Electronic paper display panel and preparation method thereof

Abstract

The present application discloses an array substrate and a preparation method thereof and an electronic paper display panel, mainly relating to the field of display technology, wherein the array substrate is used in an electronic paper display panel, wherein a first metal layer, a first insulating layer, a second metal layer, a second insulating layer, a passivation layer and a pixel electrode layer are sequentially deposited on a flexible substrate; the array substrate further comprises a pixel region and a common electrode, wherein each pixel region corresponds to a common electrode, a pixel electrode groove is provided on the passivation layer, and the positive projection of the pixel electrode groove on the flexible substrate overlaps at least partially with the positive projection of the common electrode on the flexible substrate; the pixel electrode layer comprises a pixel electrode, wherein the pixel electrode portion is located in the pixel electrode groove; the array substrate comprises a bending region, wherein the direction of the flexible substrate toward the pixel electrode is defined as a first direction, and the cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction. Through the above design, the problem of grayscale reduction when the bending region is displayed is prevented, and the display effect is improved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to an array substrate and a preparation method thereof, and an electronic paper display panel. Background Art

[0002] With the development of digital technology, more and more display devices have entered people's lives, such as electronic paper (EP) display panels. Since electronic paper display panels can maintain display for a long time in the case of power failure, and have the advantages of lightness, thinness, low power consumption, and simple process, they are becoming more and more popular.

[0003] The current electronic paper display panels use a flexible substrate made of polyimide film that can be rolled up and folded. However, when the electronic paper display panel is in use, the grayscale of the display in the bending area will decrease. Summary of the invention

[0004] The purpose of the present application is to provide an array substrate and a preparation method thereof and an electronic paper display panel to prevent the problem of grayscale reduction when displaying in a bent area and improve the display effect.

[0005] The present application discloses an array substrate, which is used in an electronic paper display panel. The array substrate comprises 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;

[0006] The array substrate further includes a pixel area and a common electrode, each pixel area corresponds to a common electrode, and the common electrode is located in the first metal layer or the second metal layer, a pixel electrode groove is provided on the passivation layer, and the positive projection of the pixel electrode groove on the flexible substrate at least partially overlaps with the positive projection of the common electrode on the flexible substrate; the pixel electrode layer includes a pixel electrode, and the pixel electrode is partially located in the pixel electrode groove;

[0007] The array substrate comprises a bending region, and a direction of the flexible substrate toward the pixel electrode is defined as a first direction, and a cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction.

[0008] Optionally, the array substrate further includes two flat areas, which are respectively arranged on both sides of the bending area, and only the cross-sectional area of ​​the pixel electrode groove in the bending area decreases successively along the first direction.

[0009] Optionally, the area of ​​each common electrode is equal, and the area of ​​the common electrode is equal to the bottom area of ​​the pixel electrode groove in the flat area;

[0010] In the same pixel area in the flat area, the orthographic projection of the pixel electrode groove coincides with the orthographic projection of the common electrode; in the same pixel area in the bent area, the orthographic projection of the pixel electrode groove covers the orthographic projection of the common electrode.

[0011] Optionally, in the bending area, the pixel electrode groove includes four side walls connected in sequence, at least one of the side walls is inclined, and an angle between the inclined side wall and the bottom of the pixel electrode groove is an acute angle.

[0012] Optionally, in the bending area, the pixel electrode groove includes four side walls connected in sequence, two opposite side walls are inclined, and the angle between the inclined side walls and the bottom of the pixel electrode groove is an acute angle, and the angle between the other two opposite side walls and the bottom of the pixel electrode groove is a right angle.

[0013] Optionally, in the bending area, the pixel electrode groove includes four side walls connected in sequence, at least one of the side walls is provided with at least one first sub-slanted wall and at least one first sub-vertical wall, the angle between the first sub-slanted 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.

[0014] Optionally, only the first sub-slanted wall and the first sub-vertical wall are provided on each of the four side walls, and two adjacent side walls are defined as the first side wall and the second side wall, and the first sub-vertical wall on the first side wall is located between the first sub-slanted wall on the first side wall and the first sub-slanted wall on the second side wall.

