Display substrate and display device

Abstract

The utility model provides a display substrate. The display substrate comprises a substrate body; the driving circuit layer is located on the substrate; the light-emitting device layer is located on the side, away from the substrate, of the driving circuit layer; the pixel defining layer is located on the side, away from the substrate, of the driving circuit layer, the pixel defining layer comprises a pixel opening part and a pixel interval part, the pixel opening part defines a pixel opening, and at least one part of the light-emitting device layer is located in the pixel opening; the spacers are located on the sides, away from the substrate, of the pixel spacing parts, the display substrate further comprises a first packaging layer, and the first packaging layer is located between the driving circuit layer and the pixel defining layer; the second packaging layer covers at least one part of the surfaces, far away from the substrate, of the light-emitting device layer, the pixel defining layer and the spacer, and at least one part of the second packaging layer is located between the pixel opening part and the pixel spacing part; the orthographic projections of the pixel spacing parts and the spacers on the substrate respectively fall into the orthographic projection of the first packaging layer on the substrate.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a display substrate and a display device. Background Art

[0002] Organic Light Emitting Diode (OLED) display panels have self-luminous properties, can achieve infinite contrast, present the purest black and richer color gradations, and have the characteristics of ultra-thin design, excellent image quality, fast response, energy saving and high efficiency, strong flexibility and good shock resistance. Existing OLED devices include a stacked anode, a light-emitting layer and a cathode. The light-emitting material of the light-emitting layer is very sensitive to water vapor and oxygen. When in contact with water vapor and oxygen, it may cause the degradation of the organic light-emitting diode device, resulting in adverse phenomena such as GDS (Grow Dark Spot) on the display screen of the display panel. Therefore, the packaging technology of OLED devices is extremely important. How to improve the packaging reliability of OLED devices and extend the service life of the products is a topic that R&D personnel continue to pay attention to.

[0003] The above information disclosed in this section is only for understanding the background of the inventive concept of the present disclosure and therefore the above information may contain information that does not constitute prior art. Utility Model Content

[0004] In order to solve at least one aspect of the above problems, embodiments of the present disclosure provide a display substrate and a display device.

[0005] In one aspect of an embodiment of the present disclosure, a display substrate is provided, comprising:

[0006] substrate;

[0007] A driving circuit layer is located on the base substrate;

[0008] a light-emitting device layer, located on a side of the driving circuit layer away from the base substrate;

[0009] a pixel defining layer, located on a side of the driving circuit layer away from the base substrate, the pixel defining layer comprising a pixel opening portion and a pixel spacing portion, the pixel opening portion defining a pixel opening, and at least a portion of the light-emitting device layer being located in the pixel opening; and

[0010] a spacer, the spacer being located on a side of the pixel spacing portion away from the base substrate,

[0011] Wherein, the display substrate further includes:

[0012] a first encapsulation layer, the first encapsulation layer being located between the driving circuit layer and the pixel defining layer; and

[0013] a second encapsulation layer, the second encapsulation layer covering at least a portion of a surface of the light-emitting device layer, the pixel defining layer, and the spacer away from the base substrate, and at least a portion of the second encapsulation layer being located between the pixel opening and the pixel spacing portion;

[0014] The orthographic projections of the pixel spacer and the spacer on the base substrate respectively fall within the orthographic projections of the first encapsulation layer on the base substrate.

[0015] In some embodiments, the pixel spacer and the spacer form a stacked structure, the first encapsulation layer at least covers the surface of the stacked structure close to the substrate, the second encapsulation layer at least covers the surface and side of the stacked structure away from the substrate, and the first encapsulation layer is connected to the second encapsulation layer.

[0016] In some embodiments, the display substrate further includes a groove structure, the groove structure being located between the pixel opening portion and the pixel spacer, the pixel opening portion and the pixel spacer being separated by the groove structure, and at least a portion of the second encapsulation layer being located in the groove structure; and

[0017] At least a portion of the second encapsulation layer located in the trench structure is connected to the first encapsulation layer.

[0018] In some embodiments, the orthographic projection of the groove structure on the base substrate is a ring structure, and the orthographic projections of the pixel spacer and the spacer on the base substrate are located inside the ring structure.

[0019] In some embodiments, the display substrate includes a plurality of pixel units, the plurality of pixel units are arrayed along a first direction and a second direction, the pixel unit includes a plurality of sub-pixels, and the plurality of sub-pixels each include a respective pixel opening;

[0020] The display substrate includes a plurality of pixel spacing regions, wherein in a first direction, the orthographic projections of the pixel spacing regions on the base substrate and the orthographic projections of the pixel openings of adjacent pixel units on the base substrate are spaced apart from each other; and in a second direction, the orthographic projections of the pixel spacing regions on the base substrate and the orthographic projections of the pixel openings of adjacent pixel units on the base substrate are spaced apart from each other; and

[0021] The orthographic projections of the pixel spacer and the spacer on the base substrate respectively fall within the orthographic projection of the pixel spacer area on the base substrate, and the orthographic projection of at least a portion of the first encapsulation layer on the base substrate falls within the orthographic projection of the pixel spacer area on the base substrate.

[0022] In some embodiments, the first packaging layer includes a plurality of packaging units, which are spaced apart and arranged in an array in a first direction and a second direction, and the orthographic projections of the plurality of packaging units on the base substrate respectively fall within the orthographic projections of the plurality of pixel spacing areas on the base substrate.

[0023] In some embodiments, the first encapsulation layer extends continuously in a first direction and a second direction, and an orthographic projection of the first encapsulation layer on the base substrate surrounds an orthographic projection of pixel openings of the plurality of sub-pixels on the base substrate.

[0024] In some embodiments, the orthographic projection of the trench structure on the substrate is located within the orthographic projection of the pixel spacing region on the substrate; and

[0025] A ratio of the width of the trench structure to the thickness of the pixel spacer is greater than 2.

