WO2012033376A2

WO2012033376A2 - Electrophoretic display device, image sheet, and method for producing the device and the image sheet

Info

Publication number: WO2012033376A2
Application number: PCT/KR2011/006689
Authority: WO
Inventors: 김재환; 조영태; 정민영; 이창빈; 이용의; 김철환
Original assignee: 주식회사 이미지앤머터리얼스
Priority date: 2010-09-09
Filing date: 2011-09-09
Publication date: 2012-03-15
Also published as: WO2012033376A3; KR20120026163A; KR101209550B1

Abstract

The present invention relates to an electrophoretic display device, to an image sheet, and to a method for producing the device and the image sheet. The method for producing the electrophoretic display device according to one embodiment of the present invention comprises the following steps: forming a plurality of separating members on a first substrate, wherein each separating member has a sidewall; filling grooves defined by the plurality of separating members with a plurality of electrophoretic particles; forming a cover layer on a second substrate; coupling the second substrate to the first substrate such that the cover layer tightly contacts the upper surfaces of the sidewalls; and hardening the cover layer.

Description

Electrophoretic display device, image sheet and manufacturing method thereof

TECHNICAL FIELD The present invention relates to display technology, and more particularly, to an electrophoretic display, an image sheet, and a manufacturing method thereof.

As an information display device for replacing a liquid crystal display device, a display device using a technique such as electrophoresis, electro-chromic, or dichroic particles rotary method has been proposed. . These technologies have recently been actively researched 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 such as paper.

Among these display devices, an electrophoretic display device uses a phenomenon in which charged particles move by an electric field applied between two electrodes. Electrophoretic display devices are common in that they are voltage driven as compared to liquid crystal display devices, but have large differences in terms of manufacturing processes. In the case of the liquid crystal display device, a liquid crystal injection process is performed in a space between the upper substrate and the lower substrate while the upper substrate and the lower substrate on which the driving element is formed are previously bonded. However, in the electrophoretic display device, there is a big difference from the liquid crystal display device in that electrophoretic particles are injected before bonding the upper substrate and the lower substrate.

As described above, in order to manufacture the electrophoretic display device, it is difficult to maintain the airtightness of the pixels themselves as well as the airtightness between the pixels because the upper substrate and the lower substrate must be combined with the electrophoretic particles in the pixel structure. In addition, not only particles may flow between adjacent pixels during the inter-substrate bonding process, but also particles may flow between adjacent pixels even after the bonding process. Due to the failure of the flow and airtightness of the particles between the pixels, the lifespan and display quality of the electrophoretic display device may be rapidly deteriorated.

The technical problem to be achieved by the present invention is to prevent the flow of electrophoretic particles between pixels or sub-pixels in the bonding process between the substrates and the sub-pixels, while maintaining the faithful mechanical strength of the bonding between the upper substrate and the lower substrate can maintain a solid airtight It is to provide an electrophoretic display device.

Another technical problem to be solved by the present invention is to provide an image sheet having the aforementioned advantages.

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

In addition, another technical problem to be achieved by the present invention is to provide a method for producing an image sheet having the advantages described above.

An electrophoretic display device according to an embodiment of the present invention for solving the above technical problem, a plurality of separation members disposed between the opposing substrate; A plurality of electrophoretic particles filled in cavities defined by the plurality of separating members; And a cover layer disposed between the cavities and any one of the substrates to maintain mechanical bonding of the substrates while ensuring airtightness of the cavities, wherein the cover layer has a pencil hardness of 5B to 7H. It includes a binder layer cured to have a.

The image sheet according to an embodiment of the present invention for solving the other technical problem, a plurality of separation members disposed between the support substrate facing each other; A plurality of electrophoretic particles filled in cavities defined by the plurality of separating members; And a cover layer disposed between the cavities and a support substrate of any one of the support substrates to maintain mechanical bonding of the substrates while ensuring airtightness of the cavities, wherein the cover layer has a pencil hardness of 5B to 7H. It includes a binder layer cured to have a.

According to another aspect of the present invention, there is provided a method of manufacturing an electrophoretic display device, including: forming a plurality of separation members having sidewalls on a first substrate; Filling a plurality of electrophoretic particles into grooves defined by the plurality of separating members; Forming a cover layer on the second substrate; Bonding the second substrate to the first substrate such that the cover layer adheres to the upper surfaces of the separation members; And curing the cover layer.

