KR102577802B1 - Electrophoretic Display Film, Electrophoretic Display Device and Method thereof - Google Patents

Abstract

Embodiments of the present invention disclose an electrophoretic display film, an electrophoretic display device, and a method of manufacturing the same.
An electrophoretic display device according to an embodiment includes a lower substrate including a plurality of pixel electrodes; An upper substrate including a common electrode and a cell layer on which a plurality of display cells are disposed on the common electrode; and a sealing layer comprising a thermoplastic resin material, covering the entire upper portion of the upper substrate, and extending to a side of the upper substrate.

Description

Electrophoretic display film, electrophoretic display device using the same, and method of manufacturing the same {Electrophoretic Display Film, Electrophoretic Display Device and Method thereof}

Embodiments of the present invention relate to an electrophoretic display film, an electrophoretic display device, and a method of manufacturing the same.

Electrophoretic display devices have advantages such as excellent visibility outdoors and excellent low-power characteristics, so they are widely used in various fields such as e-books, mobile displays, and outdoor displays.

The electrophoretic display device has a complicated process because it requires two lamination and encapsulation processes to first bond the lower substrate and the upper substrate, and then secondarily bond the protective layer to the top of the upper substrate.

Embodiments of the present invention seek to provide an electrophoretic display film that can be sealed without a separate barrier film and sealant, thereby simplifying the encapsulation process, and an electrophoretic display device using the same.

An electrophoretic display device according to an embodiment of the present invention includes a first substrate including a common electrode and a cell layer on which a plurality of display cells are disposed on the common electrode; a second substrate including a plurality of pixel electrodes; and a sealing layer comprising a thermoplastic resin material, covering the entire top of the first substrate, and extending to a side of the first substrate.

The first substrate may be sequentially provided with an adhesive layer, the cell layer, and the common electrode in a direction away from the second substrate.

The sealing layer may be in contact with the upper front surface of the common electrode and the side surfaces of the common electrode, the cell layer, and the adhesive layer.

The first substrate may be sequentially provided with an adhesive layer, the cell layer, the common electrode, and a first base substrate in a direction away from the second substrate.

The sealing layer may be in contact with an upper front surface of the first base substrate and side surfaces of the first base substrate, the common electrode, the cell layer, and the adhesive layer.

The thermoplastic resin material may be a hot melt adhesive material that melts at a temperature between 70 degrees and 120 degrees.

The second substrate may include a second base substrate and the pixel electrodes on the second base substrate.

The area of the second base substrate may be larger than the area of the upper substrate.

The sealing layer may be in contact with an upper edge surface of the second base substrate.

An electrophoretic display film according to an embodiment of the present invention includes a first protective sheet; A sealant including a thermoplastic resin material on the first protective sheet; an electrode layer on top of the sealant; a cell layer in which a plurality of display cells are disposed on the electrode layer; An adhesive layer on top of the cell layer; and a second protective sheet on top of the adhesive layer.

The sealant may have a thickness of 20 to 500 μm.

An electrophoretic display film according to an embodiment of the present invention includes a base substrate; an electrode layer on one side of the base substrate; a cell layer in which a plurality of display cells are disposed on the electrode layer; An adhesive layer on top of the cell layer; a sealant containing a thermoplastic resin material on the other side of the base substrate; and a protective sheet provided on at least one side of the adhesive layer and the sealant.

The sealant may have a thickness of 20 to 500 μm.

A method of manufacturing an electrophoretic display device according to an embodiment of the present invention includes providing a first substrate having a sealing material containing a thermoplastic resin material, a first electrode layer, and a cell layer on which a plurality of display cells are arranged; Providing a second substrate provided with a second electrode layer; aligning the first substrate and the second substrate so that the cell layer faces the first substrate; and applying heat and pressure to the first and second substrates to couple the first and second substrates, inducing a phase change in the sealing material, and causing the upper front surface of the first substrate to be formed by the phase-changed sealing material. and forming a sealing layer that seals the side surface of the cell layer.

Providing the first substrate includes preparing a protective sheet; Forming the sealing material on the top of the protective sheet; forming the first electrode layer on the sealant; forming the cell layer on top of the first electrode layer; and forming an adhesive layer on top of the cell layer.

Providing the first substrate may further include peeling off the first protective sheet.

Providing the first substrate may include preparing a first base substrate; forming the sealing material on one side of the first base substrate; forming the first electrode layer on the other side of the first base substrate; forming the cell layer on top of the first electrode layer; and forming an adhesive layer on top of the cell layer.

The sealing material has a thickness of 20 to 500 μm, and the thickness of the sealing layer may be lower than the thickness of the sealing material.

Embodiments of the present invention can manufacture an electrophoretic display device without a separate encapsulation process by providing a display film in which a sealing layer and an electrode layer are integrated, thereby simplifying the process and reducing the defect rate.

Figure 1 is a cross-sectional view schematically showing an electrophoretic display film according to an embodiment of the present invention.
Figure 2 is a cross-sectional view schematically showing an electrophoretic display device according to an embodiment of the present invention.
Figures 3A to 3H are diagrams showing a method of manufacturing the electrophoretic display device of Figure 2.
Figure 4 is a cross-sectional view schematically showing an electrophoretic display film according to an embodiment of the present invention.
Figure 5 is a cross-sectional view schematically showing an electrophoretic display device according to an embodiment of the present invention.
FIGS. 6A to 6G are diagrams showing a method of manufacturing the electrophoretic display device of FIG. 5.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, identical or corresponding components will be assigned the same reference numerals and redundant description thereof will be omitted. .

