KR101343800B1 - Electrophoretic display device and method of fabricating the same - Google Patents

Abstract

Embodiments of the present invention relate to an electro-optical display device and a manufacturing method thereof. An electrophoretic display device according to an embodiment of the present invention comprises: first and second substrates facing each other; A plurality of cells in which a space between the first substrate and the second substrate is divided in a direction parallel to a main surface of the substrates by a plurality of partition walls disposed between the first substrate and the second substrate; And a light conversion layer including a dielectric solution filling each of the plurality of cells and at least one kind of electrophoretic particles dispersed in the dielectric solution. A plurality of MOS transistors formed on the first substrate, each of the plurality of MOS transistors including a gate electrode, a source electrode, and a drain electrode spaced apart from the gate electrode; Gate lines electrically connected to the gate electrodes of the plurality of MOS transistors, respectively; Data lines intersecting the gate lines and electrically connected to the source electrodes of the plurality of MOS transistors; And individual electrodes electrically connected to the drain electrodes of the plurality of MOS transistors to apply a driving voltage to the plurality of cells. The photoconversion layer and the first substrate are formed without an adhesive layer between the bottom of the plurality of cells and the individual electrodes.

Description

Electrophoretic display device and method of fabricating the same

The present invention relates to display technology, and more particularly, to an electrophoretic display device and a method of manufacturing the same.

An information display device for replacing a liquid crystal display device, the display using a technique such as electrophoresis, electro-chromic, dichroic particles rotary method or dry powder transfer method An apparatus has been proposed. These techniques have been extensively studied as next generation display devices that can replace liquid crystal display devices due to advantages such as wide viewing angle, low power consumption and memory effect in proximity to conventional print media.

Among these display devices, an electrophoretic display device has electrophoretic particles dispersed in two electrodes and a dielectric fluid closed between the two electrodes, and the particles are separated by an electric field applied between the electrodes. Display information using the phenomenon of flow.

In the electrophoretic display device, attempts have been made to divide the space between the electrodes into smaller cells in order to improve undesirable properties such as precipitation of electrophoretic particles. A representative example is an electrophoretic device using microcapsules as disclosed in US Pat. No. 5,961,804.

However, the manufacturing process of the display device using the microcapsules is very sensitive to moisture and temperature due to the chemical properties of the capsule wall of the microcapsules, the thin capsule wall has a problem that is vulnerable to scratches. To solve these problems, a structure for inserting microcapsules using a transparent polymer matrix or a binder has been proposed between two substrates as disclosed in US Pat. No. 6312304. Conventional polymer matrices or structures employing the binder consist essentially of a method of separately manufacturing the image media comprising the lower substrate and microcapsule layer on which the drive element is formed. The image media generally includes a microcapsule layer dispersed in a binder and a common electrode sequentially stacked on the substrate. In order to complete the electrophoretic display device, a process of bonding the image media to the lower substrate on which the driving device is formed by using an adhesive layer is required. As a similar example, an image media having a microcup-shaped cell using an embossing process as disclosed in US Pat. Complete the device.

The conventional technique of manufacturing an electrophoretic display device by separately manufacturing the lower substrate on which the image media and the driving element are formed, and bonding the image media and the lower substrate on which the pixel electrode is exposed using an adhesive layer applied therebetween. Because of the adhesive layer, the distance between electrodes between the upper substrate and the lower substrate is increased, resulting in a problem of increasing the response speed of the electrophoretic particles, lowering the contrast ratio, and increasing the driving voltage. In addition, since the electrical and chemical properties must be considered separately in selecting a suitable material to improve this, there are many restrictions. In addition, alignment between the cells of the image media and the driving elements of the lower substrate is difficult, and the misalignment thereof causes deterioration in image quality due to cross-talk between adjacent cells during driving. This deterioration of image quality occurs more frequently in multi-color electrophoretic devices comprising subpixels of different colors. This misalignment may reduce the aperture ratio and result in a decrease in contrast ratio.

Therefore, the technical problem to be achieved by the present invention, unlike the conventional image media, there is no fear of increasing the distance between the electrodes, it is possible to ensure a faster response speed and a lower driving voltage without lowering the optical characteristics of the display device, It is an object of the present invention to provide an electrophoretic display device in which an alignment process between cells and a lower substrate on which a driving element is formed is easy, and image quality is not degraded by reflected light of a wiring layer formed on the lower substrate.

Another object of the present invention is to provide a method of manufacturing an electrophoretic display device having the aforementioned advantages.

According to one or more exemplary embodiments, an electrophoretic display device includes: first and second substrates facing each other; A plurality of cells in which a space between the first substrate and the second substrate is divided in a direction parallel to a main surface of the substrates by a plurality of partition walls disposed between the first substrate and the second substrate; And a light conversion layer including a dielectric solution filling each of the plurality of cells and at least one kind of electrophoretic particles dispersed in the dielectric solution. A plurality of MOS transistors formed on the first substrate and including a gate electrode, a source electrode, and a drain electrode spaced apart from each other by the gate electrode; Gate lines electrically connected to the gate electrodes of the plurality of MOS transistors, respectively; Data lines intersecting the gate lines and electrically connected to the source electrodes of the plurality of MOS transistors; And individual electrodes electrically connected to the drain electrodes of the plurality of MOS transistors to apply a driving voltage to the plurality of cells. The light conversion layer and the first substrate of the electrophoretic display device are formed without an adhesive layer between the bottom of the plurality of cells and the individual electrodes.

In some embodiments, the electrophoretic display device may further include a common electrode on a main surface facing the individual electrodes of the second substrate. In addition, the electrophoretic display apparatus may further include an opaque film on the bottom of the plurality of partition walls so as to overlap the gate lines and the data lines. The opaque film may be a black matrix.

In some embodiments, the opaque film may extend over the bottom of the cells. In this case, the opaque film may be a black layer, a white layer or a colored pattern layer.