Coupling the second substrate to the first substrate may be performed when the cover layer has a viscosity of between 1 × 10 ³ mPa · s and 1.5 × 10 ⁶ mPa · s. In some embodiments, bonding the second substrate to the first substrate may be performed when the viscosity of the capping layer has a viscosity between 1.5 × 10 ³ mPa · s and 1.0 × 10 ⁶ mPa · s. have. Viscosity control of the capping layer increases the viscosity by cooling, solvent evaporation in the capping layer composition, light irradiation, electron beam irradiation, heat or moisture exposure, crosslinking, or a combination thereof, heating, solvent application, or a combination thereof. By reducing the viscosity.

In addition, in the step of curing the cover layer, the cover layer may be cured to have a pencil hardness of 5B to 7H. Curing the cover layer may include: cooling; Solvent evaporation; Light irradiation, electron beam irradiation, heat, moisture exposure, crosslinking, or a combination thereof.

In addition, the manufacturing method of the image sheet according to an embodiment of the present invention for achieving the another technical problem, forming a plurality of separating members each having a side wall on the first support substrate; Filling a plurality of electrophoretic particles into grooves defined by the plurality of separating members; Forming a cover layer on the second support substrate; Coupling the second support substrate to the first support substrate such that the cover layer adheres to the top surfaces of the separation members; And curing the cover layer.

Coupling the second support substrate to the first support substrate may be performed when the cover layer has a viscosity between 1 × 10 ³ mPa · s and 1.5 × 10 ⁶ mPa · s. Alternatively, the step of coupling the second support substrate to the first support substrate may be performed when the cover layer has a viscosity between 1.5 × 10 ³ mPa · s and 1.0 × 10 ⁶ mPa · s. Viscosity control of the capping layer increases the viscosity by cooling, solvent evaporation in the capping layer composition, light irradiation, electron beam irradiation, heat or moisture exposure, crosslinking, or a combination thereof, heating, solvent application, or a combination thereof. By reducing the viscosity.

In the step of curing the cover layer, the cover layer may be cured to have a pencil hardness of 5B to 7H. Curing the lid layer may include cooling; Solvent evaporation; Light irradiation, electron beam irradiation, heat, moisture exposure, crosslinking, or a combination thereof.

The electrophoretic display device and the image sheet manufacturing method according to the embodiments of the present invention, the cover layer is formed on the substrate first to perform the bonding process between the substrate not only to maintain the tightness of the cavity, but also the bonding process between the substrate And airtight process can be achieved simultaneously. Further, when the cover layer has a viscosity between 1 × 10 ³ mPa · s and 1.5 × 10 ⁶ mPa · s, the second substrate is bonded to the first substrate so as to be in close contact with the upper surface of the partition wall. While the bonding of the first substrate and the second substrate maintains the faithful mechanical strength, the flow of electrophoretic particles between pixels or sub-pixels in the bonding process between the substrates can be prevented and faithful airtightness can be maintained to ensure lifespan and display device. The display quality deterioration can be reduced or prevented.

In addition, the electrophoretic display device and the image sheet according to the embodiments of the present invention maintains excellent airtight between the cavities, even in the manufacturing method of the image sheet, when the cover layer has a viscosity of the family range, the bonding process between the substrates This can be done to obtain the advantages described above.

1A to 1F 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.

2A to 2F are cross-sectional views illustrating a method of manufacturing an image sheet according to an embodiment of the present invention in a process sequence.

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 provided to more fully explain the present invention to those skilled in the art, and the following examples can be modified in various other forms, and the scope of the present invention is It is not limited to an Example. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art.

In addition, the thickness or size of each layer in the drawings is exaggerated for convenience and clarity, the same reference numerals in the drawings refer to the same elements. 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" may include the plural forms as well, unless the context clearly indicates otherwise. Also, as used herein, "comprise" and / or "comprising" specifies the presence of the mentioned shapes, numbers, steps, actions, members, elements and / or groups of these. It is not intended to exclude the presence or the addition of one or more other shapes, numbers, acts, members, 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.

Embodiments of the present invention will now be described with reference to the drawings, which schematically illustrate 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.

Full airtightness of the pixels while preventing and reducing the flow of electrophoretic particles between pixels or subpixels during the bonding process between the substrates while obtaining good mechanical strength between the partitions defining the cavity and the substrates bonded to the partitions In maintaining, it was confirmed that the viscosity of the covering layer had a greater effect than the composition of the covering layer. DESCRIPTION OF EMBODIMENTS The following describes features and advantages of various embodiments of the present invention with reference to the drawings.

Electrophoretic display device and manufacturing method thereof

1A to 1F are cross-sectional views illustrating a method of manufacturing an electrophoretic display apparatus 100 according to an embodiment of the present invention in a process sequence.

