Electro-wetting display device structure and method of manufacturing the same

Abstract

The application discloses an electrowetting display device structure and a method for preparing the same. The electrowetting display device structure comprises a first substrate, a second substrate, a sealing frame and a pixel wall. The second substrate is arranged in parallel with the first substrate, and has a first conductive layer on one side close to the first substrate. A hydrophobic insulating layer is arranged on the first conductive layer. The sealing frame is arranged between the first substrate and the second substrate, and a sealed cavity is formed between the first substrate, the sealing frame and the second substrate. The sealed cavity is filled with a polar liquid. The pixel wall is arranged on the hydrophobic insulating layer in the sealed cavity, and defines a pixel grid. The pixel grid is filled with a non-polar liquid which is immiscible with the polar liquid. The pixel wall comprises a second conductive layer, and the second conductive layer and the first conductive layer form a positive electrode and a negative electrode, respectively. The electrowetting display device structure can improve the response time and the conductive efficiency of the electrowetting display device.

Description

Technical Field

[0001] This invention relates to the technical field of electrowetting display technology, and in particular to an electrowetting display device structure and its fabrication method. Background Technology

[0002] Electrowetting generally refers to the phenomenon where applying voltage between upper and lower substrates alters the surface tension between a liquid and a solid, thereby changing the contact angle between them and causing the droplet to deform and shift.

[0003] Electrowetting display is a reflective display technology that uses this principle to achieve the display effect.

[0004] The concept of electrowetting display was proposed as early as 1981. Its core idea is to use the electrowetting effect to manipulate the movement of liquid in the pixel structure, thereby changing the optical spatial coherence within the pixel structure and achieving an optical display effect that switches between white and transparent.

[0005] In related technologies, the electrodes of electrowetting display devices are generally composed of upper and lower substrates. The ITO conductive layer of the lower substrate is etched to create the electrode structure, while the electrodes of the upper substrate can be made of a single piece of ITO conductive glass as a common electrode.

[0006] However, electrowetting display devices with this structure typically have slow response times and low conductivity. Summary of the Invention

[0007] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes an electrowetting display device structure that can improve the response time and conductivity efficiency of the electrowetting display device.

[0008] This invention also proposes a method for fabricating an electrowetting display device structure.

[0009] According to a first aspect of the present invention, an electrowetting display device structure includes a first substrate, a second substrate, a sealing frame, and a pixel wall. The second substrate is disposed parallel to the first substrate, and has a first conductive layer on the side near the first substrate. A hydrophobic insulating layer is disposed on the first conductive layer. The sealing frame is disposed between the first substrate and the second substrate, forming a sealed cavity between the first substrate, the sealing frame, and the second substrate. The sealed cavity is filled with a polar liquid. The pixel wall is located within the sealed cavity, disposed on the hydrophobic insulating layer, and defines a pixel grid. The pixel grid is filled with a non-polar liquid that is immiscible with the polar liquid. The pixel wall includes a second conductive layer, and the second conductive layer and the first conductive layer respectively constitute a positive electrode and a negative electrode.

[0010] According to some embodiments of the present invention, the pixel wall further includes a first insulating layer connected to the hydrophobic insulating layer, and a second conductive layer disposed on the side of the first insulating layer away from the hydrophobic insulating layer.

[0011] According to some embodiments of the present invention, the first insulating layer is configured as photoresist, and the second conductive layer is configured as Ag-containing photoresist.

[0012] According to some embodiments of the present invention, the height of the second conductive layer accounts for 10%-50% of the total height of the pixel wall.

[0013] According to some embodiments of the present invention, the second conductive layer is provided with conductive leads that extend outward to conduct electricity.

[0014] According to some embodiments of the present invention, the second substrate is configured as ITO conductive glass.

