Display panel and manufacturing method therefor

Abstract

Provided are a display panel and a manufacturing method therefor. The display panel comprises: a base substrate; at least one sub-pixel arranged on the base substrate, wherein the sub-pixel comprises a light-emitting unit having a first electrode, a second electrode and a light-emitting layer located between the first electrode and the second electrode, with the first electrode being located between the light-emitting layer and the base substrate; an encapsulation layer covering the light-emitting unit; a color film located on the side of the encapsulation layer away from the base substrate; and a micro-lens located on the side of the color film away from the base substrate. The surface of the microlens on the side away from the base substrate comprises a central portion and an edge portion surrounding the central portion, wherein the central portion is a flat surface parallel to the base substrate, the edge portion is a curved surface protruding from the inside of the microlens to the outside, and the roughness of the central portion is greater than the roughness of the edge portion.

Description

Display panel and manufacturing method thereof Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a display panel and a manufacturing method thereof. Background Art

[0002] With the development of display technology, the requirements for display devices are getting higher and higher. The display effect of the display device is largely related to the structure of the display panel, but most of the current display panels cannot meet the users' growing demand for display effects. Silicon-based OLED (Organic Light-Emitting Diode) is expected to become the preferred display solution for AR (Augmented Reality) / VR (Virtual Reality) due to its high contrast, high response speed and high PPI (Pixels Per Inch) characteristics. However, the brightness of silicon-based OLED is currently difficult to meet the display requirements of AR / VR. In related technologies, in order to improve the display brightness of silicon-based OLED, a microlens is set on the light-emitting side of the silicon-based OLED display device to enhance the brightness of the display device. However, while using the microlens to enhance the brightness, the viewing angle characteristics are lost, and the viewing angle and brightness requirements of AR / VR cannot be met. In addition, most silicon-based OLEDs use a structure that combines white light with color films. However, when using color films made of organic materials at a tiny size (for example, 5μm to 10μm), the overlapping height of adjacent color films of different colors is large, forming horns, which affects the viewing angle and color uniformity of the silicon-based OLED display, thereby seriously affecting the display effect.

[0003] Summary of the Invention

[0004] Embodiments of the present disclosure provide a display panel and a method for manufacturing the same.

[0005] According to one aspect of the present disclosure, there is provided a display panel, comprising:

[0006] substrate;

[0007] At least one sub-pixel is arranged on the substrate.

[0008] Wherein, the sub-pixels include:

[0009] a light-emitting unit comprising a first electrode, a second electrode, and a light-emitting layer located between the first electrode and the second electrode, wherein the first electrode is located between the light-emitting layer and the base substrate;

[0010] an encapsulation layer, covering the light-emitting unit;

[0011] a color filter, located on a side of the encapsulation layer away from the base substrate;

[0012] a microlens, located on a side of the color film away from the base substrate;

[0013] The surface of the microlens on the side away from the base substrate includes a central portion and an edge portion surrounding the central portion, wherein the central portion is a plane parallel to the base substrate, and the edge portion is an arc surface protruding from the inside to the outside of the microlens, and the roughness of the central portion is greater than that of the edge portion.

[0014] For example, the central portion is continuous with the edge portion.

[0015] For example, the microlens has a groove on a side away from the base substrate, the bottom surface of the groove serves as the central portion, and the central portion and the edge portion are connected through the sidewall of the groove.

[0016] For example, the central portion has a first height relative to the bottom of the microlens, the edge portion has a second height relative to the bottom of the microlens, and a ratio of the first height to the second height is in a range of 0.4 to 0.8.

[0017] For example, the display panel further includes a compensating microlens located between adjacent microlenses, and a height of the compensating microlens is smaller than a height of a central portion of the microlens.

[0018] For example, the roughness of the surface of the compensating microlens at a side away from the base substrate is smaller than the roughness of the central portion.

[0019] For example, the central portion and the edge portion both have a plurality of micro protrusions, and the height of the micro protrusions of the central portion is greater than that of the micro protrusions of the edge portion, so that the roughness of the central portion is greater than that of the edge portion.

[0020] For example, the height of the micro protrusions in the central area of ​​the central portion is greater than the height of the micro protrusions in the edge area of ​​the central portion, so that the roughness of the central area of ​​the central portion is greater than the roughness of the edge area of ​​the central portion.

[0021] For example, the height of each micro-protrusion in the central portion gradually decreases from the center to the edge of the central portion, so that the roughness of the central portion gradually decreases from the center to the edge.

[0022] For example, the cross section of the micro protrusion in the central portion in a direction perpendicular to the substrate is triangular, arc-shaped or rectangular.

[0023] For example, the size of the micro protrusions in the central portion in a direction parallel to the substrate is in a range of 0.01 μm to 0.1 μm, and the size in a direction perpendicular to the substrate is in a range of 5 nm to 50 nm.

[0024] For example, the roughness of the central area of ​​the surface of the color filter at the side away from the base substrate is smaller than the roughness of the edge area.

[0025] For example, the roughness of the surface of the color film on the side away from the base substrate gradually increases from the center to the edge of the color film.

[0026] For example, the color filter has micro protrusions on the surface away from the base substrate, the height of the micro protrusions in the central area of ​​the color filter is less than 5 nm, and the height of the micro protrusions in the edge area of ​​the color filter is in the range of 5 nm to 50 nm.

[0027] For example, the projection of the boundary between the central area and the edge area of ​​the color filter on the base substrate is located within the projection of the edge portion of the microlens on the base substrate.

[0028] For example, the sub-pixel also includes: a pixel defining layer, located between the base substrate and the light-emitting layer of the light-emitting unit, covering the edge of the first electrode of the light-emitting unit to define an opening area, so that a portion of the first electrode of the light-emitting unit is exposed from the opening area.

[0029] For example, the edge portion has a first projection in a direction perpendicular to the substrate, and the portion of the pixel defining layer covering the first electrode has a second projection in a direction perpendicular to the substrate, wherein the distance between the inner edge and the outer edge of the first projection is greater than the distance between the inner edge and the outer edge of the second projection.

[0030] For example, the at least one sub-pixel includes sub-pixels of multiple colors, the color of each sub-pixel is defined by the color of the color filter of the sub-pixel, and the area ratio of the central part to the opening area of ​​the sub-pixel of at least one color is greater than that of the sub-pixels of other colors.

[0031] For example, the sub-pixels of multiple colors include a first sub-pixel having a color filter of a first color, a second sub-pixel having a color filter of a second color, and a third sub-pixel having a color filter of a third color.

[0032] Among them, Src / Sr>Sgc / Sg>Sbc / Sb, where Sr represents the area of ​​the opening region of the first sub-pixel, Sg represents the area of ​​the opening region of the second sub-pixel, Sb represents the area of ​​the opening region of the third sub-pixel, Src represents the area of ​​the central portion of the microlens of the first sub-pixel, Srg represents the area of ​​the central portion of the microlens of the second sub-pixel, and Srb represents the area of ​​the central portion of the microlens of the third sub-pixel.

[0033] For example, Sr<Sg<Sb.

[0034] For example, the first color is red, the second color is green, and the third color is blue.

[0035] For example, among sub-pixels of the same color, the area ratio of the central portion of the sub-pixel located in the central area of ​​the display panel to the opening area is smaller than the area ratio of the central portion of the sub-pixel located in the edge area of ​​the display panel to the opening area.

[0036] For example, among sub-pixels of the same color, the area ratio of the central portion of each sub-pixel to the opening region gradually increases from the center to the edge of the display panel.

[0037] For example, the central portions of the microlenses of sub-pixels of different colors are located in the same plane.

[0038] For example, the microlenses in the sub-pixels are in contact with the color filter.

[0039] For example, the bottom surfaces of the microlenses of sub-pixels of different colors have height differences in a direction perpendicular to the base substrate, wherein the bottom surface of the microlens is the surface where the microlens contacts the color filter.

[0040] For example, the display panel further includes a planar layer, and the planar layer is located between the color filter and the microlens of each sub-pixel.

[0041] For example, photoresist material is filled between adjacent microlenses, so that edge portions of the microlenses are covered by the photoresist material.

[0042] For example, the refractive index of the photoresist material is smaller than the refractive index of the microlens.

[0043] For example, the refractive index of the photoresist material is in the range of 1.3-1.6, and the refractive index of the microlens is in the range of 1.6-2.1.

[0044] According to another aspect of the present disclosure, there is also provided a method for manufacturing the display panel as described above, comprising:

[0045] forming at least one light emitting unit on a base substrate;

[0046] forming an encapsulation layer covering the at least one light-emitting unit;

[0047] forming a color film on the encapsulation layer, wherein the color film includes at least one color film corresponding to the at least one light-emitting unit;

[0048] forming a microlens layer on the color filter, wherein the microlens layer includes at least one initial microlens corresponding to the at least one color filter, and a surface of the initial microlens away from the base substrate is a curved surface;

[0049] forming a first photoresist layer on the microlens layer, such that the first photoresist layer covers the at least one initial microlens, and a surface of the first photoresist layer away from the base substrate is parallel to the base substrate;

[0050] A portion of the microlens layer and a portion of the first photoresist material layer are removed by a dry etching process to obtain a microlens having a central portion and an edge portion.

