Electrowetting display panel and preparation method thereof, and display device

Abstract

The present disclosure provides an electrowetting display panel and a preparation method and a display device thereof. In the electrowetting display panel, a pixel wall is arranged on the surface of the first substrate facing the second substrate to define a plurality of pixel spaces, and the pixel spaces are filled with non-polar liquid and polar liquid; the first substrate includes: a first substrate, a pixel electrode layer and a hydrophobic layer stacked in sequence along the direction from the first substrate to the second substrate, the pixel electrode layer includes a plurality of pixel electrodes corresponding to the plurality of pixel spaces one by one, the surface of the hydrophobic layer away from the first substrate includes a plurality of groove-shaped areas corresponding to the plurality of pixel spaces one by one, the pixel electrodes are arranged opposite to the corresponding pixel spaces, and the groove-shaped areas are arranged opposite to the corresponding pixel spaces; the second substrate includes: a common electrode. The brightness and contrast of the electrowetting display panel are enhanced.

Description

Technical Field

[0001] The present disclosure belongs to the field of display technology, and particularly relates to an electrowetting display panel and a preparation method thereof, and a display device. Background Art

[0002] This section is intended to provide a background or context to the embodiments recited in the claims. No admission is made that the description herein is prior art by inclusion in this section.

[0003] Wetting is the process in which one fluid on a solid surface is replaced by another fluid. If a liquid can spread on a solid surface and the solid-liquid contact surface tends to expand, that is, the adhesion of the liquid to the solid surface is greater than its cohesion, this is wetting. If a liquid cannot spread on a solid surface and the contact surface tends to shrink into a sphere, this is non-wetting. Non-wetting means that the adhesion of the liquid to the solid surface is less than its cohesion. Electrowetting (Electrowetting, EW) refers to the phenomenon of changing the wettability of a droplet on a substrate by changing the voltage between the droplet and the insulating substrate, that is, changing the contact angle, causing the droplet to deform and displace.

[0004] In a pixel space of an electrowetting display panel, there are non-polar liquid and polar liquid, which are immiscible. Voltage can change the wetting angle between the polar liquid and the hydrophobic layer, thereby driving the non-polar liquid to move. When the non-polar liquid is spread on the hydrophobic layer, the pixel space is dark; when the non-polar liquid shrinks together, the pixel space is bright. When the pixel space is bright, the non-polar liquid occupies a certain display area, which makes the display reflectivity low and the contrast low. Summary of the invention

[0005] The present disclosure provides an electrowetting display panel and a manufacturing method thereof, and a display device.

[0006] The present invention adopts the following technical solution: an electrowetting display panel, comprising: a pixel wall, a first substrate and a second substrate arranged opposite to each other;

[0007] The pixel walls are arranged on a surface of the first substrate facing the second substrate to define a plurality of pixel spaces, wherein the pixel spaces are filled with a non-polar liquid and a polar liquid;

[0008] The first substrate comprises: a first base, a pixel electrode layer and a hydrophobic layer which are sequentially stacked in a direction from the first substrate to the second substrate, the pixel electrode layer comprises a plurality of pixel electrodes corresponding to the plurality of pixel spaces one by one, a surface of the hydrophobic layer away from the first substrate comprises a plurality of groove-shaped regions corresponding to the plurality of pixel spaces one by one, the pixel electrodes are arranged opposite to the corresponding pixel spaces, and the groove-shaped regions are arranged opposite to the corresponding pixel spaces;

[0009] The second substrate includes: a common electrode.

[0010] In some embodiments, a plurality of blind holes corresponding to the plurality of pixel spaces are disposed on a surface of the first substrate on a side close to the second substrate, the blind holes are disposed opposite to the corresponding pixel spaces, and the groove-shaped area is located at the position of the blind holes.

[0011] In some embodiments, a ratio of the depth of the blind hole to the thickness of the first substrate is in a range of 19% to 43%.

