Array substrate and manufacturing method therefor, and electronic paper display panel

Abstract

The present application discloses an array substrate (100) and a manufacturing method therefor, and an electronic paper display panel (10). Pixel electrode recesses (300) are provided on a passivation layer (260), and the orthographic projection of each pixel electrode recess (300) on a flexible base (210) at least partially overlaps with the orthographic projection of a corresponding common electrode (400) on the flexible base (210); each pixel electrode (271) is partially located in the corresponding pixel electrode recess (300); the direction of the flexible base (210) facing the pixel electrodes (271) is defined as a first direction, and the cross-sectional area of the pixel electrode recess (300) in a bending region (110) sequentially decreases along the first direction. By means of the design, the problem of grayscale reduction in the bending region during display is prevented, and the display effect is improved.

Description

Array substrate and its fabrication method and electronic paper display panel

[0001] This application claims priority to Chinese Patent Application No. 2024115168899, filed on October 29, 2024, entitled “Array Substrate and Method for Fabrication Thereof and Electronic Paper Display Panel”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of display technology, and in particular to an array substrate, a method for fabricating the same, and an electronic paper display panel. Background Technology

[0003] With the development of digital technology, more and more display devices are entering people's lives, such as electronic paper (EP) display panels. Because electronic paper display panels can maintain display for a long time when the power is off, and have advantages such as being lightweight, thin, having low power consumption, and being simple to manufacture, they are becoming increasingly popular.

[0004] Current electronic paper display panels use flexible substrates made of polyimide film, which can be rolled up and folded. However, during use, the grayscale of the display in the bending area of ​​the electronic paper display panel will decrease. Summary of the Invention

[0005] The purpose of this application is to provide an array substrate, a method for fabricating the same, and an electronic paper display panel to prevent grayscale degradation during display in bent areas and improve display performance.

[0006] This application discloses an array substrate used in an electronic paper display panel. The array substrate includes a flexible substrate, a first metal layer, a first insulating layer, a second metal layer, a second insulating layer, a passivation layer, and a pixel electrode layer. The first metal layer, the first insulating layer, the second metal layer, the second insulating layer, the passivation layer, and the pixel electrode layer are sequentially deposited on the flexible substrate.

[0007] The array substrate further includes pixel regions and common electrodes. Each pixel region corresponds to a common electrode, and the common electrode is located in the first metal layer or the second metal layer. A pixel electrode trench is provided on the passivation layer. The orthographic projection of the pixel electrode trench on the flexible substrate at least partially overlaps with the orthographic projection of the common electrode on the flexible substrate. The pixel electrode layer includes a pixel electrode, and the pixel electrode portion is located within the pixel electrode trench.

[0008] The array substrate includes a bending region, and the direction of the flexible substrate toward the pixel electrode is defined as a first direction. The cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction.

[0009] Optionally, the array substrate further includes two flat regions, which are respectively disposed on both sides of the bending region, wherein the cross-sectional area of ​​the pixel electrode grooves in the bending region decreases sequentially along the first direction.

[0010] Optionally, each of the common electrodes has an equal area, and the area of ​​the common electrode is equal to the bottom area of ​​the pixel electrode groove in the flat region;

[0011] Within the same pixel region of the flat region, the orthographic projection of the pixel electrode groove coincides with the orthographic projection of the common electrode; within the same pixel region of the bent region, the orthographic projection of the pixel electrode groove covers the orthographic projection of the common electrode.

[0012] Optionally, within the bending area, the pixel electrode groove includes four sidewalls connected in sequence, at least one of the sidewalls being inclined, and the angle between the inclined sidewall and the bottom of the pixel electrode groove being an acute angle.

[0013] Optionally, within the bending area, the pixel electrode groove includes four sidewalls connected in sequence, two of which are inclined and the angle between the inclined sidewall and the bottom of the pixel electrode groove is acute, while the angle between the other two opposite sidewalls and the bottom of the pixel electrode groove is right.

[0014] Optionally, within the bending area, the pixel electrode groove includes four sidewalls connected in sequence, at least one of the sidewalls being provided with at least one first sub-sloping wall and at least one first sub-vertical wall, the angle between the first sub-sloping wall and the bottom of the pixel electrode groove being an acute angle, and the angle between the first sub-vertical wall and the bottom of the pixel electrode groove being a right angle.

[0015] Optionally, each of the four sidewalls is provided with only the first sub-inclined wall and the first sub-vertical wall, and two adjacent sidewalls are defined as the first sidewall and the second sidewall. The first sub-vertical wall on the first sidewall is located between the first sub-inclined wall on the first sidewall and the first sub-inclined wall on the second sidewall.