[0051] For example, removing a portion of the microlens layer and a portion of the first photoresist material layer by dry etching includes: dry etching the microlens layer and the first photoresist material layer to obtain a microlens having a central portion and an edge portion, wherein the central portion is continuous with the edge portion.

[0052] For example, removing a portion of the microlens layer and the first photoresist material layer by a dry etching process includes:

[0053] forming grooves in the first photoresist material layer above each microlens through a half-mask process to obtain a patterned first photoresist material layer;

[0054] The patterned first photoresist material layer and the microlens layer are dry-etched to obtain a microlens with a groove, wherein the bottom surface of the groove serves as the central portion, and the central portion and the edge portion are connected through the sidewall of the groove.

[0055] For example, the method further includes: before forming the microlens layer on the color film,

[0056] forming a second photoresist material layer on the color filter;

[0057] The entire second photoresist layer and a portion of the color filter are removed by a dry etching process to planarize the color filter.

[0058] For example, the method further includes: forming a planar layer on the color film before forming the microlens layer on the color film.

[0059] For example, the method further includes: after forming a planar layer on the color film, forming an inorganic layer on the planar layer.

[0060] For example, forming the microlens layer includes:

[0061] depositing an organic microlens material on the color film;

[0062] removing a portion of the microlens material by exposure and development to obtain a plurality of columnar structures;

[0063] Each columnar structure is transformed into a hemispherical structure through a thermal reflow process;

[0064] The hemispherical structure is solidified to obtain an initial microlens.

[0065] According to another aspect of the present disclosure, there is provided another display panel, comprising:

[0066] substrate;

[0067] At least one sub-pixel is arranged on the substrate.

[0068] Wherein, the sub-pixels include:

[0069] a light-emitting unit comprising a first electrode, a second electrode, and a light-emitting layer located between the first electrode and the second electrode, wherein the first electrode is located between the light-emitting layer and the base substrate;

[0070] a microlens, located on a side of the light-emitting unit away from the base substrate;

[0071] The surface of the microlens on the side away from the base substrate includes a central portion and an edge portion surrounding the central portion, wherein the central portion is a plane parallel to the base substrate, and the edge portion is a curved surface protruding from the inside of the microlens to the outside;

[0072] The central portion and the edge portion both have a plurality of micro-protrusions, and the height of the micro-protrusions of the central portion is greater than the height of the micro-protrusions of the edge portion.

[0073] For example, the height of the micro-protrusions in the central region of the central portion is greater than the height of the micro-protrusions in the edge region of the central portion.

[0074] For example, the height of each micro-protrusion in the central portion gradually decreases from the center to the edge of the central portion.

[0075] For example, the cross section of the micro protrusion in the central portion in a direction perpendicular to the substrate is triangular, arc-shaped or rectangular.

[0076] For example, the size of the micro protrusions in the central portion in a direction parallel to the substrate is in a range of 0.01 μm to 0.1 μm, and the size in a direction perpendicular to the substrate is in a range of 5 nm to 50 nm.

[0077] For example, the sub-pixel further includes a color film, which is located between the light-emitting unit and the microlens, wherein the color film has a plurality of micro-protrusions on a surface away from the substrate, and the height of the micro-protrusions located in the central area of ​​the surface of the color film is smaller than the height of the micro-protrusions located in the edge area of ​​the surface of the color film.

[0078] For example, the height of the micro-protrusions on the surface of the color film at the side away from the base substrate gradually increases from the center to the edge of the color film.

[0079] For example, the height of the micro-protrusions of the color film in the central area of ​​the surface away from the substrate is less than 5 nm, and the height of the micro-protrusions of the color film in the edge area of ​​the surface away from the substrate is in the range of 5 nm to 50 nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] FIG1 shows a schematic structural diagram of a display panel according to an embodiment of the present disclosure.

[0081] FIG. 2 is a schematic cross-sectional view showing an embodiment of the microlens in FIG. 1 .

[0082] FIG3 shows a schematic structural diagram of a display panel according to another embodiment of the present disclosure.

[0083] FIG. 4 is a schematic cross-sectional view showing an embodiment of the microlens in FIG. 3 .

[0084] FIG5 shows a schematic structural diagram of a display panel according to another embodiment of the present disclosure.

[0085] FIG6 shows a schematic plan view of a display panel according to an embodiment of the present disclosure.

[0086] 7A and 7B are enlarged views of the schematic diagrams of the first sub-pixel SP1 and the fourth sub-pixel SP4 in FIG. 6 , respectively.

[0087] FIG. 8 shows an enlarged view of the schematic diagram of the first sub-pixel SP1 , the second sub-pixel SP2 , and the third sub-pixel SP3 in FIG. 6 .

[0088] FIG. 9 is a schematic cross-sectional view showing another embodiment of the microlens in FIG. 1 .

[0089] FIG. 10A shows a partially enlarged view of an embodiment of the display panel of FIG. 1 .

[0090] FIG. 10B shows a partially enlarged view of another embodiment of the display panel of FIG. 1 .

[0091] FIG10C shows a partial enlarged view of the color filter surface in FIG10B .

[0092] FIG. 10D shows a partially enlarged view of an embodiment of the display panel of FIG. 10B .

[0093] FIG. 10E is a schematic plan view showing the first projection and the second projection in FIG. 10D .

[0094] FIG. 11 shows a partially enlarged view of a display panel according to another embodiment of the present disclosure.

[0095] FIG. 12 shows a flow chart of a method for manufacturing a display panel according to an embodiment of the present disclosure.

[0096] 13A to 13K illustrate a manufacturing process of a display panel according to an embodiment of the present disclosure.

[0097] 14A to 14L illustrate a manufacturing process of a display panel according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0098] While the present disclosure will be fully described with reference to the accompanying drawings that contain preferred embodiments of the present disclosure, it should be understood before this description that one of ordinary skill in the art may modify the disclosure described herein while still achieving the technical benefits of the present disclosure. Therefore, it should be understood that the above description is intended to be a broad disclosure for one of ordinary skill in the art and is not intended to limit the exemplary embodiments described herein.

[0099] In addition, in the following detailed description, for ease of explanation, numerous specific details are set forth to provide a comprehensive understanding of the disclosed embodiments. However, it is apparent that one or more embodiments can be practiced without these specific details. In other cases, well-known structures and devices are shown in diagrammatic form to simplify the accompanying drawings.

[0100] FIG1 shows a schematic structural diagram of a display panel according to an embodiment of the present disclosure.

[0101] As shown in Figure 1, the display panel 100 includes a base substrate 110 and a plurality of sub-pixels SP1, SP2, and SP3 located on the base substrate 110. For ease of description, three sub-pixels SP1, SP2, and SP3 are shown in Figure 1. However, the embodiments of the present disclosure are not limited thereto, and the display panel may have any number of sub-pixels as needed. Each of the sub-pixels SP1, SP2, and SP3 includes a corresponding light-emitting unit, an encapsulation layer, a color filter, and a microlens. For example, the sub-pixel SP1 includes a light-emitting unit EL1, an encapsulation layer 120, a color filter CF1, and a microlens Lens1, which are sequentially arranged on the base substrate 110. In a similar manner, the sub-pixel SP2 includes a light-emitting unit EL2, an encapsulation layer 120, a color filter CF2, and a microlens Lens2 stacked in sequence, and the sub-pixel SP3 includes a light-emitting unit EL3, an encapsulation layer 120, a color filter CF3, and a microlens Lens3 stacked in sequence. 1 , the encapsulation layer 120 of each sub-pixel SP1, SP2, and SP3 can be formed as a continuous layer that covers the color filters CF1, CF2, and CF3 of each sub-pixel. In some embodiments, the layer where each color filter is located can be referred to as a color filter layer 130.

[0102] As shown in FIG1 , light emitting elements EL1, EL2, and EL3 are located on a substrate 110. Each light emitting element EL1, EL2, and EL3 includes a first electrode E1, a second electrode E2, and a light emitting layer EM located between the first and second electrodes E1 and E2. The first electrode E1 is located between the light emitting layer EM and the substrate 110.

[0103] The encapsulation layer 120 covers the light-emitting units EL1, EL2, and EL3. The encapsulation layer can be a multi-layer structure. In some embodiments, the encapsulation layer can be made of organic and / or inorganic materials, for example, a three-layer structure such as SiN+Al2O3+SiN.