[0012] In some embodiments, the orthographic projection of the pixel electrode on the first substrate covers and exceeds the corresponding blind hole.

[0013] In some embodiments, the hydrophobicity in the region of the hydrophobic layer opposite to the pixel space is non-uniformly distributed, so as to guide the non-polar liquid to move toward the groove-shaped region.

[0014] In some embodiments, the area where the hydrophobic layer is opposite to the pixel space includes multiple sub-areas, the hydrophobicity of the hydrophobic layer in the same sub-area is the same, and the hydrophobicity of the hydrophobic layer in any two sub-areas, the sub-area closer to the groove-shaped area has a stronger hydrophobicity.

[0015] In some embodiments, the opening area of ​​the blind hole gradually increases from the bottom of the blind hole to the top of the blind hole.

[0016] In some embodiments, the blind hole is located at a corner of the corresponding pixel space.

[0017] In some embodiments, the first substrate further includes pixel circuits connected to the pixel electrodes in a one-to-one correspondence.

[0018] In some embodiments, the first substrate further includes a passivation layer covering the pixel electrode layer, and the passivation layer is located on a side of the hydrophobic layer close to the first base.

[0019] The present invention adopts the following technical solution: a method for preparing an electrowetting display panel, comprising:

[0020] forming a first substrate, the first substrate comprising: a first base, a pixel electrode layer and a hydrophobic layer stacked in sequence, the pixel electrode layer comprising a plurality of pixel electrodes, a surface of the hydrophobic layer away from the first base comprising a plurality of groove-shaped regions corresponding to the plurality of pixel electrodes one by one, the groove-shaped regions being arranged opposite to the corresponding pixel electrodes;

[0021] forming a pixel wall on the hydrophobic layer, wherein the pixel wall defines a plurality of pixel spaces corresponding to the plurality of pixel electrodes one by one, the groove-shaped region is arranged opposite to the corresponding pixel space, and the pixel electrode is arranged opposite to the corresponding pixel space;

[0022] The pixel space is filled with non-polar liquid and polar liquid, and a second substrate is arranged above the opening of the pixel space, wherein the second substrate includes a common electrode.

[0023] In some embodiments, in the step of forming the first substrate, a plurality of blind holes corresponding to the plurality of pixel spaces are formed on a surface of the first substrate on a side close to the second substrate, the blind holes are arranged opposite to the corresponding pixel spaces, and the groove-shaped area is located at the position of the blind holes.

[0024] In some embodiments, in the step of forming the first substrate, the blind hole is formed by a dry etching process, and then the inner wall of the blind hole is smoothed by a wet etching process.

[0025] In some embodiments, after forming the pixel wall on the hydrophobic layer and before filling the pixel space with the non-polar liquid and the polar liquid, the preparation method further comprises:

[0026] Performing a heating reflux treatment on the hydrophobic layer;

[0027] At least part of the hydrophobic layer facing the pixel space is divided into sub-regions for plasma modification treatment of different durations, wherein, for any two sub-regions of the hydrophobic layer facing the pixel space, the sub-region farther from the corresponding blind hole has a longer plasma modification time.

[0028] The present disclosure adopts the following technical solution: a display device, including the aforementioned electrowetting display panel, or including the electrowetting display panel obtained by the aforementioned preparation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of a pixel space in an off state of the electrowetting display panel provided by an embodiment of the present disclosure.

[0030] Figure 2 This is a schematic diagram of a pixel space in an on state of the electrowetting display panel provided by an embodiment of the present disclosure.

[0031] Figure 3 It is a schematic flow chart of a method for preparing an electrowetting display panel provided in an embodiment of the present disclosure.

[0032] Figure 43 is a top perspective view of a first substrate in an electrowetting display panel provided by an embodiment of the present disclosure, wherein the pixel space shown therein is in a fully open state.