In the following embodiments, terms such as first and second are used not in a limiting sense but for the purpose of distinguishing one component from another component. Additionally, in the following examples, singular expressions include plural expressions unless the context clearly dictates otherwise.

In the following embodiments, terms such as include or have mean that the features or components described in the specification exist, and do not exclude in advance the possibility of adding one or more other features or components.

Figure 1 is a cross-sectional view schematically showing an electrophoretic display film according to an embodiment of the present invention.

Referring to FIG. 1, the electrophoretic display film 10A includes a substrate 11, an electrode layer 12, a cell layer 13, and an adhesive layer 14 sequentially disposed on one side of the substrate 11, and the substrate 11. ) may include a sealant 15 disposed on the other side of the.

The substrate 11 is an optically transparent material with high transmittance, and may be a base film formed of a material with a high transmittance of 80% or more. The substrate 11 is a transparent polymer film with excellent light transmittance, and is made of polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), and polyethylene naphthalate (PEN). ), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), etc. It can be done, but it is not limited to this.

An electrode layer 12, a cell layer 13, and an adhesive layer 14 may be sequentially provided on one side of the substrate 11.

The electrode layer 12 may include a common electrode formed in a plate shape to be common to the cell layer 13. The electrode layer 12 includes transparent conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), aluminum zinc oxide (AZO), ZnO, and transparent conductive oxide (TCO). can do.

The cell layer 13 may include a plurality of display cells. The display cell may include an electrophoretic material disposed in a fluid and containing at least one charged particle that can move through the fluid under the influence of an electric field.

The adhesive layer 14 may be formed using a pressure sensitive adhesive (PSA). Pressure-sensitive adhesive prevents changes in the optical properties of constituent members, and materials that do not require curing during adhesive treatment or high temperature processes during drying can be used. For example, the adhesive layer 14 can be made of an appropriate polymer such as acrylic polymer, silicone polymer, polyester, polyurethane, polyether, or synthetic rubber. The adhesive layer 14 may be cured by energy (eg, heat or UV, etc.) or may be uncured. The adhesive layer 14 may be formed of the same material as the sealant 15.

A sealant 15 may be provided on the other side of the substrate 11.

The sealant 15 includes a thermoplastic resin material, and the thermoplastic resin material may be a hot melt adhesive material that melts at a temperature between approximately 70 degrees and 120 degrees Celsius and has sealing properties and adhesive properties. For example, the sealant 15 may be made of polyolefin (e.g., polyethylene, polypropylene, polybutylene, and copolymers thereof), polytetrafluoroethylene, polyester (e.g., polyethylene terephthalate), polyvinyl acetate, and vinyl chloride acetic acid. Vinyl copolymer, polyvinyl butyral, acrylic resin (e.g., polyacrylate, and polymethylacrylate, polymethylmethacrylate), polyamide (i.e., nylon), polyvinyl chloride, polyvinylidene chloride, polystyrene, Polyvinyl alcohol, polyurethane, cellulose resin (i.e., cellulose nitrate, cellulose acetate, cellulose acetobutyrate, ethyl cellulose, etc.), or a copolymer of any of the above materials (e.g., ethylene-vinyl acetate copolymer, ethylene- Acrylic acid copolymer and styrene-butadiene block copolymer), but is not limited to these.

The sealant 15 may include a dehumidifying material to prevent moisture from penetrating from the outside. The sealant 15 may include an ultraviolet ray blocking material to block ultraviolet rays.

The sealant 15 may be a hardened thermoplastic resin material. The sealant 15 may have a first thickness T1 of approximately 20 to 500 μm. The first thickness T1 is the thickness remaining on the upper part of the substrate 11 to protect the upper part of the substrate 11 after the sealing material 15 melts and flows down due to heat and the thickness for sealing the side of the cell layer 13. It may be more than the sum.

The adhesive layer 14 is covered with a protective sheet (PS). The protective sheet (PS) is a means to prevent foreign substances from sticking to the surface of the adhesive layer 14, and may be formed of a release film with a very low friction coefficient or a different structure and composition from the adhesive layer 14. .

Figure 2 is a cross-sectional view schematically showing an electrophoretic display device according to an embodiment of the present invention.

Referring to FIG. 2, the electrophoretic display device 1 may include a lower substrate 300, an upper substrate 100 coupled to the lower substrate 300 and including a cell layer 130, and a sealing layer 150a. there is.

The upper substrate 100 may include a first base substrate 110, a first electrode layer 120, a cell layer 130, and an adhesive layer 140 sequentially disposed on one side of the first base substrate 110. . The first base substrate 110, first electrode layer 120, cell layer 130, and adhesive layer 140 of the upper substrate 100 are the substrate 11 of the electrophoretic display film 10A shown in FIG. 1, It may correspond to the electrode layer 12, the cell layer 13, and the adhesive layer 14, respectively.

The first base substrate 110 is an optically transparent material with high transmittance, and may be a base film formed of a material with a high transmittance of 80% or more. The first base substrate 110 is a transparent polymer film with excellent light transmittance, and includes polyethersulphone (PES, polyethersulphone), polyacrylate (PAR, polyacrylate), polyetherimide (PEI, polyetherimide), and polyethylene naphthalate (PEN). , polyethyelenen napthalate, polyethyelene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC). It can be formed as, but is not limited to this.