Referring to FIG. 1A, a first substrate 10 (which may be a lower substrate in this figure) is provided. The lower substrate 10 may be, for example, a cellulose resin, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene resin, polyvinyl chloride resin, polycarbonate (PC), poly It may be a resin substrate having flexibility such as terry sulfone (PES), polyether ether ketone (PEEK), polyphenylene sulfide (PPS), or polyimide (PI). In addition, the lower substrate 10 may be transparent. However, when no image is displayed on the lower substrate 10, the lower substrate 10 may not be transparent. In addition, the lower substrate 10 may be made of a crystalline semiconductor substrate such as glass or a silicon wafer.

In some embodiments, the lower substrate 10 includes an active matrix layer AM that is a driving member. The active matrix layer AM includes data lines (not shown) and gate lines (not shown) including a plurality of rows × a plurality of columns, and a plurality of MOS transistors 50 disposed in an area where the lines cross each other. It may include. The MOS transistors 50 include a gate electrode 50G, a gate insulating film 50I, a semiconductor layer 50A, an ohmic contact layer 50C, a source electrode 50S, and a drain electrode 50D.

The MOS transistor 50 shown in FIG. 1A has an inverted-staggered electrode structure in which the gate electrode 50G is disposed on the lower substrate 10 side, but the MOS thin film transistor 50 has a different structure. For example, it may have a well-known staggered structure. The MOS thin film transistors 50 and the surfaces of the data and gate lines may be electrically insulated by the passivation film 60.

In addition, although the active matrix layer AM is disclosed as a driving member in FIG. 1A, this is exemplary, and the electrophoretic display device of the present invention has a passive matrix wiring structure for dynamic driving on the lower substrate 10, or It should be understood that it may have a segmented wiring structure for static driving.

Referring to FIG. 1B, a planarization layer 65 may be further formed on the passivation layer 60. The planarization layer 65 can be obtained by depositing a film having excellent flatness by plasma chemical vapor deposition. Alternatively, the planarization layer 65 may be provided by forming an insulating film to be the planarization layer 65 and performing a chemical mechanical polishing process on the insulating film. 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.

In some embodiments, the individual electrodes 42 may 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. Optionally, an insulating protective film (not shown) may be further formed on the individual electrodes 42.

Referring to FIG. 1C, partition walls 30, which are separation members, are formed on the lower substrate 10 on which the passivation layer 60 or the planarization layer 65 is formed. In some embodiments, the partitions 30 are formed between the individual electrodes 42, and preferably may be formed on the data lines and the gate lines between the individual electrodes 42.

The partition walls 30 are provided with sidewalls of the cavity, which will be described later, which will be a pixel or subpixel to which electrophoretic particles are filled. The grooves RA are defined on the lower substrate 10 by sidewalls of the partition walls 30 and a part of the surface of the lower substrate 10.

The partitions 30 may be formed through, for example, lamination and photolithography processes using a dry film photoresist layer. However, the present invention is not limited thereto, and the partition walls 30 may be formed of various curable properties such as polyethylene, polystyrene, polycarbonate, epoxy resin, silicone resin, melamine resin, acrylic resin, and phenol resin. It may be patterned through an embossing process using a silkscreen or a mold using a polymer material. In another embodiment, the partitions 30 form a film made of an insulating inorganic material such as silicon oxide, a metal material coated with an insulating material, or a composition in which two or more of the above materials are mixed, and the dry or wet etching process is performed. It may be formed through.

Alternatively, as disclosed in FIG. 5 of the applicant 's Korean application 2008-97374, the barrier rib structure having a layer structure having an opening pattern may be arranged on the lower substrate 10 and then attached to the lower substrate 10. The partitions 30 may also be formed by screen printing, drill bits, imprints, softlithography, laser drilling processes, or inkjet printing processes.

Referring to FIG. 1D, the electrophoretic particles 72 are filled in the grooves RA. In the case of a wet display device, the dielectric solution 71 may be filled with the

electrophoretic particles

72R, 72G, 72B, and 72K. The dielectric solution 71 is a fluid having high resistance and low viscosity, and may be a single or a mixture of two or more fluids. In some embodiments, specific gravity of dielectric fluid 71 may be made to be substantially equal to specific gravity of

electrophoretic particles

72R, 72G, 72B, 72K. In addition to the

particles

72R, 72G, 72B, 72K, the dielectric fluid 71 may include charge-controlling agents, cationic or anionic surfactants, metal soaps, resin materials, metal-based coupling agents, and Various functional materials can be added, such as stabilizing agents.

