KR101352907B1 - Electrophoretic display deivce and method of fabrication thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing an electrophoretic display device having a reduced manufacturing cost and a simplified manufacturing process, the method comprising: providing a first substrate and a second substrate including a display unit and a non-display unit including a plurality of pixels; Forming a thin film transistor on a first substrate, forming a protective layer on a first substrate on which the thin film transistor is formed, and defining a partition wall defining a plurality of pixels on the protective layer, and sidewalls of the protective layer and the partition wall. Forming a pixel electrode on the substrate, filling an electrophoretic material in the unit pixel inside the barrier rib on the protective layer, and forming a common electrode on the second substrate; And bonding the first substrate to the second substrate.

Description

Electrophoretic display device and its manufacturing method {ELECTROPHORETIC DISPLAY DEIVCE AND METHOD OF FABRICATION THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophoretic display device and a method of manufacturing the same, and more particularly, to an electrophoretic display device and a method of manufacturing the same, which directly reduce an electrophoretic material on a substrate on which a thin film transistor is formed, thereby reducing manufacturing cost. It is about.

In general, an electrophoretic display device is an image display device using a phenomenon in which a pair of electrodes to which a voltage is applied is immersed in a colloid solution to move the colloid particles to either one of polarities. The electrophoretic display device has a wide viewing angle, a high reflectance, Power and the like, all kinds of electronic devices are attracting attention as electronic devices such as electric paper.

Such an electrophoretic display device has a structure in which an electrophoretic layer is interposed between two substrates, at least one of the two substrates is made of a transparent substrate, and the other substrate is provided with a reflector to reflect the input light. Images can be displayed in mode.

1 is a view showing a structure of a conventional electrophoretic display element 1. Fig. 1, the electrophoretic display element 1 includes a first substrate 20 and a second substrate 40, a thin film transistor and a pixel electrode 18 formed on the first substrate 20, A common electrode 42 formed on the second substrate 40 and an electrophoretic layer 60 formed between the first substrate 20 and the second substrate 40. The electrophoretic layer 60 and the pixel And an adhesive layer (56) formed between the electrodes (18).

The thin film transistor includes a gate electrode 11 formed on the first substrate 2, a gate insulating layer 22 formed on the entire first substrate 20 on which the gate electrode 11 is formed, And a source electrode 15 and a drain electrode 16 formed on the semiconductor layer 13. The source electrode 15 and the drain electrode 16 are formed on the semiconductor layer 13, A protective layer 24 is formed on the source electrode 15 and the drain electrode 16 of the thin film transistor.

On the protective layer 24, a pixel electrode 18 for applying a signal to the electrophoretic layer 60 is formed. A contact hole 28 is formed in the passivation layer 24 so that the pixel electrode 18 on the passivation layer 24 is connected to the drain electrode 16 of the thin film transistor through the contact hole.

In addition, a common electrode 42 is formed on the second substrate 40. In the electrophoretic layer 60 formed between the first substrate 20 and the second substrate 40, a capsule 70 filled with white particles 74 and black particles 76 is distributed therein. When a signal is applied to the pixel electrode 18, an electric field is generated between the common electrode 42 and the pixel electrode 18, and white particles 74 and black particles 76 are moved to implement an image.

For example, when a negative (-) voltage is applied to the pixel electrode 18, the common electrode 42 of the second substrate 40 has a relatively positive potential, and white particles (+ 74 move toward the first substrate 20 and the black particles 76 having a negative charge move toward the second substrate 40. In this state, when light is input from the outside, that is, from the upper portion of the second substrate 40, since the input light is reflected by the black particles 76, black is realized in the electrophoretic display element.

On the other hand, when a positive voltage is applied to the pixel electrode 18, the common electrode 42 of the second substrate 40 has a negative potential, and white particles 74 having a positive charge The black particles 76 moving to the second substrate 40 and having a negative charge move to the first substrate 20. In this state, when light is input from the outside, that is, from the upper portion of the second substrate 40, since the input light is reflected by the white particles 74, white is realized in the electrophoretic display element.