The first electrode layer 120 may apply the same voltage to the plurality of display cells 133. The first electrode layer 120 may include a common electrode formed in a plate shape to be common to the plurality of display cells 133. The first electrode layer 120 may be provided on the viewing side, and may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), aluminum zinc oxide (AZO), ZnO, and transparent (TCO). It can be formed of a transparent conductive material such as conductive oxide.

In the cell layer 130, a plurality of display cells 133 may be spaced apart at predetermined intervals. The plurality of display cells 133 may be arranged in a single layer or multiple layers. In this embodiment of the invention, a single layer display cell 133 is shown. The display cell 133 may be a microcapsule encapsulating at least one particle 131 and a fluid 132.

Particles 131 may be charged with (+) polarity or (-) polarity, and may have various colors. The particles 131 may be organic or inorganic compounds and may absorb or scatter light. The particles 131 may be reflective materials such as metal particles. Particles 131 may be colored particles. Although the embodiment of Figure 1 includes only particles charged with one polarity, the embodiment of the present invention is not limited thereto. For example, the particles 131 may include two types of particles with different polarities. The colors of the two types of particles may be different.

The fluid 132 is water, methanol, ethanol, propanol, butanol, propylene carbonate, toluene, benzene, and hexane. ), Chloroform, Isoparaffin oil, silicone oil, ester oil, hydrocarbon oil, triethylhexanoin, dimethicone, cetyl otanoate, dicaprylate, isopropyl myristate, toco It may contain substances such as phenol acetate. The fluid 132 may include a fluorescent material, a phosphorescent material, or a luminescent material, or a color variable material whose color characteristics change as energy is applied (e.g., a Zion pigment material, a Zion dye material, etc.). .

The display cell 133 may be fixed within the binder 135. The binder 135 may include at least one transparent polymer material selected from the group consisting of acrylic polymer, silicone polymer, ester polymer, urethane polymer, amide polymer, ether polymer, fluorine polymer, and rubber. Additionally, the binder 135 may include a fluorescent material, a phosphorescent material, a light-emitting material, or a material whose color characteristics change as energy is applied (eg, a Zion pigment material, a Zion dye material, etc.). The binder 135 may be in a hardened state.

The cell layer 130 may be combined with the lower substrate 300 through the adhesive layer 140. The adhesive layer 140 may be formed using a pressure sensitive adhesive (PSA). Pressure-sensitive adhesive prevents changes in the optical properties of constituent members, and materials that do not require curing during adhesive treatment or high temperature processes during drying can be used. For example, the adhesive layer 140 may be made of an appropriate polymer such as acrylic polymer, silicone polymer, polyester, polyurethane, polyether, or synthetic rubber. The adhesive layer 140 may be cured by energy (eg, heat or UV, etc.) or may be uncured. The adhesive layer 140 may contact the second base substrate 310 and the pixel electrode 320. The adhesive layer 140 may be formed of the same material as the sealing layer 150a.

The lower substrate 300 may include a second base substrate 310 and pixel electrodes 320.

The second base substrate 310 may be made of various materials such as plastic and metal. For example, the second base substrate 310 may be an insulating organic material, such as polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), or polyethylene naphthalate ( PEN, polyethyelenen napthalate, PET, polyethyeleneterepthalate, polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC) ), etc., but is not limited thereto. As another example, the second base substrate 310 may include a metal foil containing a metal such as silver or aluminum, or a plastic film whose back surface is coated with a metal layer.

The second base substrate 310 may be a substrate made of a flexible material that can be bent, curved, or rolled. In this case, the second base substrate 310 may be a flexible printed circuit board. However, the present invention is not limited to this, and the second base substrate 310 may be made of phenol-based or epoxy-based synthetic resin. In this case, the second base substrate 310 may be a rigid printed circuit board.

A second electrode layer on which a plurality of pixel electrodes 320 are disposed may be provided on one side of the second base substrate 310. The pixel electrode 320 may apply the same or different voltage to the plurality of display cells 133. The pixel electrode 320 is provided for each unit pixel and can be driven independently for each unit pixel. A unit pixel may be composed of one display cell 133 or a plurality of display cells 133 that can display different colors. The pixel electrode 320 has a single-layer structure of copper, aluminum, indium tin oxide (ITO), or indium zinc oxide (IZO), or a material of copper, aluminum, ITO, or IZO with nickel or gold. It can be further formed into a laminated multi-layer structure.

Although not shown, at least one passive element and wiring may be further provided between the second base substrate 310 and the pixel electrode 320, and in some cases, an active switching element using a semiconductor material such as a thin film transistor may be further included. can do.

The sealing layer 150a may cover both the upper front and side surfaces of the upper substrate 100. As shown in FIG. 1, the sealing layer 150a may be formed by melting the cured sealant integrally provided on the upper substrate 100 by heat and curing it again at room temperature.