[0033] Figure 5 3 is a top perspective view of a first substrate in an electrowetting display panel provided by an embodiment of the present disclosure, wherein the pixel space shown therein is in a partially opened state.

[0034] Figure 6 3 is a top perspective view of a first substrate in an electrowetting display panel provided by an embodiment of the present disclosure, wherein the pixel space shown therein is in a completely closed state.

[0035] The figures are marked as follows: 1. first substrate; 11. gate; 12. gate insulating layer; 13. active layer; 14. first source and drain; 15. second source and drain; 16. pixel electrode; 17. passivation layer; 18. hydrophobic layer; 18a-18e, sub-areas divided by the hydrophobic layer; 2. pixel wall; 3. non-polar liquid; 4. polar liquid; 5. second substrate; 51. common electrode; GL, gate line; DL, data line; T, transistor. DETAILED DESCRIPTION

[0036] The present disclosure is further described below in conjunction with the embodiments shown in the accompanying drawings.

[0037] Figure 1 This is a schematic diagram of a pixel space in an off state of the electrowetting display panel provided by an embodiment of the present disclosure. Figure 2 This is a schematic diagram of a pixel space in an on state of the electrowetting display panel provided by an embodiment of the present disclosure.

[0038] Combination Figure 1 and Figure 2 An embodiment of the present disclosure provides an electrowetting display panel, comprising: a pixel wall 2, a first substrate and a second substrate arranged opposite to each other.

[0039] The pixel walls 2 are arranged on the surface of the first substrate facing the second substrate to define a plurality of pixel spaces, and the pixel spaces are filled with non-polar liquid 3 and polar liquid 4 .

[0040] In some embodiments, the polar liquid 4 comprises an aqueous solution and the non-polar liquid 3 comprises a hydrophobic ink.

[0041] The pixel wall 2 is a hydrophilic structure. In some embodiments, the pixel wall 2 is formed by photoresist through an exposure and development process.

[0042] Figure 1 and Figure 2 In the illustrated embodiment, a gap is left between the pixel wall 2 and the second substrate, and the polar liquid 4 is integrated in the electrowetting display panel.

[0043] In some other embodiments, the pixel wall 2 connects the first substrate and the second substrate, and the pixel space is a closed space.

[0044] The first substrate includes: a first substrate 1, a pixel electrode layer and a hydrophobic layer 18 which are stacked in sequence along a direction from the first substrate to the second substrate, the pixel electrode layer includes a plurality of pixel electrodes 16 corresponding one-to-one to the plurality of pixel spaces, a plurality of blind holes corresponding one-to-one to the plurality of pixel spaces are arranged on a surface of the first substrate 1 on a side close to the second substrate 5, the blind holes are arranged opposite to the corresponding pixel spaces, the pixel electrodes 16 are arranged opposite to the corresponding pixel spaces, the orthographic projection of the pixel electrodes 16 on the first substrate 1 covers and exceeds the corresponding blind holes, and the surface of the hydrophobic layer 18 away from the first substrate 1 is in a groove shape at the position of the blind holes.

[0045] In some embodiments, the first substrate 1 is a glass substrate.

[0046] In some embodiments, the ratio of the depth of the blind hole to the thickness of the first substrate 1 is in the range of 19% to 43%. If the depth of the blind hole is too small, the effect of improving the contrast is not obvious. If the depth of the blind hole is too large, the structural stability of the first substrate is affected.

[0047] In some embodiments, the second substrate includes: a second base 5 and a common electrode 51 stacked in a direction from the second substrate to the first substrate.

[0048] In some other embodiments, the second substrate includes: a second base 5 and a common electrode 51 stacked and arranged in a direction from the first substrate to the second substrate.

[0049] In some embodiments, the second substrate 5 is a glass substrate. The common electrode 51 is a transparent electrode.

[0050] exist Figure 1 In the embodiment described above, the common electrode 51 is an integral structure, and each pixel electrode 16 is opposite to the common electrode 51 .