[0104] The color filter layer 130 is located on the side of the encapsulation layer 120 away from the base substrate 110. As shown in Figure 1, the color filter layer 130 includes a first surface and a second surface (the upper surface and the lower surface, respectively, in Figure 1) that are opposite to each other in a direction perpendicular to the base substrate 110. The roughness of the first surface is greater than that of the second surface. In other embodiments, both the first and second surfaces of the color filter layer 130 have micro-protrusions.

[0105] In some embodiments, the color filter layer 130 may include color filters CF1, CF2, and CF3 corresponding to the light-emitting units EL1, EL2, and EL3. The composition structure of the color filter will be different depending on the display mode. The arrangement of the color filters CF1, CF2, and CF3 can be divided into strip arrangement, dot arrangement, triangle arrangement, mosaic arrangement, or other specific pattern arrangement (such as portraits or animal patterns). Strip and dot arrangements are generally used for large-size, high-precision products. Triangle and mosaic arrangements are generally used for small-size, low-precision products. Chromaticity and transmittance are the two major optical properties of color filters, which mainly depend on the color filter material.

[0106] In some embodiments, the color filter layer 130 may include a first color filter CF1, a second color filter CF2, and a third color filter CF3. The first color filter CF1 may be a red color filter, the second color filter CF2 may be a green color filter, and the third color filter CF3 may be a blue color filter. The surface of the first color filter CF1 away from the base substrate 110 is represented by S1, the surface of the second color filter CF2 away from the base substrate 110 is represented by S2, and the surface of the third color filter CF3 away from the base substrate 110 is represented by S3.

[0107] In addition, the color filter layer 130 may further include a glass substrate, a black matrix BM, a protective layer OC, an ITO conductive film, a columnar spacer, and the like.

[0108] The microlenses Lens1, Lens2 and Lens3 are located on the side of the color filter layer 130 away from the base substrate 110, and correspond one-to-one to the color filters CF1, CF2 and CF3. The so-called one-to-one correspondence here may mean that each color filter is provided with a corresponding microlens on the side away from the base substrate. The arrangement of the microlenses Lens1 to Lens3 may be consistent with the color filters CF1 to CF3, such as strip arrangement, dot arrangement, triangle arrangement or mosaic arrangement. In this way, each light-emitting unit and the corresponding color filter and microlens above it form a light-emitting structure. The light emitted by the light-emitting unit becomes light with the color of the color filter after passing through the color filter, and then is converged by the microlenses to increase the brightness. For example, after emitting white light, the light-emitting units EL1 to EL3 form different colors of light of the display panel 100 through the color filters CF1 to CF3 of different colors.

[0109] In an embodiment of the present disclosure, the surface of each microlens Lens1, Lens2, and Lens3 on the side away from the base substrate 110 may include a central portion 170 and an edge portion 180 surrounding the central portion 170. The central portion 170 is a plane parallel to the base substrate 110, and the edge portion 180 is a curved surface protruding from the inside of the microlens to the outside. The roughness of the central portion 170 is greater than the roughness of the edge portion 180. The roughness here can refer to the average roughness of the surface; it can also refer to the roughness at a specific location, such as the roughness at any location in the region or at the geometric center. The present embodiment is not limited to this.

[0110] In some embodiments, photoresist material 190 is filled between adjacent microlenses, such that edge portions 180 of the microlenses are covered by the photoresist material 190. The refractive index of the photoresist material is lower than that of the microlenses. For example, the refractive index of the photoresist material is in the range of 1.3-1.6, and the refractive index of the microlenses is in the range of 1.6-2.1.

[0111] A dry etching process can be incorporated into the microlens formation process. For example, after forming a hemispherical initial microlens, a photoresist layer is deposited to completely cover the surface of the initial microlens and flattened. The initial microlens and the photoresist layer are then dry-etched. During the dry etching process, the roughness of the central portion 170 increases due to dry etching, while the roughness of the edge portion 180 remains unchanged due to being covered by the photoresist and not undergoing dry etching. This results in the roughness of the central portion 170 being greater than that of the edge portion 180. As shown in FIG1 , the central portion 170 of the microlens Lens 1 corresponds to the central region of the subpixel SP1. Since light in the central region of the subpixel SP1 is primarily emitted in a direction perpendicular to the substrate 110, increasing the roughness of the central portion 170 can minimize the loss of brightness of the light emitted from this central region. The roughened center portion 170 improves viewing angle characteristics and is therefore also referred to as the viewing angle improvement zone. The curved edge portion 180 focuses more light onto the center portion 170, increasing brightness and is therefore also referred to as the brightness enhancement zone. Furthermore, the microlens provided herein prevents deformation of the spherical microlens caused by the cover plate pressing against it after the cover plate and microlens are assembled, thereby improving the stability of the microlens.

[0112] In some embodiments, the display panel 100 may further include a planar layer 140 (hereinafter referred to as a first planar layer). The first planar layer 140 is located between the color filter layer 130 and the plurality of micro lenses Lens 1 to Lens 3 , as shown in FIG1 . The color filter layer 130 may be covered by the first planar layer 140 .

[0113] In some embodiments, the display panel 100 may further include an inorganic layer. The inorganic layer is located between the first planar layer 140 and the plurality of micro lenses Lens 1 to Lens 3 .

[0114] In some embodiments, the display panel 100 may further include another planar layer 150 (hereinafter referred to as a second planar layer). As shown in FIG1 , the second planar layer 150 is located between the color filter layer 130 and the encapsulation layer 120 . The thickness of the second planar layer 150 is less than that of the first planar layer 140 , and the difference in thickness between the plurality of color filters CF1 , CF2 , and CF3 is less than the thickness of the second planar layer 150 .

[0115] In some embodiments, a pixel defining layer 160 may be further disposed between the base substrate 110 and the light-emitting layer EM. The pixel defining layer 160 covers the edges of the first electrodes (e.g., anodes) E1 of each of the light-emitting units EL1 to EL3 to define an opening region OP, allowing the anodes E1 of each of the light-emitting units EL1 to EL3 to leak out of the opening region OP. The pixel defining layer 160 is used to define the plurality of light-emitting units EL1 to EL3 in the display panel 100.

[0116] FIG. 2 is a schematic cross-sectional view showing an embodiment of the microlens in FIG. 1 .

[0117] The microlens structure of Figure 2 is applicable to any microlens in Figure 1 . As shown in Figure 2 , the surface of the microlens facing away from the substrate 110 includes a central portion 270 and an edge portion 280 surrounding the central portion 270. The central portion 270 is a plane parallel to the substrate 110, while the edge portion 280 is a curved surface protruding from the interior of the microlens toward the exterior. The central portion 270 and the edge portion 280 are continuous. The central portion 270 has multiple microprotrusions Bm. For ease of description, only one microprotrusion Bm is labeled in the figure.

[0118] In some embodiments, two adjacent micro-protrusions in the plurality of micro-protrusions Bm may be closely adjacent to each other or have a certain distance therebetween.

[0119] In some embodiments, the heights of the plurality of micro-protrusions Bm may be the same or different. The so-called height of the micro-protrusions here refers to the size of the micro-protrusions Bm in the direction perpendicular to the base substrate 110. As shown in Figure 2, the distance between the highest point and the lowest point on the surface of the micro-protrusions Bm can be used as the micro-protrusion size, the so-called highest point can be the point on the surface of the micro-protrusions Bm that is farthest from the base substrate 110 (also referred to as the vertex), and the so-called lowest point can be the lowest point of the concave structure formed between the micro-protrusions Bm and the adjacent micro-protrusions. In some embodiments, the heights of the plurality of micro-protrusions Bm may also be different from each other. In some embodiments, the edge portion 280 may also have a plurality of micro-protrusions. The height of the micro-protrusions of the central portion 270 is greater than the height of the micro-protrusions of the edge portion 280, so that the roughness of the central portion 270 is greater than the roughness of the edge portion 280.

[0120] FIG2 shows the cross-sectional pattern of the micro-protrusion in the direction perpendicular to the base substrate 110 by taking a triangle as an example. However, the embodiments of the present disclosure are not limited thereto. The cross-sectional pattern of the micro-protrusion can be set as needed, for example, it can be rectangular, arc-shaped, semicircular, diamond-shaped or other shapes.

[0121] FIG3 shows a schematic structural diagram of a display panel according to another embodiment of the present disclosure.

[0122] The display panel 300 of Figure 3 is similar to the display panel 100 of Figure 1 , except that the microlens has a groove on the side away from the base substrate. For the sake of brevity and clarity, the following will mainly describe the differences in detail.