[0016] This application also discloses a method for fabricating an array substrate. The method is used to fabricate an array substrate, the array substrate including a bending region, and defining the direction of the flexible substrate toward the pixel electrode as a first direction. The steps include:

[0017] A first metal layer is formed on a flexible substrate;

[0018] A first insulating layer is formed on the first metal layer;

[0019] A second metal layer is formed on the first insulating layer;

[0020] A second insulating layer is formed on the second metal layer;

[0021] A passivation layer is formed on the second insulating layer, and a pixel electrode groove is formed on the passivation layer. The cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction.

[0022] A pixel electrode layer is formed on the passivation layer, the pixel electrode layer includes pixel electrodes, and the pixel electrode portion is located within the pixel electrode trench to form the array substrate;

[0023] The array substrate further includes a common electrode, wherein the orthographic projection of the pixel electrode groove on the flexible substrate at least partially overlaps with the orthographic projection of the common electrode on the flexible substrate.

[0024] Optionally, the step of forming a passivation layer on the second insulating layer, forming a pixel electrode groove on the passivation layer, and the step of the pixel electrode groove in the bending region having a progressively smaller cross-sectional area along the first direction includes:

[0025] A first sub-passivation layer is formed on the second insulating layer, and a first photolithographic pattern is formed on the first sub-passivation layer;

[0026] The first sub-pixel electrode groove is formed by etching the first sub-passivation layer;

[0027] A second sub-passivation layer is formed on the first sub-passivation layer;

[0028] A second photolithographic pattern is formed on the second sub-passivation layer;

[0029] The second sub-passivation layer is etched to form pixel electrode trenches;

[0030] The area covered by the first photolithographic pattern is defined as the first region, and the area covered by the second photolithographic pattern is defined as the second region. The orthographic projection of the second region is located within the orthographic projection of the first region, and the area of ​​the first region is larger than the area of ​​the second region.

[0031] This application also discloses an electronic paper display panel, which includes an electronic paper film and an array substrate. The electronic paper display panel further includes an adhesive layer disposed between the electronic paper film and the array substrate for connecting the electronic paper film and the array substrate. The array substrate is used to drive the electronic paper film to display an image.

[0032] Compared to existing array substrates where the sidewalls and bottoms of pixel electrode slots are at right or obtuse angles, this application improves the pixel electrode slots in the bending region by making the cross-sectional area of ​​the pixel electrode slots in the bending region decrease sequentially along the first direction. This ensures a larger space below the pixel electrode, i.e., redundant space. After applying optical adhesive to bond the electronic paper film, the optical adhesive will not completely fill the interior of the pixel electrode slot. Thus, when the electronic paper display panel is bent, and the space of the pixel electrode slot in the bending region becomes smaller, the optical adhesive can be squeezed to the previously unfilled position, i.e., the redundant space, without squeezing the upper electronic paper film. This avoids increasing the distance between the electronic paper film and the array substrate, preventing grayscale degradation during display, and improving the display effect. Attached Figure Description

[0033] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings:

[0034] Figure 1 is a schematic diagram of an electronic paper display panel according to an embodiment of this application;

[0035] Figure 2 is a plan view of an array substrate according to the first embodiment of this application;

[0036] Figure 3 is a cross-sectional schematic diagram of the bending region of an array substrate according to the first embodiment of this application;

[0037] Figure 4 is a schematic diagram of an array substrate including a flat region according to the first embodiment of this application;

[0038] Figure 5 is a cross-sectional schematic diagram of an array substrate including a flat region according to the first embodiment of this application;

[0039] Figure 6 is a schematic diagram of a pixel electrode groove including two inclined sidewalls according to the first embodiment of this application;

[0040] Figure 7 is a schematic diagram of a pixel electrode groove according to a second embodiment of this application;

[0041] Figure 8 is a schematic cross-sectional view of the pixel electrode groove in Figure 7 along A-A';

[0042] Figure 9 is a schematic cross-section of the pixel electrode groove along B-B' in Figure 7;

[0043] Figure 10 is a schematic flowchart of a method for fabricating an array substrate according to an embodiment of this application;

[0044] Figure 11 is a process diagram of a method for fabricating an array substrate according to an embodiment of this application;

[0045] Figure 12 is a schematic flowchart of a method for fabricating a pixel electrode groove according to an embodiment of this application;

[0046] Figure 13 is a process diagram of a pixel electrode groove fabrication method according to an embodiment of this application. Detailed Implementation

[0047] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0048] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean non-exclusive inclusion, where one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0049] In addition, terms such as “center,” “horizontal,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” that indicate orientation or positional relationship are based on the orientation or relative positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0050] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0051] The present application will now be described in detail with reference to the accompanying drawings and optional embodiments.

