KR20060134659A - The substrate for display device and method for fabricating of the same - Google Patents

Abstract

A display device and a method for manufacturing the same are provided to prevent the mixing of lights between pixels, thereby realizing high contrast, by disposing a black matrix correspondingly to switching regions of respective pixel areas and the boundaries between pixel areas. First and second substrates(B1,B2) have pixel areas(P), which are distanced from one another and respectively have switching regions. A switching element is formed in each switching region of the first substrate. A pixel electrode(222) is connected to the switching element. A common electrode(302) is formed on one surface of the second substrate. A black matrix(304) is positioned below the common electrode, wherein the black matrix is disposed correspondingly to the switching regions and the boundaries between pixel areas. A charging layer(306) formed of charge particles is formed below the black matrix and the common electrode.

Description

Display device and method for manufacturing the same {The substrate for Display device and method for fabricating of the same}

1 is a view schematically showing a liquid crystal display panel;

2 is an enlarged cross-sectional view showing a charge layer to which an electrophoresis method can be applied;

3 is an enlarged cross-sectional view schematically showing a part of a configuration of an electrophoretic display device according to a first embodiment of the present invention;

4 is an enlarged plan view of a portion of a display device according to a first embodiment of the present invention;

5A to 5C are cross-sectional views illustrating a manufacturing process of an array substrate for an electrophoretic display device according to the present invention, in a process order;

6A through 6C are cross-sectional views illustrating a manufacturing process of the lower panel for an electrophoretic display device according to the present invention, according to a process sequence;

7 is an enlarged cross-sectional view of a part of an electrophoretic display device according to a second exemplary embodiment of the present invention.

<Brief description of the main parts of the drawing>

200, 300: substrate 222: pixel electrode

302: common electrode 304: black matrix

306: charged layer 400: capsule containing charged particles

402a, b: charged particles

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophoretic display device, and more particularly, to an electrophoretic display device having improved contrast ratio and a method of manufacturing the same.

Thin display devices currently commercially available include liquid crystal displays, plasma displays, organic light emitting displays, and the like.

The liquid crystal display device is briefly described below.

In general, the driving principle of the liquid crystal display device uses the optical anisotropy and polarization of the liquid crystal.

Since the liquid crystal is thin and long in structure, the liquid crystal has directivity in the arrangement of molecules, and the direction of the molecular arrangement can be controlled by artificially applying an electric field to the liquid crystal.

Accordingly, if the molecular arrangement direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light is refracted in the molecular arrangement direction of the liquid crystal by optical anisotropy to express an image.

The liquid crystal display includes a color filter substrate (upper substrate) on which a common electrode is formed, an array substrate (lower substrate) on which a pixel electrode is formed, and a liquid crystal filled between upper and lower substrates. The liquid crystal is driven by an electric field applied up and down by the pixel electrode, so that the characteristics such as transmittance and aperture ratio are excellent.

Currently, an active matrix liquid crystal display (AM-LCD: Active Matrix LCD) in which a thin film transistor and pixel electrodes connected to the thin film transistor are arranged in a matrix manner is attracting the most attention because of its excellent resolution and video performance.

Hereinafter, a configuration of a general liquid crystal display device will be described with reference to FIG. 1.

1 is a view schematically showing a liquid crystal display device.

As shown, the liquid crystal panel 51 is composed of a first substrate 5 and a second substrate 10 spaced apart from each other with the liquid crystal layer 11 therebetween, facing the second substrate 10. One surface of the first substrate 5 is composed of a color filter 8 including a black matrix 6 and a sub-color filter (red, green, blue) 7 and a transparent common electrode 9 on the color filter. do.

A plurality of pixel regions P are defined in the second substrate 10 facing the first substrate 5, and the gate wiring 14 extending through one side of the pixel region P, and the gate wirings. The data line 26 extending beyond the other side of the pixel region P where the 14 passes is not parallel.

Due to this configuration, the pixel region P becomes an area defined by the gate wiring 14 and the data wiring 26 intersecting, and the thin film transistor T is formed at the intersection of the two wirings.

The pixel region P includes a transparent pixel electrode 42 in contact with the thin film transistor T, which is transparent conductive material having relatively high light transmittance such as indium-tin-oxide (ITO). Formed of metal.

In the above-described configuration, the thin film transistor T may include a gate electrode 30 connected to the gate line 14, a semiconductor layer 32 on the gate electrode 30, and a portion of the semiconductor layer 32. And a source electrode 34 disposed above and in contact with the data line 26, and a drain electrode 36 positioned apart from the source electrode 34 and in contact with the pixel electrode 32.