[0015] According to some embodiments of the present invention, the first substrate has a third conductive layer on the side near the second substrate, two hydrophobic insulating layers are provided, the two hydrophobic insulating layers are respectively disposed on the first conductive layer and the third conductive layer, two pixel walls are provided, the two pixel walls are respectively disposed on the side of the two hydrophobic insulating layers that are close to each other, a power supply is connected between the first conductive layer and the second conductive layer of the pixel wall on the first substrate, and another power supply is connected between the third conductive layer and the second conductive layer of the pixel wall on the second substrate.

[0016] The electrowetting display device structure according to embodiments of the present invention has at least the following beneficial effects:

[0017] 1. This invention provides a first conductive layer on a second substrate and a second conductive layer on a pixel wall. The second and first conductive layers constitute a positive electrode and a negative electrode, respectively. It is understood that conventional electrowetting display devices place two electrodes on the upper and lower substrates respectively, and activate the device by applying a voltage between the two electrodes. In these devices, the polar liquid between the electrodes and the hydrophobic insulating layer causes voltage division, resulting in a relatively high activation threshold voltage. The electrowetting display device of this invention places two electrodes on the second substrate and the pixel wall respectively, reducing the distance between the electrodes and the hydrophobic insulating layer and decreasing the distribution of polar liquid in the electric field between them. This reduces the voltage division of the polar liquid when a voltage is applied between the two electrodes to activate the electrowetting display device, lowering the activation threshold voltage and thus improving the response time and conductivity of the device.

[0018] A method for fabricating an electrowetting display device structure according to a second aspect of the present invention, used to manufacture the electrowetting display device structure according to a first aspect of the present invention, includes the following steps:

[0019] S10: Take a second substrate having a first conductive layer, spin-coat a hydrophobic insulating layer on the surface of the first conductive layer, and perform a hydrophilic treatment on the hydrophobic insulating layer.

[0020] S20: Photoresist and Ag-containing photoresist are spin-coated sequentially on the hydrophobic insulating layer, and then the second substrate with photoresist and Ag-containing photoresist spin-coated is placed under a mask with a specific pattern for exposure to form a pixel wall.

[0021] S30: Fill the pixel grid defined by the pixel wall with a non-polar liquid;

[0022] S40: Place the second substrate obtained in step S30 on a condensation stage to condense, and then coat the non-polar liquid with a pre-condensed polar liquid.

[0023] S50: Take the first substrate, attach the sealing frame to the first substrate, then fit the sealing frame outside the pixel wall and press it against the second substrate to make the polar liquid evenly distributed in the sealing frame. Excess polar liquid flows out from between the sealing frame and the second substrate. Then press the first substrate, the sealing frame and the second substrate together to seal.

[0024] According to some embodiments of the present invention, after spin-coating photoresist and Ag-containing photoresist in step S20, the second substrate with spin-coated photoresist and Ag-containing photoresist needs to be heated in an environment of 110 degrees for 120 seconds. After heating, it is allowed to cool down and then placed under a mask with a specific pattern for exposure.

[0025] According to some embodiments of the present invention, in step S20, after the second substrate coated with photoresist and Ag-containing photoresist is exposed under a mask with a specific pattern, it needs to be baked in an environment of 110 degrees for 120 seconds. After baking, it is developed and dried to obtain the required pixel wall.

[0026] The method for fabricating an electrowetting display device structure according to embodiments of the present invention has at least the following beneficial effects:

[0027] 1. This invention involves spin-coating photoresist and Ag-containing photoresist sequentially onto a hydrophobic insulating layer, then exposing a second substrate coated with both photoresist and Ag-containing photoresist under a mask with a specific pattern to form a pixel wall. This allows the Ag-containing photoresist to form a second conductive layer, thereby constructing a second conductive layer on the pixel wall. The second conductive layer and the first conductive layer constitute the positive and negative electrodes, respectively. By applying a voltage between the first and second conductive layers, an electrowetting display device can be turned on. Compared to conventional techniques that place electrodes on upper and lower substrates and apply a voltage between the two electrodes to turn on the electrowetting display device, the electrowetting display device manufactured in this embodiment of the invention places two electrodes on the second substrate and the pixel wall, respectively. This reduces the distance between the electrodes and the hydrophobic insulating layer, and reduces the distribution of polar liquid in the electric field between the electrodes and the hydrophobic insulating layer. Consequently, when a voltage is applied between the two electrodes to turn on the electrowetting display device, the voltage drop of the polar liquid is reduced, lowering the start-up threshold voltage of the electrowetting display device, and thus improving the response time and conductivity efficiency of the electrowetting display device.