However, in the conventional electrophoretic display element 1 having the above-described structure, the following problems arise.

In the conventional electrophoretic display device 1, the first substrate 20 and the second substrate 40 are separately manufactured, and then the first substrate 20 and the second substrate 40 are bonded by the adhesive layer 56. It is completed by. That is, after the thin film transistor and the pixel electrode 18 are formed on the first substrate 20 and the common electrode 42, the electrophoretic layer 60, and the adhesive layer 56 are formed on the second substrate 40, It is formed by bonding the first substrate 20 and the second substrate 40.

The first substrate 20 and the second substrate 40 are each manufactured on different processes, and are then transferred by a conveying means to be bonded to each other in a bonding process. On the other hand, the common electrode 42 is formed on the second substrate 40, and the electrophoretic layer 60 is coated and then the adhesive layer 56 is applied. In order to prevent the adhesive force of the adhesive layer 56 from being lowered or adhesion of foreign matter to the adhesive layer 56 in order to bond the first substrate 20 to the second substrate 40 by transferring the second substrate 40 to the adhesion process, 56) with a protective film attached thereto. In order to attach the transferred second substrate 40 to the first substrate 20, the protective film is peeled off from the second substrate 40, and then the first substrate 20 and the second substrate 40 are aligned. Must adhere to

As described above, in the conventional electrophoretic display device, since the first substrate 20 and the second substrate 40 are manufactured in different processes, an expensive material such as an adhesive layer 56 or a protective film is not only required, but also an adhesive layer ( There is a problem that the process is complicated, such as the coating of 56) and the adhesion and peeling of the protective film.

An object of the present invention is to provide an electrophoretic display device and a method of manufacturing the electrophoretic display device which can reduce the manufacturing cost and simplify the manufacturing process by directly forming the electrophoretic layer on the substrate on which the thin film transistor is formed The purpose.

In order to achieve the above object, the electrophoretic display device manufacturing method according to the present invention comprises an image display region in which a plurality of pixels are arranged and a non-display region outside the image display region. Providing a first substrate comprising a second substrate corresponding to the first substrate; Forming a thin film transistor for each pixel on the first substrate; Forming a barrier layer on the first substrate on which the thin film transistor is formed and defining a plurality of pixels on the passivation layer; Forming a transparent conductive layer on sidewalls of the protective layer and the partition wall; Etching the transparent conductive layer to form pixel electrodes integrally connected to the sidewalls of the protective layer and the barrier rib at once; Forming an electrophoretic layer by filling an electrophoretic material in unit pixels between the barrier ribs on the protective layer; Forming a common electrode on the second substrate; And bonding the first substrate and the second substrate to each other.

In addition, the sealing layer is formed over the first substrate or formed on the partition wall to seal the electrophoretic material, the electrophoretic material includes white particles having a charge characteristic and black particles or color particles having a charge characteristic.

The protective layer and the partition wall may be formed by separate processes, or may be formed at a time by removing a portion after forming the insulating layer.

In addition, the electrophoretic display device according to the present invention includes a first substrate and a non-display region including a display region in which a plurality of pixels are arranged and a non-display region outside the image display region. A second substrate corresponding to one substrate; A thin film transistor formed for each pixel on the first substrate; A protective layer on the first substrate on which the thin film transistor is formed; Barrier ribs formed on the passivation layer to define unit pixels; A pixel electrode integrally formed on the sidewalls of the protective layer and the partition wall; An electrophoretic material formed on a pixel between partition walls in a unit pixel and in contact with the pixel electrode; And a common electrode formed on the second substrate.