[0015] The present application also discloses a method for preparing an array substrate, the method for preparing an array substrate is used to prepare an array substrate, the array substrate includes a bending area, and a direction of the flexible substrate toward the pixel electrode is defined as a first direction, and the steps include:

[0016] forming a first metal layer on the flexible substrate;

[0017] forming a first insulating layer on the first metal layer;

[0018] forming a second metal layer on the first insulating layer;

[0019] forming a second insulating layer on the second metal layer;

[0020] forming a passivation layer on the second insulating layer, and forming a pixel electrode groove on the passivation layer, wherein the cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction;

[0021] forming a pixel electrode layer on the passivation layer, wherein the pixel electrode layer includes a pixel electrode, and the pixel electrode portion is located in the pixel electrode groove to form the array substrate;

[0022] Wherein, the array substrate further includes a common electrode, and an orthographic projection of the pixel electrode groove on the flexible substrate at least partially overlaps with an orthographic projection of the common electrode on the flexible substrate.

[0023] Optionally, the step of forming a passivation layer on the second insulating layer, forming a pixel electrode groove on the passivation layer, and the cross-sectional area of ​​the pixel electrode groove in the bending region is sequentially reduced along the first direction comprises:

[0024] forming a first sub-passivation layer on the second insulating layer, and providing a first photolithography pattern on the first sub-passivation layer;

[0025] The first sub-passivation layer is etched to form a first sub-pixel electrode groove;

[0026] forming a second sub-passivation layer on the first sub-passivation layer;

[0027] Disposing a second photolithography pattern on the second sub-passivation layer;

[0028] etching the second sub-passivation layer to form a pixel electrode groove;

[0029] The area covered by the first photolithography pattern is defined as the first area, and the area covered by the second photolithography pattern is defined as the second area. The orthographic projection of the second area is located within the orthographic projection of the first area, and the area of ​​the first area is greater than that of the second area.

[0030] The present application also discloses an electronic paper display panel, which includes an electronic paper film and an array substrate. The electronic paper display panel also includes an adhesive layer, which is arranged between the electronic paper film and the array substrate to connect the electronic paper film and the array substrate. The array substrate is used to drive the electronic paper film to display an image.

[0031] Compared with the existing array substrate in which the angle between the side wall of the pixel electrode groove and the groove bottom is a right angle or an obtuse angle, the present application improves the pixel electrode groove in the bending area so that the cross-sectional area of ​​the pixel electrode groove in the bending area decreases successively along the first direction, thereby ensuring that there is a larger space under the pixel electrode, that is, a redundant space. After the optical glue is applied to bond the electronic paper film, the optical glue will not be completely filled into the interior of the pixel electrode groove. In this way, when the electronic paper display panel is bent and the space of the pixel electrode groove in the bending area becomes smaller, the optical glue can be squeezed to the position that was not originally filled, that is, the redundant space, without squeezing the upper electronic paper film, thereby avoiding causing the distance between the electronic paper film and the array substrate to become larger, preventing the problem of grayscale reduction during display, and improving the display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation methods of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0033] Figure 1 is a schematic diagram of an electronic paper display panel according to an embodiment of the present application;

[0034] Figure 2 is a plan view of an array substrate according to the first embodiment of the present application;

[0035] Figure 3 is a cross-sectional schematic diagram of a bending area of ​​an array substrate in the first embodiment of the present application;

[0036] Figure 4 is a schematic diagram of an array substrate including a flat area according to the first embodiment of the present application;

[0037] Figure 5 is a cross-sectional schematic diagram of an array substrate including a flat area according to the first embodiment of the present application;

[0038] Figure 6 is a schematic diagram of a pixel electrode groove including two inclined side walls according to the first embodiment of the present application;

[0039] Figure 7 is a schematic diagram of a pixel electrode groove of the second embodiment of the present application;

[0040] Figure 8 yes Figure 7 A schematic cross-sectional view of the pixel electrode groove along AA';

[0041] Fig. 9 yes Figure 7 A schematic cross-sectional view of the pixel electrode groove along BB';

[0042] Fig.10 It is a schematic diagram of a process of preparing an array substrate according to an embodiment of the present application;

[0043] Fig.11 is a schematic diagram of a process of a method for preparing an array substrate according to an embodiment of the present application;

[0044] Fig.12 It is a schematic flow chart of a method for preparing a pixel electrode groove according to an embodiment of the present application;

[0045] Fig.13 It is a schematic diagram of a process of preparing a pixel electrode groove according to an embodiment of the present application.