[0026] In some embodiments, a ratio of a thickness of the pixel spacer to a thickness of the first encapsulation layer is 5-20.

[0027] In some embodiments, a ratio of a thickness of the second encapsulation layer to a thickness of the first encapsulation layer is 3-15.

[0028] In some embodiments, the materials of the first encapsulation layer and the second encapsulation layer include inorganic materials.

[0029] In some embodiments, the display substrate further includes a third encapsulation layer, which is located on a side of the second encapsulation layer away from the base substrate; the third encapsulation layer includes at least one composite layer, which includes an organic material layer and an inorganic material layer.

[0030] Another aspect of the embodiments of the present disclosure provides a display device comprising a display substrate as described in any one of the above items. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Other objects and advantages of the present disclosure will become apparent from the following description of the present disclosure with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present disclosure.

[0032] Figure 1A is a schematic plan view of a display substrate according to some exemplary embodiments of the present disclosure;

[0033] Figure 1B is a schematic plan view of a pixel spacing region in a display substrate according to some exemplary embodiments of the present disclosure;

[0034] Figure 2 is a schematic plan view of a display substrate according to some other exemplary embodiments of the present disclosure;

[0035] Figure 3A According to some exemplary embodiments of the present disclosure, the display substrate is Figure 1A A cross-sectional view taken along line AA';

[0036] Figure 3B-3C is a schematic cross-sectional view of a display substrate invaded by water and oxygen according to some exemplary embodiments of the present disclosure;

[0037] Figure 4A-4B A schematic cross-sectional view of a display substrate in the related art being invaded by water and oxygen is shown;

[0038] Figure 5 is a schematic plan view of a display substrate according to some other exemplary embodiments of the present disclosure;

[0039] Figure 6 is a schematic structural diagram of a display device provided by an embodiment of the present disclosure;

[0040] Figure 7 is a flow chart of a method for preparing a display substrate according to an exemplary embodiment of the present disclosure.

[0041] It should be noted that, for the sake of clarity, in the drawings used to describe the embodiments of the present disclosure, the sizes of layers, structures or regions may be enlarged or reduced, that is, these drawings are not drawn according to the actual scale. DETAILED DESCRIPTION

[0042] The technical solution of the present disclosure is further described in detail below through examples and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present disclosure with reference to the accompanying drawings is intended to explain the overall inventive concept of the present disclosure and should not be construed as limiting the present disclosure.

[0043] Furthermore, in the following detailed description, for ease of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it will be apparent that one or more embodiments can be practiced without these specific details.

[0044] It should be understood that, although the terms first, second, etc. can be used here to describe different elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the exemplary embodiments, the first element can be named as the second element, and similarly, the second element can be named as the first element. As used herein, the term "and / or" includes any combination and all combinations of one or more related listed items.

[0045] It should be understood that when an element or layer is referred to as being "formed on" another element or layer, the element or layer can be formed directly or indirectly on the other element or layer. That is, for example, there may be an intermediate element or intermediate layer. On the contrary, when an element or layer is referred to as being "formed directly on" another element or layer, there is no intermediate element or intermediate layer. Other words used to describe the relationship between elements or layers should be interpreted in a similar manner (for example, "between" and "directly between," "adjacent" and "directly adjacent," etc.). In addition, the X-axis, Y-axis, and Z-axis are not limited to the three axes of a rectangular coordinate system and can be interpreted in a broader sense. For example, the X-axis, Y-axis, and Z-axis may be perpendicular to each other, or may represent different directions that are not perpendicular to each other. For the purposes of this disclosure, "at least one of X, Y, and Z" and "at least one selected from the group consisting of X, Y, and Z" can be interpreted as only X, only Y, only Z, or any combination of two or more of X, Y, and Z such as XYZ, XYY, YZ, and ZZ.

[0046] The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the exemplary embodiments. As used herein, unless the context clearly indicates otherwise, the singular is intended to include the plural. It will also be understood that when the terms "comprise" and / or "include" are used herein, they indicate the presence of the described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0047] Figure 1A is a schematic plan view of a display substrate 10 according to some exemplary embodiments of the present disclosure, Figure 3A According to some exemplary embodiments of the present disclosure, the display substrate 10 is arranged along Figure 1A A cross-sectional view taken along line AA' in FIG.

[0048] Reference Figure 1AThe display substrate 10 includes a plurality of pixel units 110, and the plurality of pixel units 110 are arranged in an array along a first direction and a second direction. The pixel unit 110 includes a plurality of sub-pixels, and the plurality of sub-pixels respectively include their own pixel openings 1421. Exemplarily, the first direction intersects with the second direction. For example, in the illustrated example, the first direction is the X direction, and the second direction is the Y direction, and the first direction X and the second direction Y are perpendicular to each other. An organic light-emitting layer of one color is provided in each pixel opening 1421, for example, a red sub-pixel R, a green sub-pixel G, and a blue sub-pixel B, respectively. The red sub-pixel R, the green sub-pixel G, and the blue sub-pixel B together constitute a pixel unit 110. It should be understood that the arrangement of the red sub-pixel R, the green sub-pixel G, and the blue sub-pixel B can also be other arrangements such as RGGB, and the embodiments of the present disclosure are not limited thereto.

[0049] Combined with reference Figure 1A and Figure 3A The display substrate 10 includes: a base substrate 11; a driving circuit layer 12, located on the base substrate 11; a light-emitting device layer 15, located on the side of the driving circuit layer 12 away from the base substrate 11; a pixel defining layer 14, located on the side of the driving circuit layer 12 away from the base substrate 11, the pixel defining layer 14 includes a pixel spacer 141 and a pixel opening portion 142, the pixel opening portion 142 defines a pixel opening 1421, at least a portion of the light-emitting device layer 15 is located in the pixel opening 1421; and a spacer 16, the spacer 16 is located on the side of the pixel spacer 141 away from the base substrate 11.