[0028] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the electrowetting display device according to an embodiment of the present invention;

[0031] Figure 2 This is a top view of the electrowetting display device structure in the off state according to an embodiment of the present invention;

[0032] Figure 3 This is a top view of the electrowetting display device structure in the open state according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of a two-layer device structure for an electrowetting display device according to an embodiment of the present invention.

[0034] Reference numerals: 100-first substrate, 110-second substrate, 120-first conductive layer, 130-hydrophobic insulating layer, 140-sealing frame, 150-polar liquid, 160-pixel wall, 170-non-polar liquid, 180-second conductive layer, 190-first insulating layer, 200-conductive lead, 210-third conductive layer. Detailed Implementation

[0035] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0036] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0037] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" and "second" are mentioned, this is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0038] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation, connection, and linkage" 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; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0039] The structure and fabrication method of the electrowetting display device according to an embodiment of the present invention are described below with reference to the accompanying drawings.

[0040] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4 The present invention aims to provide embodiments of the structure of the electrowetting display device and the method for its fabrication.

[0041] Example 1

[0042] This embodiment provides an electrowetting display device structure, including a first substrate 100, a second substrate 110, a sealing frame 140, and a pixel wall 160.

[0043] The second substrate 110 is arranged parallel to the first substrate 100. The side of the second substrate 110 close to the first substrate 100 has a first conductive layer 120, and a hydrophobic insulating layer 130 is disposed on the first conductive layer 120.

[0044] Specifically, the hydrophobic insulating layer 130 can be a fluoropolymer material, including the Teflon series, Cytop series, Hyflon series, etc.

[0045] The sealing frame 140 is disposed between the first substrate 100 and the second substrate 110, and a sealing cavity is formed between the first substrate 100, the sealing frame 140 and the second substrate 110. The sealing cavity is filled with a polar liquid 150, thereby enabling the sealing cavity to prevent leakage of the polar liquid 150 and the non-polar liquid 170.

[0046] Specifically, the polar liquid 150 can be at least one of water, ethylene glycol, and propylene glycol.

[0047] The pixel wall 160 is located inside the sealed cavity and is disposed on the hydrophobic insulating layer 130. The pixel wall 160 defines a pixel grid, which is filled with a non-polar liquid 170 that is insoluble in the polar liquid 150. The pixel wall 160 includes a second conductive layer 180, and the second conductive layer 180 and the first conductive layer 120 respectively constitute a positive electrode and a negative electrode.

[0048] It is understandable that traditional electrowetting display devices have two electrodes respectively placed on the upper and lower substrates. The electrowetting display device is turned on by applying a voltage between the two electrodes on the upper and lower substrates. In this case, the polar liquid 150 between the electrode and the hydrophobic insulating layer 130 will divide the voltage, resulting in a relatively high start-up threshold voltage of the electrowetting display device. The electrowetting display device of the present invention places the two electrodes on the second substrate 110 and the pixel wall 160 respectively, reducing the distance between the electrode and the hydrophobic insulating layer 130 and reducing the distribution of polar liquid 150 in the electric field between the electrode and the hydrophobic insulating layer 130. Therefore, when a voltage is applied between the two electrodes to turn on the electrowetting display device, the voltage division of the polar liquid 150 can be reduced, the start-up threshold voltage of the electrowetting display device can be lowered, and thus the response time and conductivity efficiency of the electrowetting display device can be improved.

[0049] Specifically, the non-polar liquid 170 is ink or colored ink.