The sealing layer 150a includes a thermoplastic resin material, and the thermoplastic resin material may include a hot melt composition that melts at a temperature between 70 degrees and 120 degrees and has sealing properties and adhesive properties. For example, the sealing layer 150a may be made of polyolefin (e.g., polyethylene, polypropylene, polybutylene, and copolymers thereof), polytetrafluoroethylene, polyester (e.g., polyethylene terephthalate), polyvinyl acetate, and vinyl chloride. Vinyl acetate copolymer, polyvinyl butyral, acrylic resins (e.g., polyacrylates, and polymethylacrylate, polymethylmethacrylate), polyamides (i.e., nylon), polyvinyl chloride, polyvinylidene chloride, polystyrene. , polyvinyl alcohol, polyurethane, cellulose resin (i.e., cellulose nitrate, cellulose acetate, cellulose acetobutyrate, ethyl cellulose, etc.), or a copolymer of any of the above materials (e.g., ethylene-vinyl acetate copolymer, ethylene -acrylic acid copolymer and styrene-butadiene block copolymer), but is not limited to these.

The sealing layer 150a may include a dehumidifying material to prevent moisture from penetrating from the outside. The sealing layer 150a may include a UV blocking material to block UV rays.

The sealing layer 150a covers the entire upper part of the upper substrate 100, extends to the side of the upper substrate 100, and contacts the lower substrate 300 at the upper surface of the lower substrate 300. The sealing layer 150a can seal the entire top of the upper substrate 100, the side of the upper substrate 100, and the upper surface of the lower substrate 300 without space. The sealing layer 150a has a second thickness T2 at the top of the upper substrate 100 and a third thickness T3 at the side of the upper substrate 100. The second thickness T2 and the third thickness T3 may be lower than the first thickness T1 of the sealant 15 shown in FIG. 1 .

The area of the lower substrate 300 may be larger than the area of the upper substrate 100. The sealing layer 150a may cover both the top and sides of the upper substrate 100 and may be coupled to the upper edge of the lower substrate 300 that is exposed without the upper substrate 100.

Figures 3A to 3H are diagrams showing a method of manufacturing the electrophoretic display device of Figure 2.

Referring to FIG. 3A, a sealing material 150 may be formed on one side of the first base substrate 110. The first base substrate 110 may be a transparent polymer film such as PET, PEN, PES, PAR, PC, etc., but is not necessarily limited thereto.

The sealant 150 includes a thermoplastic resin material, and the thermoplastic resin material may include a hot melt composition that melts at a temperature between approximately 70 degrees and 120 degrees and has sealing properties and adhesive properties. The sealant 150 may include a dehumidifying material to prevent moisture from penetrating from the outside. The sealant 150 may include a UV blocking material to block UV rays. The sealant 150 may be formed to have a first thickness T1 of approximately 20 to 500 μm.

Referring to FIG. 3B, the first electrode layer 120 may be formed on the other side of the first base substrate 110. The first electrode layer 120 may be formed on the other side of the first base substrate 110 from a transparent conductive material such as ITO, IZO, IZTO, AZO, ZnO, and TCO. The first electrode layer 120 may be formed on the other side of the first base substrate 110 through a dry process. For example, the first electrode layer 120 may be formed on the upper substrate 110 through a sputtering process.

Referring to FIG. 3C, a cell layer 130 may be formed on the first electrode layer 120.

The cell layer 130 is formed by mixing the display cells 133 (FIG. 2) with the liquid binder 135 (FIG. 2) at a certain ratio, and applying the paste mixed with the liquid binder 135 and the display cells 133 to the first electrode layer. It can be formed by applying a single layer or multiple layers on (120) and coating or printing. Coating can be performed by patch die coating, slot or extrusion coating, slide or cascade coating, curtain coating, roll coating, gravure coating, dip coating, spray coating, meniscus coating, spin coating, brush coating, air knife coating, etc. there is. Printing can be performed by silk screen printing, electrostatic printing, thermal printing, ink jet printing, etc. The liquid binder 135 may be heat-cured or photo-cured by heat or UV irradiation.

Referring to FIG. 3D, the adhesive layer 140 may be applied on the cell layer 130. The adhesive layer 140 may be formed using a pressure-sensitive adhesive.

Referring to FIG. 3E, a protective sheet (PS) can be attached to the adhesive layer 140 as a means to prevent foreign substances from sticking to the surface of the adhesive layer 140. The protective sheet (PS) may have a very low coefficient of friction or may be formed of a release film that has a different texture and composition from the adhesive layer 140. The cell layer 130 can be tested with the protective sheet RS attached.

In the above-described embodiment, the sealing material 150 is formed first, but the embodiment of the present invention is not limited to this, and the sealing material 150 is formed later than the first electrode layer 120, the cell layer 130, and the adhesive layer 140. can be formed. However, in terms of preventing damage to the cell layer 130, it is preferable that the sealing material 150 is formed first.

Referring to FIG. 3F, the upper substrate (or electrophoretic display film) 100A integrally equipped with the sealing material 150 may be combined with the lower substrate 300.

The lower substrate 300 may include a second base substrate 310 (FIG. 2) and a plurality of pixel electrodes 320 (FIG. 2) on one side of the second base substrate 310.

The second base substrate 410 may be a transparent polymer film such as PET, PEN, PES, PAR, or PC. As another example, the second base board 410 may be a flexible printed circuit board (FPCB). By applying an FPCB substrate, the process can be simplified and the process yield can be improved.

Pixel electrodes 420 may be formed for each unit pixel to correspond to the unit pixel. The pixel electrode 420 is an opaque conductive layer containing Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, or an alloy thereof, or ITO, IZO, IZTO, AZO, ZnO. And it can be formed by forming a transparent conductive layer such as TCO and then patterning.