[0052] Figure 1 is a schematic diagram of an electronic paper display panel according to an embodiment of this application. As shown in Figure 1, this application discloses an electronic paper display panel 10, which includes an electronic paper film 11 and an array substrate 100. The electronic paper display panel 10 also includes an adhesive layer 12, which is disposed between the electronic paper film 11 and the array substrate 100 to connect the electronic paper film 11 and the array substrate 100. The array substrate 100 is used to drive the electronic paper film 11 to display images.

[0053] The adhesive layer 12 is made of optical adhesive. When bonding, optical adhesive is first applied to the side of the array substrate 100 where the pixel electrode layer 270 is disposed, and then the electronic paper film 11 is bonded to the array substrate 100.

[0054] The electronic paper film 11 can contain a microcapsule structure or an electrophoretic ink structure, which is not limited here. The microcapsules can be filled with black and white particles or colored particles, which is not limited here. The illustrations in this application use a microcapsule structure as an example.

[0055] The electronic paper display panel 10 also includes a common electrode 13, which is disposed on the side of the electronic paper film 11 away from the array substrate 100. An electric field is formed between the common electrode 13 and the pixel electrode 271, driving the particles in the electronic paper film 11 to move up and down to reflect light for displaying the image.

[0056] This application also discloses an array substrate 100, which can be used in the electronic paper display panel 10 described above. Regarding the array substrate 100, this application provides the following design, which is specifically described through several embodiments:

[0057] Example 1:

[0058] Figure 2 is a plan view of an array substrate according to the first embodiment of this application, and Figure 3 is a cross-sectional view of the bending region of an array substrate according to the first embodiment of this application. As shown in Figures 2 and 3, this application discloses an array substrate 100, which is used in an electronic paper display panel 10. The array substrate 100 includes a flexible substrate 210, a first metal layer 220, a first insulating layer 230, a second metal layer 240, a second insulating layer 250, a passivation layer 260, and a pixel electrode layer 270. The first metal layer 220, the first insulating layer 230, the second metal layer 240, the second insulating layer 250, the passivation layer 260, and the pixel electrode layer 270 are sequentially deposited on the flexible substrate 210.

[0059] The array substrate 100 further includes pixel regions 610 and common electrodes 400. Each pixel region 610 corresponds to a common electrode 400, and the common electrode 400 is located in the first metal layer 220 or the second metal layer 240. A pixel electrode groove 300 is provided on the passivation layer 260. The orthographic projection of the pixel electrode groove 300 on the flexible substrate 210 at least partially overlaps with the orthographic projection of the common electrode 400 on the flexible substrate 210. The pixel electrode layer 270 includes pixel electrodes 271, and the pixel electrodes 271 are partially located in the pixel electrode groove 300 to reduce the spacing between the pixel electrodes 271 and the common electrode 400, thereby increasing the size of the storage capacitance between the pixel electrodes 271 and the common electrode 400, so as to improve the display effect of the electronic paper display panel 10.

[0060] The array substrate 100 includes a bending region 110, and the direction of the flexible substrate 210 toward the pixel electrode 271 is defined as a first direction. The cross-sectional area of ​​the pixel electrode groove 300 in the bending region 110 decreases sequentially along the first direction.

[0061] The array substrate 100 also includes an active switch, which includes a bottom-gate active switch and a top-gate active switch. The pixel electrode 271 is connected to the drain of the active switch. When the active switch is a bottom-gate active switch, the gate of the active switch is located in the first metal layer 220, and the source and drain are located in the second metal layer 240. When the active switch is a top-gate active switch, the gate is located in the second metal layer 240, and the source and drain are located in the first metal layer 220. This application uses a bottom-gate active switch as an example for explanation.

[0062] Since a pixel electrode groove 300 is provided, and the sidewalls 310 of the pixel electrode grooves in the prior art are all vertically downward and perpendicular to the bottom of the groove or have an obtuse angle with the bottom of the groove, after the optical adhesive is applied between the electronic paper film 11 and the array substrate 100, the optical adhesive will quickly fill the pixel electrode groove 300.

[0063] When the array substrate 100 is used in a folded electronic paper display panel 10 or a curved electronic paper display panel 10, when the bending direction is consistent with the opening direction of the pixel electrode groove 300, the inner walls of the bent pixel electrode groove 300 will move closer together, causing the capacity of the pixel electrode groove 300 to decrease. This results in the accumulation of optical adhesive inside the pixel electrode groove 300, causing the optical adhesive to bulge upwards away from the bottom of the pixel electrode groove 300 and press against the electronic paper film 11. This increases the distance between the pixel electrode 271 and the common electrode 13 in this area, reduces the electric field force, and prevents electrophoretic particles from moving properly. Therefore, when controlling the electronic paper film 11 to reflect light, a grayscale reduction phenomenon will occur in this area when displaying the image. This area corresponds to the bending area 110 of this application.