[0050] In some embodiments of the present invention, the pixel wall 160 further includes a first insulating layer 190, the first insulating layer 190 being connected to the hydrophobic insulating layer 130, and a second conductive layer 180 being disposed on the side of the first insulating layer 190 away from the hydrophobic insulating layer 130.

[0051] It should be explained that the function of the first insulating layer 190 is to reduce the risk of breakdown and improve the reliability of the device. After the first conductive layer 120 and the second conductive layer 180 are powered on, the electric field of the second conductive layer 180 will act on the hydrophobic insulating layer 130 through the pixel grid, changing the hydrophilicity of the hydrophobic insulating layer 130. This increases the spreading area of ​​the non-polar liquid 170 on the hydrophobic insulating layer 130, causing the non-polar liquid 170 to compress and shrink the polar liquid 150 in the pixel grid. By setting the first insulating layer 190, which is connected to the hydrophobic insulating layer 130, and the second conductive layer 180 being set on the side of the first insulating layer 190 away from the hydrophobic insulating layer 130, the first insulating layer 190 is placed between the second conductive layer 180 and the hydrophobic insulating layer 130. This prevents the voltage of the second conductive layer 180 from directly acting on the hydrophobic insulating layer 130, reducing the risk of damage to the hydrophobic insulating layer 130, thus reducing the risk of breakdown and improving the reliability of the electrowetting display device.

[0052] In some embodiments of the present invention, the first insulating layer 190 is configured as photoresist, and the second conductive layer 180 is configured as Ag-containing photoresist.

[0053] It is understandable that by setting the first insulating layer 190 as photoresist and the second conductive layer 180 as Ag-containing photoresist, both the first insulating layer 190 and the second conductive layer 180 are made of photoresist. Consequently, both the first insulating layer 190 and the second conductive layer 180 can be prepared by spin coating. Photoresist and Ag-containing photoresist can be sequentially spin-coated onto the hydrophobic insulating layer 130, which facilitates the coating of the first insulating layer 190 and the second conductive layer 180. After the photoresist and Ag-containing photoresist are spin-coated, the first insulating layer 190 and the second conductive layer 180 can be simultaneously exposed under a mask with a specific pattern to form a pixel wall 160, thereby improving the fabrication efficiency of the pixel wall 160.

[0054] In some embodiments of the present invention, the height of the second conductive layer 180 accounts for 10%-50% of the total height of the pixel wall 160, thereby enabling the response time and conductivity of the driven electrowetting display device to reach the desired values.

[0055] Furthermore, the height ratio of the first insulating layer 190 to the second conductive layer 180 is 5:1, thereby making it easier to achieve the desired response time and conductivity effect when driving the electrowetting display device.

[0056] In some embodiments of the present invention, the second conductive layer 180 is provided with conductive leads 200, which extend outward to conduct electricity, thereby facilitating the connection of the second conductive layer 180 inside the sealed cavity to a power source.

[0057] In some embodiments of the present invention, the second substrate 110 is provided as ITO conductive glass, which makes it easy to obtain materials and facilitates manufacturing.

[0058] In a further embodiment of the present invention, the first substrate 100 has a third conductive layer 210 on the side near the second substrate 110, two hydrophobic insulating layers 130 are provided, the two hydrophobic insulating layers 130 are respectively provided on the first conductive layer 120 and the third conductive layer 210, two pixel walls 160 are provided, the two pixel walls 160 are respectively provided on the side of the two hydrophobic insulating layers 130 that are close to each other, a power supply is connected between the first conductive layer 120 and the second conductive layer 180 of the pixel wall 160 on the first substrate 100, and another power supply is connected between the third conductive layer 210 and the second conductive layer 180 of the pixel wall 160 on the second substrate 110.