Liquid crystal display devices are manufactured in the form described above, and these liquid crystal display devices are used for cellular phones or monitors and TVs.

Recently, as mentioned above, when the above-described liquid crystal is used, or when the gas is converted into a plasma state, the effect of the electric field is applied in addition to the method of implementing a display device using light emission principle or organic material emitting light by itself. A method of implementing a display device using a property in which a charged material or the like moves in a fluid medium has also been proposed.

In particular, the method using the charged particles is called electrophoresis method, that is, the phenomenon that the charged particles move toward the anode or cathode.

Hereinafter, an example of a display medium using an electrophoretic method will be described with reference to the drawings.

FIG. 2 is a diagram illustrating an example of encapsulating charged particles by a polycondensation reaction and using the same as a charged layer.

As shown, the ink in the form of a capsule 44 of the charged particles (40a, 40b) through the condensation polymerization reaction is used as the charge layer 46, and on one side and the other side of the charged layer 46, respectively Electrodes 48 and 50 are constructed.

In this case, the electrode on one side is partially patterned and has (+) or (-) polarity, and the electrode on the other side is the common electrode 50 formed on the entire surface of the substrate.

In general, as an example for manufacturing the charge layer 46 as described above, indium-tin-oxide (ITO), which is a white dye, and carbon, which is a black dye, are dispersed. Encapsulate through condensation polymerization.

At this time, since the size of the capsule 44 including the black die 40a and the white die 40b is not constant, only the capsule 44 having a predetermined size is selected and used through a filtering operation.

When a voltage having a positive or negative polarity is applied to the charged layer 36 manufactured as described above, the charged black dies and the white dies 40a and 40b in the capsule 44 move.

At this time, when the black die 40b moves to the upper part, it serves to reflect light, and when the white die 40a moves to the upper part, it serves to transmit light.

By using this mutual operation, an image can be displayed.

Such a display form has not been commercialized as a display device for realizing moving pictures and full colors, but its applicability has been attracting attention as a display panel for Ebooks used in electronic dictionaries or e-books which have been proposed in recent years.

SUMMARY OF THE INVENTION An object of the present invention is to propose an electrophoretic display device and a method of manufacturing the same, which are excellent in visibility and can realize a high contrast ratio.

According to an aspect of the present invention, there is provided an electrophoretic display device comprising: a first substrate and a second substrate configured to be spaced apart from each other and including a pixel region including a switching region; A switching element configured in the switching region of the first substrate; A pixel electrode connected to the switching element and positioned in the pixel area; A common electrode formed on one surface of the second substrate; Light blocking means positioned under the common electrode and configured to correspond to a boundary between the switching region and the pixel region; The light blocking means and the lower portion of the common electrode, and comprises a charged layer formed of charged particles.

The charged layer is composed of a plurality of capsule assemblies in which the black die and the white die are encapsulated by the polycondensation reaction, wherein the black die is a carbon particle, and the white die is an indium tin oxide (ITO) particle. It features.

A conductive polymer binder layer is further included below the charged layer, which functions to bond the first substrate and the second substrate.

According to an aspect of the present invention, there is provided a method of manufacturing an electrophoretic display device, the method including: defining a pixel area including a switching area on a first substrate and a second substrate that are spaced apart from each other; Forming a switching element in the switching region of the first substrate; Forming a pixel electrode connected to the switching element and positioned in the pixel area; Forming a common electrode on one surface of the second substrate; Forming a light blocking unit under the common electrode and corresponding to a boundary between the switching region and the pixel region; And forming a charged layer including charged particles under the light blocking means and the common electrode.

According to another aspect of the present invention, an electrophoretic display device includes: a first substrate and a second substrate configured to be spaced apart from each other and including a pixel region including a switching region; A switching element configured in the switching region of the first substrate; A pixel electrode connected to the switching element and positioned in the pixel area; A common electrode formed on one surface of the second substrate and positioned in a region excluding a portion corresponding to a boundary between the switching region and the pixel region; Located below the common electrode and includes a charged layer consisting of charged particles.

According to another aspect of the present invention, there is provided a method of manufacturing an electrophoretic display device, the method including: defining a pixel region including a switching region in a first substrate and a second substrate, each of which is spaced apart from each other; Forming a switching element in the switching region of the first substrate; Forming a pixel electrode connected to the switching element and positioned in the pixel area; Forming a common electrode on an area of the lower substrate except for an area corresponding to a boundary between the switching area and the pixel area; And forming a charged layer including charged particles under the second substrate including the common electrode.