[0064] It is understandable that when the electronic paper display panel 10 is bent, the pixel electrode groove 300 will find a deformed area, which is defined as the bending area 110 of this application.

[0065] When the array substrate 100 of this application is used in the curved electronic paper display panel 10, the curved electronic paper display panel 10 needs to be bent on the whole surface, which causes the pixel electrode grooves 300 on the whole surface to deform. At this time, the whole surface is defined as the bending area 110.

[0066] Compared to existing array substrates where the sidewalls and bottoms of pixel electrode slots are at right or obtuse angles, this application improves the pixel electrode slots 300 in the bending region 110 by making the cross-sectional area of ​​the pixel electrode slots 300 in the bending region 110 decrease sequentially along the first direction. This ensures that there is a larger space below the pixel electrode 271, i.e., a redundant space 710. After applying optical adhesive to bond the electronic paper film 11, the optical adhesive will not completely fill the interior of the pixel electrode slots 300. Thus, when the electronic paper display panel 10 is bent, and the space of the pixel electrode slots 300 in the bending region 110 becomes smaller, the optical adhesive can be squeezed to the previously unfilled position, i.e., the redundant space 710, without squeezing the upper electronic paper film 11. This avoids increasing the distance between the electronic paper film 11 and the array substrate 100, preventing grayscale degradation during display, and improving the display effect.

[0067] Figure 4 is a schematic diagram of an array substrate including a flat region according to the first embodiment of this application, and Figure 5 is a cross-sectional schematic diagram of an array substrate including a flat region according to the first embodiment of this application. As shown in Figures 4 and 5, when the array substrate 100 is used in the electronic paper display panel 10 of the foldable screen.

[0068] Since the electronic paper display panel 10 of the foldable screen is folded in half on the left and right sides, and the pixel electrode groove 300 in the folded area is deformed only, while the left and right sides remain flat, this embodiment defines the folded area as the bending area 110.

[0069] Specifically, the array substrate 100 further includes two flat regions 120, which are respectively disposed on both sides of the bending region 110. Only the cross-sectional area of ​​the pixel electrode groove 300 in the bending region 110 decreases sequentially along the first direction, that is, the cross-sectional area of ​​the pixel electrode groove 300 in the flat region 120 along the first direction remains unchanged or increases.

[0070] In other words, when the array substrate 100 is used in the electronic paper display panel 10 of the foldable screen, the pixel electrode groove 300 in the bending region 110 between the two flat regions 120 can be improved only. That is, the cross-sectional area of ​​the pixel electrode groove 300 in the bending region 110 is gradually reduced along the direction of the flexible substrate 210 toward the pixel electrode 271. In other words, the opening size of the pixel electrode groove 300 gradually decreases from bottom to top, thereby forming a redundant space 710 at the bottom of the pixel electrode groove 300.

[0071] After the electronic paper film 11 is bonded to the array substrate 100, the common electrode 400 is connected to the common electrode 13, and a storage capacitor is formed between the common electrode 400 and the pixel electrode 271.

[0072] Furthermore, when the array substrate 100 is used in the electronic paper display panel 10 of the foldable screen, if only the pixel electrode groove 300 in the bending region 110 between the two flat regions 120 is improved, the bottom area of ​​the pixel electrode groove 300 in the bending region 110 will be larger than the bottom area of ​​the pixel electrode groove 300 in the flat region 120. This will result in the overlap area between the pixel electrode 271 and the common electrode 400 at the bottom of the pixel electrode groove 300 in the bending region 110 being larger than the overlap area between the pixel electrode 271 and the common electrode 400 at the bottom of the pixel electrode groove 300 in the flat region 120. This will lead to an imbalance in storage capacitance between the bending region 110 and the flat region 120.

[0073] Therefore, by making the area of ​​each of the common electrodes 400 equal, and the area of ​​the common electrode 400 equal to the area of ​​the bottom of the pixel electrode groove 300 in the flat region 120.

[0074] In the same pixel region 610 within the flat region 120, the orthographic projection of the pixel electrode groove 300 coincides with the orthographic projection of the common electrode 400; in the same pixel region 610 within the bent region 110, the orthographic projection of the pixel electrode groove 300 covers the orthographic projection of the common electrode 400.

[0075] In simple terms, since the bottom area of ​​the pixel electrode groove 300 in the flat region 120 is smaller than the bottom area of ​​the pixel electrode groove 300 in the bent region 110, the area of ​​the common electrode 400 is set to be consistent with the bottom area of ​​the pixel electrode groove 300 in the flat region 120.