In the present invention, since the electrophoretic layer is directly applied to the substrate on which the thin film transistor is formed, a protective film for protecting the adhesive layer or the adhesive layer for bonding the electrophoretic layer compared to the conventional electrophoretic layer formed on a separate substrate is Not only is it unnecessary to reduce manufacturing costs, but also the electrophoretic layer can be formed on existing thin film transistor manufacturing lines, thereby simplifying the manufacturing process.

1 is a view showing a conventional electrophoretic display device.
2A-2G illustrate a method of manufacturing an electrophoretic display device according to a first embodiment of the present invention.
3A and 3B illustrate a method of forming an electrophoretic layer of an electrophoretic display device according to the present invention, respectively.
4A-4D illustrate a method of manufacturing an electrophoretic display device according to a second embodiment of the present invention.
5A-5E illustrate another method of manufacturing an electrophoretic display device according to a second exemplary embodiment of the present invention.

Hereinafter, an electrophoretic display device according to the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, the electrophoretic layer is formed on the first substrate on which the thin film transistor is formed. That is, in the present invention, an electrophoretic layer is formed in a thin film transistor manufacturing process. Therefore, since the electrophoretic layer can be formed using the manufacturing equipment of the thin film transistor, the electrophoretic layer is formed on the second substrate in another process, and then the second substrate is bonded to the first substrate, It is possible to greatly simplify the manufacturing process as compared with the conventional method of completing the manufacturing process.

In a conventional electrophoretic display device manufacturing process of forming an electrophoretic layer on a second substrate, the electrophoretic layer is supplied from another factory or even another part supplier and transferred to a manufacturing factory where the thin film transistor is formed, There is a problem that the manufacturing process is delayed and troublesome, and the second substrate is damaged in the process of transferring the second substrate by the transfer means such as a vehicle.

On the other hand, in the present invention, since the electrophoretic layer is formed on the first substrate using the existing thin film transistor manufacturing equipment, a rapid electrophoretic display device can be manufactured.

2A to 2G illustrate a method of manufacturing an electrophoretic display device according to a first exemplary embodiment of the present invention. Although the electrophoretic display device is substantially composed of a plurality of unit pixels, only one pixel is shown in the drawing for convenience of description.
Terms used in the present embodiment are defined. An area in which pixels are arranged on the first substrate is called an image display area, and an outer portion of the image display area, that is, an area where no pixel is formed, is called an image non-display area.

First, as shown in FIG. 2A, a Cr, Mo, Ta, Cu, Ti, Al or Al alloy is formed on the first substrate 120 including an image display area and an image non-display area and made of a transparent material such as glass or plastic. After laminating a highly conductive opaque metal by a sputtering process, such as by etching by a photolithography process to form a gate electrode 111, the first gate electrode 111 is formed The gate insulating layer 122 is formed by stacking an inorganic insulating material such as SiO ₂ or SiNx by the CVD (Chemicla Vapor Deposition) method over the entire substrate 120.

Subsequently, as illustrated in FIG. 2B, a semiconductor material such as amorphous silicon (a-Si) is deposited on the entire first substrate 120 by CVD and then etched to form a semiconductor layer 113. Although not shown in the drawing, an amorphous silicon doped with impurities or doped with impurities is doped in a part of the semiconductor layer 113, and the ohmic contact (not shown) in which a source electrode and a drain electrode, which will be formed later, Thereby forming an ohmic contact layer.

Thereafter, as shown in FIG. 2C, an opaque metal having good conductivity such as Cr, Mo, Ta, Cu, Ti, Al, or Al alloy is laminated on the first substrate 120 by sputtering and then etched to form a semiconductor. On the layer 113, strictly speaking, the source electrode 115 and the drain electrode 116 are formed on the ohmic contact layer, and then the entire first substrate 120 having the source electrode 115 and the drain electrode 116 formed thereon. A protective layer 124 is formed by stacking an organic insulating material such as BCB (Benzo Cyclo Butene) or photo acryl.