In some embodiments, the barrier ribs may have a pitch in a range of 15 μm to 20 mm, and the gate lines and data lines may have a pitch in a range of 1 μm to 20 mm. In addition, the electrophoretic display device may further include a color filter layer having color regions embedded between the opaque layers and disposed under the individual electrodes. In some embodiments, the display device may further include a sealing layer disposed at a boundary between the plurality of cells and the second substrate.

According to one or more exemplary embodiments, a method of manufacturing an electrophoretic display device according to an embodiment of the present invention may include a gate electrode, a source electrode spaced apart from each other by a gate electrode, and arranged in a matrix form on a first substrate; A plurality of MOS transistors including a drain electrode; Gate lines electrically connected to the gate electrodes of the plurality of MOS transistors, respectively; And forming data lines crossing the gate lines and electrically connected to the source electrodes of the plurality of MOS transistors, respectively. Forming a plurality of individual electrodes electrically connected to the drain electrodes of the plurality of transistors on the first substrate, respectively; Forming a plurality of partition walls spaced apart in a direction parallel to a main surface of the first substrate on the first substrate; Filling a dielectric solution and at least one kind of electrophoretic particles dispersed in the dielectric solution into each of the plurality of cells defined by the plurality of partitions; And coupling a second substrate to the first substrate.

In some embodiments, the forming of the common electrode on the main surface facing the individual electrodes of the second substrate may be further performed. In addition, before the forming of the plurality of barrier ribs, an opaque layer may be further formed on the first substrate to overlap the gate lines and the data lines, and the plurality of barrier ribs may be opaque. It can be formed on the film. In some embodiments, the opaque film may be a black matrix.

In some embodiments, a step of forming a planarization layer between the opaque layers may be further performed. In addition, the opaque film may be formed to extend to the entire bottom surface of the cells. In this case, the opaque film may be a black layer, a white layer or a colored pattern layer.

In addition, before the bonding of the second substrate, a step of forming a sealing layer disposed on a boundary between the plurality of cells and the second substrate may be further performed.

In the electrophoretic display device according to the embodiments of the present invention, since the light conversion layer and the first substrate are in contact with the bottom surface of the plurality of cells and without the adhesive layer between the individual electrodes, the electrophoretic display device may be connected with the conventional image media. Alternatively, the distance between the electrodes can be minimized, thereby ensuring fast response speed and low driving voltage of the electrophoretic particles. In addition, an electrophoretic display device having an easy alignment process between the lower substrate and the partition walls on which the driving element is formed by the opaque film disposed below the partition wall, and without deterioration of image quality due to the reflected light caused by the wiring structure on the lower substrate, and its A manufacturing method can be provided.

1A is a cross-sectional view and a plan view of an electrophoretic display device according to an embodiment of the present invention.
2 is a cross-sectional view showing an electrophoretic display device according to another embodiment of the present invention.
3A to 3F are cross-sectional views illustrating a method of manufacturing an electrophoretic display device according to an embodiment of the present invention in a process sequence.
4A and 4B are cross-sectional views and plan views illustrating an electrophoretic display apparatus according to one embodiment of the present invention.
5A and 5B are cross-sectional views and plan views illustrating an electrophoretic display device according to other embodiments of the present invention.
6A through 6D are cross-sectional views illustrating a method of manufacturing the electrophoretic display devices described above with reference to FIGS. 4A through 5B according to a process sequence.
7A and 7B are cross-sectional views illustrating electrophoretic display devices according to other embodiments of the present invention.
8A and 8B are cross-sectional views illustrating electrophoretic display devices according to other embodiments of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, It is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more faithful and complete, and will fully convey the scope of the invention to those skilled in the art.

In the drawings, the thickness and size of each layer are exaggerated for convenience and clarity of description, and the same reference numerals refer to the same elements in the drawings. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

Although the terms first, second, etc. are used herein to describe various members, parts, regions, and / or parts, these members, parts, regions, and / or parts should not be limited by these terms. Is self-explanatory. These terms are only used to distinguish one member, part, region or part from another region or part. Thus, the first member, part, region, or portion, which will be described below, may refer to the second member, component, region, or portion without departing from the teachings of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing ideal embodiments of the present invention. In the drawings, for example, the size and shape of the members may be exaggerated for convenience and clarity of description, and in actual implementation, variations of the illustrated shape may be expected. Accordingly, embodiments of the present invention should not be construed as limited to the specific shapes of the regions shown herein.

1A and 1B are cross-sectional views and a plan view illustrating an electrophoretic display apparatus 100 according to an exemplary embodiment of the present invention, and FIG. 1A is a cross-sectional view taken along the line IA-IB of FIG. 1B.

1A and 1B, the electrophoretic display apparatus 100 may include a first substrate 10 (which may be a lower substrate in this drawing) and a second substrate 20 facing the lower substrate 10 (in this drawing). Upper substrate). In one embodiment, at least one of the lower substrate 10 and the upper substrate 20, for example, the upper substrate 20 may be transparent, and the lower substrate 10, which is the other, may not be transparent. Alternatively, both the lower substrate 10 and the upper substrate 20 may be transparent.

The lower substrate 10 and the upper substrate 20 may be formed of an inorganic material having a glass substrate, single crystal or polycrystalline structure. The substrates 10 and 20 may be flexible, and in this case, the substrates 10 and 20 may be formed of a resin-based material. The resin material may be, for example, various cellulose resins; Polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); Polyethylene resins; Polyvinyl chloride resin; Polycarbonate (PC); Polyethersulfone (PES); Polyetheretherketone (PEEK); And polyphenylene sulfide (PPS), or a combination thereof. However, these materials are exemplary only, and the present invention is not limited thereto.

Between these substrates 10 and 20, a plurality of partitions 30 are disposed. The space between the substrates 10 and 20 by the plurality of partitions 30 is divided in a direction parallel to the main surfaces of the substrates 10 and 20, and the cells V1, V2, V3) is defined. Each cell, alone or in combination with other adjacent one or more cells, may constitute one sub-pixel or pixel. The pattern of the barrier ribs 30 may define a pixel pattern of the electrophoretic display apparatus 100. For example, the partitions 30 may have a polygonal shape such as a rectangle, a triangle, a pentagon, a circle, an ellipse, a grid, a honeycomb, a meander, or a line when viewed from the position of the observer 1. Can be arranged.