[0050] According to some exemplary embodiments, the base substrate 11 can be a rigid substrate, such as a glass substrate, a silicon substrate, etc., or can be formed of a flexible material with excellent heat resistance and durability, such as polyimide (PI), polycarbonate (PC), polyethylene terephthalate (PET), polyethylene, polyacrylate, polyarylate, polyetherimide, polyethersulfone, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polysulfone (PSF), polymethyl methacrylate (PMMA), cellulose triacetate (TAC), cycloolefin polymer (COP) and cycloolefin copolymer (COC), etc.

[0051] In an exemplary embodiment of the present disclosure, the driving circuit layer 12 may include a plurality of thin film transistors and storage capacitors forming a pixel driving circuit. In an exemplary embodiment, the driving circuit layer 12 may include, for example, a first insulating layer, a semiconductor layer, a second insulating layer, a first gate metal layer, a third insulating layer, a second gate metal layer, a fourth insulating layer, a source / drain metal layer, and a planar layer sequentially disposed on the base substrate 11.

[0052] Exemplarily, the light-emitting device layer 15 includes a first electrode 151, a light-emitting layer 152, and a second electrode 153, which are stacked. It should be noted that the "light-emitting layer" here is an overview of the various functional layers of the OLED display light-emitting element. For example, it can include various functional layers such as an electron injection layer, an electron transport layer, a hole injection layer, a hole transport layer, and an organic light-emitting layer. Optionally, the organic light-emitting layer is one of a blue light-emitting layer, a red light-emitting layer, a green light-emitting layer, or a white light-emitting layer to form a red sub-pixel R, a green sub-pixel G, a blue sub-pixel B, and a white sub-pixel.

[0053] For example, the first electrode 151 serves as an anode, and the second electrode 153 serves as a cathode. The materials of the first and second electrodes 151, 153 can be, for example, at least one of a metal and ITO. For example, the second electrode 153 can be formed as an ITO layer of a display substrate. When used as an electrode layer of a display substrate, an ITO layer has good electrical conductivity and high transmittance for visible light, enabling it to conduct current without blocking light emitted by the light-emitting layer 152.

[0054] The pixel definition layer 14 is disposed on the side of the driving circuit layer 12 away from the substrate. The pixel definition layer 14 has a plurality of pixel openings 1421 spaced apart from each other. The pixel openings 1421 are used to form sub-pixel regions such as red sub-pixels R, green sub-pixels G, and blue sub-pixels B. The pixel definition layer 14 includes a pixel spacer 141 and a pixel opening 142, both of which are formed using the same patterning process. Figure 1A 、 Figure 3A The pixel spacing portion 141 and the pixel opening portion 142 are distinguished by using different filling methods in order to more clearly illustrate the technical solution of the present disclosure.

[0055] The first electrode 151 is arranged at the bottom of the pixel opening 1421, the light-emitting layer 152 is respectively arranged on the first electrode 151 in the pixel opening 1421, and the second electrode 153 is arranged on the pixel defining layer 14, including the pixel opening and non-pixel opening areas. In this way, the first electrode 151 and the second electrode 153 can drive the light-emitting layer 152 to emit light when a voltage is connected.

[0056] For example, the pixel defining layer 14 is located on the side of the flat layer in the driving circuit layer 12 away from the base substrate, and the first electrode 151 can contact the circuits or conductive traces inside the driving circuit layer 12 through multiple vias arranged in the flat layer, so that the pixel units 110 can be driven separately through the driving circuit layer 12 to realize the display function.

[0057] A plurality of spacers 16 are provided between the second electrode 153 and the pixel-defining layer 14 in the non-pixel opening area. These spacers 16 support the evaporation mask during the deposition of the light-emitting layer 152, preventing electrostatic attraction and direct adhesion between the mask and the display substrate, which could damage the light-emitting device layer 15. A second encapsulation layer 17, such as a thin-film encapsulation layer, is also provided on the second electrode 153. This second encapsulation layer 17 prevents external moisture and oxygen from entering and diffusing into the light-emitting layer 152, thereby preventing abnormalities such as black spots on the display substrate.

[0058] Figure 3B-3C is a schematic cross-sectional view of a display substrate invaded by water and oxygen according to some exemplary embodiments of the present disclosure; Figure 4A-4B The cross-sectional view schematically shows a display substrate in the related art being invaded by water and oxygen. Figure 4A-4B Some structures of the display substrate shown can refer to the above Figure 3A Furthermore, the same or similar components or structures are denoted by the same reference numerals.

[0059] Figure 4A-4B There is only one second encapsulation layer 17 in each film. The inventors have found that during the evaporation process of the light-emitting layer 152, friction will occur between the mask used to support the evaporation and the spacer 16, causing damage or foreign matter to the spacer 16, thereby affecting the water and oxygen barrier performance of the second encapsulation layer 17. Figure 4A As shown, the generated foreign matter M and foreign matter N will cause the second encapsulation layer 17 to have encapsulation weak points, and water and oxygen can invade the light-emitting layer 152 area along the path a and the path b; Figure 4B As shown, damage O and damage P can also cause encapsulation gaps in the second encapsulation layer 17, allowing water and oxygen to invade the light-emitting layer 152 region along paths c and d. Paths a, b, and d indicate that water and oxygen can diffuse through the organic pixel defining layer 14 to the light-emitting layer 152 region, while path c indicates that water and oxygen can also invade the light-emitting layer 152 region through the organic planar layer in the driving circuit layer 12. Water and oxygen invading the light-emitting layer 152 region can oxidize the material of the light-emitting layer 152, resulting in abnormalities such as GDS.