Also, although not shown in the figure, the protective layer 124 may be formed of a plurality of layers. For example, the protective layer 124 may be formed as a double layer of the inorganic insulating layer made of an inorganic insulating material such as a layer of organic insulation made of an organic insulating material such as BCB or the picture acrylic and SiO _2, or SiNx, inorganic An insulating layer, an organic insulating layer, and an inorganic insulating layer. As the organic insulating layer is formed, the surface of the protective layer 124 is formed flat and the interface characteristic with the protective layer 124 is improved by applying the inorganic insulating layer.

In addition, a contact hole 117 is formed in the protective layer 124 to expose the drain electrode 116 of the thin film transistor to the outside.

Subsequently, as shown in FIG. 2D, the partition wall 180 is formed on the passivation layer 124. The partition wall 180 is formed between the pixel and the pixel in the image display area. Pixels are substantially defined by the partitions. Although not illustrated in the drawing, the partition wall 180 is formed along a boundary area of pixels arranged in a matrix shape on the first substrate 120, so that the partition wall 180 also has a matrix shape on the first substrate 120. Is formed.

The barrier ribs 180 may be formed by laminating an insulating layer made of resin or the like and then etching them by a photolithography method using a photoresist. Alternatively, the barrier ribs 180 may be formed by laminating a photosensitive resin and etching them by a photolithography method. In addition, the partition wall 180 may be formed by printing the partition wall 180 patterned by a printing method such as a printing roll, and after manufacturing a mold having grooves corresponding to the partition wall, the insulating material of the mold is formed. It may be formed by transferring to the first substrate 120. The barrier ribs 180 may be formed in an imprint manner.

In practice, the formation of the partition wall 180 is not limited by a specific method. The above description of specific methods is for convenience of explanation and is not intended to limit the present invention. The partition 180 may be formed by various known methods.

Subsequently, as illustrated in FIG. 2E, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is stacked and etched on each pixel on the passivation layer 124 to etch the pixel electrode 118. Form. In this case, the pixel electrode 118 is electrically connected to the drain electrode 116 of the thin film transistor through the contact hole 117.

The pixel electrode 118 is not only formed on the passivation layer 124, but is also formed on sidewalls of the partition wall 180. In this case, the pixel electrode 118 on the sidewall of the partition wall 180 is integrally formed with the pixel electrode 118 on the passivation layer 124.

As described above, the pixel electrode 118 is not formed only on the protective layer 124 but extends to the sidewall of the partition wall 180 for the following reasons.

First, image quality is improved by extending the pixel electrode 118 to the side wall of the barrier ribs 180.

When the pixel electrode 118 is formed only on the passivation layer 124 and not on the partition 180, the pixel electrode 118 at the bottom of the partition 180, that is, the partition 180 and the passivation layer 124. Since the pixel electrode 118 is not normally formed in the corner region of the pixel region, the pixel electrode 118 becomes a dead area where an electric field is abnormally applied. Such a warp region lowers the aperture ratio of the liquid crystal display element and causes many problems such as a decrease in contrast.

However, when the pixel electrode 118 is formed on the sidewall of the partition wall 180 as in the present invention, since the edge region branch pixel electrode 118 is formed between the partition wall 180 and the passivation layer 124, the dead area is formed. It does not occur, and as a result, the aperture ratio is improved, the contrast is improved, and the response speed is improved.

Second, the process is facilitated by extending the pixel electrode 118 to the side wall of the barrier rib 180.

As will be mentioned later in the process, the electrophoretic material is filled in the upper region of the first substrate 120 defined by the partition wall 180 and the protective layer 124. When the pixel electrode 118 is formed only on the passivation layer 124 and not on the sidewall of the barrier 180, the surface characteristics and the partition of the pixel electrode 118 on the passivation layer 124 when the electrophoretic material is filled. Since the surface characteristics of the 180 are different, the electrophoretic material may not be well applied to the surface of the partition wall 180 when the electrophoretic material is filled, and thus the electrophoretic material may not be easily injected. In order to prevent this, the surface of the barrier rib can be plasma-treated or chemically treated to improve the surface characteristics, but in this case, the process becomes complicated and the cost increases.