The dielectric fluid 71 may be colored with transparent or dispersed dyes and / or pigments. For example, the dielectric fluid 71 may have a light absorbing color, for example, to block

visible particles

72R, 72G, 72B, 72K that should not move toward the lower substrate 10 when actually driven. It may be colored gray or black.

The

electrophoretic particles

72R, 72G, 72B, 72K filled in the grooves RA are a single type of particles with uniform color and electrophoretic mobility, or, as shown, color and electrophoretic mobility. May include two or more different types of

particles

72R, 72G, 72B; 72K. In addition, different types of particles may be dispersed in each of the grooves RA. For example, some of the

particles

72R, 72G, 72B may be colored particles having red, green, and blue, respectively, and the other particles 72K may be black particles. However, this is exemplary, and the

color particles

72R, 72G, 72B may have a color of cyan, magenta and yellow, respectively, and the other particles 72K may be white particles. Such a particle system may be appropriately selected according to the color system, and may have only black and white particles in one cavity for monochrome display as described below.

The dielectric solution 71 and the

electrophoretic particles

72R, 72G, 72B, 72K may be filled in the groove RA by a method such as spraying or dipping with a dispenser. If the type of electrophoretic particles to be filled in each cavity is different, a mask layer (not shown) for selectively opening the grooves is formed, and the process of filling the exposed grooves is repeated several times, so that different electrophoresis in each groove is obtained. The

phoretic particles

72R, 72G, 72B, 72K can be filled.

Alternatively, as shown in FIG. 1D, different types of dielectric solutions and / or electrophoretic particles may be filled in the grooves RA by an inkjet method using the nozzles N1, N2, and N3. . In the inkjet method, the nozzles N1, N2, N3 scan the lower substrate 10 in the direction of the arrow A, and the dielectric solution 71 and the corresponding electrophoretic particles 72R in each groove portion RA. , 72G, 72B, 72K). Such an inkjet method has an advantage of omitting a mask forming process.

Referring to FIG. 1E, a second substrate 20 (in this figure, the upper substrate) on which the cover layer 80 is formed is provided. The upper substrate 20 may be a transparent substrate. The transparent substrate may be a transparent resin substrate having flexibility as described above.

In some embodiments, an optical layer such as a barrier layer 21 or an antireflection film 22 may be further formed on the upper substrate 20 to prevent the penetration of oxygen or moisture. Optionally, it may further comprise a protective layer 23 for surface protection. These

layers

21, 22, 23 coat the resin-based material by roll coating, gravure coating, knife coating, air knife coating, silk screen printing, electrostatic printing, thermal printing, dip coating, spin coating, spray coating and inkjet printing. Can be formed. In other embodiments, these

layers

21, 22, 23 may be provided by laminating corresponding solid films in sequence. Optionally, curing the

layers

21, 22, 23 stacked on the upper substrate 20 by heat treatment or crosslinking may be further performed.

In addition, on the other main surface of the upper substrate 20, the transparent electrode 41 may be further formed before the cover layer 80 is formed. The transparent electrode 41 may be a common electrode for generating an electric field perpendicular to the

substrates

10 and 20 opposite the individual electrodes 42.

The cover layer 80 formed on the transparent electrode 41 may be electrically insulating, but the present invention is not limited thereto. The cover layer 80 may be conductive, in which case, the resistance of the transparent electrode 41 may be reduced or the transparent electrode 41 may be replaced.

The cover layer 80 may be formed by coating on the second substrate 20 using a suitable binder resin material. The binder resin-based material may include, for example, the cover layer 80 may include oligomers and / or monomers, and the cover layer 80 may further include additives such as photoinitiators, crosslinkers, catalysts, and / or surfactants. It may be. As the monomers and oligomers, urethane acrylate-based or epoxy acrylate-based materials may be used. However, this is exemplary and the present invention is not limited thereto. The cover layer 80 may be used with other aryl, vinyl and silane based materials, for example.

The cover layer 80 may be provided in the form of a liquid, a paste, or a solid film, may be formed as a single layer, or may include a plurality of layers. For example, the cover layer 80 may include an elastic layer 81 having elasticity and a viscosity adjusting layer 82 laminated on the elastic layer 81 to provide a suitable viscosity. At least one of these layers, for example the viscosity control layer, may be formed of a material that is incompatible with the dielectric fluid (U). The elastic layer 81 may be a known composition used as a general adhesive layer, or may be used including the oligomer, monomer, photoinitiator. In this case, the viscosity control layer 82 may be formed of a material which is incompatible with the particles or the fluid.