[0051] refer to Figure 1 and Figure 6 The surface of the hydrophobic layer 18 away from the first substrate 1 is in a groove shape. When no voltage is applied between the pixel electrode 16 and the common electrode 51, the hydrophobicity of the surface of the hydrophobic layer 18 is very strong, the non-polar liquid 3 spreads on the hydrophobic layer 18, and the polar liquid 4 fills into the groove above the hydrophobic layer 18, and the pixel space is in a closed state.

[0052] refer to Figure 2 and Figure 4When a sufficiently large voltage is applied between the pixel electrode 16 and the common electrode 51, the hydrophobicity of the surface of the hydrophobic layer 18 is very weak, and the non-polar liquid 3 is gathered in the area where the blind hole is located. Since the surface of the hydrophobic layer 18 away from the first substrate 1 is in a groove shape, the non-polar liquid 3 is gathered in the groove-shaped space, and the display area occupied by the non-polar liquid 3 is reduced, thereby improving the reflectivity and contrast of the display panel.

[0053] refer to Figure 5 When a relatively small voltage is applied between the pixel electrode 16 and the common electrode 51, the non-polar liquid 3 is partially gathered in the area where the blind hole is located. The reflectivity of the pixel space corresponds to an intermediate gray scale.

[0054] Since the first substrate has an independent ink storage space, the liquid volume in the display panel is distributed, the thickness of the display panel is reduced, and the light efficiency of the electrowetting display panel is improved.

[0055] In order to form a plurality of groove-shaped areas on the surface of the hydrophobic layer 18 corresponding to the pixel spaces one by one, in other embodiments, blind holes are not drilled on the first substrate 1, and grooves are formed in the hydrophobic layer 18 above the passivation layer 17 by grooves being formed in the passivation layer 17 and / or the gate insulation layer 12.

[0056] In some embodiments, the hydrophobicity in the region of the hydrophobic layer 18 opposite to the pixel space is non-uniformly distributed to guide the non-polar liquid 3 to move toward the blind hole.

[0057] exist Figure 1 In the illustrated embodiment, the hydrophobic layer 18 is an integral structure. In the region opposite to the pixel space, the hydrophobicity of the hydrophobic layer 18 tends to increase along the direction pointing to the corresponding blind hole.

[0058] The grooves on the surface of the hydrophobic layer 18 and the non-uniform distribution of the hydrophobicity of the hydrophobic layer 18 together cause the non-polar liquid 3 to occupy a smaller area of ​​the opening region when in the on state, making the pixel brighter when in the on state, thereby increasing the upper limits of both the reflectivity and contrast of the electrowetting display panel.

[0059] The non-uniform distribution of the hydrophobicity of the hydrophobic layer 18 in the pixel space guides the shrinkage direction of the non-polar liquid 3 to be consistent (the shrinkage direction points to the grooves formed on the surface of the hydrophobic layer 18), avoiding the problem of uneven display caused by different splitting directions of the non-polar liquid 3.

[0060] In some embodiments, the area of ​​the hydrophobic layer 18 opposite to the pixel space includes multiple sub-areas, the hydrophobicity of the hydrophobic layer 18 in the same sub-area is the same, and the hydrophobicity of the hydrophobic layer 18 in any two sub-areas is stronger in the sub-area closer to the blind hole.

[0061] refer to Figures 4 to 6, the area in the hydrophobic layer 18 that is opposite to the pixel space is divided into five sub-areas 18a to 18e. The hydrophobicity of the hydrophobic layer 18 in the sub-area 18e is less than the hydrophobicity of the hydrophobic layer 18 in the sub-area 18d. The hydrophobicity of the hydrophobic layer 18 in the sub-area 18d is less than the hydrophobicity of the hydrophobic layer 18 in the sub-area 18c. The hydrophobicity of the hydrophobic layer 18 in the sub-area 18c is less than the hydrophobicity of the hydrophobic layer 18 in the sub-area 18b. The hydrophobicity of the hydrophobic layer 18 in the sub-area 18b is less than the hydrophobicity of the hydrophobic layer 18 in the sub-area 18a.