[0123] As shown in Figure 3, microlenses Lens1', Lens2', and Lens3' are located on the side of the color filter layer 130 away from the base substrate 110, and correspond one-to-one with the color filters CF1, CF2, and CF3. In an embodiment of the present disclosure, each microlens Lens1', Lens2', and Lens3' may have a groove on the surface away from the base substrate 110. The bottom surface of the groove serves as a center portion 370, which is a plane parallel to the base substrate 110. The edge portion 380 is a curved surface protruding from the inside of the microlens to the outside. The center portion 370 is connected to the edge portion 380 surrounding the center portion 370 by the sidewall 390 of the groove. The roughness of the center portion 370 is greater than that of the edge portion 380.

[0124] In some embodiments, during the microlens formation process, a groove can be patterned at the center of the corresponding initial microlens using a half-mask process. A dry etching process is then performed to form the grooved microlens, so that the roughness of the center portion 370 of the microlens is greater than the roughness of the edge portion 380.

[0125] FIG. 4 is a schematic cross-sectional view showing an embodiment of the microlens in FIG. 3 .

[0126] The microlens structure shown in Figure 4 is applicable to any of the microlenses in Figure 3 . As shown in Figure 4 , the surface of the microlens facing away from the substrate also includes a central portion 470 and an edge portion 480 surrounding the central portion 470. Unlike the structure in Figure 2 , the microlens in Figure 4 has a groove on the side facing away from the substrate. The bottom surface of the groove serves as the central portion 470, and the central portion 470 and the edge portion 480 are connected by the groove's sidewalls 490. For the microlens shown in Figure 4 , the central portion 470 and the edge portion 480 are connected by the groove's sidewalls 490.

[0127] As shown in FIG4 , the center portion 470 has a first height H1 relative to the bottom 460 of the microlens, and the edge portion 480 has a second height H2 relative to the bottom 460 of the microlens. The first height H1 is less than the second height H2. In some embodiments, the ratio of the first height H1 to the second height H2 is in a range of 0.4 to 0.8.

[0128] Existing microlenses are generally hemispherical and thick, generally comparable to the size of a sub-pixel (for example, in the range of 5 to 10 μm). Although hemispherical microlenses can improve brightness by converging light, the thicker microlens material absorbs light, resulting in a loss of brightness. The structure of the microlens provided in the present disclosure, as shown in FIG4 , further thins the portion corresponding to the central portion of the microlens while maintaining the portion corresponding to the edge portion of the microlens at a higher height. This allows the edge portion to converge more light with a wide viewing angle to the middle area of ​​the microlens to improve brightness. The portion corresponding to the central portion of the microlens is thinner, which improves the transmittance of light, thereby improving the brightness of the silicon-based OLED display panel.

[0129] The above description of the micro protrusions Bm in FIG. 2 is also applicable to the micro protrusions Bm provided on the central portion 470 and will not be repeated here.

[0130] FIG5 shows a schematic structural diagram of a display panel according to another embodiment of the present disclosure.

[0131] The display panel 500 of Figure 5 is similar to the display panel 300 of Figure 3, except that a compensating microlens is provided between adjacent microlenses. For the sake of brevity and clarity, the following will mainly describe in detail the differences.

[0132] FIG5 exemplarily illustrates two compensating microlenses CLens1 and CLens2 between three adjacent microlenses Lens1′, Lens2′, and Lens3′. Compensating microlens CLens1 is disposed between adjacent microlenses Lens1′ and Lens2′, and compensating microlens CLens2 is disposed between adjacent microlenses Lens1′ and Lens3′. However, the embodiments of the present disclosure are not limited thereto, and compensating microlenses may be disposed between other adjacent microlenses as needed.

[0133] In some embodiments, the height of the compensating microlens is smaller than the height of the center portion of the microlens. For example, the height of the compensating microlens CLens1 is smaller than the height of the center portions of the adjacent microlenses Lens1' and Lens2', and the height of the compensating microlens CLens2 is smaller than the height of the center portions of the adjacent microlenses Lens1' and Lens3'.

[0134] For example, as shown in FIG5 , the height H3 of the compensating microlens CLens1 is smaller than the height H1 of the central portion 370 of the microlens Lens 1′. Thus, since the compensating microlenses are provided between the sub-pixels, stray light between the sub-pixels can be converged to prevent crosstalk between adjacent sub-pixels. Furthermore, by setting the height of the compensating microlens lower than the height of the central portion of the microlens, the impact of the compensating microlens on the principal light can be reduced.

[0135] In some embodiments, the height of the compensating microlens CLens1 may be the same as or different from the height of the compensating microlens CLens2 , and the embodiments of the present disclosure are not limited thereto, as long as the height of the compensating microlens is less than the height of the central portion of the microlens.

[0136] In some embodiments, in order to achieve a better viewing angle improvement effect, the roughness of the surface of the compensation microlens away from the base substrate 110 may be set to be smaller than the roughness of the central portion of the microlens.

[0137] In some embodiments, the roughness of the surface of the compensating microlens CLens1 on the side away from the base substrate 110 may be the same as or different from the roughness of the surface of the compensating microlens CLens2 on the side away from the base substrate 110. The embodiments of the present disclosure are not limited to this, as long as the roughness of the surface of the compensating microlens on the side away from the base substrate 110 is less than the roughness of the central part of the microlens.

[0138] FIG5 shows a cross-sectional pattern of a compensating microlens in a direction perpendicular to the base substrate 110 by taking a semicircle as an example. However, the embodiments of the present disclosure are not limited thereto. The cross-sectional pattern of the compensating microlens can be set as needed, for example, it can be a triangle, rectangle, diamond or ellipse, etc.; or it can also be an irregular shape.

[0139] In some embodiments, a compensating microlens may also be provided in the display panel 100 shown in Figure 1. The above description of the compensating microlens is also applicable to the compensating microlens provided in the display panel 100, and will not be repeated here.

[0140] FIG6 shows a schematic plan view of a display panel according to an embodiment of the present disclosure.

[0141] As shown in FIG6 , a display panel 600 includes an active display area AA. Subpixels SP1 to SP4 of various colors are disposed in the active display area AA. Each subpixel SP1, SP2, SP3, and SP4 is configured to emit light of a corresponding color. For ease of description, FIG6 shows four subpixels SP1, SP2, SP3, and SP4. However, the embodiments of the present disclosure are not limited thereto, and the display panel may have any number of subpixels as desired.

[0142] In some embodiments, the subpixel structures in the display panels of Figures 1, 3, and 5 can be applied to the subpixels shown in Figure 6. The color of each subpixel is defined by the color of the color filter of the subpixel. For example, the color of subpixel SP1 is defined by the color of the color filter CF1 of the subpixel, the color of subpixel SP2 is defined by the color of the color filter CF2 of the subpixel, and the color of subpixel SP3 is defined by the color of the color filter CF3 of the subpixel.

[0143] In some embodiments, the sub-pixels SP1 to SP4 of multiple colors include a first sub-pixel SP1 having a color filter of a first color, a second sub-pixel SP2 having a color filter of a second color, a third sub-pixel SP3 having a color filter of a third color, and a fourth sub-pixel SP4 having a color filter of the first color.

[0144] 6 , the active display area AA includes a central area CA and an edge area EA located on at least one side of the central area CA. The first subpixel SP1, the second subpixel SP2, and the third subpixel SP3 are located in the central area CA, and the fourth subpixel SP4 is located in the edge area EA.

[0145] 6 , the first subpixel SP1 , the second subpixel SP2 , and the third subpixel SP3 are adjacently disposed. However, the present disclosure is not limited thereto, and the first subpixel SP1 , the second subpixel SP2 , and the third subpixel SP3 may also be alternately disposed.

[0146] In the embodiment of the present disclosure, the fourth sub-pixel SP4 has the first color. However, the embodiment of the present disclosure is not limited thereto, and the fourth sub-pixel SP4 may also have the second color or the third color.

[0147] 6 shows a sub-pixel having a regular hexagonal planar shape. However, the embodiments of the present disclosure are not limited thereto, and the sub-pixel may also have other planar shapes, such as a rectangle, a diamond, a circle, and / or an ellipse.

[0148] 7A and 7B are enlarged views of the schematic diagrams of the first sub-pixel SP1 and the fourth sub-pixel SP4 in FIG. 6 , respectively.

[0149] With reference to Figures 1, 6, and 7A-B, a first subpixel SP1 located in a central area CA of the display panel 600 includes an opening area OP1 and a central portion 1701. A fourth subpixel SP4 located in an edge area EA of the display panel 600 includes an opening area OP4 and a central portion 1704. The first subpixel SP1 and the fourth subpixel SP4 have the same color. In some embodiments, an area ratio of the central portion 1701 of the first subpixel SP1 to the opening area OP1 is smaller than an area ratio of the central portion 1704 of the fourth subpixel SP4 to the opening area OP4.

[0150] In some embodiments, the area of ​​the opening region OP1 of the first subpixel SP1 may be the same as or different from the area of ​​the opening region OP4 of the fourth subpixel SP4. When the area of ​​the opening region OP1 of the first subpixel SP1 is the same as the area of ​​the opening region OP4 of the fourth subpixel SP4, the area of ​​the central portion 1701 of the first subpixel SP1 is smaller than the area of ​​the central portion 1704 of the fourth subpixel SP4.

