0093] A prefabricated first inorganic encapsulation layer 130a' is formed on the light-emitting element 120;

[0094] A thin film is formed on the prefabricated first inorganic encapsulation layer 130a' using the material of the buffer layer to obtain the prefabricated first buffer layer 150a'.

[0095] In one specific embodiment, see Figure 4 As shown, the method for fabricating the encapsulation structure includes the following steps:

[0096] A pre-encapsulation structure is provided, wherein the pre-encapsulation structure includes a pre-encapsulation unit, and the pre-encapsulation unit includes a stacked pre-encapsulated first inorganic encapsulation layer 130a', a pre-encapsulated first buffer layer 150a' and a pre-encapsulated second inorganic encapsulation layer 130b', wherein the material of the pre-encapsulated first buffer layer 150a' includes an organic polymer having the structural formula Si-OR, wherein R represents a hydrocarbon group;

[0097] The pre-package structure is heat-treated to form a first transition layer between the pre-fabricated first buffer layer 150a' and the pre-fabricated first inorganic encapsulation layer 130a', and a second transition layer between the pre-fabricated first buffer layer 150a' and the pre-fabricated second inorganic encapsulation layer 130b', resulting in an encapsulation unit composed of a stacked structure of the first inorganic encapsulation layer 130a, the first transition layer 140a, the first buffer layer 150a, the second transition layer 140b, and the second inorganic encapsulation layer 130b. The first and second transition layers are both SiON layers; the pre-fabricated first and second inorganic encapsulation layers are both silicon nitride films, and further, the silicon nitride films contain H atoms.

[0098] For further information, please refer to [link / reference]. Figure 4 A substrate 110 with a light-emitting element 120 is provided, and a pre-fabrication of an encapsulation structure is performed thereon, including:

[0099] A prefabricated first inorganic encapsulation layer 130a' is formed on the light-emitting element 120;

[0100] A thin film is formed on the prefabricated first inorganic encapsulation layer 130a' using the material of the buffer layer to obtain the prefabricated first buffer layer 150a';

[0101] A prefabricated second inorganic encapsulation layer 130b' is formed on the prefabricated first buffer layer 150a'.

[0102] In some embodiments, the organic polymer containing the Si-OR structure can be an organosilane. Further, the organosilane can be prepared from polyurethane acrylate (PUA) and polydimethylsiloxane (PDMS). The buffer layer has a relatively soft film and low stress, and can generally be prepared by solution processing. It exhibits good planarization properties, and by planarizing the deposited surface, the barrier capability of the inorganic encapsulation layer can be effectively improved.

[0103] In this embodiment, the first inorganic encapsulation layer, the second inorganic encapsulation layer, and other inorganic encapsulation layers have strong water and oxygen blocking capabilities; in addition, they also have high visible light transmittance. The inorganic encapsulation layers of this application can be deposited using plasma-enhanced chemical vapor deposition (PECVD) and contain a film layer with a large number of H atoms doped within them. Specifically, if SiH4 gas is used as the reaction source gas during the PECVD process, the resulting silicon nitride film will itself contain a large number of H atoms.

[0104] In some embodiments, the formation of the prefabricated first inorganic encapsulation layer of this application can be achieved by using common deposition techniques such as magnetron sputtering, evaporation, chemical vapor deposition, atomic layer deposition, molecular layer deposition, and inkjet printing to deposit the inorganic encapsulation layer on the display area / encapsulation area of ​​the substrate. Other prefabricated inorganic encapsulation layers of this application can also be prepared using this method.

[0105] In some embodiments, a prefabricated first buffer layer is formed on the prefabricated first inorganic encapsulation layer. Specifically, embodiments of this application can use methods such as slot coating, inkjet printing, chemical vapor deposition, and liquid phase deposition to form the prefabricated first buffer layer on the display area of ​​the display screen, i.e., on the prefabricated first inorganic encapsulation layer. Other prefabricated buffer layers of this application can also be prepared using this method.