However, when the pixel electrode 118 extends to the side wall of the partition wall 180 as in the present invention, the electrophoretic material is easily formed on the side surface of the partition wall 180, that is, the side wall on which the pixel electrode 118 is formed, without any surface treatment. Since the coating, the electrophoretic material can be smoothly filled into the partition wall 180.

Thereafter, as shown in FIG. 2F, the electrophoretic material is filled in the pixels between the partition walls 180 to form the electrophoretic layer 160.

The electrophoretic material is composed of particles having positive and negative charge characteristics. In this case, the particles may be white particles 164 and black particles 165, color particles such as cyan, magenta, yellow, or R (Red), G (Green), B It may be a color particle such as (Blue).
In the case of white particles 164, particles having good reflectance such as TiO ₂ are used. In the case of black particles 165, particles having black characteristics such as carbon black are used. In this case, the white particles 164 may be negatively charged, the black particles 165 may be positively charged, the white particles 164 may be positively charged, and the black particles 165 may be negatively charged.

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In addition, in the case of the color particles as a dye having a charge characteristic, the color particles may be negatively charged or may be positively charged.

The electrophoretic material may include a dispersion medium such as a liquid polymer. This dispersion medium is a black particle, a white particle, or a colored particle, and may be a liquid such as a liquid polymer or air itself. As described above, when the dispersion medium is the air itself, it means that the particles move in the air as the voltage is applied without the dispersion medium.

The electrophoretic material may be a material in which capsules filled with a polymer binder are filled with an electronic ink. At this time, the electronic ink distributed in the capsule is composed of white particles (or white ink) and black particles (or black ink). At this time, the white particles and the black particles have positive and negative charge characteristics, respectively.

On the other hand, white particles, black particles, and color particles may not be used for only specific materials, but all known particles may be used.

The charging of the electrophoretic material to the pixels between the partition walls 180 may be performed by various methods, which will be described below.

3A and 3B illustrate a method of forming an electrophoretic layer 160 by filling an electrophoretic material with pixels between partitions 180 formed on the first substrate 120.

The method illustrated in FIG. 3A relates to an inkjet method or a nozzle method. As shown in FIG. 3A, an electrophoretic material 160a is filled in a syringe (or nozzle) 185 and then the first substrate ( 120) The syringe 185 is positioned on the top. Thereafter, the partition wall 180 is moved by moving the syringe 185 on the first substrate 120 in a state where pressure is applied to the syringe 185 by an external air supply device (not shown). The electrophoretic material 160a is dropped on the pixels therebetween to form the electrophoretic layer 160 on the first substrate 120.

The method illustrated in FIG. 3B relates to a squeeze method, and as shown in FIG. 3B, after the electrophoretic material 160a is applied to an upper portion of the first substrate 120 on which the plurality of partition walls 180 are formed, a squeeze bar ( The electrophoretic material 160a is filled in the pixels between the pixels by the pressure of the squeeze bar 187 by moving on the first substrate 120 by 187 to form the electrophoretic layer 160.

Of course, the present invention is not limited to the above-described method. The above-described method shows an example of a process of forming the electrophoretic layer 160 that can be used in the present invention, and the present invention is not limited to this specific process. For example, various electrophoresis layer forming processes such as cast printing, bar coating printing, screen printing, and mold printing may be applied to the present invention.

Subsequently, as shown in FIG. 2F, a sealing material is coated on the electrophoretic layer 160 as described above to form a sealing layer 168 to seal the electrophoretic layer 160, and then the first substrate 120. Is bonded to the second substrate 140 to complete the electrophoretic display device. In this case, the color filter layer 169 may be formed on the sealing layer 168.