[0151] In some embodiments, referring to Figures 1, 6 and 7A-B, among sub-pixels of the same color, the area ratio of the central portion 170 of each sub-pixel to the opening area OP gradually increases from the center to the edge of the display panel 600.

[0152] Since the edge area of ​​the display panel needs to ensure a larger viewing angle to ensure that the light of the display panel enters the human eye, setting the area of ​​the central part of the edge area of ​​the display panel to a larger proportion can improve the display uniformity of the display panel.

[0153] FIG. 8 shows an enlarged view of the schematic diagram of the first sub-pixel SP1 , the second sub-pixel SP2 , and the third sub-pixel SP3 in FIG. 6 .

[0154] 1 , 6 and 8 , the first sub-pixel SP1 having the first color includes an opening area OP1 and a central portion 1701 , the second sub-pixel SP2 having the second color includes an opening area OP2 and a central portion 1702 , and the third sub-pixel SP3 having the third color includes an opening area OP3 and a central portion 1703 .

[0155] In some embodiments, the area ratio of the center portion of a sub-pixel of at least one color to the opening region is greater than that of sub-pixels of other colors. Taking the three sub-pixels SP1, SP2, and SP3 of different colors as an example, the area ratios of the center portion of the sub-pixels SP1, SP2, and SP3 to the opening region have the following relationship:

[0156] Src / Sr>Sgc / Sg>Sbc / Sb

[0157] Among them, Sr represents the area of ​​the opening area OP1 of the first sub-pixel SP1, Sg represents the area of ​​the opening area OP2 of the second sub-pixel SP2, Sb represents the area of ​​the opening area OP3 of the third sub-pixel SP3, Src represents the area of ​​the central portion 1701 of the microlens of the first sub-pixel SP1, Srg represents the area of ​​the central portion 1702 of the microlens of the second sub-pixel SP2, and Srb represents the area of ​​the central portion 1703 of the microlens of the third sub-pixel SP3.

[0158] In some embodiments, the area Sr of the opening region OP1 of the first subpixel SP1 is smaller than the area Sg of the opening region OP2 of the second subpixel SP2 , and the area Sg of the opening region OP2 of the second subpixel SP2 is smaller than the area Sb of the opening region OP3 of the third subpixel SP3 .

[0159] Figures 6 and 8 illustrate three sub-pixels of different colors located in the central area CA as an example. However, the embodiments of the present disclosure are not limited to this. The area ratio of the central part of the sub-pixels of different colors located in the edge area EA to the opening area also satisfies the above relationship.

[0160] In some embodiments, the first color is red, the second color is green, and the third color is blue. In silicon-based OLED display panels, red subpixels are more susceptible to color shift. In the disclosed embodiments, the central portion of the red subpixel is enlarged to improve the color uniformity of the display panel.

[0161] FIG. 9 is a schematic cross-sectional view showing another embodiment of the microlens in FIG. 1 .

[0162] The microlens in Figure 9 is similar to the microlens in Figure 2, except that the microprotrusions in the central portion of the microlens are different. For the sake of brevity and clarity, the following will mainly describe the differences in detail.

[0163] As shown in FIG9 , the microlens also includes a central portion 970 and an edge portion 980. The central portion 970 has a plurality of microprotrusions. The plurality of microprotrusions includes a first microprotrusion Bm1, a second microprotrusion Bm2, and a third microprotrusion Bm3. The first microprotrusion Bm1 is located in the edge region of the central portion 970, the second microprotrusion Bm2 is located in the center region of the central portion 970, and the third microprotrusion Bm3 is located between the first microprotrusion Bm1 and the second microprotrusion Bm2.

[0164] In some embodiments, the height of the second micro protrusions Bm2 is greater than the height of the first micro protrusions Bm1 , such that the roughness of the central region of the central portion 970 is greater than the roughness of the edge region of the central portion 970 .

[0165] In some embodiments, the heights of the micro-bumps Bm2, Bm3, and Bm1 in the central portion 970 gradually decrease from the center to the edge of the central portion 970. That is, the height of micro-bump Bm2 is greater than the height of micro-bump Bm3, and the height of micro-bump Bm3 is greater than the height of micro-bump Bm1. This results in the roughness of the central portion 970 gradually decreasing from the center to the edge. By designing the height of the micro-bumps in the central portion with a gradient, i.e., the micro-bumps increase in height closer to the center of the sub-pixel, the viewing angle characteristics of the central portion can be finely adjusted, thereby ensuring a better viewing angle effect and minimal brightness loss.

[0166] In some embodiments, the dimension (also referred to as width) of each of the microbumps Bm1, Bm2, and Bm3 in the central portion in a direction parallel to the substrate 110 is in the range of 0.01 μm to 0.1 μm, and the dimension (also referred to as height) in a direction perpendicular to the substrate 110 is in the range of 5 nm to 50 nm. Here, the width of the microbump may refer to the maximum dimension of the microbump in a direction parallel to the substrate, and the height of the microbump may refer to the maximum dimension in a direction perpendicular to the substrate.

[0167] FIG9 illustrates the cross-sectional pattern of each micro-bump in a direction perpendicular to the substrate 110, using a triangle as an example. However, the embodiments of the present disclosure are not limited thereto. The cross-sectional pattern of the micro-bumps can be configured as desired, for example, in the form of a rectangle, an arc, a column, a semicircle, a diamond, or other shapes. In some embodiments, micro-bumps of different heights can have different shapes. For example, the cross-sectional pattern of the second micro-bump Bm2 is a triangle, while the cross-sectional pattern of the first micro-bump Bm1 is a semicircle. The embodiments of the present disclosure are not limited thereto.

[0168] The above description of each micro-protrusion is also applicable to any micro-lens on the display panel shown in FIG. 1 , FIG. 3 and FIG. 5 , and will not be repeated here.

[0169] FIG. 10A shows a partially enlarged view of an embodiment of the display panel of FIG. 1 .

[0170] As shown in FIG10A , the first, second, and third color films CF1, CF2, and CF3 of the display panel are arranged parallel to the base substrate 110, with the first color film CF1 positioned between the second and third color films CF2 and CF3. The second color film CF2 partially covers the first and third color films CF1 and CF3, such that the portion of the second color film CF2 covering the first color film CF1 forms a first micro-bump B21, and the portion of the second color film CF2 covering the third color film CF3 forms a second micro-bump B23.

[0171] In display technology, color shift is an important indicator for evaluating the performance of display devices. If the color shift viewing angle of a display device is small, color shift phenomena such as reddish and greenish colors are more likely to occur as the viewing angle increases, affecting the visual effect. In display devices, especially high-PPI display devices such as silicon-based organic light-emitting diodes (OLEDoS, OLED on silicon), there is inevitably a surface height difference between the color filters corresponding to different sub-pixels, which makes the color filter have a shape similar to a bull's horn in cross-section (concave in the middle and raised at the edges). This height difference is also called the bull's horn height or step difference. This step difference is usually in the range of 300nm to 630nm, resulting in different light emission effects of color filters of different colors at side viewing angles. The color shift value Δu′v′<0.025 corresponds to a viewing angle of less than about 17°. In addition, the color filter is usually formed in multiple times. When the later formed color filter fills the gap between the previously formed color filters, it will form a concave lens morphology, resulting in large viewing angle color shift. Under the premise of ensuring transmittance and brightness, in order to ensure the color gamut DCI-P3 ≥ 80%, the thickness of the weak cavity process color film is usually around 1.3±0.1μm.

[0172] In some embodiments, by using a back-etching process after forming the color filter material layer, the aforementioned horn-shaped gap can be reduced or even eliminated, improving the flatness of the color filter layer surface and thereby alleviating the color shift problem. As shown in FIG10B , the protrusions on both sides of the color filter unit CF2 in the color filter material layer (i.e., the so-called horn structure) are substantially removed, resulting in a color filter surface with a high degree of flatness. For example, the portion of the color filter within the dotted box in FIG10B has a substantially flat surface.

[0173] With reference to Figures 1 and 10B , the top surfaces S1, S2, and S3 of the first through third color films CF1 through CF3 can be substantially flush. For example, the height difference between the top surfaces of the respective color films can be controlled to be approximately 100 nm. For example, the first, second, and third color films CF1, CF2, and CF3 can have thicknesses D1, D2, and D3, respectively, with the difference between thicknesses D1, D2, and D3 being less than 100 nm. For example, D1, D2, and D3 can be in the range of 1.1 μm to 1.3 μm. In some embodiments, D2 < D1 < D3. In some embodiments, the difference between D1 and D2 is in the range of 10 nm to 30 nm, and the difference between D1 and D3 is in the range of 20 nm to 50 nm. The color film thickness herein can refer to the average thickness of the color film, the thickness at a specific location, such as the thickness at the geometric center of the color film, or the maximum or minimum thickness of the color film. In some embodiments, the ratio of the thickness of the first planar layer 140 to the width of the overlapping portions of the plurality of color films CF1 to CF3 is in a range of 1 to 1.8. In other words, the thickness of the first planar layer 140 is greater than the overlapping width of the color films CF1 to CF3 and less than 1.8 times the overlapping width.