[0106] For example, the preparation of the prefabricated first buffer layer includes the following steps: forming a flowable liquid film on the prefabricated first inorganic encapsulation layer using a buffer layer material, and then curing it to obtain the first buffer layer; wherein, the curing is UV curing and / or thermal curing. Further, a flowable liquid film is formed on the prefabricated first inorganic encapsulation layer using an immersion method, a coating process, or an inkjet process. The buffer layer material is a precursor to the buffer layer, a liquid with low viscosity, which can be formed into a flowable liquid film on the prefabricated first encapsulation layer using an immersion method, a coating process, or an inkjet process; subsequently, the internal precursor is cross-linked by methods such as UV curing or thermal curing to finally form a solid film. UV curing is used for the buffer layer because UV curing is fast and provides better uniformity; in this case, the buffer layer material may include a photoinitiator and a photosensitive material.

[0107] In this application, the prefabricated second inorganic encapsulation layer can be made of the same materials and prepared using the same method as the prefabricated first inorganic encapsulation layer.

[0108] Furthermore, a prefabricated second inorganic encapsulation layer is formed on the prefabricated first buffer layer, and the prefabricated second inorganic encapsulation layer should have a coating area at least larger than that of the prefabricated buffer layer (such as the first buffer layer). Specifically, in conjunction with the above, the coating area of ​​the buffer layer is slightly smaller than that of the first inorganic encapsulation layer; for example, the edge of the buffer layer is 0.1–5 mm smaller than that of the first inorganic encapsulation layer; while the edge of the second inorganic encapsulation layer should be 0.1–5 mm larger than that of the first buffer layer. In the formed encapsulation structure, the first inorganic encapsulation layer and the second inorganic encapsulation layer together encapsulate the first buffer layer, thereby ensuring that the edge portion of the encapsulation will not fail due to water and oxygen intrusion caused by the weaker barrier properties of the first buffer layer. In other words, the size of the buffer layer should be smaller than the size of the inorganic encapsulation layers above and below it to prevent water and oxygen intrusion at the edge.

[0109] In some embodiments, the thickness of the buffer layer can be 0.1–20 μm. The thickness of the buffer layer can be determined based on the actual thin-film encapsulation (TFE) structure.

[0110] In this embodiment, the main function of the buffer layer is to buffer the stress experienced by the display when it is bent. Simultaneously, its high fluidity effectively covers impurities and dust on the pixels, blunting the edges of these impurities and thus effectively improving the encapsulation effect of the buffer layer. Furthermore, by adjusting its thickness, the stress neutral axis of the flexible display screen when bent can be adjusted. Strategically placing the neutral axis at locations of more vulnerable device structures can effectively improve the display screen's resistance to bending.

[0111] The prefabricated buffer layer of this application has a large number of Si-OR bonds. These chemical bonds are prone to hydrolysis and condensation reaction with silicon nitride (SiNx:H) in the inorganic encapsulation layer, and form a dense SiON film, i.e., a transition layer, between the inorganic encapsulation layer and the buffer layer.

[0112] In some embodiments, this application can form a dense thin film layer, namely a transition layer (SiON layer), between the prefabricated inorganic encapsulation layer and the prefabricated buffer layer through heat treatment.

[0113] Specifically, the deposited thin film is heat-treated to react the organic polymer with two adjacent SiNx:H thin films, forming a dense SiON layer between the two films. Further, the thickness of the SiON layer is 2–30 nm. By forming this dense film layer, the WVTR of this application embodiment can be reduced by 1–2 orders of magnitude compared to the original encapsulation structure, resulting in better water and oxygen barrier performance. For example, the heating device can be a heating oven (OVEN).

[0114] In this embodiment, by heat-treating the film layer, a hydrolysis-condensation reaction occurs between the SiNx:H in the silicon nitride film layer and the Si-OR chemical bonds in the organic polymer, thereby forming a dense thin film layer, namely the SiON layer, which is located near the interface between the inorganic encapsulation layer and the buffer layer.