The common electrode may be formed using a photolithography process or a shadow mask.

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

First Embodiment

The present invention is a display device for displaying an image by using an electrophoretic method, characterized in that it is proposed to display a display device that implements a high contrast by designing to accurately partition the area from which light is emitted.

3 is an enlarged plan view illustrating an enlarged portion of an electrophoretic display device according to a first exemplary embodiment of the present invention.

As shown in the drawing, the electrophoretic display device 100 according to the present invention bonds the thin film transistor array substrate B1 to the charged plate B2 coated with the ink layer 104 including the charged particles. To configure.

In this case, the thin film transistor array substrate B1 may include a thin film transistor disposed on each side of the switching region S on one surface of the insulating substrate 200 in which a plurality of pixel regions P including the switching region S are defined. T), a gate wiring (not shown) and a data wiring (not shown) positioned on one side and the other side of the pixel region P while applying a signal to the thin film transistor T.

In addition, the pixel region P includes a pixel electrode 222 in contact with the thin film transistor T.

The charged substrate B2 is formed on the insulating substrate 300 and the transparent common electrode 302 formed on the entire surface of the insulating substrate 300, and is disposed below the common electrode 302 to correspond to the thin film transistor T. And a black matrix 304 formed at a position corresponding to a circumference of the pixel area P.

The capsule 400 of the ink includes charged particles 402a and 402b composed of a black die 402a and a white dye 402b as shown.

As an example, indium tin oxide (ITO) may be used as the white dye 402b, and carbon may be used as the black dye 402a.

In this case, the charged particles 402a and 402b are moved by an electric field generated between the common electrode 302 and the pixel electrode 222. When a negative voltage is applied to the pixel electrode 222, Of the charged particles, a white dye (402b) charged with (+) is moved toward the pixel electrode 222, and a black dye (402a) charged with (-) is the common electrode. It moves in the direction (302).

This change in movement can transmit or reflect light, which can result in black or white.

According to the present invention, in the display panel expressing an image by the above-described operation, since the light emitting region can be precisely limited to the pixel region P using the black matrix 304, the inter-pixel light This mixing can be prevented.

As a result, spreading can be prevented, so that a clear contrast characteristic can be obtained, thereby making it possible to fabricate a display device having good visibility.

4 is a diagram schematically illustrating a planar configuration of a display device according to the present invention. (Upper substrate and ink film are omitted for convenience of explanation.)

As illustrated, the display device 200 according to the present invention is defined as a plurality of pixel regions P, and the gate electrode 204, the semiconductor layer 210, and the source electrode 214 are defined for each pixel region P. FIG. The thin film transistor T including the drain electrode 216 and the pixel electrode 222 are formed.

On one side and the other side of the pixel region P, a gate line 202 and a data line 218 contacting the gate electrode 204 and the source electrode 214 of the thin film transistor T are formed.

In this case, it is characteristic that the black matrix 304 is formed on an upper substrate (not shown) corresponding to an upper portion of the gate wiring 202 and the data wiring 218 positioned at the boundary between the thin film transistor T and the pixel region P. FIG. ).

In this configuration, the shape of the black matrix 304 is configured in a matrix shape as shown.

By the presence of the black matrix 304, even if the charged particles of the portion corresponding to the black matrix 304 is driven, since the light cannot enter this portion, there is an advantage that the light mixing between the pixels can be sufficiently prevented. .

At the same time, since the light incident on the thin film transistor T can also be blocked, there is an advantage of preventing deterioration of the thin film transistor T due to light.

5A to 5D are cross-sectional views illustrating a manufacturing process of a thin film transistor array unit according to the present invention in a process sequence.

As shown in FIG. 5A, the pixel area P including the switching area S is defined on the substrate 200.

In this case, the substrate 200 may use a metal substrate having a thickness of 70 μm or less so as to have more flexible characteristics.

A single metal such as aluminum (Al), aluminum alloy (AlNd), tungsten (W), chromium (Cr), molybdenum (Mo) or aluminum (Al) / chromium (Cr) (or molybdenum) on the front surface of the substrate 200 A gate structure 202 of FIG. 4 and a gate electrode 204 connected to the gate wiring 202 of FIG. 4 and positioned in the switching region S, and having a double metal layer structure such as (Mo). ).