[0059] It is understandable that by setting two hydrophobic insulating layers 130 and two pixel walls 160, with the two hydrophobic insulating layers 130 respectively disposed on the first conductive layer 120 and the third conductive layer 210, and the two pixel walls 160 respectively disposed on the side of the two hydrophobic insulating layers 130 that are close to each other, the electrowetting display device can form a double-junction pixel structure. At the same time, a power supply is connected between the first conductive layer 120 and the second conductive layer 180 of the pixel wall 160 on the first substrate 100, and another power supply is connected between the third conductive layer 210 and the second conductive layer 180 of the pixel wall 160 on the second substrate 110. Thus, the two power supplies can control the upper and lower pixel structures of the electrowetting display device respectively, realizing the switching of the upper and lower pixel structures of the electrowetting display device.

[0060] In some embodiments of the present invention, the first substrate 100 is configured as ITO conductive glass, thereby making it easy to obtain materials and manufacture.

[0061] Example 2

[0062] This embodiment provides a method for fabricating an electrowetting display device structure, including the following steps:

[0063] S10: Take a second substrate 110 having a first conductive layer 120, spin-coat a hydrophobic insulating layer 130 on the surface of the first conductive layer 120, and perform a hydrophilic treatment on the hydrophobic insulating layer 130.

[0064] In some embodiments of the present invention, two pieces of ITO conductive glass are taken before step S10, cleaned and dried, and the two pieces of ITO glass serve as the first substrate 100 and the second substrate 110, respectively.

[0065] In some embodiments of the present invention, in step S10, after spin-coating a hydrophobic insulating layer 130 onto the surface of the first conductive layer 120, the second substrate 110 is placed on a hot stage and heated at a specific temperature for 90 seconds. After cooling, it is placed in an etching machine for hydrophilic treatment.

[0066] S20: Photoresist and Ag-containing photoresist are spin-coated sequentially on the hydrophobic insulating layer 130. Then, the second substrate 110 with the spin-coated photoresist and Ag-containing photoresist is placed under a mask with a specific pattern for exposure to form a pixel wall 160.

[0067] In some embodiments of the present invention, after spin-coating photoresist and Ag-containing photoresist in step S20, the second substrate 110 with spin-coated photoresist and Ag-containing photoresist needs to be placed in an environment of 110 degrees Celsius and heated for 120 seconds. After heating is completed, it is allowed to cool down and then placed under a mask with a specific pattern for exposure.

[0068] In some embodiments of the present invention, after the second substrate 110, which is spin-coated with photoresist and Ag-containing photoresist, is placed under a mask with a specific pattern for exposure in step S20, it needs to be baked in an environment of 110 degrees for 120 seconds. After baking, it is developed and dried, and the required pixel wall 160 can be obtained.

[0069] In some embodiments of the present invention, the developing process specifically involves rinsing in the developing solution for 1-2 minutes.

[0070] In some embodiments of the present invention, the second substrate 110 with a distinct pixel wall 160 structure needs to be etched and subjected to high-temperature reflow to restore the hydrophobicity of the insulating hydrophobic layer surface.

[0071] S30: Fill the pixel grid defined by the pixel wall 160 with non-polar liquid 170.

[0072] In some embodiments of the present invention, the nonpolar liquid 170 is specifically an ink or colored ink.

[0073] In some embodiments of the present invention, the non-polar liquid 170 is filled by inkjet printing, in which ink is printed and filled into the pixel grid formed by the pixel wall 160.

[0074] S40: Place the second substrate 110 obtained in step S30 on a condensation stage to condense, and then coat the non-polar liquid 170 with the pre-condensed polar liquid 150.

[0075] In some embodiments of the present invention, the second substrate 110 is placed on a condensation stage and condensed for 1-2 minutes.

[0076] S50: Take the first substrate 100, attach the sealing frame 140 to the first substrate 100, then fit the sealing frame 140 outside the pixel wall 160 and press it against the second substrate 110 so that the polar liquid 150 is evenly distributed in the sealing frame 140, and the excess polar liquid 150 flows out from between the sealing frame 140 and the second substrate 110. Then press the first substrate 100, the sealing frame 140 and the second substrate 110 together to seal.