[0046] Among them, 10, electronic paper display panel; 11, electronic paper film; 12, adhesive layer; 13, common electrode; 100, array substrate; 110, bending area; 120, flat area; 210, flexible substrate; 220, first metal layer; 230, first insulating layer; 240, second metal layer; 250, second insulating layer; 260, passivation layer; 261, first sub-passivation layer; 262, second sub-passivation layer; 270, pixel electrode layer; 271, pixel electrode; 300, pixel electrode groove; 310, side wall; 311, first side wall; 312, second side wall; 320, first sub-oblique wall; 330, first sub-vertical wall; 340, first sub-pixel electrode groove; 400, common electrode; 510, first photolithography pattern; 520, second photolithography pattern; 610, pixel area; 710, redundant space; 810, first area; 82, second area. DETAILED DESCRIPTION

[0047] It should be understood that the terms used herein, the specific structures and functional details disclosed are only for describing specific embodiments and are representative, but the present application can be implemented in many alternative forms and should not be construed as being limited to only the embodiments described herein.

[0048] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, unless otherwise specified, features defined as "first" and "second" may explicitly or implicitly include one or more of the features; "plurality" means two or more. The term "including" and any variation thereof means non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components and / or combinations thereof may exist or be added.

[0049] In addition, terms indicating orientation or positional relationships, such as “center,” “lateral,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inside,” and “outside,” are described based on the orientation or relative positional relationships shown in the accompanying drawings and are merely simplified descriptions for the convenience of describing the present application. They do not indicate that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limitations on the present application.

[0050] In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internally connected between two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0051] The present application is described in detail below 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 the present application, such as Figure 1 As shown, the present 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, and the adhesive layer 12 is arranged between the electronic paper film 11 and the array substrate 100, and is used 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 a picture.

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

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

[0055] The electronic paper display panel 10 further includes a common electrode 13, which is disposed on a 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 to drive particles in the electronic paper film 11 to move up and down to reflect light for displaying images.

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

[0057] Embodiment 1:

[0058] Figure 2 is a plan view of an array substrate according to the first embodiment of the present application. Figure 3 is a cross-sectional schematic diagram of a bending region of an array substrate in the first embodiment of the present application, such as Figure 2-Figure 3 As shown, the present application discloses an array substrate 100, which is used in an electronic paper display panel 10, and 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 a pixel area 610 and a common electrode 400, each pixel area 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, and the orthographic projection of the pixel electrode groove 300 on the flexible substrate 210 overlaps with the orthographic projection of the common electrode 400 on the flexible substrate 210 at least partially; the pixel electrode layer 270 includes a pixel electrode 271, and the pixel electrode 271 is partially located in the pixel electrode groove 300 to reduce the distance between the pixel electrode 271 and the common electrode 400, thereby increasing the size of the storage capacitor between the pixel electrode 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 a direction from 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 the 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 the drain are located in the first metal layer 220. This application takes the active switch as a bottom-gate active switch as an example for explanation.

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

[0063] After 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 curved pixel electrode groove 300 will be close to each other, resulting in a decrease in the capacity of the pixel electrode groove 300, and the optical glue entering the pixel electrode groove 300 is accumulated, causing the optical glue to bulge upward in the direction away from the bottom of the pixel electrode groove 300, and squeeze the electronic paper film 11, resulting in a larger distance between the pixel electrode 271 and the common electrode 13 in the area, a reduced electric field force, and the electrophoretic particles cannot move into place, so when the electronic paper film 11 is controlled to reflect light, the grayscale will be reduced in this area when the picture is displayed. This area corresponds to the bending area 110 of the present application.