The protective sheet (PS) can be peeled off from the upper substrate 100A, and the upper substrate 100A can be aligned on the upper part of the lower substrate 300 so that the exposed adhesive layer 140 faces the lower substrate 300. . Additionally, the upper substrate 100A and the lower substrate 300 can be joined by a lamination process such as thermal compression or rolling.

Referring to FIG. 3G, energy (eg, heat) may be applied to the upper substrate 100A and/or the lower substrate 300 to form the sealing layer 150a. The upper substrate 100A and/or the lower substrate 300 may be placed on a hot plate or in a heated oven.

The upper substrate 100A and the lower substrate 300 may be heated to a temperature at which the sealing material 150 can melt. This temperature may be about 70 to 120 degrees to the extent that the upper substrate 100A and the lower substrate 300 are not damaged.

The sealant 150 is melted by heat. The dissolved sealant 150 passes from the upper surface of the first base substrate 110 through the sides of the first base substrate 110, the first electrode layer 120, the cell layer 130, and the adhesive layer 140 to the second base substrate. It may flow down to the edge of the substrate 310.

Thereafter, when the upper substrate 100A and the lower substrate 300 are placed at room temperature, the sealing material 150 solidifies again to form the sealing layer 150a. Accordingly, the second thickness T2 of the sealing layer 150a formed on the top of the first base substrate 110 and the second thickness T2 of the sealing layer 150a formed on the side of the upper substrate 100A are different from the sealing material 150. ) may be lower than the first thickness (T1). The fourth thickness T4 at the edge of the sealing layer 150a may be lower than the second thickness T2 and the third thickness T3.

The sealing layer 150a is formed on the top of the first base substrate 110, the side (peripheral portion) of the first base substrate 110, the first electrode layer 120, the cell layer 130, and the adhesive layer 140, and The upper edge of the lower substrate 300 can be integrally covered. Specifically, the sealing layer 150a is formed on the upper front surface of the first base substrate 110, the side surfaces of the first base substrate 110, the first electrode layer 120, the cell layer 130, and the adhesive layer 140, and may be in direct contact with the edge upper surface of the lower substrate 300. Accordingly, the sealing layer 150a, the first base substrate 110, the first electrode layer 120, the cell layer 130, and the adhesive layer 140 can be sealed without space.

The joining process of the upper substrate 100A and the lower substrate 300 shown in FIG. 3F and the forming process of the sealing layer 150a shown in FIG. 3G simultaneously apply heat and pressure to the upper substrate 100A and the lower substrate 300. This can be done simultaneously by authorizing it.

Figure 4 is a cross-sectional view schematically showing an electrophoretic display film according to an embodiment of the present invention.

Referring to FIG. 4, the electrophoretic display film 10B includes an electrode layer 12, a cell layer 13 and an adhesive layer 14 arranged in that order on one side of the electrode layer 12, and an electrode layer 12 on the other side of the electrode layer 12. It may include a disposed sealant 15.

The electrophoretic display film 10B shown in FIG. 4 differs from the electrophoretic display film 10A shown in FIG. 1 in that the substrate 11 is removed. Hereinafter, detailed descriptions of other identical configurations will be omitted.

A cell layer 13 and an adhesive layer 14 may be sequentially provided on one side of the electrode layer 12.

A sealant 15 may be provided on the other side of the electrode layer 12. The sealant 15 includes a thermoplastic resin material, and the thermoplastic resin material may be a hot melt adhesive material that melts at a temperature between approximately 70 degrees and 120 degrees Celsius and has sealing properties and adhesive properties. The sealant 15 may include a dehumidifying material to prevent moisture from penetrating from the outside. The sealant 15 may include an ultraviolet ray blocking material to block ultraviolet rays. The sealant 15 may have a first thickness T1 of approximately 20 to 500 μm. The first thickness T1 is the thickness remaining on the upper part of the substrate 11 to protect the upper part of the substrate 11 after the sealing material 15 melts and flows down due to heat and the thickness for sealing the side of the cell layer 13. It may be more than the sum.

A first protective sheet (PS1) may be attached to the exposed surface of the sealant 15, and a second protective sheet (PS) may be attached to the exposed surface of the adhesive layer 14. The first protective sheet PS1 and the second protective sheet PS may function as a means to prevent foreign substances from adhering to the surfaces of the sealant 15 and the adhesive layer 14, respectively. The first protective sheet (PS1) and the second protective sheet (PS) may have a very low coefficient of friction or may be formed of a release film having a different structure and composition from the sealing material 15 and the adhesive layer 14, respectively.

In the electrophoretic display film 10B shown in FIG. 4, the sealing material 15 functions as a base material on which the first electrode layer 12 is formed, thereby reducing the thickness of the entire display module, reducing raw material costs, and reducing Fresnel reflection due to the substrate. It has the effect of preventing degradation of optical characteristics due to .

Figure 5 is a cross-sectional view schematically showing an electrophoretic display device according to an embodiment of the present invention.

The electrophoretic display device 2 shown in FIG. 5 differs from the electrophoretic display device 1 shown in FIG. 2 in that the substrate 110 is removed. Hereinafter, detailed descriptions of other identical configurations will be omitted.