Then, when the cover layer 80 has a viscosity of between 1 × 10 ³ mPa · s and 1.5 × 10 ⁶ mPa · s, the upper substrate 20 is first adhered to closely contact the upper surfaces of the partitions 30. To the substrate 10. The viscosity of the lid layer 80 in the bonding process between the

substrates

10, 20 may preferably be in the range of 1.5 × 10 ³ mPa · s to 1.0 × 10 ⁶ mPa · s. The viscosity of the capping layer 80 may be maintained within the aforementioned range while being formed on the second substrate 20, or may be controlled within the aforementioned range for the bonding process between the

substrates

10 and 20. Viscosity control of the cover layer 80 may be cooled; Solvent evaporation in the overcoat composition; It may be carried out by a method of increasing the viscosity by crosslinking by light irradiation, electron beam irradiation, heat or moisture exposure, or by decreasing the viscosity by heating or applying a suitable solvent.

When the viscosity of the cover layer 80 is in the range between 1 × 10 ³ mPa · s and 1.5 × 10 ⁶ mPa · s, the flow of the lower substrate 10 and the upper substrate 20 during the bonding process is possible, The shape of the cover layer 80 is not deformed by the electrophoretic particles or the electrophoretic particles in the groove and the fluid present on the upper surface of the partition 30. As a result, during the bonding process between the

substrates

10 and 20, the flow of the

electrophoretic particles

72R, 72G, 72B, 72K between adjacent grooves is reduced or prevented, and the composition of the covering layer 80 This separation is suppressed from flowing down into the dielectric solution in the groove portion RA. When the viscosity of the actual covering layer 80 is less than 1000 mPa · s, when the bonding process is performed, the thickness and shape of the covering layer are easily easily locally modified by electrophoretic particles and / or partitions, so that subsequent In the curing process, the resin was cured while being deformed and airtightness was not maintained, or the cover layer 80 did not have sufficient adhesive strength. In addition, when the viscosity of the cover layer 80 exceeds 1.5 X 10 ⁶ mPa · s, it is very difficult to handle and insufficient contact surface with the partition wall in the subsequent curing process may fail to secure the airtight between the substrate and the partition wall. have.

As described above, by forming the cover layer 80 on the upper substrate 20 in advance and performing the bonding process when the cover layer 80 has the aforementioned viscosity range, Inter-cell flow of

electrophoretic particles

72R, 72B, 72B, 72K in the bonding process can be prevented and unintentional contamination of the fluid in the groove RA can be prevented during the bonding process. In addition, by forming the cover layer 80 on the upper substrate 20 in advance to perform the bonding process, it is possible to seal the cavity at the same time as the bonding process, the dielectric solution 71 and the particles (72R, 72G) , 72B, 72K) has the advantage that a separate process for sealing the filled groove portion can be omitted.

In the case where a separate sealing layer is formed on the surface of the dielectric solution 71 and the partition walls 30 before bonding the upper substrate 20 to seal the groove RA filled with the dielectric solution 71 and the particles, It is preferable that the density of the composition constituting the sealing layer is smaller than the density of the dielectric solution 71, but in this embodiment, there is less demand on the density of the covering layer 80, so that the wet cell structure as well as the dry cell structure There is an advantage that can be applied. In addition, when the sealing layer is formed on the dielectric solution 71 and the partition walls 30, the dielectric solution 71 comes out of the groove RA, so that it is difficult to control the viscosity, and the dielectric solution 71 comes out as necessary. It may be required to separately remove the process. However, as described above, when the cover layer 80 is formed in advance on the substrate 20 to seal the groove RA at the same time as the bonding process between the

substrates

10 and 20, the dielectric solution 71 is formed in the groove portion ( RA) coming out can be reduced or suppressed.

Subsequently, while the

substrates

10 and 20 are bonded to each other, the hardening process of the lid layer 80 is performed. The hardening process of the cover layer 80 is cooled; Solvent evaporation; Light irradiation, electron beam irradiation, heat, moisture exposure, crosslinking, or a combination thereof. The curing process of the lid layer 80 is performed such that the hardness of the lid layer 80 has a pencil hardness of 5B to 7H. When the hardness of the cover layer 80 is less than 5B, the mechanical strength of the coupling between the partition wall 30 and the upper substrate 20 is weak, so that the partition wall 30 and the upper substrate 20 may be separated by external impact. . In addition, when the hardness of the cover layer 80 is 7H or more, the bonding between the partition 30, the cover layer 80 and the upper substrate 20 is not good, and local separation occurs. Therefore, when the hardness of the cover layer 80 is in the above-mentioned range, the hardening process of the cover layer 80 is completed.