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

[0065] When the array substrate 100 of the present application is used in a curved electronic paper display panel 10 , the curved electronic paper display panel 10 needs to be bent on its entire surface, causing the pixel electrode grooves 300 on the entire surface to be deformed. In this case, the entire surface is defined as a bending area 110 .

[0066] Compared with the existing solution in which the angle between the side wall of the pixel electrode groove and the groove bottom in the array substrate is a right angle or an obtuse angle, the present application improves the pixel electrode groove 300 in the bending area 110 so that the cross-sectional area of ​​the pixel electrode groove 300 in the bending area 110 is reduced successively along the first direction, thereby ensuring that there is a larger space under the pixel electrode 271, namely, the redundant space 710. After the optical glue is applied to bond the electronic paper film 11, the optical glue will not be completely filled into the interior of the pixel electrode groove 300. In this way, when the electronic paper display panel 10 is bent and the space of the pixel electrode groove 300 in the bending area 110 becomes smaller, the optical glue can be squeezed to the position that was not originally filled, namely, the redundant space 710, without squeezing the upper electronic paper film 11, thereby avoiding causing the distance between the electronic paper film 11 and the array substrate 100 to increase, preventing the problem of grayscale reduction during display, and improving the display effect.

[0067] Figure 4 is a schematic diagram of an array substrate including a flat area according to the first embodiment of the present application, Figure 5 is a cross-sectional schematic diagram of an array substrate including a flat area according to the first embodiment of the present application, such as Figure 4-Figure 5 As shown, when the array substrate 100 is used in the electronic paper display panel 10 of a folding screen.

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

[0069] Specifically, the array substrate 100 also includes two flat areas 120, and the two flat areas 120 are respectively arranged on both sides of the bending area 110, and only the cross-sectional area of ​​the pixel electrode groove 300 in the bending area 110 decreases successively along the first direction, that is, the cross-sectional area of ​​the pixel electrode groove 300 in the flat area 120 remains unchanged or increases along the first direction.

[0070] That is, when the array substrate 100 is used in the electronic paper display panel 10 of a folding screen, the present application can only improve the pixel electrode groove 300 in the bending area 110 between the two flat areas 120, that is, the cross-sectional area of ​​the pixel electrode groove 300 in the bending area 110 is reduced successively in the direction from the flexible substrate 210 to 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 a folding screen, only the pixel electrode groove 300 in the bending area 110 between the two flat areas 120 is improved. Then, the bottom area of ​​the pixel electrode groove 300 in the bending area 110 will be larger than the bottom area of ​​the pixel electrode groove 300 in the flat area 120. This will cause the overlapping area between the pixel electrode 271 and the common electrode 400 at the bottom of the pixel electrode groove 300 in the bending area 110 to be larger than the overlapping area between the pixel electrode 271 and the common electrode 400 at the bottom of the pixel electrode groove 300 in the flat area 120, thereby causing a storage capacitance imbalance problem in the bending area 110 and the flat area 120.

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

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

[0075] Simply put, since the bottom area of ​​the pixel electrode groove 300 in the flat area 120 is smaller than the bottom area of ​​the pixel electrode groove 300 in the bending area 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 area 120 .

[0076] 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 area 610 in the flat area 120 can be made 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 area 610 in the bent area 110, thereby achieving uniformity in the capacity of the storage capacitor in each pixel area 610 of the entire surface.

[0077] In order to achieve that the cross-sectional area of ​​the pixel electrode groove 300 in the bending region 110 is reduced successively along the first direction, the present embodiment arranges the side wall 310 of the pixel electrode groove 300 at an angle. Specifically, in the bending region 110, the pixel electrode groove 300 includes four side walls 310 connected in sequence, wherein at least one of the side walls 310 is arranged at an angle, and the angle between the inclined side wall 310 and the bottom of the pixel electrode groove 300 is an acute angle.

[0078] By setting at least one of the side walls 310 at an angle, it can be ensured that the cross-sectional area of ​​the pixel electrode groove 300 decreases gradually along the first direction, and it can also be avoided that the pixel electrode 271 at the bottom of the pixel electrode groove 300 and the pixel electrodes 271 in other areas are disconnected due to the excessively large inclination angle when the side wall 310 is tilted, and it can also be avoided that the redundant space 710 is small due to the insufficient inclination angle when the side wall 310 is tilted.