[0062] When the non-polar liquid 3 changes from the flat state to the contracted state, the differential hydrophobicity of the surface of the hydrophobic layer 18 drives the non-polar liquid 3 to move toward the area where the blind hole is located. This is beneficial to improving the reflectivity and contrast of the display panel and preventing the non-polar liquid 3 from splitting.

[0063] In some embodiments, the opening area of ​​the blind hole gradually increases from the bottom to the top of the blind hole, so that the groove formed by the region of the hydrophobic layer 18 opposite to the blind hole has an inclined sidewall, thereby reducing the resistance of the non-polar liquid 3 when flowing out of the groove.

[0064] In some embodiments, the blind hole is located at a corner of the corresponding pixel space. Such a design can make the bright area of ​​the pixel space connected into a relatively concentrated whole when the pixel space is in an open state.

[0065] In some embodiments, the blind hole is a circular hole or an oval hole.

[0066] In some embodiments, the first substrate further includes pixel circuits connected one-to-one with the pixel electrodes 16. That is, the pixel electrodes 16 are actively driven.

[0067] Figures 4 to 6 A transistor T in the pixel circuit is shown as an example. The gate electrode 11 of the transistor T is connected to the gate line GL, the first source and drain electrode 14 of the transistor T is connected to the data line DL, and the second source and drain electrode 15 of the transistor T is connected to the pixel electrode 16 .

[0068] Then refer to Figure 1 and Figure 2 The transistor T includes a gate 11, an active layer 13, a gate insulating layer 12, a first source and drain electrode 14, and a second source and drain electrode 15. The present disclosure does not limit the specific structure of the transistor T. The present disclosure does not limit the conductor layer where the gate line GL and the data line DL are located and the insulating layer between these conductor layers.

[0069] In some embodiments, the first substrate further includes a passivation layer 17 covering the pixel electrode layer, and the passivation layer 17 is located on a side of the hydrophobic layer 18 close to the first base 1 .

[0070] In some embodiments, the material of the passivation layer 17 includes silicon nitride.

[0071] Based on the same inventive concept as the above embodiment, Figure 3 , an embodiment of the present disclosure further provides a method for preparing an electrowetting display panel, comprising:

[0072] Step 101, forming a first substrate, the first substrate comprising: a first substrate 1, a pixel electrode layer and a hydrophobic layer 18 stacked in sequence, the pixel electrode layer comprising a plurality of pixel electrodes 16, a surface of the hydrophobic layer 18 away from the first substrate 1 comprising a plurality of groove-shaped regions corresponding to the plurality of pixel electrodes 16 one by one, the groove-shaped regions being arranged opposite to the corresponding pixel electrodes 16;

[0073] Step 102, forming a pixel wall 2 on the hydrophobic layer 18, wherein the pixel wall 2 defines a plurality of pixel spaces corresponding to the plurality of pixel electrodes 16 one by one, the groove-shaped region is arranged opposite to the corresponding pixel space, and the pixel electrode 16 is arranged opposite to the corresponding pixel space;

[0074] Step 103 , filling the pixel space with non-polar liquid 3 and polar liquid 4 , and fixing the second substrate above the opening of the pixel space, wherein the second substrate includes: a common electrode 51 .

[0075] In some embodiments, in the step of forming the first substrate, a plurality of blind holes corresponding to a plurality of pixel spaces are formed on the surface of the first substrate 1 on the side close to the second substrate 5, the blind holes are arranged opposite to the corresponding pixel spaces, and the groove-shaped area is located at the position of the blind holes.

[0076] In some embodiments, in the step of forming the first substrate, a blind hole is formed by dry etching, and then the inner wall of the blind hole is smoothed by wet etching. The surface of the inner wall of the blind hole is smooth, so that the surface of the hydrophobic layer 18 is smooth, reducing the resistance of the non-polar liquid 3 to movement.