[0115] The hydrolysis-condensation reaction can be referenced in the following reaction formula through heat treatment:

[0116]

[0117] In this embodiment, firstly, the organic polymer (e.g., organosilane) near the interface hydrolyzes to form an intermediate product with -H bonds, while the H bonds in SiNx:H are formed by the pretreatment containing O and the reaction with a small amount of H2O generated from the hydrolysis of the organic polymer to form an intermediate product with -OH bonds. Under heating conditions, the two intermediate products undergo a dehydration condensation reaction to form tightly connected Si-O-Si-N bonds, thereby forming a SiON layer. During the continued reaction, under the induction of the organic polymer, the H atoms in the originally loose SiNx:H film layer containing more H atoms are continuously consumed and form tightly bound N-Si-O bonds, causing the originally loose SiNx film layer to form a dense SiON film layer in the interface region. Furthermore, due to the formation of film layers with different densities, the water and oxygen channels originally present in SiNx:H and the buffer layer are altered, making the water and oxygen channels longer, thereby further improving the water and oxygen barrier capacity.

[0118] Please continue reading. Figure 5 This application also provides a light-emitting device, including:

[0119] substrate 110;

[0120] A light-emitting element 120 is disposed on a substrate 110;

[0121] The encapsulation structure 100 is disposed on the light-emitting element 120.

[0122] The packaging structure 100 in the light-emitting device can be referred to the packaging structure described above or the packaging structure prepared by the method described above.

[0123] In some embodiments of this application, the substrate is used to support TFT, OLED, QLED, or liquid crystal components, and can be a rigid substrate or a flexible substrate. For example, a rigid substrate can be made of ceramic material, various types of glass material, etc.; for example, a flexible substrate can be PI (polyimide film) and its derivatives, PEN (polyethylene naphthalate), PEP (phosphoenolpyruvate), diphenylene ether resin, etc.

[0124] In some embodiments of this application, the light-emitting element can be an OLED device or other functional devices / films. Different technologies and applications have different structures, but ultimately, the light-emitting element is exposed and requires a protective film to cover it. An OLED device may include a cathode, anode, hole injection layer, hole transport layer, light-emitting layer, electron transport layer, etc. Other functional devices / films, such as PMOLED (passive-matrix OLED), will include a pixel definition layer, support pillar layer, etc.; while AMOLED (active-matrix OLED) will contain thin-film transistor driving devices, pixel definition layers, etc. An OLED device refers to an organic light-emitting diode, whose electrode materials can be metals, alloys, conductive oxides, or conductive organic materials; its other materials can be various organic materials, quantum dot materials, or functional organic materials. The most significant characteristic of OLED devices is that they will fail and cease to function when exposed to water and oxygen.

[0125] In some embodiments of this application, the light-emitting element includes an anode layer, a hole-functional layer, a light-emitting layer, an electron-functional layer, and a cathode layer stacked sequentially.

[0126] In some embodiments, the light-emitting device includes:

[0127] An anode layer is disposed on the substrate;

[0128] The hole-functional layer is located on the anode layer;

[0129] The light-emitting layer is positioned on the hole-functional layer;

[0130] An electronic functional layer is disposed on the light-emitting layer;

[0131] The cathode layer is disposed on the electronic functional layer;

[0132] The encapsulation structure is located on the cathode layer.

[0133] In some embodiments, the light-emitting device includes:

[0134] A cathode layer is disposed on a substrate;

[0135] An electronic functional layer is disposed on the cathode layer;

[0136] The light-emitting layer is disposed on the electronic functional layer;

[0137] Hole functional layer, disposed on the light-emitting layer;

[0138] The anode layer is positioned on the hole functional layer;

[0139] The encapsulation structure is located on the anode layer.

[0140] This application provides a display device having the packaging structure described above. The display device includes, but is not limited to, mobile phones, televisions, tablet computers, monitors, VR / AR devices, computers, automotive displays, or any product or component with display functionality.

[0141] This application has undergone multiple experiments, and some of the test results are presented here for reference to further describe the invention in detail. The following is a detailed description in conjunction with specific embodiments.

[0142] Example 1

[0143] This embodiment provides a packaging structure, including a packaging unit. The packaging unit includes a first inorganic packaging layer (500 nm thick), a first transition layer (4 nm thick), and a buffer layer (4000 nm thick) stacked together. The buffer layer is made of an organic polymer having the structural formula Si-OR, where R represents a hydrocarbon group; the first transition layer is a SiON layer; and the first inorganic packaging layer is a silicon nitride film layer.