[0079] Figure 6 is a schematic diagram of a pixel electrode groove including two inclined side walls according to the first embodiment of the present application, such as Figure 6 As shown, in the present embodiment, it is preferred that the pixel electrode groove 300 is only provided with two inclined side walls, and in the bending area 110, the pixel electrode groove 300 includes four side walls 310 connected in sequence, two opposite side walls 310 are inclined, and the angle between the inclined side walls 310 and the pixel electrode groove 300 is an acute angle, and the angle between the other two opposite side walls 310 and the bottom of the pixel electrode groove 300 is a right angle.

[0080] In simple terms, two inclined side walls 310 are provided at the same time, and the two inclined side walls 310 are relative to each other, so that when bending occurs, it can be ensured that the pixel electrode groove 300 has sufficient redundant space 710. Furthermore, the two inclined side walls 310 can be selected as the two side walls 310 on the left and right sides in the length direction of the folding area, so as to guide the optical glue in the pixel electrode groove 300 to move only to the left and right sides in the length direction of the folding line when squeezed, so as to avoid excessive stress concentration caused by squeezing to a single side.

[0081] Example 2

[0082] Figure 7 is a schematic diagram of a pixel electrode groove of the second embodiment of the present application, Figure 8 yes Figure 7 A schematic cross-sectional view of the pixel electrode groove along A-A', Fig. 9 yes Figure 7 A schematic cross-sectional view of the pixel electrode groove along BB' in FIG. Figure 7-Figure 9As shown, different from the first embodiment, the side wall 310 of the pixel electrode groove 300 in this embodiment includes a portion with an acute angle to the groove bottom and a portion with a right angle to the groove bottom, that is, one side wall 310 is not entirely inclined.

[0083] Specifically, in the bending area 110, the pixel electrode groove 300 includes four side walls 310 connected in sequence, at least one of the side walls 310 is provided with at least one first sub-slanted wall 320 and at least one first sub-vertical wall 330, the angle between the first sub-slanted 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, a portion of the side wall 310 is provided on each side wall 310, and the angle between the side wall 310 and the bottom of the groove is an acute angle, and the angle between the other portion of the side wall 310 and the bottom of the groove is a right angle. In simple terms, each side wall 310 is divided into two left and right parts, which are respectively defined as a first sub-vertical wall 330 and a first sub-slanted wall 320, that is, each of the side walls 310 is provided with a first sub-slanted wall 320 and a first sub-vertical wall 330, so that redundant space is provided in the four directions of the top, bottom, left and right of the pixel electrode groove 300 at the same time, and it can also ensure that the pixel electrode 271 at the bottom of the pixel electrode groove 300 can remain connected to the active switch.

[0085] Compared with the solution of the first embodiment, the solution of this embodiment is that a portion of the side walls 310 on each of the four side walls 310 has an acute angle with the bottom of the groove, and another portion has a right angle with the bottom of the groove. This ensures that there is redundant space in the four directions of up, down, left and right of the pixel electrode groove 300, and also ensures that the pixel electrode 271 at the bottom of the pixel electrode groove 300 is not disconnected from the pixel electrodes 271 at other positions, thereby ensuring that each pixel area 610 can participate in the display normally.

[0086] And when only the first sub-slanted wall 320 and the first sub-vertical wall 330 are provided on the four side walls 310, the 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-slanted wall 320 on the first side wall 311 and the first sub-slanted wall 320 on the second side wall 312.

[0087] This can prevent the redundant spaces 710 formed by the first sub-slanted walls 320 on two adjacent side walls 310 from being too close, causing the optical adhesive to move in one direction during bending, thereby preventing excessive stress concentration.