The sealing layer 168 is intended to prevent the electrophoretic layer 160 made of a dye having a low viscosity flows so that the dye overflows to an external or adjacent pixel. In addition, the sealing layer 168 prevents moisture from penetrating into the electrophoretic layer 160 and the electrophoretic layer 160 becomes defective.
The sealing layer 168 may be formed on both an upper surface of the electrophoretic layer 160 and an upper end of the sealing layer 168. However, in this case, some of the charged electrophoretic particles may be electrically attached to the silicide layer 168 to cause an error in the initial arrangement of the electrophoretic particles, so that the sealing layer 168 may be the electrophoretic layer 160. It may not be formed over the entire upper surface of the partition wall 160 may be formed only on the top.
On the other hand, in order to solve the problem that the electrophoretic particles are electrically attached to the sealing layer 168, after the electrophoretic layer is filled for each subpixel, an additional layer is further formed on the electrophoretic layer, whereby the electrophoretic particles directly contact the silicide layer. Contact can be prevented. In this case, the electrophoretic particles do not stick to the silicide layer, thereby reducing the occurrence of defective pixels.
The interlayer may be a photosensitive organic material such as a partition wall, and in particular, may be methyl ethyl ketone. The intermediate layer is formed by coating a thickness of several nanometers on top of the electrophoretic layer and the partition wall. The intermediate layer temporarily seals the electrophoretic layer to allow the formation of a silicide layer, as well as to solve the problem of the electrophoretic particles sticking to the sealing layer.

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Although the first substrate 120 and the second substrate 140 are bonded together by the sealing layer 168 in order to improve the bonding strength between the first substrate 120 and the second substrate 140, May be formed. The adhesive layer may be formed only on the outer region of the electrophoretic display device, that is, on the sealing layer 168 above the barrier ribs 180, or on the entire sealing layer 168 above the electrophoretic layer 160.

The common electrode 142 is formed on the second substrate 140 made of a transparent material such as glass or plastic. The common electrode 142 is formed by stacking a transparent conductive material such as ITO or IZO.

Although not shown in the drawings, a color filter layer may be formed on the second substrate 140. The color filter layer 146 is composed of R (Red), G (Green), B (Blue) color filters, and implements color when the electrophoretic material is composed of black particles and white particles.

The structure of the electrophoretic display device manufactured by the above method will be described in detail with reference to FIG. 2G.

As shown in FIG. 2G, in the electrophoretic display device of the present invention manufactured by the above method, the partition wall 180 is directly formed on the first substrate 120 and the electrophoretic layer 160 is also the first. Since the electrophoretic layer 160 is directly formed on the pixel electrode 118 to be directly contacted with the pixel electrode 118 by filling between the partition walls 180 of the substrate 120, unlike the conventional electrophoretic display device. There is no need for a separate adhesive layer for attaching the electrophoretic layer 160 between the electrophoretic layer 160, the pixel electrode 118, and the protective layer 124.

The driving of the electrophoretic display device having such a structure will be described below. When the electrophoretic material 160 is composed of the white particles 164 and the black particles 165, since the white particles 164 have a positive charge or negative charge characteristic, The white particles 164 and the electrophoretic layer 160 are moved by the electric field generated between the pixel electrode 118 and the common electrode 142 when a signal is applied to the pixel electrode 118 through the thin film transistor .

For example, when the white particles 164 have positive (+) electric charges, when a positive voltage is applied to the pixel electrode 118, the common electrode 142 of the second substrate 140 has a relatively negative potential The white particles 164 having positive charge move toward the second substrate 140. Therefore, when light is input from the outside, that is, from the upper portion of the second substrate 140, the inputted light is mostly reflected by the white particles 164, so that white is realized in the electrophoretic display element.

Since the density of the white particles 164 moving toward the second substrate 140 or the interval between the white particles 164 and the second substrate 140 varies depending on the intensity of the voltage applied to the pixel electrode 118, The intensity of the light reflected by the white particles 164 is also changed, so that a desired luminance can be realized.