[0144] The method for preparing the packaging structure in this embodiment includes the following steps:

[0145] A pre-encapsulation structure is provided, comprising a pre-encapsulation unit, the pre-encapsulation unit comprising a stacked pre-encapsulated first inorganic encapsulation layer and a pre-encapsulated buffer layer, the material of the pre-encapsulated buffer layer comprising an organic polymer having the structural formula Si-OR, wherein R represents a hydrocarbon group;

[0146] The packaging structure precursor is heat-treated at 120°C for 5 hours to generate a first transition layer between the pre-made buffer layer and the pre-made first inorganic packaging layer, resulting in a packaging unit composed of a stacked structure of the first inorganic packaging layer, the first transition layer, and the buffer layer.

[0147] Example 2

[0148] This embodiment provides a packaging structure, including a packaging unit. The packaging unit includes a stacked first inorganic packaging layer (400 nm thick), a first transition layer (4 nm thick), a buffer layer (4000 nm thick), a second transition layer (3.8 nm thick), and a second inorganic packaging layer (500 nm thick). In this embodiment, the buffer layer is made of an organic polymer with the structural formula Si-OR, where R represents a hydrocarbon group; both the first and second transition layers are SiON layers; and both the first and second inorganic packaging layers are silicon nitride films.

[0149] The method for preparing the packaging structure in this embodiment includes the following steps:

[0150] A pre-encapsulation structure is provided, comprising a pre-encapsulation unit, the pre-encapsulation unit comprising a stacked pre-encapsulated first inorganic encapsulation layer, a pre-encapsulated buffer layer and a pre-encapsulated second inorganic encapsulation layer, the material of the pre-encapsulated buffer layer comprising an organic polymer having the structural formula Si-OR, wherein R represents a hydrocarbon group;

[0151] The pre-encapsulation structure is heat-treated at 120°C for 5 hours to generate a first transition layer between the pre-made buffer layer and the pre-made first inorganic encapsulation layer, and a second transition layer between the pre-made second inorganic encapsulation layer and the pre-made buffer layer, resulting in an encapsulation unit composed of a stacked structure of the first inorganic encapsulation layer, the first transition layer, the buffer layer, the second transition layer, and the second inorganic encapsulation layer.

[0152] Example 3

[0153] This embodiment provides a packaging structure including a stacked first packaging unit and a second packaging unit. The first packaging unit includes a stacked first inorganic packaging layer, a first transition layer, and a buffer layer. The second packaging unit includes a stacked first inorganic packaging layer, a first transition layer, a buffer layer, a second transition layer, and a second inorganic packaging layer. A third transition layer is disposed between the first packaging unit and the second packaging unit. Specifically, the packaging structure of this embodiment includes a stacked first inorganic packaging layer (500nm thick), a first transition layer (4nm thick), a buffer layer (2000nm thick), a third transition layer (3.8nm thick), a first inorganic packaging layer (400nm thick), a first transition layer (3nm thick), a buffer layer (2000nm thick), a second transition layer (3.5nm thick), and a second inorganic packaging layer (500nm thick).

[0154] In this embodiment, the material of the buffer layer includes an organic polymer with the structural formula Si-OR, where R represents a hydrocarbon group; the first transition layer, the second transition layer, and the third transition layer are all SiON layers; the first inorganic encapsulation layer and the second inorganic encapsulation layer are both silicon nitride film layers.

[0155] The method for preparing the packaging structure in this embodiment includes the following steps:

[0156] A pre-encapsulation structure is provided, comprising two pre-encapsulation units. The first pre-encapsulation unit comprises a stacked pre-encapsulated first inorganic encapsulation layer and a pre-encapsulated buffer layer. The second pre-encapsulation unit comprises a stacked pre-encapsulated first inorganic encapsulation layer, a pre-encapsulated buffer layer, and a pre-encapsulated second inorganic encapsulation layer. The material of the pre-encapsulated buffer layer comprises an organic polymer having the structural formula Si-OR, where R represents a hydrocarbon group.

[0157] The pre-encapsulation structure is heat-treated at 120°C for 5 hours to generate a third transition layer between the two pre-encapsulation units, a first transition layer between the pre-buffer layer and the pre-first inorganic encapsulation layer, and a second transition layer between the pre-second inorganic encapsulation layer and the pre-buffer layer. This results in an encapsulation structure consisting of a stacked structure of a first inorganic encapsulation layer, a first transition layer, a buffer layer, a third transition layer, a first inorganic encapsulation layer, a first transition layer, a buffer layer, a second transition layer, and a second inorganic encapsulation layer.