[0076] This ensures that the overlapping area between the pixel electrode 271 and the common electrode 400 at the bottom of the pixel electrode groove 300 in a single pixel region 610 within the flat region 120 is consistent with the overlapping area between the pixel electrode 271 and the common electrode 400 at the bottom of the pixel electrode groove 300 in a single pixel region 610 within the bent region 110, thereby achieving uniformity of the storage capacitor capacity in each pixel region 610 across the entire surface.

[0077] To achieve a sequential decrease in cross-sectional area along the first direction of the pixel electrode groove 300 within the bending region 110, this embodiment achieves this by tilting the sidewalls 310 of the pixel electrode groove 300. Specifically, within the bending region 110, the pixel electrode groove 300 includes four sequentially connected sidewalls 310, wherein at least one sidewall 310 is tilted, and the angle between the tilted sidewall 310 and the bottom of the pixel electrode groove 300 is an acute angle.

[0078] By tilting at least one of the sidewalls 310, it is possible to ensure that the cross-sectional area of ​​the pixel electrode groove 300 decreases sequentially along the first direction. It is also possible to avoid the pixel electrode 271 at the bottom of the pixel electrode groove 300 from being disconnected from the pixel electrode 271 in other areas due to an excessively large tilt angle when the sidewall 310 is tilted. It is also possible to avoid the situation where the redundant space 710 is small due to insufficient tilt angle when the sidewall 310 is tilted.

[0079] Figure 6 is a schematic diagram of a pixel electrode groove including two inclined sidewalls according to the first embodiment of this application. As shown in Figure 6, in this embodiment, the pixel electrode groove 300 is preferably provided with only two inclined sidewalls. In the bending area 110, the pixel electrode groove 300 includes four sidewalls 310 connected in sequence. Two opposite sidewalls 310 are inclined and the angle between the inclined sidewalls 310 and the pixel electrode groove 300 is an acute angle. The angle between the other two opposite sidewalls 310 and the bottom of the pixel electrode groove 300 is a right angle.

[0080] In simple terms, two inclined sidewalls 310 are set simultaneously, and the two inclined sidewalls 310 are also opposite each other. This ensures that the pixel electrode groove 300 has sufficient redundant space 710 when bending occurs. Furthermore, the two inclined sidewalls 310 can be selected as the left and right sidewalls 310 on the left and right sides in the length direction of the folded area, so as to guide the optical adhesive in the pixel electrode groove 300 to move only to the left and right sides in the length direction of the fold line when squeezed, avoiding excessive stress concentration caused by squeezing to one side.

[0081] Example 2

[0082] Figure 7 is a schematic diagram of a pixel electrode groove according to the second embodiment of this application. Figure 8 is a cross-sectional schematic diagram of the pixel electrode groove in Figure 7 along A-A'. Figure 9 is a cross-sectional schematic diagram of the pixel electrode groove in Figure 7 along B-B'. As shown in Figures 7-9, unlike the first embodiment, the sidewall 310 of the pixel electrode groove 300 in this embodiment includes a portion with an acute angle to the bottom of the groove and a portion with a right angle to the bottom of the groove. That is, a sidewall 310 is not entirely inclined.

[0083] Specifically, within the bending region 110, the pixel electrode groove 300 includes four sidewalls 310 connected in sequence. At least one of the sidewalls 310 is provided with at least one first sub-sloping wall 320 and at least one first sub-vertical wall 330. The angle between the first sub-sloping wall 320 and the bottom of the pixel electrode groove 300 is an acute angle, and the angle between the first sub-vertical wall 330 and the bottom of the pixel electrode groove 300 is a right angle.

[0084] Preferably, each sidewall 310 has a portion where the angle between the sidewall 310 and the bottom of the groove is acute, and another portion where the angle between the sidewall 310 and the bottom of the groove is right. Simply put, each sidewall 310 is divided into two parts, left and right, which are defined as the first sub-vertical wall 330 and the first sub-sloping wall 320, respectively. That is, each sidewall 310 has a first sub-sloping wall 320 and a first sub-vertical wall 330, so that there is redundant space in the four directions of the pixel electrode groove 300, and the pixel electrode 271 at the bottom of the pixel electrode groove 300 can be kept connected to the active switch.

[0085] Compared to the solution in the first embodiment, the solution in this embodiment, by providing a portion of each of the four sidewalls 310 with an acute angle between the sidewall 310 and the bottom of the slot, and another portion with a right angle between the sidewall 310 and the bottom of the slot, ensures that there is redundant space in the four directions of the pixel electrode slot 300, and also ensures that the pixel electrode 271 at the bottom of the slot 300 is not disconnected from the pixel electrodes 271 at other locations, thus ensuring that each pixel area 610 can participate in the display normally.