The height of the partitions 30 may be within 1 μm to 0.1 mm, and the width of the partitions 30 may be 5 μm to 10 mm. In addition, the spacing between the partitions 30 may be 10 ㎛ to 10 mm. The pitch of adjacent partitions 30 may range from 15 μm to 20 mm. The cross-sectional profile of the partitions 30 may be substantially perpendicular to the major surface of the lower substrate 10, as shown. However, the present invention is not limited thereto, and the cross-sectional profile of the partition walls 30 may have a tapered shape or a reverse tapered shape in which the width gradually decreases toward the upper substrate.

The plurality of partitions 30 may be formed of, for example, a polymer material such as polyethylene, polystyrene, polycarbonate, polyimide, epoxy resin, silicone resin, melamine resin, acrylic resin, phenol resin, or a combination thereof. Can be. Alternatively, the partitions 30 may be formed of a photosensitive resin material capable of performing a photolithography process. However, the present invention is not limited thereto, and the partition walls 30 may be formed of an insulating inorganic material such as ceramic, a metal material coated with an insulating material, or a combination of two or more of the above materials, for example, coated with an insulating material. It may be formed of a polymer material including metal particles or a polymer material including inorganic particles.

The electrophoretic display apparatus 100 includes electrodes for generating an electric field in the cells V1, V2, V3. In the embodiment illustrated in FIG. 1A, the electrodes may include electrodes 41 and 42 facing each other to generate an electric field perpendicular to the main surfaces of the substrates 10 and 20. The electrodes 42 on the lower substrate 10 may include individual electrodes 42R, 42G, and 42B for each cell. In addition, the electrode on the upper substrate 20 may include a common electrode 30c opposite the individual electrodes 42. Although not shown, in some embodiments, a plurality of individual electrodes may be formed in each cell defined by the partitions so that a plurality of individual electrodes may be assigned to each cell, in which case the gradation within one cell Can be expressed.

At least one of these electrodes 41 and 42 may be a transparent electrode. For example, the common electrode 41 on the upper substrate 20 that provides the viewer 1 with a visible surface is a transparent electrode. In addition, to form a transmissive display device, the pixel electrodes 42 may also be transparent electrodes. The transparent electrode may include, for example, Indium-Tin-Oxide (ITO), Fluorinated Tin Oxide (FTO), Indium Oxide (IO), and Tin Oxide; It may be formed of any one or a combination of a transparent metal oxide such as SnO ₂ ), a transparent conductive resin such as polyacetylene, or a conductive resin containing conductive metal fine particles, but the present invention is not limited thereto. . On these electrodes 41 and 42, a suitable electrically insulating protective film (not shown) for protecting them may be formed.

Individual electrodes 42 may be driven by a suitable switch element, for example MOS thin film transistor 50. The MOS thin film transistor 50 has a semiconductor layer 50A having a channel region and a source / drain region, a gate electrode 50G, a gate insulating film 50I between the semiconductor layer 50A and the gate 50G, and a gate 50G. The source electrode 50S and the drain electrode 50D may be electrically connected to the source / drain regions spaced apart from each other. In some embodiments, an ohmic contact layer 50C may be formed between the source / drain region of the semiconductor layer 50A and the source electrode 50S and the drain electrode 50D. The MOS thin film transistor 50 may be electrically isolated from other adjacent members by the passivation film 60 formed of a suitable insulating material.

Although the MOS thin film transistor 50 of FIG. 1A is disclosed as having an inverted-staggered electrode structure in which the gate electrode 50G is disposed toward the lower substrate 10, those skilled in the art will appreciate that It will be appreciated that 50 may have a known staggered structure.

As shown in FIG. 1B, the MOS thin film transistors 50 may be disposed on the lower substrate 10, for example, in an array of a plurality of rows by a plurality of columns. In order to drive the MOS thin film transistors 50, the source electrode 50S may be electrically connected to the data lines 51 extending in the x direction. In addition, the gate electrode 50G of the MOS thin film transistors 50 may extend in the y direction to be electrically connected to the gate lines 52 crossing the data lines 51. The pitch of each of the adjacent gate lines and data lines may range from 1 μm to 20 mm. Data pads 51P and gate pads 52P are respectively provided at one end of the data lines 51 and the gate lines 52 and electrically connected to a peripheral circuit (not shown). Individual electrodes 42R, 42G, 42B are driven through drain electrode 50D of MOS thin film transistors 50 addressed by data lines 51 and gate lines 52.

In the embodiment shown in FIG. 1B, an active matrix having a row by column array in which the MOS thin film transistors 50 are orthogonal is illustrated, but the MOS thin film transistors according to the embodiment of the present invention are rectangular, triangular, circular, It is apparent that the array may have other types of arrays corresponding to the pixel shape of the grid type or honeycomb type. In addition, in the present embodiment, the active matrix by the MOS thin film transistors 50 is shown, but this is only illustrative, those skilled in the art, a passive matrix electrode configuration for other dynamic driving, or a segmentation scheme for static driving It will be appreciated that the electrode configuration of may also be included in the embodiment of the present invention.

Referring again to FIG. 1A, a plurality of cells defined by the partitions 30 are filled with a dielectric solution and at least one kind of electrophoretic particles dispersed in the dielectric solution. The dielectric fluid 71 is a fluid having high resistance and low viscosity. The dielectric fluid 71 may be a single fluid or a mixture of two or more fluids. The specific gravity of the dielectric fluid 71 may be made to be substantially the same as the specific gravity of the particles 72a and 72b dispersed in the dielectric fluid 71.