[0158] Example 4

[0159] This embodiment provides a packaging structure including a packaging unit. The packaging unit includes a stacked first inorganic packaging layer (50 nm thick), a first transition layer (2 nm thick), a buffer layer (500 nm thick), a second transition layer (2 nm thick), and a second inorganic packaging layer (500 nm thick). In this embodiment, the buffer layer is made of an organic polymer with the structural formula Si-OR, where R represents a hydrocarbon group. Both the first and second transition layers are SiON layers. Both the first and second inorganic packaging layers are silicon nitride films. Other conditions are the same as in Embodiment 2.

[0160] Example 5

[0161] This embodiment provides a packaging structure including a packaging unit. The packaging unit includes a stacked first inorganic packaging layer (1000 nm thick), a first transition layer (12 nm thick), a buffer layer (10 μm thick), a second transition layer (10 nm thick), and a second inorganic packaging layer (1000 nm thick). In this embodiment, the buffer layer is made of an organic polymer with the structural formula Si-OR, where R represents a hydrocarbon group. Both the first and second transition layers are SiON layers. Both the first and second inorganic packaging layers are silicon nitride films. Other conditions are the same as in Embodiment 2.

[0162] Example 6

[0163] This embodiment provides a packaging structure including a packaging unit. The packaging unit includes a stacked first inorganic packaging layer (500 nm thick), a first transition layer (30 nm thick), a buffer layer (5 μm thick), a second transition layer (9 nm thick), and a second inorganic packaging layer (2000 nm thick). In this embodiment, the buffer layer is made of an organic polymer with the structural formula Si-OR, where R represents a hydrocarbon group. Both the first and second transition layers are SiON layers. Both the first and second inorganic packaging layers are silicon nitride films. Other conditions are the same as in Embodiment 2.

[0164] Example 7

[0165] This embodiment provides a packaging structure including a packaging unit. The packaging unit includes a stacked first inorganic packaging layer (2000 nm thick), a first transition layer (30 nm thick), a buffer layer (20 μm thick), a second transition layer (20 nm thick), and a second inorganic packaging layer (1000 nm thick). In this embodiment, the buffer layer is made of an organic polymer with the structural formula Si-OR, where R represents a hydrocarbon group. Both the first and second transition layers are SiON layers. Both the first and second inorganic packaging layers are silicon nitride films. Other conditions are the same as in Embodiment 2.

[0166] Comparative Example 1

[0167] Comparative Example 1 provides a packaging structure including an inorganic packaging layer, which is a silicon nitride film layer. The thickness of the inorganic packaging layer in Comparative Example 1 is basically the same as the total thickness of the inorganic packaging layer, transition layer and buffer layer stacked in Example 1 (the difference is less than 50 nm).

[0168] Experimental Example 1

[0169] Prepare a substrate with light-emitting elements, and fabricate OLED light-emitting devices using the packaging structures of Examples 1-3 and Comparative Example 1 of this application, respectively, denoted as Device Examples 1-3 and Device Comparative Example 1. The water and oxygen barrier capabilities (such as water vapor transmission rate WVTR) of the OLED light-emitting devices are tested, as detailed in Table 1.

[0170] Table 1

[0171] Example 1 0.000018 Example 2 0.000015 Example 3 0.00001 Comparative Example 1 0.0014

[0172] As shown in Table 1, the water vapor transmission rate (WVTR) of Example 1 is 0.000011 g / m³. 3 / day, the water vapor transmission rate of the example is 0.000015 g / m 3 / day, the water vapor transmission rate of Example 3 is 0.000018 g / m 3 / day, while the water vapor transmission rate of Comparative Example 1 was as high as 0.0013 g / m². 3 As can be seen, the water vapor transmission rates of Examples 1-3 of this application are all lower than those of Comparative Example 1. Obviously, the water and oxygen barrier capabilities of Examples 1-3 of this application are stronger than those of Comparative Example 1. Therefore, the water and oxygen barrier performance of the packaging structure of this application is excellent, meeting the application requirements of light-emitting devices.