[0077] Example 3

[0078] This embodiment provides a method for fabricating an electrowetting display device structure, which, based on Embodiment 2, simultaneously constructs a hydrophobic insulating layer 130 and a pixel structure on a first substrate 100. Specifically, before step S50, the following steps are included:

[0079] S11: Take another piece of ITO conductive glass as the first substrate 100, spin-coat a hydrophobic insulating layer 130 on the surface of the conductive layer of the ITO conductive glass, and perform hydrophilic treatment on the hydrophobic insulating layer 130.

[0080] In some embodiments of the present invention, in step S11, after spin-coating the hydrophobic insulating layer 130 onto the surface of the first conductive layer 120, the first substrate 100 is placed on a hot stage and heated at a specific temperature for 90 seconds. After cooling, it is placed in an etching machine for hydrophilic treatment.

[0081] S21: Photoresist and Ag-containing photoresist are spin-coated sequentially on the hydrophobic insulating layer 130. Then, the first substrate 100 with spin-coated photoresist and Ag-containing photoresist is placed under a mask with a specific pattern for exposure to form a pixel wall 160.

[0082] In some embodiments of the present invention, after spin-coating photoresist and Ag-containing photoresist in step S21, the first substrate 100 with spin-coated photoresist and Ag-containing photoresist needs to be heated in an environment of 110 degrees for 120 seconds. After heating, it is allowed to cool down and then placed under a mask with a specific pattern for exposure.

[0083] In some embodiments of the present invention, after the first substrate 100 coated with photoresist and Ag-containing photoresist is exposed under a mask with a specific pattern in step S21, it needs to be baked in an environment of 110 degrees for 120 seconds. After baking, it is developed and dried, and the required pixel wall 160 can be obtained.

[0084] In some embodiments of the present invention, the developing process specifically involves rinsing in the developing solution for 1-2 minutes.

[0085] In some embodiments of the present invention, the first substrate 100 having a distinct pixel wall 160 structure needs to be etched and subjected to high-temperature reflow to restore the hydrophobicity of the insulating hydrophobic layer surface.

[0086] S31: Fill the pixel grid defined by the pixel wall 160 with non-polar liquid 170.

[0087] In some embodiments of the present invention, the nonpolar liquid 170 is specifically an ink or colored ink.

[0088] In some embodiments of the present invention, the non-polar liquid 170 is filled by inkjet printing, in which ink is printed and filled into the pixel grid formed by the pixel wall 160.

[0089] S41: Place the first substrate 100 obtained in step S31 on a condensation stage for condensation, and then coat the non-polar liquid 170 with the pre-condensed polar liquid 150.

[0090] In some embodiments of the present invention, the first substrate 100 is placed on a condensation stage and condensed for 1-2 minutes.

[0091] Example 4

[0092] This embodiment provides a method for fabricating an electrowetting display device structure, including the following steps:

[0093] Prepare two 3cm x 3cm ITO conductive glass pieces and clean them thoroughly.

[0094] One of them is taken as the second substrate 110, and a hydrophobic insulating layer 130 is constructed on the second substrate 110.

[0095] 2-3 ml of Hyflon solution is coated on the first conductive layer 120 of the second substrate 110. The solution is then spin-coated at a spin speed of 320 rpm for 65 seconds. After spin-coating, the solution is placed on a flat surface and left to stand for 5-10 minutes. Then, it is heated at a high temperature of 85 degrees Celsius for 90 seconds. After cooling, the desired hydrophobic insulating layer 130 structure is formed.

[0096] The second substrate 110, which is spin-coated with a hydrophobic insulating layer 130, is placed in the etching chamber for surface modification. After the surface of the hydrophobic insulating layer 130 becomes hydrophilic, the pixel wall 160 can be further constructed.