[0088] Fig.10is a schematic flow chart of a method for preparing an array substrate according to an embodiment of the present application. Fig.11 FIG. 1 is a schematic diagram of a process for preparing an array substrate according to an embodiment of the present application. Figure 10-11 As shown, the present application also discloses a method for preparing an array substrate 100, the method for preparing the array substrate 100 is used to prepare the array substrate 100, the array substrate 100 includes a bending area 110, and the direction of the flexible substrate 210 toward the pixel electrode 271 is defined as a first direction, and the steps include:

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

[0090] S2: forming a first insulating layer on the first metal layer;

[0091] S3: forming a second metal layer on the first insulating layer;

[0092] S4: forming a second insulating layer on the second metal layer;

[0093] S5: forming a passivation layer on the second insulating layer, and forming a pixel electrode groove on the passivation layer, wherein the cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction;

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

[0095] The array substrate 100 further includes a common electrode 400 , and 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 with the existing solution in which the angle between the side wall of the pixel electrode groove and the groove bottom in the array substrate is a right angle or an obtuse angle, the present application improves the pixel electrode groove 300 in the bending area 110 so that the cross-sectional area of ​​the pixel electrode groove 300 in the bending area 110 is reduced successively along the first direction, thereby ensuring that there is a larger space under the pixel electrode 271, namely, the redundant space 710. After the optical glue is applied to bond the electronic paper film 11, the optical glue will not be completely filled into the interior of the pixel electrode groove 300. In this way, when the electronic paper display panel 10 is bent and the space of the pixel electrode groove 300 in the bending area 110 becomes smaller, the optical glue can be squeezed to the position that was not originally filled, namely, the redundant space 710, without squeezing the upper electronic paper film 11, thereby avoiding causing the distance between the electronic paper film 11 and the array substrate 100 to increase, preventing the problem of grayscale reduction during display, and improving the display effect.

[0097] Fig.12 is a schematic flow chart of a method for preparing a pixel electrode groove according to an embodiment of the present application. Fig.13 FIG. 1 is a schematic diagram of a process for preparing a pixel electrode groove according to an embodiment of the present application. Figure 12-13 As shown, the step S5: forming a passivation layer on the second insulating layer, forming a pixel electrode groove on the passivation layer, and the step of sequentially reducing the cross-sectional area of ​​the pixel electrode groove in the bending region along the first direction includes:

[0098] S51: forming a first sub-passivation layer on the second insulating layer, and setting a first photolithography pattern on the first sub-passivation layer;

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

[0100] S53: forming a second sub-passivation layer on the first sub-passivation layer;

[0101] S54: Arranging a second photolithography pattern on the second sub-passivation layer;

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

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

[0104] Exemplarily, when it is necessary to form the pixel electrode groove 300 in the bending area 110 by etching so that the side wall 310 is inclined, and the angle between the inclined side wall 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 area 820 to coincide with the three edges of the projection of the first area 810, and to set a gap between the other edge of the projection of the second area 820 and the other edge of the projection of the first area 810.

[0105] Moreover, 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 irradiated, and the irradiation time is controlled, the second sub-passivation layer 262 on the upper surface of the first sub-passivation layer 261 is solidified, while the first sub-passivation layer 261 in the first sub-pixel electrode groove 340 is not solidified. In this way, it can be ensured that the shape of the etched pixel electrode groove 300 is that the side wall 310 is set at an angle.

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

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

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

[0109] It should be noted that the limitations on the various steps involved in this solution, without affecting the implementation of the specific solution, are not deemed to limit the order of the steps. The steps written in front can be executed first, or later, or even simultaneously. As long as this solution can be implemented, it should be deemed to fall within the scope of protection of this application.

[0110] It should be noted that the inventive concept of the present application can form a large number of embodiments, but the length of the application document is limited and it is impossible to list them one by one. Therefore, under the premise of no conflict, the embodiments or technical features described above can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effects will be enhanced.

[0111] The above content is a further detailed description of the present application in combination with specific optional implementation methods, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the concept of the present application, which should be deemed to fall within the scope of protection of the present application.

Claims

1. An electronic paper display panel, characterized in that: The electronic paper display panel comprises an electronic paper film and an array substrate, and the electronic paper display panel further comprises an adhesive layer, wherein the adhesive layer is arranged between the electronic paper film and the array substrate, and is used to connect the electronic paper film and the array substrate, and the array substrate is used to drive the electronic paper film to display images; The array substrate comprises 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 a pixel area and a common electrode, each pixel area corresponds to a common electrode, and the common electrode is located in the first metal layer or the second metal layer, a pixel electrode groove is provided on the passivation layer, and an orthographic projection of the pixel electrode groove on the flexible substrate at least partially overlaps with an 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 in the pixel electrode groove; The array substrate comprises a bending region, and a direction of the flexible substrate toward the pixel electrode is defined as a first direction, and a cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction.