[0173] Furthermore, the encapsulation structure of Example 2 includes a stacked inorganic encapsulation layer, a transition layer, a buffer layer, and another inorganic encapsulation layer, compared to the encapsulation structure of Example 1, which includes an inorganic encapsulation layer, a transition layer, and a buffer layer. According to Table 1, the water vapor transmission rate of Example 2 is lower than that of Example 1. In other words, the water and oxygen barrier capability of Example 2 is stronger than that of Example 1; that is, the water vapor transmission rate of the encapsulation structure with two transition layers is lower than that of the encapsulation structure with one transition layer. Similarly, the water and oxygen barrier capability of Example 3 is stronger than that of Example 2; that is, the water vapor transmission rate of the encapsulation structure with four transition layers is lower than that of the encapsulation structure with two transition layers. Therefore, within an appropriate thickness range of the encapsulation structure, the more layers of inorganic encapsulation layer, transition layer, and buffer layer stacked in this application, the stronger the water and oxygen barrier capability.

[0174] In summary, the SiON layer, the transition layer between the inorganic encapsulation layer and the buffer layer in this application's packaging structure, is formed through a reaction. This SiON layer is very thin and possesses excellent density, thus not only reducing the overall thickness of the packaging structure but also improving the product's bendability and ensuring its water and oxygen barrier properties. This packaging structure is completed during the display panel manufacturing process, reducing the thickness of the encapsulation film by introducing a process for forming a dense encapsulation film. This packaging structure can be applied to flat panel displays, television displays, electronic paper, logic and memory circuits, flexible displays, and other fields.

[0175] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0176] The above provides a detailed description of the packaging structure, the method for preparing the packaging structure, and the light-emitting device provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A packaging structure, characterized in that, The encapsulation structure includes an encapsulation unit, which comprises a first inorganic encapsulation layer, a first transition layer, and a buffer layer; or, the encapsulation unit comprises a first inorganic encapsulation layer, a first transition layer, a buffer layer, and a second inorganic encapsulation layer; or, the encapsulation unit comprises a first inorganic encapsulation layer, a first transition layer, a buffer layer, a second transition layer, and a second inorganic encapsulation layer; or, The encapsulation structure includes multiple stacked encapsulation units and a third transition layer; each encapsulation unit includes a first inorganic encapsulation layer, a first transition layer, and a buffer layer stacked sequentially; the third transition layer is disposed between two adjacent encapsulation units; The first inorganic encapsulation layer is an undoped or hydrogen-doped silicon nitride film; the buffer layer is made of an organic polymer having the structural formula Si-OR, where R represents a hydrocarbon group; the first transition layer is made of silicon-containing oxide nitride.

2. The packaging structure according to claim 1, characterized in that, The material of the second inorganic encapsulation layer includes at least one of silicon nitride, silicon oxynitride, silicon dioxide, and silicon boron nitride.

3. The package structure of claim 1, wherein, The material of the second transition layer includes silicon nitride.

4. The package structure of claim 1, wherein, The material of the third transition layer includes silicon nitride.

5. The package structure of claim 1, wherein, The material of the buffer layer also includes at least one of oxides and nitrogen oxides.

6. The packaging structure according to claim 5, characterized in that, The oxide is selected from at least one of silicon dioxide, aluminum oxide, zirconium oxide, and hafnium oxide; the nitrogen oxide includes at least one of silicon oxynitride, aluminum oxynitride, zirconium oxynitride, and hafnium oxynitride; and / or The average particle size of the oxide is 1~15 nm; and / or The average particle size of the nitrogen oxides is 1~15nm.

7. The packaging structure according to any one of claims 1 to 4, characterized in that, The silicon-containing nitrogen oxides include silicon oxynitride.

8. The packaging structure according to any one of claims 1 to 4, characterized in that, The material of the first transition layer is silicon oxynitride; and / or The material of the second transition layer is silicon oxynitride; and / or The material of the second transition layer is silicon oxynitride.

9. The packaging structure according to any one of claims 1 to 4, characterized in that, In the encapsulation unit, the thickness of the buffer layer is 0.1~20μm; and / or The thickness of the first transition layer is 2~30nm; and / or The thickness of the second transition layer is 2~30nm; and / or The thickness of the third transition layer is 2~30nm; and / or The thickness of the first inorganic encapsulation layer is 50~2000nm.