[0086] Furthermore, when only the first sub-inclined wall 320 and the first sub-vertical wall 330 are provided on each of the four side walls 310, two adjacent side walls 310 are defined as the first side wall 311 and the second side wall 312, and the first sub-vertical wall 330 on the first side wall 311 is located between the first sub-inclined wall 320 on the first side wall 311 and the first sub-inclined wall 320 on the second side wall 312.

[0087] This avoids the redundant space 710 formed by the first sub-sloping wall 320 on two adjacent sidewalls 310 being too close, causing the optical adhesive to move in one direction during bending, thus avoiding excessive stress concentration.

[0088] Figure 10 is a flowchart illustrating a method for fabricating an array substrate according to an embodiment of this application, and Figure 11 is a process diagram illustrating a method for fabricating an array substrate according to an embodiment of this application. As shown in Figures 10 and 11, this application also discloses a method for fabricating an array substrate 100. The method for fabricating an array substrate 100 is used to fabricate an array substrate 100, which includes a bending region 110. The direction of the flexible substrate 210 toward the pixel electrode 271 is defined as a first direction. The steps include:

[0089] S1: Forming a first metal layer on a flexible substrate;

[0090] S2: A first insulating layer is formed on the first metal layer;

[0091] S3: A second metal layer is formed on the first insulating layer;

[0092] S4: A second insulating layer is formed on the second metal layer;

[0093] S5: A passivation layer is formed on the second insulating layer, and a pixel electrode groove is formed on the passivation layer. The cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction.

[0094] S6: A pixel electrode layer is formed on the passivation layer, the pixel electrode layer includes a pixel electrode, and the pixel electrode portion is located in the pixel electrode trench to form the array substrate;

[0095] The array substrate 100 further includes a common electrode 400, wherein the orthographic projection of the pixel electrode groove 300 on the flexible substrate 210 at least partially overlaps with the orthographic projection of the common electrode 400 on the flexible substrate 210.

[0096] Compared to existing array substrates where the sidewalls and bottoms of pixel electrode slots are at right or obtuse angles, this application improves the pixel electrode slots 300 in the bending region 110 by making the cross-sectional area of ​​the pixel electrode slots 300 in the bending region 110 decrease sequentially along the first direction. This ensures that there is a larger space below the pixel electrode 271, i.e., a redundant space 710. After applying optical adhesive to bond the electronic paper film 11, the optical adhesive will not completely fill the interior of the pixel electrode slots 300. Thus, when the electronic paper display panel 10 is bent, and the space of the pixel electrode slots 300 in the bending region 110 becomes smaller, the optical adhesive can be squeezed to the previously unfilled position, i.e., the redundant space 710, without squeezing the upper electronic paper film 11. This avoids increasing the distance between the electronic paper film 11 and the array substrate 100, preventing grayscale degradation during display, and improving the display effect.

[0097] Figure 12 is a flowchart illustrating a method for fabricating a pixel electrode groove according to an embodiment of this application, and Figure 13 is a process diagram illustrating a method for fabricating a pixel electrode groove according to an embodiment of this application. As shown in Figures 12 and 13, step S5: forming a passivation layer on the second insulating layer, forming a pixel electrode groove on the passivation layer, and the step of the pixel electrode groove in the bending region having a progressively smaller cross-sectional area along the first direction includes:

[0098] S51: A first sub-passivation layer is formed on the second insulating layer, and a first photolithographic pattern is formed on the first sub-passivation layer;

[0099] S52: Etching the first sub-passivation layer to form the first sub-pixel electrode groove;

[0100] S53: A second sub-passivation layer is formed on the first sub-passivation layer;

[0101] S54: A second photolithographic pattern is formed on the second sub-passivation layer;

[0102] S55: Etching the second sub-passivation layer to form a pixel electrode trench;

[0103] The area covered by the first photolithographic pattern 510 is defined as the first region 810, and the area covered by the second photolithographic pattern 520 is defined as the second region 820. The orthographic projection of the second region 820 is located within the orthographic projection of the first region 810, and the area of ​​the first region 810 is larger than the area of ​​the second region 820.

[0104] For example, when it is necessary to etch the pixel electrode groove 300 in the bending region 110 into an inclined arrangement of the sidewall 310, and the angle between the inclined sidewall 310 and the bottom of the pixel electrode groove 300 is an acute angle, it is only necessary to control the three edges of the projection of the second region 820 to coincide with the three edges of the projection of the first region 810, and to set a gap between the other edge of the projection of the second region 820 and the other edge of the projection of the first region 810.