[0077] In some embodiments, after forming the pixel wall 2 on the hydrophobic layer 18 and before filling the non-polar liquid 3 and the polar liquid 4 in the pixel space, the preparation method further includes:

[0078] The hydrophobic layer 18 is subjected to a heating reflux treatment;

[0079] At least part of the hydrophobic layer 18 facing the pixel space is divided into sub-regions for plasma modification treatment of different durations, wherein, for any two sub-regions of the hydrophobic layer 18 facing the pixel space, the sub-region farther from the corresponding blind hole has a longer plasma modification treatment time.

[0080] The following combination Figure 1 and Figure 2 Introduces the complete preparation process of electrowetting display panels.

[0081] A glass substrate having a thickness greater than 1 mm is provided, and a plurality of trapezoidal blind holes having a depth less than the thickness of the glass substrate and being wide at the top and narrow at the bottom are etched on the glass substrate by inductively coupled plasma (ICP) etching technology (or other glass fine drilling technology, such as laser induced etching, photosensitive glass method, plasma etching, etc.). The blind hole serves as a storage cavity for the non-polar liquid 3 when the pixel space is in an open state. The trapezoidal blind hole is placed at a corner of the pixel space. By designing an asymmetric structure in the pixel space, the non-polar liquid 3 tends to gather in the blind hole. For example, the hydrophobicity of the hydrophobic layer 18 is gradually designed so that the non-polar liquid 3 is subjected to a gradient force directed toward the blind hole on the hydrophobic layer 18.

[0082] Subsequently, the glass substrate is etched with hydrofluoric acid of appropriate concentration for a certain period of time to smooth the inner wall of the blind hole, making it more conducive to the flow of the non-polar liquid 3 and the polar liquid 4 in the blind hole and reducing the flow resistance.

[0083] Subsequently, a pixel circuit, an ITO pixel electrode 16, a gate line GL, and a data line DL are prepared on the glass substrate.

[0084] Then, a passivation layer 17 (eg, SiNx) is formed. The passivation layer 17 is a transparent structure and serves as a protection layer for the pixel circuit and a dielectric layer in the electrowetting device.

[0085] When determining the thickness of the passivation layer 17, in addition to considering the minimum thickness allowed by the deposition rate in the process and the risk of scratching the metal wires under the passivation layer 17, the dielectric breakdown effect and the required driving voltage must also be considered to ensure that the passivation layer 17 cannot be broken down and can meet the requirements for changing the droplet contact angle within the voltage range without breakdown.

[0086] For a multilayer dielectric wetting system with functional separation, the series connection of the capacitance of the passivation layer 17, the capacitance of the hydrophobic layer 18 and the double-layer capacitance constitutes the equivalent capacitance of the system. Since the double-layer is usually only a few nanometers thick, it can be ignored in the calculation, so the equivalent capacitance C is as follows:

[0087]

[0088] Among them, C dielectric is the capacitance of the passivation layer 17, C hydrophobic is the capacitance of the hydrophobic layer 18.

[0089] In order to obtain the largest possible change in liquid contact angle under the same voltage, the capacitance C of the passivation layer 17 should be as large as possible. Therefore, materials with large dielectric constants and as thin a film as possible that will not be broken down are usually selected for the passivation layer 17 and the hydrophobic layer 18.

[0090] Subsequently, an amorphous fluorine-containing resin is spin-coated on the passivation layer 17 as a hydrophobic layer 18 material. The adhesion between the hydrophobic layer 18 and the photoresist is enhanced by plasma modification. The hydrophilic pixel wall 2 is obtained by coating a photoresist (such as SU-8) and subsequent exposure and development processes. After the preparation of the pixel wall 2 is completed, the first substrate is heated and refluxed to restore the hydrophobicity of the hydrophobic layer 18, and the non-polar liquid 3 is filled into the pixel space, and the second substrate is fixed above the pixel space in an underwater environment.