[0060] In order to solve this problem, the display substrate of the embodiment of the present disclosure is further provided with at least one first encapsulation layer 13 .

[0061] In the exemplary embodiment of the present disclosure, referring to Figure 3B-3CA first encapsulation layer 13 is further provided between the driving circuit layer 12 and the pixel defining layer 14. The first encapsulation layer 13 and the second encapsulation layer 17 jointly isolate the pixel spacer 141 from the spacer 16. The paths a, b, c, and d for water and oxygen intrusion are all blocked by the first encapsulation layer 13, thereby preventing water and oxygen from entering the light-emitting layer 152 from the pixel defining layer 14 or the flat layer, thereby improving the water and oxygen barrier performance of the display substrate and reducing the risk of abnormal conditions such as black spots.

[0062] In some embodiments of the present disclosure, the encapsulation structure includes a first encapsulation layer 13 and a second encapsulation layer 17, which together encapsulate a stacked structure consisting of a pixel spacer 141 and a spacer 16. The first encapsulation layer 13 at least covers the surface of the stacked structure close to the base substrate 11, and the second encapsulation layer 17 at least covers the surface and side of the stacked structure away from the base substrate 11. The first encapsulation layer 13 is connected to the second encapsulation layer 17. The orthographic projections of the pixel spacer 141 and the spacer 16 on the base substrate 11 respectively fall within the orthographic projection of the first encapsulation layer 13 on the base substrate 11. The second encapsulation layer 17 also covers the light-emitting device layer 15 and the pixel opening 142, and at least a portion of the second encapsulation layer 17 is located between the pixel opening 142 and the pixel spacer 141.

[0063] The first encapsulation layer 13 and the second encapsulation layer 17 are connected around the pixel spacer 141 to separately encapsulate the stacked structure. When the spacer 16 is scratched or foreign matter is generated, due to the coordinated blocking of the first encapsulation layer 13 and the second encapsulation layer 17, water and oxygen cannot diffuse into the light-emitting layer 152 through the pixel spacer 141 or the flat layer, thereby isolating the water and oxygen outside the light-emitting layer 152 and improving the reliability of the package.

[0064] Reference Figure 1B The display substrate 10 includes a plurality of pixel spacing regions 120. The pixel spacing regions are regions other than the regions where the pixel units 110 are located, and are disposed around the plurality of pixel units 110. In the first direction X, the orthographic projections of the pixel spacing regions 120 on the base substrate 11 are spaced apart from the orthographic projections of the pixel openings of adjacent pixel units 110 on the base substrate 11. Exemplarily, the pixel spacing regions 120 include a plurality of cross-shaped regions. The cross-shaped regions are located between four adjacent pixel units 110 that form the four vertices of a quadrilateral, and the cross-shaped regions are separated by the pixel units 110 in the first direction X.

[0065] In the second direction Y, the orthographic projection of the pixel spacing region 120 on the substrate 11 and the orthographic projection of the pixel opening of the adjacent pixel unit on the substrate 11 are both spaced apart. For example, the pixel spacing region 120 includes a plurality of cross-shaped regions, each of which is located between four adjacent pixel units 110 that form the four vertices of a quadrilateral. The cross-shaped regions are separated by the pixel units 110 in the second direction Y.

[0066] Exemplarily, the orthographic projections of the pixel spacers 141 and the spacers 16 on the substrate 11 respectively fall within the orthographic projections of the pixel spacing region 120 on the substrate 11. In a first direction X, the orthographic projections of the stacked structure composed of the pixel spacers 141 and the spacers 16 on the substrate 11 are spaced apart from the orthographic projections of adjacent pixel units 110 on the substrate 11. In a second direction Y, the orthographic projections of the stacked structure on the substrate 11 are spaced apart from the orthographic projections of adjacent pixel units 110 on the substrate 11. When the pixel units 110 are arranged in a rectangular array, the stacked structure is preferably located at the center of the rectangle, i.e., at the center of the cross-shaped region.

[0067] Figure 2 1 is a plan view of a display substrate 10 according to some other exemplary embodiments of the present disclosure. Figure 2 Some structures of the display substrate 10 shown can refer to the above Figure 1A Furthermore, the same or similar components or structures are denoted by the same reference numerals.

[0068] Reference Figure 1A The first encapsulation layer 13 includes a plurality of encapsulation units 130, which are spaced apart and arranged in an array in the first direction and the second direction. The orthographic projections of the plurality of encapsulation units 130 on the base substrate 11 fall within the orthographic projections of the plurality of pixel spacing regions 120 on the base substrate 11.

[0069] Reference Figure 2 , the first encapsulation layer 13 extends continuously in the first direction X and the second direction Y, the orthographic projection of the first encapsulation layer 13 on the base substrate 11 surrounds the orthographic projection of the pixel openings 1421 of the plurality of sub-pixels on the base substrate 11, and the orthographic projection of at least a portion of the first encapsulation layer 13 on the base substrate 11 falls within the orthographic projection of the pixel spacing region 120 on the base substrate 11. Providing the entire first encapsulation layer 13 on the side of the pixel defining layer 14 close to the base substrate 11 can simplify the process of the encapsulation structure. It should be noted that the first encapsulation layer 13 is located in the layer below the pixel spacing portion 141. In order to more clearly illustrate the relative positional relationship between the first encapsulation layer 13 and the stacked structure and the pixel unit 110, the structure of the first encapsulation layer 13 is shown in perspective.