On the other hand, when a negative voltage is applied to the pixel electrode 118, the common electrode 142 of the second substrate 140 has a (+) potential, and the white particles 164 having (+ When the light is moved from the first substrate 120 to the first substrate 120, the input light is substantially not reflected, thereby realizing black.

On the other hand, in the case where the white particles 164 have a negative charge, when the positive voltage is applied to the pixel electrode 118, the common electrode 142 of the second substrate 140 has a relatively negative potential So that the white particles 164 having a negative charge move toward the first substrate 120. Therefore, when light is input from the outside, that is, from the upper part of the second substrate 140, most of the input light is not reflected, so that black is implemented in the electrophoretic display device.

On the contrary, when a negative voltage is applied to the pixel electrode 118, the common electrode 142 of the second substrate 140 has a (+) potential, and white particles 164 having a negative charge When the light is moved from the second substrate 140 to the second substrate 140, the input light is reflected by the white particles 164, thereby realizing white.

When the electrophoretic material is composed of color particles, R, G, and B color particles or color particles such as cyan, magenta, and yellow are formed in accordance with a signal applied to the pixel electrode 118, The substrate 140 can be moved to implement a color mixed with the corresponding color or other pixels.

When the electrophoretic material is composed of a polymer polymer in which capsules are distributed in which white particles and black particles are distributed, white particles and black particles contained in the electronic ink distributed in the capsules have positive and negative charge characteristics, respectively, The white particles and the black particles are separated from each other in the capsule by the electric field generated between the pixel electrode 118 and the common electrode 142. [ For example, when a negative (-) voltage is applied to the pixel electrode 118, the common electrode 142 of the second substrate 140 has a (+) potential, so that white particles The black particles moving toward the first substrate 120 and the (-) charged charges move toward the second substrate 140. In this state, when light is input from the outside, that is, from the upper portion of the second substrate 140, since the inputted light is reflected by the black particles, black is realized in the electrophoretic display element.

On the contrary, when a positive voltage is applied to the pixel electrode 118, the common electrode 142 of the second substrate 140 has a negative potential, so that white particles having a positive charge are formed on the second substrate. Moving to 140, the black particles having a negative charge is moved to the first substrate 140.

In this state, when light is input from the outside, that is, from the upper part of the second substrate 140, since the input light is reflected by the white particles, white is realized.

At this time, when the white particles and the black particles in the capsule have negative charge and positive charge characteristics, white and black can be realized by the opposite operation.

As described above, in the present invention, since the electrophoretic layer 160 is directly formed on the first substrate 120, the electrophoretic layer is attached to the second substrate as compared with the conventional method in which the electrophoretic layer is formed on the second substrate. There is no need for a protective film or the like for protecting the adhesive layer or the adhesive layer. Further, in the present invention, since the electrophoretic layer 160 can be formed in a process line such as a conventional thin film transistor formation process line, for example, an insulation layer formation, a separate process line is not required, .

In addition, compared with the prior art in which an electrophoresis layer is manufactured by a separate factory or a manufacturer, and the electrophoresis layer is transported and attached to the second substrate and the second substrate is bonded to the first substrate again, It is possible to simplify the manufacturing process since the process such as adhesion of layers is not required.

4A to 4D illustrate a method of manufacturing an electrophoretic display device according to a second exemplary embodiment of the present invention.

First, as shown in FIG. 4A, a gate electrode 211, a gate insulating layer 222, a semiconductor layer 213, a source electrode 215, and a drain electrode 216 are formed in a unit pixel of the first substrate 220. A thin film transistor is formed.