[0091] The hydrophobicity of the surface of the hydrophobic layer 18 obtained by spin coating an amorphous fluorine-containing resin (or other suitable hydrophobic material) on the entire first substrate 1 is uniform. A negative photoresist with good adhesion (such as SU8, AR-N-4400, etc.) is selected to form the pixel wall 2.

[0092] The hydrophobic layer 18 is then thermally reflowed to restore its hydrophobicity.

[0093] Then, a positive photoresist (such as AR-P 3500, AR-P 3500T, etc.) is applied. The positive photoresist selected has different etching solutions from the negative photoresist used to form the pixel wall, thereby ensuring that the pixel wall is not damaged in subsequent processes. After the positive photoresist is exposed and developed, the surface to be processed of the hydrophobic layer 18 is exposed. Then, plasma bombardment is used to modify the exposed surface of the hydrophobic layer 18. The positive photoresist is removed.

[0094] Then, a positive photoresist (such as AR-P 3500, AR-P 3500T, etc.) is applied again. The positive photoresist selected has different etching solutions from the negative photoresist used to form the pixel wall, thereby ensuring that the pixel wall is not damaged in subsequent processes. After the positive photoresist is exposed and developed, another part of the surface to be processed of the hydrophobic layer 18 is exposed. Then, plasma bombardment is used to modify the exposed surface of the hydrophobic layer 18. The positive photoresist is removed.

[0095] By analogy, different sub-regions of the hydrophobic layer 18 are plasma bombarded respectively. Under the premise that the process parameters such as plasma power and vacuum degree remain unchanged, the surface of the hydrophobic layer 18 with different hydrophobic properties is obtained by adjusting different plasma bombardment times. Within a certain range, the longer the plasma bombardment time, the weaker the hydrophobicity of the surface of the hydrophobic layer 18.

[0096] Based on the same inventive concept, an embodiment of the present disclosure further provides a display device, comprising the aforementioned electrowetting display panel, or comprising the electrowetting display panel obtained according to the aforementioned preparation method.

[0097] The display device can be any product or component with a display function, such as electronic paper, a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, etc.

[0098] The various embodiments in the present disclosure are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0099] The protection scope of the present disclosure is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the scope and spirit of the present disclosure. If these changes and modifications fall within the scope of the claims of the present disclosure and their equivalents, the intention of the present disclosure also includes these changes and modifications.

Claims

1. An electrowetting display panel, characterized in that: include: A pixel wall (2), a first substrate and a second substrate arranged opposite to each other; The pixel wall (2) is arranged on a surface of the first substrate facing the second substrate to define a plurality of pixel spaces, wherein the pixel spaces are filled with a non-polar liquid (3) and a polar liquid (4); The first substrate comprises: a first substrate (1), a pixel electrode layer and a hydrophobic layer (18) which are stacked in sequence along a direction from the first substrate to the second substrate, the pixel electrode layer comprising a plurality of pixel electrodes (16) corresponding one-to-one to the plurality of pixel spaces, a surface of the hydrophobic layer (18) away from the first substrate (1) comprising a plurality of groove-shaped areas corresponding one-to-one to the plurality of pixel spaces, the pixel electrodes (16) being arranged opposite to the corresponding pixel spaces, and the groove-shaped areas being arranged opposite to the corresponding pixel spaces; The second substrate comprises: a common electrode (51); The hydrophobicity in the hydrophobic layer (18) is non-uniformly distributed in the area opposite to the pixel space, so as to guide the non-polar liquid (3) to move toward the groove-shaped area.

2. The electrowetting display panel according to claim 1, characterized in that: A plurality of blind holes corresponding to the plurality of pixel spaces are arranged on a surface of the first base (1) on one side close to the second substrate, the blind holes are arranged opposite to the corresponding pixel spaces, and the groove-shaped area is located at the position of the blind holes.