[0105] Furthermore, when the second sub-passivation layer 262 is set on the first sub-passivation layer 261, the first sub-pixel electrode groove 340 will also be filled with the second sub-passivation layer 262. Then, when the area outside the second photolithography pattern 520 is illuminated, and the illumination time is controlled, the second sub-passivation layer 262 on the upper surface of the first sub-passivation layer 261 is cured, while the first sub-passivation layer 261 in the first sub-pixel electrode groove 340 is not cured. In this way, it can be ensured that the etched pixel electrode groove 300 is shaped such that the sidewall 310 is inclined.

[0106] For example, when the two opposite sidewalls 310 that need to form the pixel electrode groove 300 are both inclined, that is, the two opposite sidewalls 310 are inclined and the angle between the inclined sidewalls 310 and the pixel electrode groove 300 is an acute angle, and the angle between the other two opposite sidewalls 310 and the bottom of the pixel electrode groove 300 is a right angle.

[0107] At this point, it is only necessary to control the two opposite edges of the projection of the second region 820 to coincide with the two opposite edges of the projection of the first region 810, and to set a gap between the other two opposite edges of the projection of the second region 820 and the other two opposite edges of the projection of the first region 810 for photolithography.

[0108] For example, when the shape of the pixel electrode groove 300 needs to be formed, each sidewall 310 is provided with a portion of the sidewall 310 having an acute angle between it and the bottom of the groove, and the other portion of the sidewall 310 having a right angle between it and the bottom of the groove; the shape of the first photolithographic pattern 510 includes a main body and four protrusions, the main body is rectangular, and the four protrusions are respectively provided on the four sides of the main body; the shape of the second photolithographic pattern 520 is consistent with the main body pattern of the first photolithographic pattern 510. When etching the pixel electrode groove 300, the first sub-passivation layer 261 is etched first with the first photolithographic pattern 510, and then the second sub-passivation layer 262 is etched with the second photolithographic pattern 520. It is necessary to keep the orthographic projection of the second photolithographic pattern 520 coincides with the orthographic projection of the main body of the first photolithographic pattern 510.

[0109] It should be noted that the limitations on each step involved in this solution are not considered as limiting the order of steps, provided that they do not affect the implementation of the specific solution. The steps listed first can be executed first, later, or even simultaneously. As long as this solution can be implemented, it should be considered to fall within the scope of protection of this application.

[0110] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.

[0111] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. An array substrate, wherein, The array substrate is used in an electronic paper display panel. The array substrate includes a flexible substrate, a first metal layer, a first insulating layer, a second metal layer, a second insulating layer, a passivation layer, and a pixel electrode layer. The first metal layer, the first insulating layer, the second metal layer, the second insulating layer, the passivation layer, and the pixel electrode layer are sequentially deposited on the flexible substrate. The array substrate further includes pixel regions and common electrodes. Each pixel region corresponds to a common electrode, and the common electrode is located in the first metal layer or the second metal layer. A pixel electrode trench is provided on the passivation layer. The orthographic projection of the pixel electrode trench on the flexible substrate at least partially overlaps with the orthographic projection of the common electrode on the flexible substrate. The pixel electrode layer includes pixel electrodes, and the pixel electrode portion is located within the pixel electrode groove; The array substrate includes a bending region, and the direction of the flexible substrate toward the pixel electrode is defined as a first direction. The cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction.

2. The array substrate according to claim 1, wherein, The array substrate further includes two flat regions, which are respectively disposed on both sides of the bending region, and the cross-sectional area of ​​the pixel electrode grooves in the bending region decreases sequentially along the first direction.

3. The array substrate according to claim 2, wherein, Each of the common electrodes has an equal area, and the area of ​​the common electrode is equal to the area of ​​the bottom of the pixel electrode groove in the flat area; Within the same pixel region of the flat area, the orthographic projection of the pixel electrode slot coincides with the orthographic projection of the common electrode; Within the same pixel region of the bending area, the orthographic projection of the pixel electrode groove overlaps the orthographic projection of the common electrode.

4. The array substrate according to claim 2, wherein, The cross-sectional area of ​​the pixel electrode groove within the flat region remains constant along the first direction.

5. The array substrate according to claim 2, wherein, The cross-sectional area of ​​the pixel electrode groove in the flat area increases along the first direction.

6. The array substrate according to claim 1, wherein, Within the bending area, the pixel electrode groove includes four sidewalls connected in sequence, at least one of the sidewalls being inclined, and the angle between the inclined sidewall and the bottom of the pixel electrode groove being an acute angle.