[0174] FIG10C shows a partial enlarged view of the color filter surface in FIG10B .

[0175] As shown in FIG. 10C , taking the second color film CF2 as an example, the surface S1 of the second color film CF2 on the side away from the base substrate 110 includes a central area S11 and an edge area S12 surrounding the central area S11 .

[0176] In some embodiments, the central region S11 has multiple microbumps Bm11, and the edge region S12 has multiple microbumps Bm12. As shown in FIG10C , the height H11 of microbumps Bm11 is less than the height H12 of microbumps Bm12, resulting in a lower roughness in the central region S11 than in the edge region S12. In some embodiments, the height H11 of microbumps Bm11 is less than 5 nm, while the height H12 of microbumps Bm12 is greater than 5 nm.

[0177] In some embodiments, the height of the multiple micro-protrusions on the surface S1 of the second color film CF2 on the side away from the substrate 110 increases gradually from the center to the edge of the second color film CF2, such that the roughness of the surface S1 of the second color film CF2 on the side away from the substrate 110 gradually increases from the center to the edge of the second color film CF2. The first color film CF1 and the third color film CF3 have similar structures and are not further described here.

[0178] FIG. 10D shows a partially enlarged view of an embodiment of the display panel of FIG. 10B .

[0179] As shown in FIG10D , taking a green sub-pixel as an example, the sub-pixel includes a light-emitting unit having a first electrode E1, a second electrode E2, and a light-emitting layer EM, a color filter CF2, and a microlens Lens 2. The microlens Lens 2 can have the structure described above with reference to FIG9 , namely, the height of each microprotrusion in the central portion 1170 of the microlens Lens 2 gradually decreases from the center to the edge of the central portion 1170, such that the roughness of the central portion 1170 gradually decreases from the center to the edge. The color filter CF2 can have the structure described above with reference to FIG10C , namely, the roughness of the surface on the side away from the base substrate 110 gradually increases from the center to the edge of the color filter CF2. In some embodiments, the height of the microprotrusions can be used to define the center and edge regions of the color filter. For example, the height of the microprotrusions in the center region of the color filter can be less than 5 nm, while the height of the microprotrusions in the edge regions of the color filter can be within a range of 5 nm to 50 nm. For example, in FIG10D , two dashed lines illustrate the boundary between the center and edge regions of the color filter. The area between the two dashed lines represents the center region of the color filter, and the area on the side of the two dashed lines facing away from the center region represents the edge region of the color filter. In some embodiments, as shown in FIG10D , the projection of the boundary between the center and edge regions of the color filter CF2 on the base substrate 110 lies within the projection of the edge portion 1180 of the microlens Lens 2 on the base substrate 110.

[0180] Because the roughness of the edge areas of the color filter is greater than that of the center area, the roughness at the edges is higher, causing light to diverge. This can hinder brightness improvement in some scenarios. However, the surface roughness of the microlenses provided by the present disclosure complements the surface roughness of the color filter. For example, the center portion 1170 of the microlens Lens 2 has high center roughness and low edge roughness. The surface roughness of the color filter CF2 beneath the microlens Lens 2 is the opposite, with low center roughness and high edge roughness. These two surface roughnesses complement each other, further improving display uniformity.

[0181] In the embodiment of the present disclosure, a first flat layer 140 is provided between the micro lens Lens 2 and the color film CF2. However, the embodiment of the present disclosure is not limited thereto. In other embodiments, the micro lens Lens 2 and the color film CF2 may be in contact with each other.

[0182] In some embodiments, an inorganic layer 200 may be further disposed between the first planar layer 140 and the microlens Lens 2 .

[0183] In other embodiments, the microlens shown in FIG10D may also have any of the microlens structures described in the above embodiments of the present disclosure, or a combination thereof. The green color filter CF2 shown in FIG10D is shown only as an example. The red and blue color filters of the present embodiment may have similar structures, and the present disclosure does not limit this.

[0184] Continuing with reference to Figure 10D , the subpixel further includes a pixel-defining layer 160 covering the edge of the first electrode E1. In some embodiments, the edge portion 1180 has a first projection perpendicular to the substrate 110, and the portion of the pixel-defining layer 160 covering the anode E1 has a second projection perpendicular to the substrate 110. The second projection falls within the first projection. Referring to Figures 10D and 10E , the first projection includes a first edge 1801 and a second edge 1802. The first edge 1801 is the outer edge of the first projection, and the second edge 1802 is the inner edge of the first projection. The second projection includes a third edge 1601 and a fourth edge 1602. The third edge 1601 is the inner edge of the second projection, and the fourth edge 1602 is the outer edge of the second projection.

[0185] In an embodiment of the present disclosure, the shape of the first edge 1801, the second edge 1802, the third edge 1601 and the fourth edge 1602 is a regular hexagon. The distance between the first edge 1801 and the second edge 1802 is d1, and the distance between the third edge 1601 and the fourth edge 1602 is d2, where d1>d2, so that the second projection falls within the first projection, thereby ensuring the convergence of edge light. The distance between the two edges here can be the minimum or maximum value of the distance between the two edges. In an embodiment of the present disclosure, the first projection and the second projection can have the shape of equal-width strips, as shown in Figure 10E, so the strip widths are consistent, that is, the distance between the inner edge and the outer edge of the projection is consistent at all positions.

[0186] In some other embodiments, each edge may also have other shapes, such as rectangular, circular or irregular shapes, as long as the orthographic projection of the portion of the pixel defining layer covering the anode on the base substrate falls within the orthographic projection of the edge portion on the base substrate. This disclosure does not impose any restrictions on this.

[0187] FIG. 11 shows a partially enlarged view of a display panel according to another embodiment of the present disclosure.

[0188] Similar to FIG10 , the display substrate of FIG11 includes a first color film CF1 , a second color film CF2 , a third color film CF3 , and a first microlens Lens1 , a second microlens Lens2 , and a third microlens Lens3 thereon.

[0189] Unlike Figure 10A , in Figure 11 , each microlens, Lens 1, Lens 2, and Lens 3, contacts the corresponding color filters, CF1, CF2, and CF3. As shown in Figure 11 , the surface of microlens Lens 1 contacting color filter CF1 is represented by BL1. The surface of microlens Lens 2 contacting color filter CF2 is represented by BL2. The surface of microlens Lens 3 contacting color filter CF3 is represented by BL3.

[0190] In the embodiments of the present disclosure, due to the different thicknesses of the color filters CF1 to CF3, there are height differences between the surfaces BL1 to BL3 of the microlenses Lens1 to Lens3 that contact the color filters. For example, the color filter CF2 can be a green color filter, which is thicker than the color filters CF1 and CF3 and has a bullhorn structure. Therefore, the bottom surface BL2 of the microlens Lens2 is higher than the bottom surface BL2 of the microlens Lens1 and the bottom surface BL3 of the microlens Lens1 in a direction perpendicular to the substrate. Because a dry etching process is introduced during the formation of the microlenses Lens1 to Lens3 to flatten the hemispherical microlenses, the central portions 170 of the microlenses Lens1, Lens2, and Lens3 are located in the same plane, thereby avoiding the display unevenness problem caused by the related art of directly placing the hemispherical microlenses on the color filter, which causes the light-emitting surfaces of the microlenses to be on different horizontal planes.

[0191] In some embodiments, a flat layer may be provided between the microlens of each sub-pixel and the color filter to further alleviate the adverse effects of the horn structure of the color filter.

[0192] FIG. 12 shows a flow chart of a method for manufacturing a display panel according to an embodiment of the present disclosure.

[0193] As shown in FIG. 12 , the method 1200 for manufacturing a display panel includes steps S1210 to S1260 .

[0194] In step S1210, at least one light emitting unit is formed on a base substrate.

[0195] In step S1220 , an encapsulation layer covering at least one light emitting unit is formed.

[0196] In step S1230 , a color filter layer is formed on the encapsulation layer, wherein the color filter layer includes at least one color filter corresponding to at least one light-emitting unit.

[0197] In step S1240 , a microlens layer is formed on the color filter layer, wherein the microlens layer includes at least one initial microlens corresponding to at least one color filter, and a surface of the initial microlens away from the base substrate is a curved surface.

[0198] In step S1250 , a first photoresist layer is formed on the microlens layer, such that the first photoresist layer covers at least one initial microlens, and a surface of the first photoresist layer away from the substrate is parallel to the substrate.