Referring to FIG. 5, the electrophoretic display device 2 includes a lower substrate 300, an upper substrate 100' coupled to the lower substrate 300, and a sealing material 150a covering the upper substrate 100'. can do.

The upper substrate 100' may include a first electrode layer 120, a cell layer 130, and an adhesive layer 140. The first electrode layer 120, cell layer 130, and adhesive layer 140 of the upper substrate 100' are the electrode layer 12, cell layer 13, and adhesive layer of the electrophoretic display film 10B shown in FIG. 4. Each of (14) can be responded to.

The first electrode layer 120 may apply the same voltage to the plurality of display cells 133. The first electrode layer 120 may include a common electrode formed in a plate shape to be common to the plurality of display cells 133. The first electrode layer 120 may be provided on the viewing side, and may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), aluminum zinc oxide (AZO), ZnO, and transparent (TCO). It can be formed of a transparent conductive material such as conductive oxide.

In the cell layer 130, a plurality of display cells 133 may be spaced apart at predetermined intervals. The plurality of display cells 133 may be arranged in a single layer or multiple layers. In this embodiment of the invention, a single layer display cell 133 is shown. The display cell 133 may be a microcapsule encapsulating at least one particle 131 and a fluid 132. The display cell 133 may be fixed within the binder 135. The binder 135 may be in a hardened state.

The cell layer 130 may be combined with the lower substrate 300 through the adhesive layer 140. The adhesive layer 140 may be formed using a pressure sensitive adhesive (PSA). The adhesive layer 140 may be in contact with the lower substrate 310 and the pixel electrode 320. The adhesive layer 140 may be formed of the same material as the sealing layer 150a.

The lower substrate 300 may include a second base substrate 310 and pixel electrodes 320.

The second base substrate 310 may be made of various materials such as plastic and metal. A second electrode layer on which a plurality of pixel electrodes 320 are disposed may be provided on one side of the second base substrate 310. The pixel electrode 320 may apply the same or different voltage to the plurality of display cells 133. The pixel electrode 320 is provided for each unit pixel and can be driven independently for each unit pixel. A unit pixel may be composed of one display cell 133 or a plurality of display cells 133 that can display different colors.

Although not shown, at least one passive element and wiring may be further provided between the lower substrate 310 and the pixel electrode 320, and in some cases, an active switching element using a semiconductor material such as a thin film transistor may be further included. there is.

The sealing layer 150a may cover both the upper front and side surfaces of the upper substrate 100'. As shown in FIG. 4, the sealing layer 150a may be formed by melting the cured sealant integrally provided on the upper substrate 100' by heat and curing it again at room temperature.

The sealing layer 150a includes a thermoplastic resin material, and the thermoplastic resin material may include a hot melt composition that melts at a temperature between 70 degrees and 120 degrees and has sealing properties and adhesive properties. The sealing layer 150a may include a dehumidifying material to prevent moisture from penetrating from the outside. The sealing layer 150a may include a UV blocking material to block UV rays.

The sealing layer 150a covers the entire upper part of the upper substrate 100', extends to the side of the upper substrate 100', and contacts the lower substrate 300 at the upper surface of the lower substrate 300. The sealing layer 150a can seal the entire top of the upper substrate 100', the side of the upper substrate 100, and the upper surface of the lower substrate 300 without space. The sealing layer 150a has a second thickness T2 at the top of the upper substrate 100' and a third thickness T3 at the side of the upper substrate 100'. The second thickness T2 and the third thickness T3 may be lower than the first thickness T1 of the sealant 15 shown in FIG. 1 .

The area of the lower substrate 300 may be larger than the area of the upper substrate 100'. The sealing layer 150a may cover both the top and sides of the upper substrate 100' and may be coupled to the upper edge of the lower substrate 300 that is exposed without the upper substrate 100'.

FIGS. 6A to 6G are diagrams showing a method of manufacturing the electrophoretic display device of FIG. 5.

Referring to FIG. 6A, a sealant 150 may be formed on one side of the first protective sheet PS1.

The first protective sheet PS1 may be formed of a release film that has a different structure and composition from the sealant 15. The sealant 150 includes a thermoplastic resin material, and the thermoplastic resin material may include a hot melt composition that melts at a temperature between approximately 70 degrees and 120 degrees and has sealing properties and adhesive properties. The sealant 150 may include a dehumidifying material to prevent moisture from penetrating from the outside. The sealant 150 may include a UV blocking material to block UV rays. The sealant 150 may be formed to have a first thickness T1 of approximately 20 to 500 μm.

Referring to FIG. 6B, the first electrode layer 120 may be formed on the sealing material 150. The first electrode layer 120 may be formed on the sealant 150 using a transparent conductive material such as ITO, IZO, IZTO, AZO, ZnO, and TCO through a dry process such as a sputtering process.

Referring to FIG. 6C, a cell layer 130 may be formed on the first electrode layer 120.

The cell layer 130 is formed by mixing the liquid binder 135 (FIG. 5) with the display cells 133 (FIG. 5) at a certain ratio, and applying the paste mixed with the liquid binder 135 and the display cells 133 to the first electrode layer. It can be formed by applying a single layer or multiple layers on (120) and coating or printing. The liquid binder 135 may be heat-cured or photo-cured by heat or UV irradiation to become a hardened binder 135.

Referring to FIG. 6D, the adhesive layer 140 may be applied on the cell layer 130. The adhesive layer 140 may be formed using a pressure-sensitive adhesive.