[0070] Exemplarily, the orthographic projection of the pixel spacer 141 on the base substrate 11 is a rectangle or a polygon, and the orthographic projection of the spacer 16 on the base substrate 11 is a rectangle or a polygon. The orthographic projection of the spacer 16 on the base substrate 11 is located within the orthographic projection of the pixel spacer 141 on the base substrate 11, that is, the size of the cross section of the spacer 16 perpendicular to the third direction Z is smaller than the size of the cross section of the pixel spacer 141 perpendicular to the third direction Z, wherein the third direction Z is parallel to the light emitting direction of the display substrate. The material of the spacer 16 can be a photoresist, such as a negative photoresist, and the pattern of the spacer 16 can be obtained by a photolithography process. The material of the pixel defining layer 14 can be the same as that of the spacer 16, or it can be other organic materials, such as colorless polyimide. The materials of the spacer 16 and the pixel defining layer 14 are easily affected by water and oxygen, and therefore need to be protected by packaging to avoid further affecting the light-emitting layer 152, causing the display panel to have black spots and other poor display conditions.

[0071] In some embodiments of the present disclosure, the display substrate 10 also includes a groove structure 143, which is located between the pixel opening portion 142 and the pixel spacer portion 141, and the pixel opening portion 142 and the pixel spacer portion 141 are separated by the groove structure 143, and at least a portion of the second encapsulation layer 17 is located in the groove structure 143; and at least a portion of the second encapsulation layer 17 located in the groove structure 143 is connected to the first encapsulation layer 13.

[0072] When manufacturing the pixel definition layer 14 of the present disclosure, a pixel definition layer material can be first formed on the entire surface at the corresponding position, and then the pixel opening 1421 and the trench structure 143 can be formed by etching. The trench structure 143 can be formed by a wet etching process, and the support structure formed by the side etching serves to isolate the second electrode 153.

[0073] The pixel opening portion 142 is an important component of the display substrate and is mainly used to define the shape, size, arrangement, spacing and connection method between pixel units, etc. Its process quality directly affects the display effect of the display substrate. The pixel opening portion 142 of the embodiment of the present disclosure can be at least partially a rectangular structure in a cross section parallel to the third direction Z. For example, since there is a gap 1422 between the first electrode 151 and the first encapsulation layer 13, part of the pixel definition layer material is filled therein, so that the pixel opening portion 142 formed after etching has a protrusion. It can be understood that depending on the relative position of the first electrode 151 and the first encapsulation layer 13, the pixel opening portion 142 will have different structures.

[0074] A portion of the second electrode 153 and a portion of the second encapsulation layer 17 are also formed in the trench structure 143. During the evaporation process to form the second electrode 153, due to the structural influence of the trench structure 143, the second electrode material will be disconnected at the top of the trench structure 143 and cannot form a continuous film structure. However, some second electrode material can be deposited at the bottom of the trench structure 143. Then, when forming the second encapsulation layer 17, a chemical vapor deposition process is used. The deposited second encapsulation layer material can form a continuous film structure. As a result, the second encapsulation layer 17 is connected to the first encapsulation layer 13 in the trench structure 143. The two encapsulation layers cooperate to encapsulate the spacer 16 and the pixel spacer 141.

[0075] Reference Figure 1A 、 Figure 2 , the orthographic projection of the groove structure 143 on the base substrate 11 is a ring structure, and the orthographic projections of the pixel spacer 141 and the spacer 16 on the base substrate are located inside the ring structure. By forming the groove structure 143 around the spacer 16 and the pixel spacer 141, the spacer 16 and the pixel spacer 141 form an island structure, and at the same time, the pixel spacer 141 is completely isolated from the pixel opening 142, and then the second encapsulation layer 17 is connected to the first encapsulation layer 13 in the groove structure 143 to form a complete encapsulation structure. According to this setting, the encapsulation structure can effectively block water, oxygen and other impurities from invading the interior of the display substrate, thereby preventing water, oxygen and other impurities from invading the light-emitting layer 152 from the pixel defining layer 14 or the flat layer, causing poor display. That is, by setting up this encapsulation structure, the encapsulation reliability of the display substrate can be greatly improved.

[0076] In some embodiments of the present disclosure, the orthographic projection of the groove structure 143 on the base substrate 11 is located within the orthographic projection of the pixel spacing region on the base substrate 11 ; and the ratio of the width of the groove structure 143 to the thickness of the pixel spacing portion 141 is greater than 2.

[0077] Reference Figure 3BWhen the spacer 16 is scratched or foreign matter is generated, the groove structure 143 needs to have a large width to facilitate the foreign matter falling into the groove structure 143. For example, the width d1 of the groove structure 143 is 5 to 15 μm. The thickness of the pixel spacer 141 determines the height of the groove structure 143. To ensure the continuity of the second encapsulation layer 17 in the groove structure 143, the ratio of the width d1 of the groove structure 143 to the thickness t1 of the pixel spacer 141 is set to be greater than 2 based on the step coverage of the second encapsulation layer 17 in the groove structure 143. Here, the width of the groove structure 143 refers to the length of the cross section of the groove structure 143 parallel to the substrate 11, the height of the groove structure 143 refers to the length of the cross section of the groove structure 143 along the second direction Y, and the cross section of the groove structure 143 refers to the cross section of the groove structure 143 parallel to the third direction Z. The thickness of the pixel spacer 141 refers to the length of the cross section of the pixel spacer 141 along the third direction Z, and the cross section of the pixel spacer 141 refers to the cross section of the pixel spacer 141 parallel to the third direction Z.

[0078] In some embodiments of the present disclosure, the ratio of the thickness of the second encapsulation layer 17 to the thickness of the first encapsulation layer 13 is 3 to 15. The ratio of the thickness of the pixel spacer 141 to the thickness of the first encapsulation layer 13 is 5 to 20.