The dielectric fluid 71 may be a nonaqueous solution or a nonpolar liquid. For example, the dielectric fluid 71 is a hydrocarbon-containing solution such as decahydronaphthalene (DECALIN), 5-ethylidene-2-norbornene, fatty acid ester and paraffin oil, toluene, xylene, phenylxylylylethane, dodecylbenzene and alkylnaphtalene Aromatic hydrocarbon-containing solutions such as perfluorodecalin, perfluorotoluene, perfluoroxylene, dichlorobenzotrifluoride, 3,4,5-trichlorobenzotrifluoride, chloropentafluro-benzene, dichlorononane, pentachlorobenzene and tetrachloroethylene. In addition to the particles 42 within the dielectric fluid 71, charge-controlling agents, cationic or anionic surfactants, metal soaps, resin materials, metal-based coupling agents and stabilizing agents Various functional additives such as can be added.

The dielectric fluid 71 may be colored with transparent or dispersed dyes and / or pigments. In some embodiments, dielectric fluid 71 may be colored with a light absorbing color, such as gray or black, to block the color of visible particles 72a and 72b.

Particles 72a and 72b dispersed in dielectric fluid 71 are a kind of electrophoresis having a single color, for example, one of black and white, in each cell to achieve a mono chrome display. Particles or two kinds of electrophoretic particles.

Alternatively, as illustrated in FIG. 1A, the particles may include two or more kinds of electrophoretic particles 72a and 72b having different colors in each cell V1, V2, and V3, and these particles may be different from each other. It may have a mobilization mobility. Particles 72a and 72b may include electrophoretic particles having different colors, such as red, green, and blue, rather than achromatic colors, in each cell. For example, in order to implement a multi-color display according to the additive color mixing method using the RGB color system, the first cell V1, the second cell V2, and the third cell V3 are respectively a red, green, and blue subfields. In the case of a pixel, the first cell V1 may include red electrophoretic color particles 72R. Similarly, the second cell V2 and the third cell V3 may include green and blue electrophoretic color particles 72G and 72B, respectively. In another embodiment, the color particles 72b of the first cell V1, the second cell V2, and the third cell V3 are cyan and magenta, respectively, in order to implement multi-color by the CMY color system. It may comprise colored and yellow electrophoretic color particles. In some embodiments, each of the cells V1, V2, and V3 may further include black particles 72a having electrophoretic mobility along with these color particles 72R, 72G, and 72B. The distinguishing drive of the color particles 72b and the black particles 72a causes the observer 1 to identify the displayed information.

In some embodiments, the plurality of cells V1, V2, V3 filled with the dielectric fluid and the electrophoretic particles may be sealed by a sealing layer 80 disposed at the boundary in contact with these cells and the upper substrate 20. Can be. The sealing layer 80 may have a thickness of about 0.01 μm to about 1000 μm. The sealing layer 80 may be a transparent resin layer such as acrylate, vinylbenzene, epoxide, oligomer, silicone resin, polyimide resin, polyalkene resin or other crosslinkable polymer. Sealing layer 80 may be provided by applying the sealing composition onto dielectric fluid 71 and performing a suitable curing process, such as UV irradiation, electron beam irradiation, or heating. Optionally, the sealing composition may further include any one or a combination of polymer-based adhesives, photoinitiators, catalysts, fillers and surfactants as an additive. The above-described sealing composition is exemplary and the present invention is not limited thereto. For example, the sealing composition may comprise other materials that are not mixed with the dielectric fluid 71 and are less than the specific gravity of the dielectric fluid and electrophoretic particles.

2 is a cross-sectional view illustrating an electrophoretic display apparatus 200 according to another embodiment of the present invention.

Referring to FIG. 2, the electrophoretic display apparatus 200 further includes a color filter layer 90 between the upper substrate 20 and the partition wall 30, unlike the apparatus 100 illustrated in FIG. 1A. For example, the color filter layer 90 may be disposed between the substrate 20 and the common electrode 41 as shown in FIG. 2. Optionally, the color filter layer 90 may be disposed between the light conversion layer 70 and the common electrode 41. When the color filter layer is formed on the upper surface of the upper substrate 20, that is, the surface opposite to the surface in contact with the light conversion layer 70, the light loss increases due to the light guiding effect of the upper substrate 20. As a result, light transmittance may be reduced. However, when the color filter layer 90 is formed between the illustrated embodiment and, optionally, the light conversion layer 70 and the common electrode 41, the light loss is minimized and the light transmittance is improved, resulting in excellent color. Can express.

The color filter layer 90 may include color regions 90R, 90G, and 90B separated from each other by the partition wall 30. For example, in order to implement a multi-color display according to the additive color mixing method using the RGB color system, the first cell V1, the second cell V2, and the third cell V3 are respectively a red, green, and blue subfields. In the case of a pixel, the color filter layer 90 may include a red region on the first cell V1, a green region on the second cell V2, and a blue region on the third cell V3. In this case, the particles in cells V1, V2, V3 may contain only a single type of electrophoretic particles of white or black, as described above. Alternatively, as shown in FIG. 2, two types such as black electrophoretic particles 72a and white electrophoretic particles 72b having different electrophoretic mobility determined according to the sign of the charge and / or the magnitude of the charge amount It may include the above electrophoretic particles.

These two or more kinds of particles, unlike the electrophoretic display apparatus 100 of FIG. 1A, may be commonly dispersed in the cells V1, V2, and V3. These particles can be combined with the color regions 90R, 90G, 90B of the color filter layer 90 to achieve multi-color by distinct drive.

In the embodiments described above with reference to FIGS. 1A-2, electrophoretic particles 72a, 72b flow by an electric field applied within each cell V1, V2, V3, while the dielectric solution 71 and Together with the partitions 30, a light conversion layer 70 for displaying information by light reflection and / or light absorption is constituted. In the above-described embodiments, there is no adhesive layer between the light conversion layer 70 and the individual electrode 42R. That is, the electrophoretic display apparatuses according to the embodiment of the present invention are manufactured by fabricating a lower substrate including individual electrodes through a separate manufacturing process from the image media, and then bonding them by using an adhesive layer. It is distinguished by. According to the embodiment of the present invention, since there is no adhesive layer between the individual electrodes and the cell, the distance between the upper electrode 42c and the individual electrodes can be minimized, thereby reducing the reaction time of the electrophoretic particles. In addition, it has the advantage that the driving voltage of the electrophoretic particles can be reduced.