[0199] In step 1260 , a portion of the microlens layer and a portion of the first photoresist layer are removed by a dry etching process to obtain a microlens having a central portion and an edge portion.

[0200] In some embodiments, step S1260 may include the following steps: dry etching the microlens layer and the first photoresist material layer to obtain a microlens having a central portion and an edge portion, wherein the central portion is continuous with the edge portion.

[0201] In other embodiments, step S1260 may include the following steps: forming grooves in the first photoresist material layer above each microlens through a half-mask process to obtain a patterned first photoresist material layer; and dry etching the patterned first photoresist material layer and the microlens layer to obtain microlenses having grooves, wherein the bottom surface of the groove serves as the central portion, and the central portion is connected to the edge portion through the sidewalls of the groove.

[0202] In some embodiments, before executing step S1240 , the following steps may be further performed: forming a second photoresist layer on the color filter layer; and removing the entire second photoresist layer and a portion of the color filter layer by a dry etching process to planarize the color filter layer.

[0203] In some embodiments, before performing step S1240, a planarization layer may be formed on the color filter layer. In some embodiments, after forming the planarization layer on the color filter layer, an inorganic layer may be formed on the planarization layer.

[0204] In some embodiments, step S1240 may include the following steps: depositing an organic microlens material on the color filter layer; removing a portion of the microlens material through exposure and development to obtain a plurality of columnar structures; converting each columnar structure into a hemispherical structure through a thermal reflow process; and curing the hemispherical structure to obtain an initial microlens. In some embodiments, during the thermal reflow process, when the columnar structure is heated, the organic material in the columnar structure has a certain fluidity at a certain temperature, causing the columnar structure to naturally form a hemispherical microlens under the action of gravity.

[0205] 13A to 13K illustrate a manufacturing process of a display panel according to an embodiment of the present disclosure.

[0206] As shown in FIG. 13A , a plurality of light emitting units EL1 to EL3 , a pixel defining layer 160 , an encapsulation layer 120 and a second planarization layer 150 are sequentially formed on a base substrate 110 .

[0207] Then, a color filter material layer 130_1 is formed on the structure shown in FIG13A , resulting in the structure shown in FIG13B . As shown in FIG13B , the color filter material layer 130_1 may include a plurality of color filter units CF1_1, CF2_1, and CF3_1 corresponding one-to-one to the plurality of light-emitting units EL1 to EL3. For example, the plurality of color filter units CF1_1, CF2_1, and CF3_1 may be made of red, green, and blue color filter materials, respectively. The green color filter unit CF2_1 covers a portion of the red and blue color filter units CF1_1 and CF3_1 on either side of it, thereby forming a raised structure on both sides.

[0208] Next, as shown in Figure 13C, a photosensitive material PR (also called a second photoresist layer) is applied to the color filter material layer 130_1, completely covering the color filter material layer 130_1. The thickness of the photosensitive material PR is greater than the height of the protruding structures on either side of the color filter cell CF2_1 in the color filter material layer 130_1, ensuring that the photosensitive material PR completely covers the color filter material layer 130_1 for subsequent etching. The etching selectivity ratio between the photosensitive material PR and the material in the color filter material layer 130_1 is substantially 1:1, ensuring that the etching rate of each color filter cell in the color filter material layer is substantially consistent with that of the photosensitive material during subsequent etching. In actual operation, due to material differences between the color filter cells, there may be slight differences in the etching rate between the color filter cells, but this does not significantly affect the desired flatness of the entire color filter material layer.

[0209] 13D , the photosensitive material PR and the color filter material layer 130_1 covered by it are etched until the color filter material layer 130_1 is thinned to a first thickness, thereby obtaining a color filter material layer 130_2 of a first thickness. The first thickness may be within the range of 1.4 μm ± 0.1 μm.

[0210] Next, as shown in FIG13E , the color filter material layer 1302 of the first thickness is overetched until the color filter material layer 1302 is further thinned to the second thickness, thereby obtaining a color filter layer 130 of the second thickness. The color filter layer 130 has a structure as described in any of the above embodiments. In some embodiments, the second thickness may be within the range of 1.2 μm ± 0.1 μm. By performing overetching, the residual photoresist may be removed and the flatness of the color filter layer may be further improved. The etching depth may be set as needed to obtain the desired surface structure of the color filter layer. For example, the protrusions on both sides of the color filter unit CF2_1 in the color filter material layer (i.e., the so-called horn structure) may be completely removed, thereby obtaining a color filter layer surface with a higher flatness as shown in FIG10B .

[0211] Next, as shown in FIG. 13F , a first planarization layer 140 is formed on the color filter layer 130 .

[0212] 13G , an organic microlens material is deposited on the first planar layer 140 to obtain a microlens material layer Lens_L. The microlens material layer Lens_L is then exposed and developed to remove a portion of the microlens material layer Lens_L, thereby obtaining columnar structures Lens1_1 , Lens2_1 , and Lens3_1 as shown in FIG13H .

[0213] Then, a thermal reflow process is performed on the columnar structures Lens1_1 , Lens2_1 and Lens3_1 as shown in FIG13H , so that the columnar structures Lens1_1 , Lens2_1 and Lens3_1 naturally form hemispherical structures under the action of gravity.

[0214] The hemispherical structure is then cured to obtain the initial microlenses Lens1_2, Lens2_2, and Lens3_2 as shown in Figure 13I. The initial microlenses Lens1_2, Lens2_2, and Lens3_2 correspond to the first color film CF1, the second color film CF2, and the third color film CF3, respectively. In some embodiments, the surfaces of the initial microlenses Lens1_2, Lens2_2, and Lens3_2 facing away from the base substrate 110 are curved.

[0215] 13J , a first photoresist layer 190_1 is formed on the initial microlenses Lens1_2 , Lens2_2 , and Lens3_2 . A surface of the first photoresist layer 190_1 away from the base substrate 110 is parallel to the base substrate 110 .

[0216] Then, a dry etching process is performed on the first photoresist layer 190_1 and the initial microlenses Lens1_2, Lens2_2, and Lens3_2 to remove a portion of the first photoresist layer 190_1 and a portion of the initial microlenses Lens1_2, Lens2_2, and Lens3_2, thereby obtaining the structure shown in FIG13K , that is, the display panel structure shown in FIG1 . The microlenses Lens1, Lens2, and Lens3 in the display panel each have a planar center portion and a curved edge portion. Due to the dry etching process, the roughness of the center portion is greater than the roughness of the edge portion.

[0217] 14A to 14L illustrate a manufacturing process of a display panel according to another embodiment of the present disclosure.

[0218] The manufacturing process of the display panel shown in FIG. 14A to FIG. 14I is the same as the manufacturing process shown in FIG. 13A to FIG. 13I , and will not be repeated here.

[0219] 14J , a first photoresist layer 190_1 ′ is formed on the structure shown in FIG14I , covering the initial microlenses Lens1_2 , Lens2_2 , and Lens3_2 . The thickness of the first photoresist layer 190_1 ′ may be the same as or different from the thickness of the first photoresist layer 190_1 shown in FIG13J .

[0220] Next, a half-mask process is performed on the first photoresist layer 190_1' shown in FIG14J to form grooves in the first photoresist layer 190_1' above each of the initial microlenses Lens1_2, Lens2_2, and Lens3_2. For example, groove V1 is formed above initial microlens Lens1_2, groove V2 is formed above initial microlens Lens2_2, and groove V3 is formed above initial microlens Lens3_2, thereby obtaining the patterned first photoresist layer 190_2 shown in FIG14K. The shape and size of grooves V1 to V3 can be set as needed, for example, according to the size of the central portion to be formed.

[0221] Then, the patterned first photoresist material layer 190_2 and each of the initial microlenses Lens1_2, Lens2_2, and Lens3_2 are dry-etched to obtain the structure shown in FIG14L , i.e., the display panel structure shown in FIG3 or FIG5 . The microlenses Lens1', Lens2', and Lens3' in this display panel have grooves, where the bottom surface of the groove serves as the center portion, and the center portion and the edge portion are connected by the sidewalls of the groove. Due to the dry-etching process, the roughness of the center portion of each microlens is greater than the roughness of the edge portion.

[0222] Those skilled in the art will appreciate that the embodiments described above are exemplary and that they may be improved upon. The structures described in the various embodiments may be freely combined without causing any conflict in structure or principle.

[0223] After describing the preferred embodiments of the present disclosure in detail, those skilled in the art will clearly understand that various changes and modifications may be made without departing from the scope and spirit of the appended claims, and that the present disclosure is not limited to the exemplary embodiments described in the specification.