[0079] The first encapsulation layer 13 is located inside the display substrate 10, and a thinner thickness can achieve the desired water and oxygen blocking effect. The second encapsulation layer 17 is located on the outermost side of the display substrate 10 and is in direct contact with water and oxygen in the air. The risk of water and oxygen intrusion is greater, and a thicker thickness is required to achieve the desired water and oxygen blocking effect. Exemplarily, the thickness d2 of the first encapsulation layer is 100 to 300 nm, and the thickness d3 of the second encapsulation layer is 900 to 1500 nm. For the sake of clarity, in the drawings used to describe the embodiments of the present disclosure, the sizes of layers, structures, or regions may be exaggerated or reduced, and the thickness of the first encapsulation layer and the thickness of the second encapsulation layer are not drawn according to the actual scale.

[0080] The first encapsulation layer 13 is located on the side of the pixel defining layer 14 that is closest to the base substrate 11. To prevent water and oxygen in the pixel defining layer 14 from penetrating the first encapsulation layer 13 and entering the light-emitting layer 152, the thickness of the first encapsulation layer 13 is positively correlated with the thickness of the pixel spacer 141. That is, the thickness of the first encapsulation layer 13 increases as the thickness of the pixel spacer 141 increases. Preferably, the ratio of the thickness of the pixel spacer 141 to the thickness of the first encapsulation layer 13 is 5 to 20. For example, the thickness t1 of the pixel spacer 141 is 1.5 to 2 μm, and the thickness d2 of the first encapsulation layer 13 is 100 to 300 nm.

[0081] In some embodiments of the present disclosure, the materials of the first encapsulation layer 13 and the second encapsulation layer 17 include inorganic materials.

[0082] Inorganic materials have better water and oxygen barrier properties than organic materials. Inorganic materials include SiN x , SiON, Al2O3. The first encapsulation layer 13 and the second encapsulation layer 17 can be made of the same inorganic material or different inorganic materials. When the two are made of the same inorganic material, they can be better connected in the groove structure 143 and have better encapsulation performance. SiN x , SiON materials can be produced by chemical vapor deposition (CVD) process, and Al2O3 materials can be produced by atomic layer deposition (ALD) process.

[0083] Figure 5 1 is a plan view of a display substrate 10 according to some other exemplary embodiments of the present disclosure.

[0084] In some embodiments of the present disclosure, the display substrate 10 further includes a third encapsulation layer 18, which is located on a side of the second encapsulation layer 17 away from the base substrate 11. Exemplarily, the third encapsulation layer includes at least one composite layer, which includes an organic material layer and an inorganic material layer.

[0085] Inorganic thin films offer strong water and oxygen barrier properties, but their inherent brittleness, along with the inevitable pinholes and cracks caused by grain boundary defects that form during the film formation process, can compromise their barrier capabilities. Single-layer organic thin films offer weak water and oxygen barrier properties and cannot meet packaging requirements. However, alternating inorganic / organic composite films can effectively reduce defects and stress within inorganic thin films, enhancing packaging effectiveness and extending device life.

[0086] In one possible implementation, Figure 5 As shown, the second encapsulation layer 17 covers the second electrode 153, and the third encapsulation layer 18 covers the second encapsulation layer 17, which is used to encapsulate the display substrate. Exemplarily, the third encapsulation layer 18 is a composite layer, which includes an organic material layer and an inorganic material layer stacked in sequence. By arranging a composite organic material layer and an inorganic material layer on the inorganic thin film layer, the overall water and oxygen barrier performance can be improved. Exemplarily, the inorganic material layer can be formed by deposition or the like, and the organic material layer can be formed by inkjet printing. Furthermore, the inorganic material layer can be formed of inorganic materials such as silicon nitride, silicon oxide, and silicon oxynitride. The material of the inorganic material layer in the third encapsulation layer 18 can be the same as that of the first encapsulation layer 13 or the second encapsulation layer 17; the organic thin film layer can be formed of organic materials such as polyimide (PI) and epoxy resin.

[0087] The present disclosure also provides a display device, such as Figure 6 As shown, Figure 6This is a structural schematic diagram of a display device 100 provided in an embodiment of the present disclosure. The display device 100 includes a device body 30 and a display substrate 10 disposed on the device body 30. The device body 30 includes a shell and components such as a processor, a power supply, and a camera disposed in the shell. The display device 100 can adopt the display substrate 10 provided in the above embodiment.

[0088] The display device 100 may include any device or product having a display function. For example, the display device 100 may be a smart phone, a mobile phone, an e-book reader, a desktop computer (PC), a laptop PC, a netbook PC, a personal digital assistant (PDA), a portable multimedia player (PMP), a digital audio player, a mobile medical device, a camera, a wearable device (such as a head-mounted device, electronic clothing, an electronic bracelet, an electronic necklace, an electronic accessory, an electronic tattoo, or a smart watch), a television, etc.

[0089] It should be understood that the display device 100 according to some exemplary embodiments of the present disclosure has all the features and advantages of the above-mentioned display substrate 10 , which can be referred to in the above description of the display substrate 10 and will not be repeated here.

[0090] Figure 7 The flowchart of the method for preparing a display substrate according to an embodiment of the present disclosure is schematically shown.

[0091] According to some exemplary embodiments, referring to Figure 1A 、 Figure 3A , the method for preparing the display substrate includes the following steps S710 to S750.

[0092] In step S710 , a driving circuit layer 12 is formed on the base substrate 11 .

[0093] In step S720 , a first encapsulation layer 13 is formed on a side of the driving circuit layer 12 away from the base substrate 11 .

[0094] In step S730, a light-emitting device layer 15 and a pixel defining layer 14 are formed on the side of the driving circuit layer 12 away from the base substrate 11; wherein, the pixel defining layer 14 includes a pixel opening portion 142 and a pixel spacing portion 141, the pixel opening portion 142 defines a pixel opening 1421, and at least a portion of the light-emitting device layer 15 is located in the pixel opening.

[0095] In step S740 , a spacer 16 is formed on a side of the pixel separator 141 away from the base substrate 11 .