Next, a gate insulating film 208 is formed on the entire surface of the substrate 200 on which the gate wiring 202 and the gate electrode 204 are formed.

The gate insulating layer 208 may be formed of an inorganic insulating material containing silicon nitride (SiN _x ), silicon oxide (SiO ₂ ), or the like, or in some cases, benzocyclobutene (BCB) and acrylic resin (resin). It is formed by depositing one of the included organic insulating materials.

Next, after laminating amorphous silicon (a-Si: H) and impurity amorphous silicon (n + or p + a-Si: H) on the entire surface of the substrate 200 on which the gate insulating film 208 is formed, the pattern is formed. The active layer 210 and the ohmic contact layer 212 are formed on the gate insulating layer 208 corresponding to the gate electrode 204.

As illustrated in FIG. 5B, one or more metals selected from the aforementioned conductive metal groups may be deposited and patterned on the front surface of the substrate 200 on which the ohmic contact layer 212 is formed to form the ohmic contact layer 212. The source electrode 214 and the drain electrode 216 spaced apart from each other while being in contact with each other are formed. At the same time, a data line (218 in FIG. 4) is formed to contact the source electrode 214 and intersect with the gate line (202 in FIG. 4).

Next, as shown in FIG. 5C, an inorganic insulating material group including silicon nitride (SiN _X ) or silicon oxide (SiO ₂ ) is formed on the entire surface of the substrate 200 on which the source and drain electrodes 214 and 216 are formed. Depositing one, or optionally, applying and patterning one selected from a group of organic insulating materials including benzocyclobutene (BCB) and an acrylic resin (resin) to expose a portion of the drain electrode 216 The protective film 220 is formed.

Next, by depositing and patterning a selected one of a transparent conductive metal group including indium tin oxide (ITO) and indium zinc oxide (IZO) on the entire surface of the substrate 200 on which the protective film 220 is formed, The pixel electrode 222 positioned in the pixel region P is formed while contacting the drain electrode 216.

The manufacturing process of the thin film transistor array substrate for display device according to the present invention has been described above.

Hereinafter, a process of forming a charger plate according to the present invention for forming a display device in contact with the thin film transistor array unit will be described with reference to the process drawings.

6A to 6C are cross-sectional views illustrating a process of forming a charged substrate according to the present invention in a process sequence.

As shown in FIG. 6A, indium tin oxide (ITO) and indium zinc oxide are formed on a flexible transparent substrate 300 on which a pixel region P including a switching region S is defined. A common electrode 302 is formed by depositing one selected from the group of transparent conductive metals including (IZO).

Next, a black layer is formed on the entire surface of the substrate 300 on which the common electrode 302 is formed, and then patterned to form a black matrix corresponding to a boundary between the switching region S and the pixel region P. ).

In this case, the black layer may be formed by depositing carbon (Cr) or stacking carbon oxide (CrO _X ) and carbon (Cr).

As shown in FIG. 6B, a charge layer 306 coated with ink formed of a capsule containing charged particles is formed on a surface of the substrate 300 on which the common electrode 302 and the black matrix 304 are formed.

As shown in FIG. 6C, a conductive polymer binder layer 308 is formed on the entire surface of the substrate 300 on which the charged layer 306 is formed.

As described above, it is possible to form the lower plate of the electrophoretic display device according to the present invention, which is attached to the thin film transistor array substrate prepared through the conductive polymer binder layer 308.

Through the above steps, the electrophoretic display device according to the first embodiment of the present invention can be manufactured.

As mentioned above, a characteristic of the first embodiment described above is that a black matrix is formed at the boundary between the switching area and the pixel area.

Hereinafter, the second embodiment proposes a electrophoretic display device having a new structure which can achieve the same effect without forming the black matrix.

Second Embodiment

FIG. 7 is an enlarged cross-sectional view of a part of an electrophoretic display device according to a second exemplary embodiment of the present invention.

As shown in the drawing, the electrophoretic display device 400 according to the second embodiment of the present invention bonds the thin film transistor array substrate B1 and the charged substrate B2 coated with a charge ink layer. Configure.

In this case, the thin film transistor array substrate B1 may include a thin film transistor T positioned at each switching region S on one surface of the insulating substrate 500 in which a plurality of pixel regions P are defined, and the thin film transistor (T). Gate lines (not shown) and data lines (not shown) are disposed on one side and the other side of the pixel region P while applying a signal to T).