7. The array substrate according to claim 1, wherein, Within the bending area, the pixel electrode groove includes four sidewalls connected in sequence. Two of the opposite sidewalls are inclined, and the angle between the inclined sidewalls and the bottom of the pixel electrode groove is an acute angle. The angle between the other two opposite sidewalls and the bottom of the pixel electrode groove is a right angle.

8. The array substrate according to claim 7, wherein, The two inclined sidewalls are the left and right sidewalls on the left and right sides along the length of the folded area.

9. The array substrate according to claim 1, wherein, Within the bending area, the pixel electrode groove includes four sidewalls connected in sequence. At least one of the sidewalls is provided with at least one first sub-sloping wall and at least one first sub-vertical wall. The angle between the first sub-sloping wall and the bottom of the pixel electrode groove is an acute angle, and the angle between the first sub-vertical wall and the bottom of the pixel electrode groove is a right angle.

10. The array substrate according to claim 9, wherein, Each of the four side walls is provided with only the first sub-inclined wall and the first sub-vertical wall. Two adjacent side walls are defined as the first side wall and the second side wall. The first sub-vertical wall on the first side wall is located between the first sub-inclined wall on the first side wall and the first sub-inclined wall on the second side wall.

11. The array substrate according to claim 8, wherein, Each of the aforementioned sidewalls is provided with a first sub-sloping wall and a first sub-vertical wall.

12. A method for fabricating an array substrate, wherein, The method for fabricating the array substrate is used to fabricate the array substrate as described in any one of claims 1-11, wherein the array substrate includes a bending region, and the direction of the flexible substrate toward the pixel electrode is defined as a first direction, and the steps include: A first metal layer is formed on a flexible substrate; A first insulating layer is formed on the first metal layer; A second metal layer is formed on the first insulating layer; A second insulating layer is formed on the second metal layer; A passivation layer is formed on the second insulating layer, and a pixel electrode groove is formed on the passivation layer. The cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction. A pixel electrode layer is formed on the passivation layer, the pixel electrode layer includes pixel electrodes, and the pixel electrode portion is located within the pixel electrode trench to form the array substrate; The array substrate further includes a common electrode, wherein the orthographic projection of the pixel electrode groove on the flexible substrate at least partially overlaps with the orthographic projection of the common electrode on the flexible substrate.

13. The method for fabricating an array substrate according to claim 12, wherein, The step of forming a passivation layer on the second insulating layer, forming a pixel electrode groove on the passivation layer, and wherein the cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction includes: A first sub-passivation layer is formed on the second insulating layer, and a first photolithographic pattern is formed on the first sub-passivation layer; The first sub-pixel electrode groove is formed by etching the first sub-passivation layer; A second sub-passivation layer is formed on the first sub-passivation layer; A second photolithographic pattern is formed on the second sub-passivation layer; The second sub-passivation layer is etched to form pixel electrode trenches; The area covered by the first photolithographic pattern is defined as the first region, and the area covered by the second photolithographic pattern is defined as the second region. The orthographic projection of the second region is located within the orthographic projection of the first region, and the area of ​​the first region is larger than the area of ​​the second region.

14. The method for fabricating an array substrate according to claim 13, wherein, When the pixel electrode groove needs to be etched into a sidewall that is tilted, and the angle between the tilted sidewall and the bottom of the pixel electrode groove is an acute angle, the three edges of the projection of the second region are controlled to coincide with the three edges of the projection of the first region, and a gap is provided between the other edge of the projection of the second region and the other edge of the projection of the first region.

15. The method for fabricating an array substrate according to claim 13, wherein, When it is necessary to set the two opposite sidewalls of the pixel electrode groove at an angle, and the angle between the angled sidewalls and the pixel electrode groove is an acute angle, and the angle between the other two opposite sidewalls and the bottom of the pixel electrode groove is a right angle, the two opposite edges of the second region projection are controlled to coincide with the two opposite edges of the first region projection, and a gap is set between the other two opposite edges of the second region projection and the other two opposite edges of the first region projection for photolithography.

16. An electronic paper display panel, wherein, The electronic paper display panel includes an electronic paper film and an array substrate as described in any one of claims 1-11. The electronic paper display panel further includes an adhesive layer disposed between the electronic paper film and the array substrate for connecting the electronic paper film and the array substrate. The array substrate is used to drive the electronic paper film to display an image.

17. The electronic paper display panel according to claim 16, wherein, The electronic paper display panel also includes a common electrode, which is disposed on the side of the electronic paper film facing away from the array substrate, and an electric field is formed between the common electrode and the pixel electrode.

18. The electronic paper display panel according to claim 16, wherein, The adhesive layer is made of optical adhesive.

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