[0096] In step S750, a second encapsulation layer 17 is formed on the side of the light-emitting device layer 15, the pixel defining layer 14 and the spacer 16 away from the base substrate 11, wherein the second encapsulation layer 17 covers at least a portion of the surface of the light-emitting device layer 15, the pixel defining layer 14 and the spacer 16 away from the base substrate 11, and at least a portion of the second encapsulation layer 17 is located between the pixel opening portion 142 and the pixel spacer 141, wherein the orthographic projections of the pixel spacer 141 and the spacer 16 on the base substrate 11 respectively fall within the orthographic projections of the first encapsulation layer 13 on the base substrate 11.

[0097] In some embodiments of the present disclosure, the method for preparing a display substrate further includes: forming a groove structure 143 between the pixel opening portion 142 and the pixel spacer portion 141 to separate the pixel opening portion 142 from the pixel spacer portion 141, wherein at least a portion of the second encapsulation layer 17 is located in the groove structure 143, and at least a portion of the second encapsulation layer 17 located in the groove structure 143 is connected to the first encapsulation layer 13.

[0098] For example, in the stacked structure of the display substrate, a thin film transistor (TFT) is usually first made on the base substrate 11, and then a flat layer is made to play a flattening role, and the first electrode 151 is continued to be made above the flat layer, as well as the pixel defining layer 14, the light-emitting layer 152, the second electrode 153 and the second encapsulation layer 17 located above the first electrode 151.

[0099] In some embodiments of the present disclosure, after forming the driving circuit layer 12 on the base substrate 11, the first electrode 151 and the first encapsulation layer 13 are formed on the side of the driving circuit layer 12 away from the base substrate 11. There is no restriction on the order in which the first electrode 151 and the first encapsulation layer 13 are formed. The first encapsulation layer 13 can be deposited first, and then a portion of the first encapsulation layer material is removed by dry etching to reserve the area where the first electrode 151 and the pixel opening are located, and then the first electrode 151 is deposited. Alternatively, the first electrode material can be deposited first, patterned to form the first electrode 151, and then the first encapsulation layer 13 can be deposited. The thickness of the first electrode 151 and the first encapsulation layer 13 can be the same or different.

[0100] For example, the first encapsulation layer 13 is an inorganic material, and the preparation method is related to the material selection, for example, SiN is deposited by chemical vapor deposition process. x , SiON material, or Al2O3 material deposited by atomic layer deposition process. Exemplarily, the first electrode 151 is an anode, and the first electrode 151 can be a transparent electrode made of metal oxide materials such as ITO and IZO.

[0101] The coverage area of ​​the first encapsulation layer 13 can be the surface of the pixel spacer 141 near the base substrate 11 and the smaller area around it. That is, the first encapsulation layer 13 includes multiple encapsulation units, which are arranged in an array in the pixel spacer area and staggered with the pixel units. The coverage area of ​​the first encapsulation layer 13 can also be the surface of the pixel spacer 141 near the base substrate 11 and the larger area around it. That is, the first encapsulation layer 13 extends continuously in the first and second directions on the drive circuit layer 12, and is arranged around the multiple pixel units.

[0102] Next, the pixel defining layer 14 is fabricated by coating the pixel defining layer material on the base substrate 11 having the aforementioned structure to form a pixel defining layer thin film. The pixel defining layer thin film is then exposed and developed through a patterning process to form a pixel opening 1421. Within each sub-pixel, a pixel opening 1421 is defined in the pixel defining layer 14. The pixel defining layer material within the pixel opening 1421 is removed by development, exposing the surface of the first electrode 151.

[0103] At the same time, a wet etching process is used to groove the pixel defining layer 14 in the non-pixel opening area to form a trench structure 143. The trench structure 143 separates the pixel defining layer 14 into a pixel opening portion 142 and a pixel spacer 141, isolating the pixel spacer 141. It should be noted that the trenching step requires that the pixel defining layer material on the first encapsulation layer 13 at the corresponding position be completely etched away. The trench structure 143 surrounds the pixel spacer 141, thereby enabling the first encapsulation layer 13 to be connected to the subsequently deposited second encapsulation layer 17. In an exemplary embodiment, the pixel defining layer 14 can be made of materials such as polyimide, acrylic, or polyethylene terephthalate.

[0104] Subsequently, spacers 16 are formed on the side of the pixel spacer 141 away from the base substrate 11. A thin film of organic material is coated on the base substrate 11 having the aforementioned structure, and the thin film of organic material is exposed and developed through a patterning process to form a plurality of spacers (PS) 16. The material of the spacers 16 can be a photoresist, such as a negative photoresist, and the material of the pixel defining layer 14 can be the same as that of the spacers 16.

[0105] A light-emitting layer 152 and a second electrode 153 are sequentially formed on the substrate 11 forming the aforementioned structure. In each sub-pixel, the light-emitting layer 152 is formed within the pixel opening to connect the light-emitting layer 152 to the first electrode 151. The second electrode 153 is formed on the light-emitting layer 152, the pixel defining layer 14, and the spacer 16 to connect the second electrode 153 to the light-emitting layer 152. The second electrodes 153 of the multiple sub-pixels are an integral structure, but the second electrodes 153 are disconnected at the opening of the groove structure 143. In an exemplary embodiment, the light-emitting layer 152 includes a stacked hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, and an electron injection layer. For example, the second electrode 153 is a cathode, and the material of the second electrode 153 may include a metal such as Mg, Ca, Li, or Al, or an alloy thereof, or a metal oxide such as IZO or ZTO, or an organic material with conductive properties such as PEDOT / PSS (poly-3,4-ethylenedioxythiophene / polystyrene sulfonate).