Referring to FIG. 6E, a second protective sheet PS2 may be attached to the adhesive layer 140 as a means to prevent foreign substances from sticking to the surface of the adhesive layer 140. The second protective sheet PS2 may have a very low coefficient of friction or may be formed of a release film that has a different texture and composition from the adhesive layer 140. The cell layer 130 may be tested while the second protective sheet PS2 is attached.

Referring to FIG. 6F, the upper substrate (or electrophoretic display film) 100B integrally equipped with the sealing material 150 may be combined with the lower substrate 300.

The lower substrate 300 may include a second base substrate 310 (FIG. 5) and a plurality of pixel electrodes 320 (FIG. 5) on one side of the second base substrate 310.

The second base substrate 310 may be a transparent polymer film such as PET, PEN, PES, PAR, or PC. As another embodiment, the second base board 310 may be a flexible printed circuit board (FPCB). By applying an FPCB substrate, the process can be simplified and the process yield can be improved.

Pixel electrodes 320 may be formed for each unit pixel to correspond to the unit pixel. The pixel electrode 320 is an opaque conductive layer containing Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, or an alloy thereof, or ITO, IZO, IZTO, AZO, ZnO. And it can be formed by forming a transparent conductive layer such as TCO and then patterning.

Peel the first protective sheet (PS1) and the second protective sheet (PS2) from the upper substrate (100B), and attach the upper substrate (100B) to the lower substrate ( 300) can be aligned at the top. Additionally, the upper substrate 100B and the lower substrate 300 can be joined by a lamination process such as thermal compression or rolling.

Referring to FIG. 6G, energy (eg, heat) may be applied to the upper substrate 100B and/or the lower substrate 300 to form the sealing layer 150a.

The upper substrate 100B and the lower substrate 300 may be heated to a temperature at which the sealing material 150 can melt. This temperature may be about 70 to 120 degrees to the extent that the upper substrate 100B and the lower substrate 300 are not damaged.

The sealant 150 is melted by heat. The dissolved sealant 150 passes from the upper surface of the first base substrate 110 through the sides of the first base substrate 110, the first electrode layer 120, the cell layer 130, and the adhesive layer 140 to the second base substrate. It may flow down to the edge of the substrate 310.

Thereafter, when the upper substrate 100B and the lower substrate 300 are placed at room temperature, the sealing material 150 solidifies again to form the sealing layer 150a. Accordingly, the second thickness T2 of the sealing layer 150a formed on the top of the first base substrate 110 and the second thickness T2 of the sealing layer 150a formed on the side of the upper substrate 100A are the sealing material 150. ) may be lower than the first thickness (T1). The fourth thickness T4 at the edge of the sealing layer 150a may be lower than the second thickness T2 and the third thickness T3.

The sealing layer 150a is formed on the top of the first base substrate 110, the side (peripheral portion) of the first base substrate 110, the first electrode layer 120, the cell layer 130, and the adhesive layer 140, and The upper edge of the lower substrate 300 can be integrally covered. Specifically, the sealing layer 150a is formed on the upper front surface of the first base substrate 110, the side surfaces of the first base substrate 110, the first electrode layer 120, the cell layer 130, and the adhesive layer 140, and may be in direct contact with the edge upper surface of the lower substrate 300. Accordingly, the sealing layer 150a, the first base substrate 110, the first electrode layer 120, the cell layer 130, and the adhesive layer 140 can be sealed without space.

The joining process of the upper substrate 100B and the lower substrate 300 shown in FIG. 6F and the forming process of the sealing layer 150a shown in FIG. 6G apply heat and pressure to the upper substrate 100B and the lower substrate 300 at the same time. This can be done simultaneously by authorizing it.

Display products using electrophoretic display devices have different panel designs and processes depending on the application, and producing products by unifying everything from materials to panel manufacturing and device assembly requires enormous manufacturing facility line construction costs, operation and maintenance costs, and manufacturing costs. It may be caused by an increase. For this reason, in the past, the cell layer (display layer) was coated and dried on a transparent substrate coated with transparent electrodes, and then an adhesive layer was formed or attached to the exposed cell layer, and a release film was finally attached to prevent external impurities from entering and to protect the product. A display film was manufactured. At this time, a separate release film may be optionally attached to protect the exposed area of the upper transparent substrate. The display film is cut and aligned to fit the lower substrate designed/manufactured according to the intended application, and then laminated and adhered by applying heat or pressure. Electrophoretic display materials are vulnerable to external moisture permeation, and are especially vulnerable to moisture permeating from the side, so an encapsulation process must be performed after lamination. In order to block moisture from entering from the outside, the edge area must be sealed using a sealant or a film with a sealing function. To secure the sealing area, the process to remove the edges of the cell layer and adhesive layer coated on the display film is very difficult. It is difficult, and during this process, the capsule of the cell layer may be destroyed and the solvent in the capsule may contaminate the surrounding cell layer, or residual impurities may remain on the electrode surface, causing poor contact with the conductive material. Therefore, after lamination, the sides may be damaged. It is finished with a sealant, and final sealed with a separate barrier film, or after lamination, a separate barrier film is attached to the top of the display film, and the side is injected with a sealant and then cured. In this encapsulation process, the cost of equipment such as a separate barrier film increases, and the difficulty of the process increases as multiple processes such as alignment and lamination are added along with problems with bubble inflow at the interface between the barrier film and the upper display film and during the lamination process. This can lead to problems with increased yield, productivity, and manufacturing costs.