In addition, the pixel electrode 522 is disposed in the pixel region P while contacting the thin film transistor T.

The charged plate B2 constitutes a transparent common electrode 602 on the insulating substrate 600 and the upper portion of the insulating substrate 600, and a charge layer 606 on the lower portion of the common electrode 602. Form.

In this case, when the common electrode 602 is formed, the common electrode 602 is not formed at a portion corresponding to the boundary between the thin film transistor T and the pixel region P. FIG.

As described above, the common electrode 602 may be formed using a photolithography process when the thickness is 10 μm or less, and may be formed by using a shadow mask method using a metal mask when the thickness of the electrode is 10 μm or more.

When the common electrode is patterned as described above, the black particles 602a and the white die 602b are mixed in the charged particles 602a and 602b in the capsule located in the charge layer of the portion where the common electrode 602 is not formed. It becomes the state that it is.

Therefore, since black is implemented, the same result as that of forming the black matrix mentioned above can be obtained.

Therefore, it is possible to prevent the phenomenon of spreading due to the mixing of light between pixels, thereby obtaining a clear contrast characteristic, and thus, a display device having good visibility can be manufactured.

The configuration and manufacturing method of the electrophoretic display device according to the first and second embodiments of the present invention have been described above.

Therefore, the electrophoretic display device according to the present invention forms a black matrix in a portion corresponding to the pixel region and the switching region, or uses a common electrode in a portion corresponding to the boundary of the switching region and the pixel region so as to obtain a black effect. By removing it, light mixing between pixels can be prevented, resulting in a high contrast ratio.

Therefore, there is an effect that can produce a display device that implements a clear image quality.

In addition, since the thin film transistor positioned in the switching region may be blocked from external light, the thin film transistor may be prevented from deteriorating due to light.

Claims (12)

A first substrate and a second substrate spaced apart from each other and including a pixel region including a switching region; A switching element configured in the switching region of the first substrate; A pixel electrode connected to the switching element and positioned in the pixel area; A common electrode formed on one surface of the second substrate; Light blocking means positioned under the common electrode and configured to correspond to a boundary between the switching region and the pixel region; Charged layer formed under the light blocking means and the common electrode, formed of charged particles Display device comprising a. The method of claim 1, The charge layer is a display device, characterized in that the black die and the white die is composed of a plurality of capsule assemblies encapsulated by a condensation polymerization reaction. The method of claim 2, The black die is a carbon particle, and the white die is an indium tin oxide (ITO) particle. The method of claim 1, And a conductive polymer binder layer beneath the charged layer, which functions to bond the first substrate and the second substrate. Defining a pixel region including a switching region in the first substrate and the second substrate spaced apart from each other; Forming a switching element in the switching region of the first substrate; Forming a pixel electrode connected to the switching element and positioned in the pixel area; Forming a common electrode on one surface of the second substrate; Forming a light blocking unit under the common electrode and corresponding to a boundary between the switching region and the pixel region; Charge layer comprising charged particles in the lower portion of the light blocking means and the common electrode Forming steps Display device manufacturing method comprising a. The method of claim 5, The charged layer is a display device manufacturing method, characterized in that the black die and the white die is formed of a plurality of capsule assemblies encapsulated by a condensation polymerization reaction. The method of claim 5, The black die is a carbon particle, and the white die is an indium tin oxide (ITO) particle. The method of claim 5, And a conductive polymer binder layer beneath the charged particle layer, which functions to bond the first substrate and the second substrate. The method of claim 5, And the switching element is a thin film transistor including a gate electrode, an active layer, a source electrode, and a drain electrode. A first substrate and a second substrate spaced apart from each other and including a pixel region including a switching region; A switching element configured in the switching region of the first substrate; A pixel electrode connected to the switching element and positioned in the pixel area; A common electrode formed on one surface of the second substrate and positioned in a region excluding a portion corresponding to a boundary between the switching region and the pixel region; Charged layer composed of charged particles located under the common electrode Display device comprising a. Defining a pixel region including a switching region in the first substrate and the second substrate spaced apart from each other; Forming a switching element in the switching region of the first substrate; Forming a pixel electrode connected to the switching element and positioned in the pixel area; Forming a common electrode on an area of the lower substrate except for an area corresponding to a boundary between the switching area and the pixel area; Forming a charged layer including charged particles under the second substrate including the common electrode; Display device manufacturing method comprising a. The method of claim 11, The common electrode is formed using a photolithography process or a shadow mask.

Images