Through the above-described processes, the electrophoretic display apparatus 100 having the structures V1, V2, and V3 defined by the partitions 30 and the upper and

lower substrates

10 and 20 may be completed. In the above-described embodiment, the partition wall 30 is disclosed as the separating member defining the cavities V1, V2, V3, but this is exemplary and the present invention is not limited thereto. For example, the separating member may have a micro cup structure well known in the art. In this case, the bottom of the cavities V1, V2, v3 may be the bottom of the microcup structure, unlike the partition structure described above.

In addition, although the above-described embodiment discloses forming the partition wall 30 on the substrate 10 on which the driving element AM is formed, this is exemplary, and the partition wall 30 is formed on the upper substrate 20. And a cover layer 80 may be formed on the lower substrate 10 on which the driving element AM is formed.

Further, in the above-described embodiment, the

electrodes

41 and 42 for driving the

electrophoretic particles

72R, 72G and 72B have a counter electrode configuration, but this is exemplary and the present invention is not limited thereto. For example, it is to be understood that known in-plane electrode configurations in which drive electrodes are formed on any of the substrates, or combinations of opposing electrode configurations and in-plane electrode configurations, are also within the scope of the present invention.

Image Sheets and Methods for Making the Same

2A to 2F are cross-sectional views illustrating a method of manufacturing an image sheet according to an embodiment of the present invention in a process sequence. Descriptions of components having the same reference numerals as those of FIGS. 1A to 1F among the components illustrated below may refer to those disclosed with reference to FIGS. 1A to 1F unless there is a contradiction. , Duplicate descriptions are omitted.

Referring to FIG. 2A, a support substrate 15 on which a partition 30 is to be formed is provided. The support substrate 15, unlike the lower substrate 10 disclosed with reference to FIG. 1A, does not include a drive element AM for driving electrophoretic particles. In some embodiments, the support substrate 15 may include a separate electrode layer 43 for electrical coupling with the substrate 10 having the drive element described below. The individual electrode layer 43 may include

conductive patterns

44 and 45 formed on both main surfaces of the support substrate 15 and conductive vias 46 connecting the

conductive patterns

44 and 45. However, the present invention is not limited thereto, and the individual electrode layers 43 may not be formed on the support substrate 15. In this case, the individual electrodes 42 and the cavity formed on the lower substrate 10 are electrically separated by the supporting substrate 15, and the individual electrodes 42 serve as the individual electrode layers 43.

Referring to FIG. 2B, barrier ribs 30 are formed on the support substrate 15. The partitions 30 provide a portion of the outer wall of the cavity that will be the pixel or sub-pixel to which the electrophoretic particles are filled. The grooves RA are defined on the support substrate 15 by sidewalls of the partition walls 30 and a part of the surface of the support substrate 15.

The barrier ribs 30 may be formed through a lamination and photolithography process using a dry film photoresist layer, as described above. However, the present invention is not limited thereto, and the partition walls 30 may be formed of various curable properties such as polyethylene, polystyrene, polycarbonate, epoxy resin, silicone resin, melamine resin, acrylic resin, and phenol resin. It may be formed through an embossing process using a silk screen or a mold using a polymer material. In another embodiment, the partitions 30 form a film made of an insulating inorganic material such as silicon oxide, a metal material coated with an insulating material, or a composition in which two or more of the above materials are mixed, and the dry or wet etching process is performed. It may be patterned through. The partitions 30 may also be formed by screen printing, drill bits, imprints, softlithography, laser drilling processes, or inkjet printing processes.

Referring to FIG. 2C, the dielectric part 71 and the electrophoretic particles 72 dispersed in the dielectric solution 71 are filled in the groove RA. In addition to the particles 72 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 materials such as can be added. The dielectric fluid 71 may be colored with transparent or dispersed dyes and / or pigments. In other embodiments, gas may be used instead of the dielectric solution as the dielectric fluid.

Particles 72 filled in each groove include white particles 72W and black particles 72K, but this is exemplary. In another embodiment, as described above with reference to FIG. 1D, different types of particles may be filled in each of the grooves.

Referring to FIG. 2D, a second support substrate 20 (which may be an upper substrate in this drawing) having a cover layer 80 is provided. The upper substrate 20 may be a transparent substrate. The transparent substrate may be a transparent resin substrate as described above. However, the present invention is not limited thereto, and the upper substrate may be a glass substrate. In some embodiments, an optical layer such as a barrier layer 21 or an anti-reflection film 22 may be further formed on the upper substrate 20 to prevent the penetration of oxygen or moisture. Optionally, it may further comprise a protective layer 23 for surface protection.