3. The electrowetting display panel according to claim 2, characterized in that: The ratio of the depth of the blind hole to the thickness of the first substrate (1) is in the range of 19% to 43%.

4. The electrowetting display panel according to claim 2, characterized in that: The orthographic projection of the pixel electrode (16) on the first substrate (1) covers and exceeds the corresponding blind hole.

5. The electrowetting display panel according to claim 1, characterized in that: The area where the hydrophobic layer (18) is opposite to the pixel space includes a plurality of sub-areas, the hydrophobicity of the hydrophobic layer (18) in the same sub-area is the same, and the hydrophobicity of the hydrophobic layer (18) in any two of the sub-areas is stronger in the sub-area that is closer to the groove-shaped area.

6. The electrowetting display panel according to claim 2, characterized in that: The opening area of ​​the blind hole gradually increases from the bottom of the blind hole to the top of the blind hole.

7. The electrowetting display panel according to claim 2, characterized in that: The blind hole is located at a corner of the corresponding pixel space.

8. The electrowetting display panel according to claim 1, characterized in that: The first substrate also includes a pixel circuit connected to the pixel electrodes (16) in a one-to-one correspondence.

9. The electrowetting display panel according to claim 1, characterized in that: The first substrate further comprises a passivation layer (17) covering the pixel electrode layer, and the passivation layer (17) is located on a side of the hydrophobic layer (18) close to the first base (1).

10. A method for preparing an electrowetting display panel, characterized in that: include: A first substrate is formed, the first substrate comprising: a first base (1), a pixel electrode (16) layer and a hydrophobic layer (18) which are stacked in sequence, the pixel electrode layer comprising a plurality of pixel electrodes (16), a surface of the hydrophobic layer (18) away from the first base (1) comprising a plurality of groove-shaped regions corresponding one-to-one to the plurality of pixel electrodes (16), the groove-shaped regions being arranged opposite to the corresponding pixel electrodes (16); A pixel wall (2) is formed on the hydrophobic layer (18), the pixel wall (2) defining a plurality of pixel spaces corresponding one to one with the plurality of pixel electrodes (16), the groove-shaped region being arranged opposite to the corresponding pixel space, and the pixel electrode (16) being arranged opposite to the corresponding pixel space; A non-polar liquid (3) and a polar liquid (4) are filled in the pixel space, and a second substrate is arranged above the opening of the pixel space, wherein the second substrate comprises a common electrode; The hydrophobicity in the hydrophobic layer (18) is non-uniformly distributed in the area opposite to the pixel space, so as to guide the non-polar liquid (3) to move toward the groove-shaped area.

11. The preparation method according to claim 10, characterized in that: In the step of forming the first substrate, a plurality of blind holes corresponding to the plurality of pixel spaces are formed on a surface of the first base (1) on a side close to the second substrate, the blind holes being arranged opposite to the corresponding pixel spaces, and the groove-shaped area being located at the position of the blind holes.

12. The preparation method according to claim 11, characterized in that: In the step of forming the first substrate, the blind hole is formed by a dry etching process, and then the inner wall of the blind hole is smoothed by a wet etching process.

13. The preparation method according to claim 10, characterized in that: After forming the pixel wall (2) on the hydrophobic layer (18) and before filling the pixel space with the non-polar liquid (3) and the polar liquid (4), the preparation method further comprises: The hydrophobic layer (18) is subjected to a heating reflux treatment; At least part of the hydrophobic layer (18) facing the pixel space is divided into sub-regions for plasma modification treatment of different durations, wherein, for any two sub-regions of the hydrophobic layer (18) facing the pixel space, the sub-region that is farther away from the corresponding blind hole has a longer plasma modification time.

14. A display device, characterized in that: The invention comprises the electrowetting display panel according to any one of claims 1 to 9.

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