3A to 3F are cross-sectional views illustrating a method of manufacturing an electrophoretic display device according to an embodiment of the present invention in a process sequence. In these figures, descriptions of constituent members having the same reference numerals as FIGS. 1A to 2 may refer to the disclosure of FIGS. 1A to 2 unless there is a contradiction.

Referring to FIG. 3A, as is well known in the art, a gate electrode 50G, a gate insulating film 50I, a semiconductor layer 50A, an ohmic contact layer 50C, and a source electrode may be formed on the lower substrate 10. MOS thin film transistors 50 including the 50S) and the drain electrode 50D are formed. These transistors 50 are arranged in an array of a plurality of rows x a plurality of columns on the lower substrate 10, as described above with reference to FIG. 1B, such that the data lines 51 and the gate lines are arranged. 52 can be formed in each of the areas where they cross. The data lines 51 and the gate lines 52 may be formed of aluminum, silver, copper, molybdenum, chromium, titanium, tantalum, alloys thereof, conductive oxides, or a combination thereof, and may form a single layer or multilayer structure. Can have

Surfaces of the MOS thin film transistors 50, the data lines 51 and the gate lines 52 may be electrically insulated from the adjacent members by the passivation layer 60. The passivation film 60 may include a low dielectric constant layer such as Si: C: O or Si: O: F formed by plasma chemical vapor deposition. In some embodiments, the passivation film 60 is patterned to expose the surfaces of the data lines 51 and one ends of the gate lines 52 to provide data pads 51P and gate pads 52P. Can be.

Referring to FIG. 3B, a planarization layer 65 may be further formed on the passivation film 60. The planarization layer 65 may also be formed by plasma chemical vapor deposition, like the passivation film 60, and may include a low dielectric constant layer. However, the passivation film 60 may be replaced with the planarization layer 65 by forming a film having excellent flatness or by forming an insulating film on the lower substrate 10 and subsequently planarizing it by a chemical mechanical polishing process. Thereafter, a conductive layer is formed on the passivation film 60 or the planarization layer 65 and patterned to form individual electrodes 42 each connected to the drain electrode 50D of the MOS thin film transistors. Individual electrodes 42 may have a rectangular pattern, as shown in FIG. 1B, but this is exemplary and may have a polygonal, circular, elliptical, honeycomb, line, or meander pattern, such as triangles and pentagons. .

In some embodiments, the data pads 51P and the gate pads 52P described above may be simultaneously formed along with the process of forming the individual electrodes 42. Individual electrodes 42 may be transparent electrodes as described above. Optionally, an insulating protective film (not shown) may be further formed on the individual electrodes 42.

Referring to FIG. 3C, barrier ribs 30 are formed on the passivation layer 60 or the planarization layer 65. The partitions 30 are formed between the individual electrodes 42, and preferably, may be formed on the data lines 51 and the gate lines 52 between the individual electrodes 42. The partition walls 30 are formed of a polymer material such as polyethylene, polystyrene, polycarbonate, epoxy resin, silicone resin, melamine resin, acrylic resin, phenol resin, or a combination thereof, as described above. Can be. Alternatively, the partitions 30 may be formed of a photosensitive resin-based material, or may be formed of an insulating inorganic material such as ceramic, a metal material coated with an insulating material, or a combination of two or more of the above materials.

The partitions 30 formed of the photosensitive photoresist may be formed through a known photolithography process by exposure and development. The barrier ribs 30 using a material other than the photosensitive photoresist may be formed by depositing a material layer to be the barrier ribs 30, forming a mask pattern on the material layer, and then performing an etching process. have. However, the process of forming such barrier ribs 30 is exemplary and the present invention is not limited thereto. For example, the barrier ribs 30 may be attached after aligning the barrier rib structure having a layer structure on the lower substrate 10 as disclosed in FIG. 5 of the applicant's Korean application 2008-97374. May be provided. Alternatively, the partitions 30 may also be formed by screen printing, drill bits, imprints, softlithography, laser drilling processes, or ink jet printing processes.

Referring to FIG. 3D, the dielectric solution 71 and the electrophoretic particles 72 dispersed in the dielectric solution 71 are filled in the cells defined by the partitions 30. If cells V1, V2, V3 contain the same dielectric solution and electrophoretic particles, electrophoresis dispersed in dielectric solution 71 and dielectric solution 71 by methods such as spraying and dipping with a dispenser Particles 72 may be filled into cells V1, V2, V3. However, if the composition of the dielectric solution 71 and / or the electrophoretic particles 72 is different for each of the cells V1, V2, V3, for example, the implementation of a multi-color display device as shown in eh 3d. For this purpose, each of the cells V1, V2, V3 corresponds to any one of the red, green and blue subpixels, and the red, green and blue color particles 72R, 72G, 72B within the cells V1, V2, V3. ), A mask layer (not shown) for selectively opening each of the cells V1, V2, and V3 is formed, and the process of filling the exposed cells is repeated several times, whereby different dielectric solutions and / or Or electrophoretic particles.

Optionally, nozzles, as shown in FIG. 3D, to fill different dielectric solutions 71 and / or electrophoretic particles 72 for the cells V1, V2, V3 constituting each subpixel. An inkjet method using (N1, N2, N3) can also be used. Particles 72 dispersed in each of the cells (V1, V2, V3) may include two kinds of particles (72K; 72R, 72G, 72B) different in color and electrophoretic mobility. In the inkjet method, the nozzles N1, N2, and N3 selectively spraying droplets on the respective cells scan the lower substrate 10 in the direction of the arrow A, and the dielectric solution 71 is formed in each of the cells. The electrophoretic particles 72 may be filled. Such an inkjet method has an advantage of omitting a mask forming process.

In some embodiments, the sealing layer 80 may subsequently be formed on the cells V1, V2, V3 filled with the dielectric fluid 71 and the electrophoretic particles 72, as shown in FIG. 3E. have. The sealing layer 80 may be provided by, for example, mixing the sealing layer composition together in the dielectric solution 71 to fill the cells, and then separating the sealing layer composition and the dielectric solution from each other. To this end, the sealing layer material may be a suitable material having a low solubility in the dielectric solution and a specific gravity smaller than that of the dielectric solution and the electrophoretic particles. For example, the sealing layer material may include any one or a combination of UV curing compositions including acrylates, acrylate oligomers, and photoinitiators having a multifunctional group, but the present invention is not limited thereto.