[0106] A second encapsulation layer 17 is formed on the substrate 11 having the aforementioned structure. In an exemplary embodiment, the second encapsulation layer material is deposited using plasma-enhanced chemical vapor deposition (PECVD) to form the second encapsulation layer 17. The second encapsulation layer 17 is a continuous structure that fills the trench structure 143 and connects to the first encapsulation layer 13 within the trench structure 143. The two encapsulation layers combine to isolate the pixel spacer 141 from the spacer 16. Even if the spacer 16 is scratched or contains foreign matter, the first encapsulation layer 13 can block the intrusion path of water and oxygen, thereby improving the reliability of the encapsulation.

[0107] In the embodiments of the present disclosure, the GDS failure caused by scratches on spacers or foreign matter on spacers is improved by blocking the water and oxygen pathways at the package failure location.

[0108] As used herein, the terms "substantially," "about," "approximately," and other similar terms are used as terms of approximation rather than as terms of degree, and are intended to account for the inherent deviations in measured or calculated values ​​that would be recognized by one of ordinary skill in the art. To account for factors such as process fluctuations, measurement problems, and errors associated with the measurement of a particular quantity (i.e., limitations of the measurement system), "about" or "approximately," as used herein, are inclusive of the stated value and mean within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art. For example, "approximately" can mean within one or more standard deviations, or within ±10% or ±5% of the stated value.

[0109] Although some embodiments according to the general inventive concept of the present disclosure have been illustrated and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the general inventive concept of the present disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A display substrate, comprising: substrate; A driving circuit layer is located on the base substrate; a light-emitting device layer, located on a side of the driving circuit layer away from the base substrate; a pixel defining layer, located on a side of the driving circuit layer away from the base substrate, the pixel defining layer comprising a pixel opening portion and a pixel spacing portion, the pixel opening portion defining a pixel opening, and at least a portion of the light-emitting device layer being located in the pixel opening; as well as a spacer, the spacer being located on a side of the pixel spacing portion away from the base substrate, Wherein, the display substrate further includes: a first encapsulation layer, the first encapsulation layer being located between the driving circuit layer and the pixel defining layer; and a second encapsulation layer, the second encapsulation layer covering at least a portion of a surface of the light-emitting device layer, the pixel defining layer, and the spacer away from the base substrate, and at least a portion of the second encapsulation layer being located between the pixel opening and the pixel spacing portion; The orthographic projections of the pixel spacer and the spacer on the base substrate respectively fall within the orthographic projections of the first encapsulation layer on the base substrate.

2. The display substrate according to claim 1, wherein The pixel spacer and the spacer form a stacked structure, the first encapsulation layer at least covers the surface of the stacked structure close to the base substrate, the second encapsulation layer at least covers the surface and side of the stacked structure away from the base substrate, and the first encapsulation layer is connected to the second encapsulation layer.

3. The display substrate according to claim 1, wherein The display substrate further includes a groove structure, the groove structure is located between the pixel opening portion and the pixel spacer, the pixel opening portion and the pixel spacer are separated by the groove structure, and at least a portion of the second encapsulation layer is located in the groove structure; as well as At least a portion of the second encapsulation layer located in the trench structure is connected to the first encapsulation layer.

4. The display substrate according to claim 3, wherein: The orthographic projection of the groove structure on the base substrate is a ring structure, and the orthographic projections of the pixel spacer and the spacer on the base substrate are located inside the ring structure.

5. The display substrate according to any one of claims 3 to 4, wherein: The display substrate includes a plurality of pixel units, the plurality of pixel units are arrayed along a first direction and a second direction, the pixel unit includes a plurality of sub-pixels, and the plurality of sub-pixels each include a respective pixel opening; The display substrate includes a plurality of pixel spacing regions, wherein in a first direction, the orthographic projections of the pixel spacing regions on the substrate and the orthographic projections of the pixel openings of adjacent pixel units on the substrate are spaced apart from each other; and in a second direction, the orthographic projections of the pixel spacing regions on the substrate and the orthographic projections of the pixel openings of adjacent pixel units on the substrate are spaced apart from each other; as well as The orthographic projections of the pixel spacer and the spacer on the base substrate respectively fall within the orthographic projection of the pixel spacer area on the base substrate, and the orthographic projection of at least a portion of the first encapsulation layer on the base substrate falls within the orthographic projection of the pixel spacer area on the base substrate. The display substrate according to claim 5 , wherein: The first encapsulation layer includes a plurality of encapsulation units, which are spaced apart and arranged in an array in a first direction and a second direction, and the orthographic projections of the plurality of encapsulation units on the base substrate respectively fall within the orthographic projections of the plurality of pixel spacing areas on the base substrate.

7. The display substrate according to claim 5, wherein: The first encapsulation layer continuously extends in a first direction and a second direction, and an orthographic projection of the first encapsulation layer on the base substrate surrounds an orthographic projection of pixel openings of the plurality of sub-pixels on the base substrate.

8. The display substrate according to claim 5, wherein: The orthographic projection of the trench structure on the substrate is located within the orthographic projection of the pixel spacing region on the substrate; and A ratio of the width of the trench structure to the thickness of the pixel spacer is greater than 2.

9. The display substrate according to claim 1, wherein: The ratio of the thickness of the pixel spacer to the thickness of the first encapsulation layer is 5-20.

10. The display substrate according to claim 1, wherein The ratio of the thickness of the second encapsulation layer to the thickness of the first encapsulation layer is 3-15.

11. The display substrate according to claim 1, wherein: The materials of the first encapsulation layer and the second encapsulation layer include inorganic materials.

12. The display substrate according to claim 1, wherein The display substrate further includes a third encapsulation layer, which is located on a side of the second encapsulation layer away from the base substrate; the third encapsulation layer includes at least one composite layer, which includes an organic material layer and an inorganic material layer.

13. A display device, characterized in that: The display substrate comprises the display substrate according to any one of claims 1 to 12.

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