10. A method for preparing a packaging structure, characterized in that, Includes the following steps: A pre-encapsulation structure is provided, wherein the pre-encapsulation structure includes a pre-encapsulation unit or a plurality of stacked pre-encapsulation units; each pre-encapsulation unit includes a stacked pre-encapsulated first inorganic encapsulation layer and a pre-encapsulated buffer layer, wherein the material of the pre-encapsulated buffer layer includes an organic polymer having the structural formula Si-OR, wherein R represents a hydrocarbon group; The packaging structure precursor is subjected to heat treatment to generate a first transition layer between the pre-made buffer layer and the pre-made first inorganic packaging layer, thereby obtaining a packaging unit composed of a stacked structure of a first inorganic packaging layer, a first transition layer, and a buffer layer; wherein, the first transition layer includes silicon oxide nitride.

11. The method for preparing the packaging structure according to claim 10, characterized in that, Before heat treatment of the pre-encapsulation structure, a pre-formed second inorganic encapsulation layer is provided on the side of the pre-formed buffer layer of at least one of the pre-formed encapsulation units away from the pre-formed first inorganic encapsulation layer. The material of the prefabricated second inorganic encapsulation layer is selected from at least one of silicon nitride, silicon oxynitride, silicon dioxide, and silicon boron nitride.

12. The method for preparing the packaging structure according to claim 11, characterized in that, After heat treatment, a second transition layer is generated between the prefabricated second inorganic encapsulation layer and the prefabricated buffer layer, resulting in an encapsulation unit composed of a stacked structure of a first inorganic encapsulation layer, a first transition layer, a buffer layer, a second transition layer, and a second inorganic encapsulation layer; wherein, the second transition layer includes silicon oxide nitride.

13. The method for preparing the packaging structure according to claim 10, characterized in that, The packaging structure precursor includes multiple stacked pre-fabricated packaging units. The packaging structure precursor is heat-treated to generate a third transition layer between two adjacent pre-fabricated packaging units, resulting in a packaging structure composed of a stacked structure of packaging units, a third transition layer, and packaging units; wherein, the third transition layer includes silicon oxide nitride.

14. The method for preparing the packaging structure according to any one of claims 10 to 13, characterized in that, The material of the prefabricated first inorganic encapsulation layer includes silicon nitride; The silicon-containing nitrogen oxides include silicon oxynitride; The material of the prefabricated buffer layer also includes at least one of oxides and nitrogen oxides; the oxides include at least one of silicon dioxide, aluminum oxide, zirconium oxide, and hafnium oxide; the nitrogen oxides include at least one of silicon oxynitride, aluminum oxynitride, zirconium oxynitride, and hafnium oxynitride; the average particle size of the oxides is 1~15nm; the average particle size of the nitrogen oxides is 1~15nm.

15. The method for preparing the packaging structure according to any one of claims 10 to 13, characterized in that, The heat treatment temperature is 80~150℃; and / or The heat treatment time is 0.5~10h; and / or The first transition layer is a silicon oxynitride layer.

16. The method for preparing the packaging structure according to claim 10, characterized in that, A prefabricated first inorganic encapsulation layer is formed; a prefabricated buffer layer is formed on the prefabricated first inorganic encapsulation layer; before forming the prefabricated buffer layer on the prefabricated first inorganic encapsulation layer, a surface pretreatment step is further included for the prefabricated first inorganic encapsulation layer; The surface pretreatment includes ozone treatment or plasma treatment, wherein the surface pretreatment time is 0.5-10 min.

17. The method for preparing the packaging structure according to claim 10, characterized in that, The organic polymer is obtained by polymerizing polyurethane acrylate with polydimethylsiloxane; and / or The thickness of the buffer layer is 0.1~20µm; and / or The thickness of the first inorganic encapsulation layer is 50~2000nm.

18. A light-emitting device, characterized in that, It includes a substrate, a light-emitting element, and a packaging structure according to any one of claims 1 to 9; or, it includes a substrate, a light-emitting element, and a packaging structure prepared by the method according to any one of claims 10 to 17. The light-emitting element is disposed on the substrate, and the encapsulation structure is disposed on the light-emitting element.

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