Optionally, the sealing layer 80 applies a sealing composition, such as acrylate, vinylbenzene, epoxide, oligomer, crosslinkable polymer, on the dielectric fluid 71 filled between the partition walls 30, It may then be provided by carrying out a suitable curing process such as UV irradiation, electron beam irradiation, or heating.

After completing the light conversion layer 70 composed of the plurality of cells (V1, V2, V3), the dielectric solution 71 and the electrophoretic particles 72 defined as the partition walls 30, shown in Figure 3f As described above, the electrophoretic display device (see 100 of FIG. 1) may be completed by combining the resultant and the upper substrate 20 on which the common electrode 41 is formed.

Optionally, in order to manufacture the electrophoretic display apparatus 200 having the color filter layer 90 as shown in FIG. 2, the color filter layer 90 and the common electrode 41 on the upper substrate 2 in order. After forming, it can be obtained by combining the upper substrate 20 and the lower substrate 10 as shown in Figure 3f.

4A and 4B are cross-sectional and plan views illustrating an electrophoretic display apparatus 300 according to one embodiment of the present invention. 4A is a cross-sectional view taken along the line IVA-IVB of FIG. 4B. In these figures, descriptions of the constituent members having the same reference numerals as the constituent members of FIGS. 1A to 3F may refer to the foregoing disclosure unless otherwise contradicted.

Referring to FIGS. 4A and 4B, the electrophoretic display apparatus 300, unlike the above-described devices (100 in FIG. 1A and 200 in FIG. 2), uses an opaque film 310 on the bottom of the partition walls 30. It includes more. The opaque film 310 may be an opaque layer for a wavelength range of any band of visible light or all wavelength bands of the visible light. For example, when the opaque film 310 has a predetermined pattern, such as the pattern of the partition walls 30, the opaque film 310 may be a black matrix. The opaque film 310 may be disposed on the MOS thin film transistor 50, the data lines 51 and the gate lines 52, as shown in FIG. 4B. The opaque film 310 is a polyethylene, polystyrene, polycarbonate, polyimide, epoxy resin, silicone resin, melamine resin, acrylic resin, phenolic resin containing a metal or dye and / or pigment such as chromium having excellent light shielding properties. It may be formed of a polymer resin material such as a resin. Preferably, the polymer resin material may be a photosensitive resin composition capable of a photolithography process. These opaque film materials are exemplary, and this invention is not limited to this. For example, the opaque film 310 may be an insulating inorganic material such as metal oxide and ceramic.

In some embodiments, the opaque film 310 may be formed on the passivation film 60 formed on the MOS thin film transistor 50, as shown in FIG. 4A. Optionally, the opaque film 310 may be formed on the planarization film (65 in FIG. 1A) deposited on the MOS thin film passivation film 60, as described above with reference to FIG. 1A.

In some embodiments, the space between the opaque films 310 may be filled with the planarization layer 66, as shown in FIG. 4A, to improve the step by the opaque film 310. The planarization layer 66 may be, for example, a silicon oxide film, a silicon nitride film, or a combination thereof. The upper surface of the planarization layer 66 may have the same height as the upper surface of the opaque film 310A by the planarization process described later. The individual electrodes 42 are formed on the planarization layer 66 and are electrically connected to the drain electrodes of the MOS thin film transistor 50 through the planarization layer 66.

The electrophoretic display device 300 includes a dielectric solution 71 and electrophoretic particles 72 in the cells V1, V2, V3 defined by the partitions 30, as described above, and the partition wall On the fields 30, the upper substrate 20 on which the common electrode 41 is formed may be disposed. In some embodiments, the electrophoretic display apparatus 300 includes a color region corresponding to each of the cells V1, V2, and V3 between the upper substrate 20 and the common electrode 41, as shown in FIG. 2. It may further include a color filter 90 having the fields 90R, 90G, 90B.

In general, the data lines and the gate lines are formed of a metal film. In view of this, in the case of an electrophoretic display device, particularly a reflective electrophoretic display device, light incident through the upper substrate 20 is reflected by the data lines and the gate lines to be observed by the observer 1. Can be. In particular, when the arrangement period of the partition walls 30 disposed on the data lines and the gate lines and the arrangement period of the lines correspond to a period in which incident light and reflected light can interfere, regular with new periods. Optical interference fringes or grid fringes may occur, and the image quality of the display device is degraded by such interference.

The inventors have shown that the partitions 30 are transparent, the partitions 30 have a pitch in the range of 30 μm to 500 μm, and the pitch of the data lines and gate lines formed on the lower substrate is in the range of 5 μm to 500 μm. When there was, it was observed that interference fringes occurred badly depending on the viewing angle of the observer. However, according to the present embodiment, as the incident light i _x is absorbed by the opaque film 310 as shown in FIG. 4A, the reflected light caused by the data lines and the gate lines is not generated. In this way, generation of fringes due to light interference can be suppressed. Therefore, according to embodiments of the present invention, while the response speed and the driving voltage of the particles are reduced by the barrier rib structure without the adhesive layer, the reduction in the contrast ratio and the image quality deterioration due to the optical interference, which may result from the repeated barrier rib structure, are reduced. It can be suppressed. In addition, as an additional advantage of the opaque film 310, the alignment margin between the partition wall 30, the data lines, and the gate lines is increased when the partition walls 30 are formed, thereby facilitating the process.

5A and 5B are cross-sectional and plan views illustrating an electrophoretic display apparatus 400 according to other embodiments of the present invention. FIG. 5A is a cross-sectional view taken along the line VA-VB of FIG. 5B. In these figures, descriptions of the constituent members having the same reference numerals as the constituent members of FIGS. 1A to 4B may refer to the foregoing disclosure unless otherwise contradicted.