On one main surface of the upper substrate 20, the transparent common electrode 41 may be further formed before the capping layer 80 is formed. The cover layer 80 may be electrically insulating, but the present invention is not limited thereto. The cover layer 80 may be conductive, in which case, the resistance of the transparent electrode 41 may be reduced or the transparent electrode 41 may be replaced.

The binder resin-based material may include, for example, oligomers and / or monomers, and the cover layer 80 may further include additives such as photoinitiators, crosslinkers, catalysts, and / or surfactants. The cover layer 80 may be provided in the form of a liquid, a paste, or a solid film. In addition, as described above, the cover layer 80 may be formed of a single layer or a plurality of layers.

When the cover layer 80 has a viscosity of between 1 × 10 ³ mPa · s and 1.5 × 10 ⁶ mPa · s, the upper substrate 20 is supported to adhere to the upper surfaces of the partition walls 30. To combine. Preferably, the bonding process of the

substrates

15 and 20 may be performed at a viscosity of the lid layer 80 between 1.5 × 10 ³ mPa · s and 1.0 × 10 ⁶ mPa · s. Viscosity control of the cover layer 80 may be cooled; Evaporation of the solvent; It may be carried out by a method of increasing the viscosity by crosslinking by light irradiation, electron beam irradiation, heat or moisture exposure, or by decreasing the viscosity by heating or liquid coating.

Referring to FIG. 2E, in a state in which the

substrates

15 and 20 are bonded to each other, a curing process of the cover layer 80 is performed. The hardening process of the cover layer 80 is cooling; Solvent evaporation; It may be carried out by a crosslinking process by light irradiation, electron beam irradiation, heat or moisture exposure. The curing process of the lid layer 80 is performed such that the hardness of the lid layer 80 has a pencil hardness of 5B to 7H. When the hardness of the cover layer 80 is less than 5B, the mechanical strength of the coupling between the partition wall 30 and the upper substrate 20 is weak, so that the partition wall 30 and the upper substrate 20 may be separated by an external impact. . In addition, when the hardness of the cover layer 30 is 7H or more, the coupling between the partition wall 30, the cover layer 80, and the upper substrate 20 is not good, and local separation may occur. Therefore, when the hardness of the cover layer 80 is in the above-mentioned range, the hardening process of the cover layer 80 is completed. The image sheet 200 is completed through the above-described processes.

As described above, by forming the capping layer 80 on the upper substrate 20 in advance and performing the bonding process when the capping layer 80 has the aforementioned viscosity range, the

substrates

15, 20 Inter-cell flow of electrophoretic particles 72 in the bonding process can be prevented and unintentional contamination of the fluid in the groove RA can be prevented during the bonding process. In addition, since the cover layer 80 is formed on the upper substrate 20 in advance, the bonding process may be performed, thereby simultaneously sealing the cavities V1, V2, and V3 at the same time as the bonding process. ) And a separate process for sealing the groove part filled with the particles 72 may be omitted.

Referring to FIG. 2F, an electrophoretic display device may be provided as shown in FIG. 1F by combining an image sheet 200 and a lower substrate 10 including a driving element layer such as an active matrix layer AM. . Bonding between the image sheet 200 and the lower substrate 10 may be accomplished by an adhesive layer 85. The adhesive layer 85 may be any suitable resin-based adhesive layer or an anisotropic conductive adhesive layer. When the adhesive layer 85 is an anisotropic conductive adhesive layer, the adhesive layer 85 may extend over the entire area of the image sheet 200 and the lower substrate 10.

In the above-described embodiments of the image sheet 200, the partition wall 30 is disclosed as the separating member defining the cavities (V1, V2, V3), but this is exemplary and the present invention is not limited thereto. For example, the separating member may have a micro cup structure well known in the art. In this case, the bottom of the cavity becomes the bottom of the microcup structure, unlike the partition structure described above.

Further, although the

electrodes

41 and 44 for driving the electrophoretic particles 72 have opposing electrode configurations in the illustrated embodiment, this is exemplary and the present invention is not limited thereto. For example, it is to be understood that known in-plane electrode configurations in which drive electrodes are formed on any of the substrates are within the scope of the present invention.