[0097] To construct the pixel wall 160, approximately 5 ml of photoresist is coated onto the upper surface of the second substrate 110. The substrate is then spin-coated at 1200 rpm for 65 seconds. After spin-coating, approximately 1 ml of conductive photoresist is spin-coated onto the surface, and the same spin speed is applied for 65 seconds. Following spin-coating, the substrate is cured by placing it at 110 degrees Celsius for 120 seconds. After cooling to room temperature, the substrate is placed in a photolithography machine for exposure using a photomask with a specific pattern. After exposure, the substrate is developed in a 0.4% KOH solution for 90 seconds, repeated twice. It is then developed in clean water for 50 seconds, rinsed in flowing liquid for 50 seconds, and finally dried with nitrogen. The cleaned substrate is then observed under a microscope, revealing a stable pixel wall 160 structure.

[0098] The second substrate 110, on which the pixel wall 160 structure is fabricated, is placed in a dust-free oven at 210°C for 2 hours for high-temperature reflow, and then removed after cooling.

[0099] The second substrate 110, which has the pixel wall 160 structure prepared above, is filled with ink. The filling method here is inkjet printing, and the ink is printed and filled into the pixel grid formed by the pixel wall 160.

[0100] Finally, the encapsulation process is carried out. First, a portion of the polar liquid 150 is taken with a dropper and placed on the cooling platform for condensation. Then, the second substrate 110, which is filled with non-polar liquid 170, needs to be placed on the cooling platform for encapsulation. Specifically, the second substrate 110 is first condensed for 1-2 minutes to condense the non-polar liquid 170, and then the polar liquid 150 is dripped with a dropper.

[0101] The sealing frame 140 is attached to the first substrate 100, and then the first substrate 100 and the second substrate 110 are tightly attached to each other, so that the pixel structure of the second substrate 110 is placed inside the sealing frame 140. Excess polar liquid 150 is squeezed out in the form of pressing, and the desired electrowetting display device is obtained.

[0102] In some embodiments of the present invention, if a dual-layer electrowetting display device is to be fabricated, the above-described second basic operations of constructing the hydrophobic insulating layer 130, constructing the pixel wall 160, and filling the non-polar liquid 170 are repeated on the first substrate 100 to obtain the same pixel structure as on the second substrate 110, and the encapsulation is the same as the above operations.

[0103] In an embodiment of the present invention, photoresist and Ag-containing photoresist are sequentially spin-coated onto a hydrophobic insulating layer 130. Then, a second substrate 110 with both photoresist and Ag-containing photoresist spin-coated is placed under a mask with a specific pattern for exposure to form a pixel wall 160. This allows the Ag-containing photoresist to form a second conductive layer 180. Thus, a second conductive layer 180 is constructed on the pixel wall 160, making the second conductive layer 180 and the first conductive layer 120 constitute a positive electrode and a negative electrode, respectively. By applying a voltage between the first conductive layer 120 and the second conductive layer 180, an electrowetting display device can be activated. This method is significantly different from conventional techniques that involve spin-coating photoresist onto a hydrophobic insulating layer 130. Electrodes are provided on the lower substrate to enable the electrowetting display device by applying a voltage between the two electrodes on the upper and lower substrates. In the embodiment of the present invention, the electrowetting display device has two electrodes respectively disposed on the second substrate 110 and the pixel wall 160, reducing the distance between the electrodes and the hydrophobic insulating layer 130, and reducing the distribution of polar liquid 150 in the electric field between the electrodes and the hydrophobic insulating layer 130. As a result, when a voltage is applied between the two electrodes to enable the electrowetting display device, the voltage division of the polar liquid 150 can be reduced, the start-up threshold voltage of the electrowetting display device can be lowered, and thus the response time and conductivity efficiency of the electrowetting display device can be improved.