Referring to FIGS. 5A and 5B, the electrophoretic display apparatus 400 may further include an opaque film 410 on the bottom of the partition walls 30, like the electrophoretic display apparatus 300 described above with reference to FIG. 4A. Include. The opaque film 410 may be a black matrix. Some of the individual electrodes 42R, 42G, 42B may extend over the edge of the adjacent opaque film 410. In some embodiments, the individual electrodes 42R, 42G, 42B surround, as in the illustrated embodiment, all adjacent data lines 51 and gate lines 51, i.e., surrounding each subpixel. It may extend all over the edges of the opaque film 410 formed on the data lines 51 and the gate lines 52.

The opaque film 410 is a polyethylene, polystyrene, polyimide, polycarbonate, epoxy resin, silicone resin, melamine resin, acrylic resin, phenol resin, or the like containing a metal such as chromium, metal oxide or dye and pigment It may be formed of a polymeric resin material. Preferably, the polymer resin material may be a photosensitive resin composition capable of a photolithography process. These opaque film materials are exemplary, and this invention is not limited to this. For example, the opaque film 310 may be an insulating inorganic material such as ceramic. In some embodiments, when the opaque film is formed of a conductive material, an insulating layer 415 may be further formed on the opaque film 410 to electrically insulate the individual electrodes 42R, 42G, and 42B. In addition, in order to improve the level difference caused by the opaque film 410, the space between the opaque films 410 may be filled with the planarization layer 66.

The individual electrodes 42 are electrically connected to the drain electrode 50D of the MOS thin film transistor 50 through the planarization layer 66. In some embodiments, the electrophoretic display apparatus 400 includes color regions 90R, 90G, and 90B corresponding to the cells V1, V2, and V3 between the upper substrate 20 and the common electrode 41. It may further include a color filter 90 having. According to the exemplary embodiments of the present invention, incident light i _x passing through the partition walls 30 is absorbed by the opaque film 410, and thus, anti-phase light does not occur. Therefore, according to the embodiment of the present invention, along with image quality improvement, the alignment margin of the partition wall may be increased.

6A through 6D are cross-sectional views illustrating a method of manufacturing the electrophoretic display devices 300 and 400 described above with reference to FIGS. 4A through 5B according to a process sequence. In these figures, descriptions of the constituent members having the same reference numerals as the constituent members of the above-described drawings may refer to the foregoing disclosure unless otherwise contradicted.

Referring to FIG. 6A, an opaque film 310 is formed on the lower substrate 10. For example, an opaque film 310 is formed on the MOS thin film transistors 50 arranged in an array of a plurality of rows × a plurality of columns and a lower substrate 10 on which wiring structures such as data lines and gate lines are formed. After forming the insulating polymer material layer or insulating inorganic material layer to be formed, a photolithography and / or etching process may be performed to form an opaque film 310 having an opening that exposes the region where the planarization layer 66 is to be formed. have.

In some embodiments, the passivation film 60 may be further formed on the surfaces of the MOS thin film transistors 50, the data lines 51 and the gate lines 52 before forming the opaque film 310. Can be. Alternatively, a planarization layer (see 65 in FIG. 3B) may be further formed on the passivation film 60. The passivation film and the planarization layer may include a silicon oxide film, a silicon nitride film, or a low dielectric film such as Si: C: O and Si: O: F formed by plasma chemical vapor deposition.

Subsequently, in order to improve the step by the opaque film 310, a space between the opaque films 310 may be filled with the planarization layer 66. For example, an insulating layer filling the space between the opaque films 310 is deposited on the lower substrate 10 by using a plasma chemical vapor deposition process having excellent step coverage, and a chemical mechanical polishing process on the insulating layer. Alternatively, the planarization layer 66 may be formed by performing a planarization process such as an etch back process.

Referring to FIG. 6B, individual electrodes 42R, 42G, and 42B are formed through the planarization layer 66 and connected to the drain electrode 50D of the MOS thin film transistor. For example, an opening for exposing the drain electrode 50D is formed in the planarization layer 66 through a known photolithography and etching process, and an electrode material layer filling the opening is formed on the planarization layer 66. do. The electrode material layer may then be patterned to form individual electrodes 42R, 42G and 42B as shown in FIG. 6B.

As illustrated in FIG. 6B, the individual electrodes 42R, 42G, and 42B may be spaced apart from the opaque film 310 by a predetermined distance in a direction horizontal to the main surface of the substrate. Optionally, as shown in FIG. 5A, some of the individual electrodes 42R, 42G, 42B may be formed to extend over the edge of the opaque film 310. In this case, when the opaque film 310 is conductive, an insulating film 415 may be further formed on the opaque film 410, as shown in FIG. 6C. Thereafter, the space between the opaque layers 410 may be filled with the planarization layer 66. Subsequently, as shown in FIG. 6D, penetrating the planarization layer 66 and the insulating layer 415 is connected to the drain electrode 50D of the MOS thin film transistor and extends over the edge of the opaque film 410. Individual electrodes 42R, 42G, 42B can be formed.

7A and 7B are cross-sectional views illustrating electrophoretic display devices 500 and 600 according to other embodiments of the present invention. In these figures, descriptions of the constituent members having the same reference numerals as the constituent members of FIGS. 1A to 6D may refer to the foregoing disclosure unless otherwise contradicted.

7A and 7B, a color filter layer 90 may be further formed between the opaque films 510 and 610. The color filter layer 90 may have, for example, a red region 90R, a green region 90G, and a blue region 90B corresponding to the cells V1, V2, and V3 constituting the subpixel. As such, when the opaque films 510 and 610 and the color filter layer 90 are formed on the same substrate 10, there is an advantage in that alignment is easier than when they are formed on different substrates.

The color filter layer 90 may be formed of a polymer resin having a color by a pigment and / or a dye, and may be formed by at least one photolithography process or an inkjet process. The individual electrodes 42R, 42G, and 42B are spaced apart by a predetermined distance in the horizontal direction of the main surface of the opaque film 510 and the substrate 20, as shown in FIG. 7A, or as shown in FIG. 7B. It may extend over the edge of the membrane 610. In some embodiments, an insulating layer 615 may be further formed on the opaque film 610.