Features disclosed with respect to the electrophoretic display device and image sheet described above can be implemented interchangeably or in combination, unless inconsistent. For example, a particle system associated with an electrophoretic display device may be applied to the image sheet and may form separating members 30 on the substrate 20 of the image sheet. Also, in the case of the electrophoretic display device, the cover layer 80 having the single layer structure shown in FIG. 2D may be applied.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope not departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

Claims

Forming a plurality of separation members each having sidewalls on the first substrate;

Filling a plurality of electrophoretic particles into grooves defined by the plurality of separating members;

Forming a cover layer on the second substrate;

Bonding the second substrate to the first substrate such that the cover layer adheres to the upper surfaces of the separation members; And

Hardening the cover layer comprises a method of manufacturing an electrophoretic display device.
The method of claim 1,

Coupling the second substrate to the first substrate is performed when the cover layer has a viscosity between 1 × 10 3 mPa · s and 1.5 × 10 6 mPa · s. Method of preparation.
In claim 1,

Bonding the second substrate to the first substrate is performed when the viscosity of the lid layer has a viscosity between 1.5 × 10 3 mPa · s and 1.0 × 10 6 mPa · s. Method of manufacturing a display device.
In claim 1,

Viscosity control of the capping layer increases the viscosity by cooling, solvent evaporation in the capping layer composition, light irradiation, electron beam irradiation, heat or moisture exposure, crosslinking, or a combination thereof, heating, solvent application, or a combination thereof. A method of manufacturing an electrophoretic display device, characterized by reducing the viscosity by
The method of claim 1, wherein in the step of curing the cover layer,

The cover layer is a manufacturing method of an electrophoretic display device, characterized in that cured to have a pencil hardness of 5B to 7H.
In claim 1,

Curing the lid layer may include cooling; Solvent evaporation; A method of manufacturing an electrophoretic display device, characterized in that it is carried out by light irradiation, electron beam irradiation, heat, moisture exposure, crosslinking or a combination thereof.
In claim 1,

The separating member has a partition or microcup structure, characterized in that the manufacturing method of the electrophoretic display device.
In claim 1,

The cover layer is a manufacturing method of an electrophoretic display device, characterized in that the multi-layer structure.
In claim 1,

The cover layer is a manufacturing method of an electrophoretic display device, characterized in that provided in the form of a liquid, paste or solid film.
In claim 1,

The electrophoretic display device manufacturing method of the electrophoretic display device, characterized in that the dry or wet.
Forming a plurality of separation members each having side walls on the first support substrate;

Filling a plurality of electrophoretic particles into grooves defined by the plurality of separating members;

Forming a cover layer on the second support substrate;

Coupling the second support substrate to the first support substrate such that the cover layer adheres to the top surfaces of the separation members; And

Hardening the cover layer.
The method of claim 11,

Bonding the second support substrate to the first support substrate is performed when the cover layer has a viscosity between 1 × 10 3 mPa · s and 1.5 × 10 6 mPa · s. Method of manufacturing the sheet.
The method of claim 11,

Bonding the second support substrate to the first support substrate is performed when the cover layer has a viscosity between 1.5 × 10 3 mPa · s and 1.0 × 10 6 mPa · s. Method of manufacturing the sheet.
In claim 11,

Viscosity control of the capping layer increases the viscosity by cooling, solvent evaporation in the capping layer composition, light irradiation, electron beam irradiation, heat or moisture exposure, crosslinking, or a combination thereof, heating, solvent application, or a combination thereof. Achieved by reducing the viscosity by means of a method for producing an image sheet.
The method of claim 11, wherein in the step of curing the cover layer,

The cover layer is hardened to have a pencil hardness of 5B to 7H, characterized in that the manufacturing method of the image sheet.
In claim 11,

Curing the lid layer may include cooling; Solvent evaporation; A method for producing an image sheet, characterized in that it is carried out by light irradiation, electron beam irradiation, heat, moisture exposure, crosslinking or a combination thereof.
In claim 11,

And said separating member has a partition or microcup structure.
In claim 11,

The cover layer has a multilayer structure, characterized in that the manufacturing method of the image sheet.
In claim 11,

The cover layer is a manufacturing method of the image sheet, characterized in that provided in the form of a liquid, paste or solid film.
In claim 11,

And the image sheet is dry or wet.
In claim 11,

And said support substrate comprises a separate electrode layer.
A plurality of separating members disposed between the substrates facing each other;

A plurality of electrophoretic particles filled in cavities defined by the plurality of separating members; And

A cover layer disposed between the cavities and one of the substrates to maintain the mechanical bonding of the substrates while ensuring the airtightness of the cavities;

The cover layer is an electrophoretic display device comprising a binder layer cured to have a pencil hardness of 5B to 7H.
A plurality of separating members disposed between the supporting substrates facing each other;

A plurality of electrophoretic particles filled in cavities defined by the plurality of separating members; And

A cover layer disposed between the cavities and the supporting substrate of any one of the supporting substrates to maintain the mechanical bonding of the substrates while ensuring the airtightness of the cavities;

The cover layer is an image sheet, characterized in that it comprises a binder layer cured to have a pencil hardness of 5B to 7H.