[0104] In the description of this specification, the references to terms such as "an embodiment, some embodiments, illustrative embodiments, example, specific example, or examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0105] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. The structure of an electrowetting display device, characterized in that, include: First substrate (100); The second substrate (110) is arranged parallel to the first substrate (100), and has a first conductive layer (120) on the side close to the first substrate (100). A hydrophobic insulating layer (130) is provided on the first conductive layer (120). A sealing frame (140) is disposed between the first substrate (100) and the second substrate (110), forming a sealing cavity between the first substrate (100), the sealing frame (140) and the second substrate (110), and the sealing cavity is filled with a polar liquid (150). A pixel wall (160) is located inside the sealed cavity and is disposed on the hydrophobic insulating layer (130), defining a pixel grid. The pixel grid is filled with a non-polar liquid (170) that is insoluble in the polar liquid (150). The pixel wall (160) includes a second conductive layer (180). The second conductive layer (180) and the first conductive layer (120) respectively constitute a positive electrode and a negative electrode. A voltage is applied between the first conductive layer (120) and the second conductive layer (180) to turn on the electrowetting display device. The pixel wall (160) further includes a first insulating layer (190) connected to the hydrophobic insulating layer (130), and a second conductive layer (180) disposed on the side of the first insulating layer (190) away from the hydrophobic insulating layer (130).

2. The electrowetting display device structure according to claim 1, characterized in that, The first insulating layer (190) is a photoresist, and the second conductive layer (180) is an Ag-containing photoresist.

3. The electrowetting display device structure according to claim 1, characterized in that, The height of the second conductive layer (180) accounts for 10%-50% of the total height of the pixel wall (160).

4. The electrowetting display device structure according to claim 1, characterized in that, The second conductive layer (180) is provided with conductive leads (200), which extend outward to conduct electricity.

5. The electrowetting display device structure according to claim 1, characterized in that, The second substrate (110) is made of ITO conductive glass.

6. The electrowetting display device structure according to claim 1, characterized in that, The first substrate (100) has a third conductive layer (210) on the side near the second substrate (110). Two hydrophobic insulating layers (130) are provided, which are respectively disposed on the first conductive layer (120) and the third conductive layer (210). Two pixel walls (160) are provided, which are respectively disposed on the side of the two hydrophobic insulating layers (130) that are close to each other. A power source is connected between the first conductive layer (120) and the second conductive layer (180) of the pixel wall (160) on the first substrate (100). Another power source is connected between the third conductive layer (210) and the second conductive layer (180) of the pixel wall (160) on the second substrate (110).

7. A method for preparing an electrowetting display device structure, used to prepare the electrowetting display device structure according to any one of claims 1-6, characterized in that, Includes the following steps: S10: Take a second substrate (110) having a first conductive layer (120), spin-coat a hydrophobic insulating layer (130) on the surface of the first conductive layer (120), and perform hydrophilic treatment on the hydrophobic insulating layer (130); S20: Photoresist and Ag-containing photoresist are spin-coated sequentially on the hydrophobic insulating layer (130), and then the second substrate (110) with photoresist and Ag-containing photoresist spin-coated is placed under a mask with a specific pattern for exposure to form a pixel wall (160). S30: Fill the pixel grid defined by the pixel wall (160) with a non-polar liquid (170); S40: The second substrate (110) obtained in step S30 is placed on a condensation stage for condensation, and then a pre-condensed polar liquid (150) is coated on the non-polar liquid (170). S50: Take the first substrate (100), attach the sealing frame (140) to the first substrate (100), then put the sealing frame (140) on the outside of the pixel wall (160) and press it against the second substrate (110) so that the polar liquid (150) is evenly distributed in the sealing frame (140), and excess polar liquid (150) flows out from between the sealing frame (140) and the second substrate (110). Then press and seal the first substrate (100), the sealing frame (140) and the second substrate (110).

8. The method for fabricating the electrowetting display device structure according to claim 7, characterized in that, In step S20, after spin-coating photoresist and Ag-containing photoresist in sequence, the second substrate (110) with spin-coated photoresist and Ag-containing photoresist needs to be placed in an environment of 110 degrees Celsius and heated for 120 seconds. After heating, it is allowed to cool down and then placed under a mask with a specific pattern for exposure.

9. The method for fabricating the electrowetting display device structure according to claim 7, characterized in that, In step S20, after the second substrate (110) coated with photoresist and Ag-containing photoresist is exposed under a mask with a specific pattern, it needs to be baked in an environment of 110 degrees for 120 seconds. After baking, it is developed and dried to obtain the required pixel wall (160).

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