2. The electronic paper display panel according to claim 1, characterized in that: The array substrate further includes two flat areas, which are respectively arranged on both sides of the bending area, and only the cross-sectional area of ​​the pixel electrode groove in the bending area decreases successively along the first direction.

3. The electronic paper display panel according to claim 2, characterized in that: The area of ​​each common electrode is equal, and the area of ​​the common electrode is equal to the bottom area of ​​the pixel electrode groove in the flat area; In the same pixel area in the flat area, the orthographic projection of the pixel electrode groove coincides with the orthographic projection of the common electrode; In the same pixel area within the bending area, the orthographic projection of the pixel electrode groove covers the orthographic projection of the common electrode.

4. The electronic paper display panel according to claim 1, characterized in that: In the bending region, the pixel electrode groove includes four side walls connected in sequence, at least one of the side walls is inclined, and an angle between the inclined side wall and the bottom of the pixel electrode groove is an acute angle.

5. The electronic paper display panel according to claim 1, characterized in that: In the bending area, the pixel electrode groove includes four side walls connected in sequence, two opposite side walls are inclined, and the angle between the inclined side walls and the bottom of the pixel electrode groove is an acute angle, and the angle between the other two opposite side walls and the bottom of the pixel electrode groove is a right angle.

6. The electronic paper display panel according to claim 1, characterized in that: In the bending area, the pixel electrode groove includes four side walls connected in sequence, at least one of the side walls is provided with at least one first sub-inclined wall and at least one first sub-vertical wall, the angle between the first sub-inclined 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.

7. The electronic paper display panel according to claim 6, characterized in that: Only the first sub-slanted wall and the first sub-vertical wall are provided on each of the four side walls, and 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-slanted wall on the first side wall and the first sub-slanted wall on the second side wall.

8. A method for preparing an electronic paper display panel, characterized in that: The method for preparing the electronic paper display panel is used to prepare the electronic paper display panel as claimed in any one of claims 1 to 7, wherein the array substrate includes a bending area, and a direction of the flexible substrate toward the pixel electrode is defined as a first direction, and the steps include: forming a first metal layer on the flexible substrate; forming a first insulating layer on the first metal layer; forming a second metal layer on the first insulating layer; forming a second insulating layer on the second metal layer; forming a passivation layer on the second insulating layer, and forming a pixel electrode groove on the passivation layer, wherein the cross-sectional area of ​​the pixel electrode groove in the bending region decreases sequentially along the first direction; forming a pixel electrode layer on the passivation layer, wherein the pixel electrode layer includes a pixel electrode, and the pixel electrode portion is located in the pixel electrode groove to form the array substrate; Wherein, the array substrate further includes a common electrode, and an orthographic projection of the pixel electrode groove on the flexible substrate at least partially overlaps with an orthographic projection of the common electrode on the flexible substrate.

9. The method for preparing an electronic paper display panel according to claim 8, characterized in that: The step of forming a passivation layer on the second insulating layer, forming a pixel electrode groove on the passivation layer, and the cross-sectional area of ​​the pixel electrode groove in the bending region is reduced in sequence along the first direction comprises: forming a first sub-passivation layer on the second insulating layer, and providing a first photolithography pattern on the first sub-passivation layer; The first sub-passivation layer is etched to form a first sub-pixel electrode groove; forming a second sub-passivation layer on the first sub-passivation layer; Disposing a second photolithography pattern on the second sub-passivation layer; etching the second sub-passivation layer to form a pixel electrode groove; The area covered by the first photolithography pattern is defined as the first area, and the area covered by the second photolithography pattern is defined as the second area. The orthographic projection of the second area is located within the orthographic projection of the first area, and the area of ​​the first area is greater than that of the second area.

Images