Claims

1. A display panel, include: substrate substrate; At least one sub-pixel is arranged on the substrate. Wherein, the sub-pixel comprises: A light-emitting unit, comprising a first electrode, a second electrode and a light-emitting layer located between the first electrode and the second electrode, wherein the first electrode is located between the light-emitting layer and the base substrate; An encapsulation layer, covering the light-emitting unit; A color film is located on a side of the encapsulation layer away from the substrate; A micro lens, located on a side of the color film away from the base substrate; The surface of the microlens on the side away from the substrate includes a central portion and an edge portion surrounding the central portion, wherein the central portion is a plane parallel to the substrate, and the edge portion is an arc surface protruding from the inside of the microlens to the outside, and the roughness of the central portion is greater than that of the edge portion.

2. The display panel according to claim 1, in, The central portion is continuous with the edge portion.

3. The display panel according to claim 1, in, The microlens has a groove on a side away from the base substrate, the bottom surface of the groove serves as the central portion, and the central portion and the edge portion are connected through the side wall of the groove.

4. The display panel according to claim 3, in, The central portion has a first height relative to the bottom of the microlens, the edge portion has a second height relative to the bottom of the microlens, and a ratio of the first height to the second height is in a range of 0.4 to 0.

8. 5 . The display panel according to claim 1 , further comprising a compensating microlens located between adjacent microlenses, wherein a height of the compensating microlens is smaller than a height of a central portion of the microlens.

6. The display panel according to claim 5, in, The roughness of the surface of the compensating microlens at a side away from the base substrate is smaller than the roughness of the central portion.

7. The display panel according to any one of claims 1 to 6, in, The central portion and the edge portion both have a plurality of micro protrusions, and the height of the micro protrusions of the central portion is greater than that of the micro protrusions of the edge portion, so that the roughness of the central portion is greater than that of the edge portion.

8. The display panel according to claim 7, in, The height of the micro protrusions in the central area of ​​the central portion is greater than the height of the micro protrusions in the edge area of ​​the central portion, so that the roughness of the central area of ​​the central portion is greater than the roughness of the edge area of ​​the central portion.

9. The display panel according to claim 8, in, The height of each micro protrusion in the central portion gradually decreases from the center to the edge of the central portion, so that the roughness of the central portion gradually decreases from the center to the edge.

10. The display panel according to any one of claims 7 to 9, in, The cross section of the micro protrusion in the central portion in a direction perpendicular to the substrate is triangular, arc-shaped or rectangular.

11. The display panel according to any one of claims 7 to 10, in, The micro protrusions of the central portion have a size in a direction parallel to the substrate in a range of 0.01 μm to 0.1 μm, and a size in a direction perpendicular to the substrate in a range of 5 nm to 50 nm.

12. The display panel according to any one of claims 1 to 11, in, The roughness of the central area of ​​the surface of the color film at the side away from the base substrate is smaller than the roughness of the edge area.

13. The display panel according to claim 12, in, The roughness of the surface of the color film on the side away from the base substrate gradually increases from the center to the edge of the color film.

14. The display substrate according to claim 12 or 13, in, The color film has micro protrusions on a surface away from the base substrate. The height of the micro protrusions in the central area of ​​the color film is less than 5 nm, and the height of the micro protrusions in the edge area of ​​the color film is in the range of 5 nm to 50 nm.

15. The display substrate according to claim 14, in, The projection of the boundary between the central area and the edge area of ​​the color filter on the base substrate is located within the projection of the edge portion of the microlens on the base substrate.

16. The display panel according to any one of claims 1 to 15, in, The sub-pixel further includes: a pixel defining layer, located between the base substrate and the light-emitting layer of the light-emitting unit, covering the edge of the first electrode of the light-emitting unit to define an opening area so that a portion of the first electrode of the light-emitting unit is exposed from the opening area.

17. The display substrate according to claim 16, in, The edge portion has a first projection in a direction perpendicular to the substrate, and the portion of the pixel defining layer covering the first electrode has a second projection in a direction perpendicular to the substrate, wherein the distance between the inner edge and the outer edge of the first projection is greater than the distance between the inner edge and the outer edge of the second projection.

18. The display panel according to claim 16 or 17, in, The at least one sub-pixel includes sub-pixels of multiple colors, the color of each sub-pixel is defined by the color of the color filter of the sub-pixel, wherein the area ratio of the central part to the opening area of ​​the sub-pixel of at least one color is greater than that of the sub-pixels of other colors.

19. The display panel according to claim 18, in, The sub-pixels of multiple colors include a first sub-pixel having a color filter of a first color, a second sub-pixel having a color filter of a second color, and a third sub-pixel having a color filter of a third color. Among them, Src / Sr>Sgc / Sg>Sbc / Sb, wherein Sr represents the area of ​​the opening region of the first sub-pixel, Sg represents the area of ​​the opening region of the second sub-pixel, Sb represents the area of ​​the opening region of the third sub-pixel, Src represents the area of ​​the central part of the microlens of the first sub-pixel, Srg represents the area of ​​the central part of the microlens of the second sub-pixel, and Srb represents the area of ​​the central part of the microlens of the third sub-pixel.

20. The display panel according to claim 19, in, Sr<Sg<Sb.

21. The display panel according to claim 19 or 20, in, The first color is red, the second color is green, and the third color is blue.

22. The display panel according to any one of claims 16 to 21, in, Among sub-pixels of the same color, an area ratio of a central portion of a sub-pixel located in a central region of the display panel to an opening region is smaller than an area ratio of a central portion of a sub-pixel located in an edge region of the display panel to the opening region.

23. The display panel according to claim 22, in, Among sub-pixels of the same color, the area ratio of the central portion of each sub-pixel to the opening region gradually increases from the center to the edge of the display panel.

24. The display panel according to any one of claims 1 to 23, in, The central parts of the microlenses of sub-pixels of different colors are located in the same plane.

25. The display panel according to any one of claims 1 to 24, in, The microlenses in the sub-pixels are in contact with the color film.

26. The display panel according to claim 25, in, The bottom surfaces of the microlenses of sub-pixels of different colors have a height difference in a direction perpendicular to the base substrate, wherein the bottom surface of the microlens is the surface where the microlens contacts the color filter.

27. The display panel according to any one of claims 1 to 24, further comprising: include: A flat layer is located between the color film and the microlens of each sub-pixel.

28. The display panel according to any one of claims 1 to 27, in, Photolithography material is filled between adjacent microlenses, so that edge portions of the microlenses are covered by the photolithography material.

29. The display panel according to claim 28, in, The refractive index of the photolithographic material is smaller than the refractive index of the microlens.

30. The display panel according to claim 29, in, The refractive index of the photolithography material is in the range of 1.3-1.6, and the refractive index of the microlens is in the range of 1.6-2.

1.

31. A display panel, include: substrate substrate; At least one sub-pixel is arranged on the substrate. Wherein, the sub-pixel comprises: A light-emitting unit, comprising a first electrode, a second electrode and a light-emitting layer located between the first electrode and the second electrode, wherein the first electrode is located between the light-emitting layer and the base substrate; A micro lens, located on a side of the light emitting unit away from the substrate; The surface of the microlens on the side away from the substrate includes a central portion and an edge portion surrounding the central portion, wherein the central portion is a plane parallel to the substrate, and the edge portion is an arc surface protruding from the inside of the microlens to the outside; Wherein, the central portion and the edge portion both have a plurality of micro protrusions, and the height of the micro protrusions of the central portion is greater than the height of the micro protrusions of the edge portion.

32. The display panel according to claim 31, in, The height of the micro-protrusions in the central region of the central portion is greater than the height of the micro-protrusions in the edge region of the central portion.

33. The display panel according to claim 32, in, The height of each micro protrusion in the central portion gradually decreases from the center to the edge of the central portion.

34. The display panel according to any one of claims 31 to 33, in, The cross section of the micro protrusion in the central portion in a direction perpendicular to the substrate is triangular, arc-shaped or rectangular.

35. The display panel according to any one of claims 31 to 34, in, The micro protrusions of the central portion have a size in a direction parallel to the substrate in a range of 0.01 μm to 0.1 μm, and a size in a direction perpendicular to the substrate in a range of 5 nm to 50 nm.

36. The display panel according to any one of claims 31 to 35, in, The sub-pixel also includes a color film, which is located between the light-emitting unit and the microlens, wherein the color film has a plurality of micro-protrusions on a surface away from the substrate, and the height of the micro-protrusions located in the central area of ​​the surface of the color film is smaller than the height of the micro-protrusions located in the edge area of ​​the surface of the color film.

37. The display panel according to claim 36, in, The height of the micro-protrusions on the surface of the color film at the side away from the base substrate gradually increases from the center to the edge of the color film.

38. The display substrate according to claim 36 or 37, in, The height of the micro-protrusions of the color film in the central area of ​​the surface away from the substrate side is less than 5nm, and the height of the micro-protrusions of the color film in the edge area of ​​the surface away from the substrate side is in the range of 5nm to 50nm.

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