Embodiments of the present invention include forming a cured sealant on a transparent substrate coated with a transparent electrode before or after coating the cell layer with a material that melts only at a certain temperature to provide adhesive strength, such as a hot melt, and hardens again below a certain temperature. , a display film that is finally laminated with an adhesive layer and a release film can be manufactured. At this time, the sealing material formed on the top of the transparent substrate performs the function of preventing moisture penetration by mixing with a material that can prevent certain moisture penetration from the outside, or has the function of blocking ultraviolet rays of a certain intensity by combining with particles or substances that have an ultraviolet ray blocking function. It can be done.

Additionally, if the electrode layer is formed directly on the sealant instead of the transparent substrate, it can be expected to reduce the thickness of the entire module, reduce raw material costs, and prevent degradation of optical characteristics due to Fresnel reflection.

By laminating the display film according to embodiments of the present invention with the lower substrate, a separate barrier film is not required to protect the upper part of the electrophoretic display device, so the thickness of the panel after laminating is relatively thin and raw material costs can be reduced. there is. In addition, it is a simplified process without the need for an alignment process for bonding the barrier film and a process for filling the sealant. After bonding the lower substrate and the display film, the materials of the sealant melt and flow to the side area due to the heat applied from the outside, enabling sealing. .

Unless the order of each step constituting the manufacturing method according to the present invention is explicitly stated or contradictory, each step may be performed in an appropriate order. The present invention is not limited to performing each step in the described order.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims.

Claims (18)

A first substrate including a common electrode and a cell layer including a plurality of display cells on a first surface of the common electrode;
a second substrate including a plurality of pixel electrodes, the pixel electrodes facing the common electrode with the cell layer interposed therebetween, and coupled to the first substrate; and
A single-layer sealing layer comprising a thermoplastic resin material and covering the upper surface of the first substrate, the side of the common electrode, the side of the cell layer, and the edge of the second substrate,
An electrophoretic display device in which the sealing layer directly contacts the side of the common electrode and the side of the cell layer without a sealing material between the side of the common electrode and the side of the cell layer and the sealing layer. The method of claim 1, wherein the first substrate is:
An electrophoretic display device comprising an adhesive layer, the cell layer, and the common electrode in that order in a direction away from the second substrate. The method of claim 2, wherein the sealing layer is:
An electrophoretic display device in contact with a second surface opposite to the first surface of the common electrode and a side surface of the common electrode, the cell layer, and the adhesive layer. The method of claim 1, wherein the first substrate is:
An electrophoretic display device comprising an adhesive layer, a cell layer, a common electrode, and a first base substrate in that order in a direction away from the second substrate. The method of claim 4, wherein the sealing layer is:
An electrophoretic display device in contact with a second surface of the first base substrate opposite to the first surface on which the common electrode is disposed, and a side surface of the first base substrate, the common electrode, the cell layer, and the adhesive layer. According to paragraph 1,
The thermoplastic resin material is a hot melt adhesive material that melts at a temperature between 70 degrees and 120 degrees. The method of claim 1, wherein the second substrate is:
An electrophoretic display device comprising a second base substrate and the pixel electrodes on the second base substrate. In clause 7,
An electrophoretic display device wherein an area of the second base substrate is larger than an area of the first substrate. In clause 7,
The sealing layer is in contact with an upper edge surface of the second base substrate. delete delete delete delete Providing a first substrate sequentially provided with a sealant containing a thermoplastic resin material, a first electrode layer, and a cell layer containing a plurality of display cells;
Providing a second substrate provided with a second electrode layer;
Aligning the first substrate and the second substrate so that the first electrode layer faces the second electrode layer of the second substrate with the cell layer interposed therebetween; and
The first substrate and the second substrate are combined, heat is applied to the first substrate and the second substrate to induce a phase change in the sealing material disposed on the first electrode layer, and the phase-changed sealing material causes a change in the phase of the sealing material. Forming a sealing layer that seals the upper surface of the first electrode layer, the side surface of the first electrode layer, and the side surface of the cell layer by covering the side surface of the first electrode layer and the side surface of the cell layer and then curing the sealant material; Contains,
A method of manufacturing an electrophoretic display device, wherein the thickness of the sealing layer is lower than the thickness of the sealing material. 15. The method of claim 14, wherein providing the first substrate comprises:
Preparing a protective sheet;
Forming the sealing material on the top of the protective sheet;
forming the first electrode layer on the sealant;
forming the cell layer on top of the first electrode layer;
A method of manufacturing an electrophoretic display device, comprising: forming an adhesive layer on top of the cell layer. The method of claim 15, wherein providing the first substrate comprises:
A method of manufacturing an electrophoretic display device, further comprising: peeling off the protective sheet. 15. The method of claim 14, wherein providing the first substrate comprises:
Preparing a first base substrate;
forming the sealing material on one side of the first base substrate;
forming the first electrode layer on the other side of the first base substrate;
forming the cell layer on top of the first electrode layer; and
A method of manufacturing an electrophoretic display device, comprising: forming an adhesive layer on top of the cell layer. According to clause 14,
A method of manufacturing an electrophoretic display device, wherein the sealing material has a thickness of 20 to 500㎛.

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