8A and 8B are cross-sectional views illustrating electrophoretic display apparatuses 700 and 800 according to other embodiments of the present invention. In these figures, descriptions of the constituent members having the same reference numerals as the constituent members of FIGS. 1A to 7B may refer to the foregoing disclosure unless otherwise contradicted.

Referring to FIG. 8A, the opaque film 710 is different from the opaque film described above with reference to FIGS. 4A to 7B, and MOS thin film transistors 50 and data lines arranged in an array of a plurality of rows by a plurality of columns. And not only onto the wiring structure as the gate lines, but also to the bottom of the cells V1, V2, V3. For example, as shown in FIG. 8A, the opaque film 710 may extend from the bottom of the partition walls 30 to the entire bottom surface of the cells V1 V2 and V3. In this case, the opaque film 710 may be a black layer, a white layer, or a colored layer.

In order to form the opaque film 710, a material layer to be an opaque film, for example, a metal layer or a dye such as chromium, on the entire lower substrate 10 on which the MOS thin film transistors 50 and the wiring structures 51 and 52 are formed. And / or a polymer resin material layer such as polyethylene, polyimide, polystyrene, polycarbonate, epoxy resin, silicone resin, melamine resin, acrylic resin, or phenol resin containing a pigment. Thereafter, in order to form the data pads 51P and the gate pads 52P, a process of forming an opening for exposing the pad portion in these material layers may be performed. Referring to FIG. 8B, the planarization layer 65 may be further formed before the opaque film 810 is formed. Accordingly, the flatness of the opaque film 810 extended to the entire bottom surface of the cells V1, V2, and V3 may be improved.

Individual electrodes 42R, 42G, and 42B are electrically connected to the drain electrodes 50D of the MOS transistors through the opaque films 710 and 810. Although not shown, an insulating layer (see 615 of FIG. 7B) may be further formed between the opaque films 710 and 810 and the individual electrodes 42R, 42G, and 42B. Optionally, the color filter layer 90 may be disposed between the upper substrate 20 and the common electrode 41. Optionally, the color filter layer 90 may be disposed between the light conversion layer 70 and the common electrode 41. When the color filter layer is formed on the upper surface of the upper substrate 20, that is, the surface opposite to the surface in contact with the light conversion layer 70, the light loss increases due to the light guiding effect of the upper substrate 20. This decreases the light transmittance. However, by forming the color filter layer 90 between the illustrated embodiment and, optionally, the light conversion layer 70 and the common electrode 41, the light loss is minimized and the light transmittance is improved, resulting in excellent color expression. Can be obtained.

As such, when the opaque films 710 and 810 extend from the bottom of the partitions 30 to the entire bottom surface of the cells V1, V2, and V3, the partitions 30 and the MOS thin film transistors 50 and data There is an advantage that the process burden for aligning with wiring structures such as lines and gate lines can be minimized.

Although the above-described embodiments illustrate electrode configurations opposed to each other, those skilled in the art will appreciate that a cell structure having an in-plane electrode structure in a cell defined by a partition wall is also included in the scope of the present invention.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and alterations are possible within the scope without departing from the technical spirit of the present invention, which are common in the art. It will be obvious to those who have knowledge

.

Claims (21)

Lower and upper substrates facing each other;
A plurality of cells in which a space between the lower substrate and the upper substrate is divided in a direction parallel to a main surface of the substrates by a plurality of partition walls disposed between the lower substrate and the upper substrate; And a light conversion layer including a dielectric solution filling each of the plurality of cells and at least one kind of electrophoretic particles dispersed in the dielectric solution.
A plurality of MOS transistors formed on the lower substrate, each of the plurality of MOS transistors including a gate electrode, a source electrode, and a drain electrode spaced apart from the gate electrode;
Gate lines electrically connected to the gate electrodes of the plurality of MOS transistors, respectively;
Data lines intersecting the gate lines and electrically connected to the source electrodes of the plurality of MOS transistors;
Individual electrodes electrically connected to the drain electrodes of the plurality of MOS transistors to apply a driving voltage to the plurality of cells;
An opaque film extending below the plurality of cells from below the plurality of partitions; And
It includes a color filter layer formed on the upper substrate,
And an adhesive layer is not formed on an upper surface of one or more of the individual electrodes formed on the lower substrate. delete delete delete delete The method of claim 1,
The opaque film is an electrophoretic display device, characterized in that the black layer, white layer or colored layer. The method of claim 1,
And an insulating protective film is formed on one or more of the individual electrodes. delete delete delete delete A plurality of MOS transistors arranged in a matrix form on a lower substrate and each including a gate electrode, a source electrode, and a drain electrode spaced apart from the gate electrode; Gate lines electrically connected to the gate electrodes of the plurality of MOS transistors, respectively; And forming data lines crossing the gate lines and electrically connected to the source electrodes of the plurality of MOS transistors, respectively.
Forming a plurality of individual electrodes electrically connected to the drain electrodes of the plurality of transistors on the lower substrate;
One end may be formed on the lower substrate while defining a plurality of cells spaced apart in a direction parallel to a main surface of the lower substrate, without forming an adhesive layer on an upper surface of one or more of the individual electrodes formed on the lower substrate. Forming a plurality of attached partitions;
Filling a dielectric solution and at least one kind of electrophoretic particles dispersed in the dielectric solution into each of the plurality of cells defined by the plurality of partitions; And
Coupling an upper substrate to the other end of the plurality of partition walls so as to face the lower substrate,
Prior to forming the plurality of partitions, further comprising forming an opaque film extending below the plurality of cells from below the plurality of partitions,
And forming a color filter layer on the upper substrate before coupling the upper substrate to the other ends of the plurality of partition walls so as to face the lower substrate. . delete delete delete delete delete 13. The method of claim 12,
The opaque film is a manufacturing method of an electrophoretic display device, characterized in that the black layer, white layer or colored layer. 13. The method of claim 12,
A method of manufacturing an electrophoretic display device, characterized in that an insulating protective film is further formed on one or more of the individual electrodes. delete delete

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