In this case, the thin film transistor is manufactured by the same process as that of the first embodiment shown in FIGS. 2A and 2B.
Thereafter, the insulating layer 224a is stacked over the entire substrate on which the thin film transistor is formed. In this case, the insulating layer 224a may be formed of a photosensitive resin.
Subsequently, as shown in FIG. 4B, a mask 270 is positioned on the insulating layer 224a. The mask 270 is a half-tone mask, and includes a blocking part 270a, a transflective part 270b, and a transmissive part 270c, and an insulating layer 224a in a region corresponding to a pixel to be completely exposed is formed. Only a part of the insulating layer 224a of the region corresponding to the drain electrode which is completely removed and is partially exposed is removed, and the insulating layer 224a of the region corresponding to the non-exposed region that is not exposed is not removed. Instead, a diffraction mask may be used that includes a plurality of slits and partially transmits light into this region.
Thereafter, as illustrated in FIG. 4C, the developer is applied to etch the insulating layer 224a in the fully exposed and partially exposed regions, thereby partitioning the barrier rib 280, the protective layer 224, and the contact hole 217. ).

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Thereafter, as illustrated in FIG. 4D, the pixel electrode 218 is formed on the protective layer 224 and on the sidewall of the partition wall 280 to be electrically connected to the drain electrode 216 through the contact hole 217. Thereafter, an electrophoretic material is filled in the pixels between the barrier ribs 280 to form the electrophoretic layer 260. Subsequently, after the electrophoretic layer 260 is sealed by the sealing layer 268, the second substrate 240 having the common electrode 242 is formed on the first substrate 220 by the sealing layer 268 or an adhesive. The electrophoretic display device is completed by adhering to the electrophoretic display device. In this case, a color filter layer 269 may be formed on the sealing layer 268.

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At this time, the formation of the electrophoretic layer 260 and the bonding of the substrates 220 and 240 proceed in the same manner as in the first embodiment shown in FIGS. 2F and 2G.

The structure of the electrophoretic display device manufactured by the above process will be described with reference to FIG. 4D.

As shown in FIG. 4D, the structure of the electrophoretic display device according to this embodiment is the same as that of the electrophoretic display device according to the first embodiment shown in FIG. 2G. The only difference is that the electrophoretic display device manufactured according to the first embodiment may have the barrier 180 and the protective layer 224 formed by different processes so that the barrier 180 and the protective layer 124 may be formed of different materials. However, in this embodiment, since the partition wall 280 and the protective layer 224 are formed by one process after forming the insulating layer, the partition wall 280 and the protective layer 224 is made of the same material.

Therefore, the electrophoretic display device of this embodiment can simplify the manufacturing process, thereby reducing the manufacturing cost.
5A-5D illustrate another method of manufacturing an electrophoretic display device according to a second exemplary embodiment of the present invention.
First, as shown in FIG. 5A, a gate electrode 311, a gate insulating layer 322, a semiconductor layer 313, a source electrode 315, and a drain electrode 316 are formed on a unit pixel of the first substrate 320. To form a thin film transistor consisting of. In this case, the thin film transistor is manufactured by the same process as that of the first embodiment shown in FIGS. 2A and 2B.
Thereafter, the insulating layer 324a and the photoresist layer 360 are sequentially stacked over the entire substrate on which the thin film transistor is formed, and then the blocking portion 370a, the transflective portion 370b, and the transmissive portion are formed on the photoresist layer 360. A halftone mask 370 made of 370c is positioned and light is exposed to expose the photoresist layer 360.
Thereafter, as illustrated in FIG. 5B, the developer is applied to the photoresist layer 360 to form the first photoresist pattern 360a, and then the insulating layer 324a is formed by the first photoresist pattern 360a. ) And the insulating layer 324a which is not blocked by the first photoresist pattern 360a is etched by the etching solution.
As shown in FIG. 5C, a contact hole 317 is formed by the etching process as described above. Thereafter, the first photoresist pattern 360a is ashed to form a second photoresist pattern 360b in which pixels are exposed, and then an etching solution is applied to the second photoresist pattern 360b. The insulating layer 324 of the non-blocking pixel is etched.
As shown in FIG. 5D, the partition wall 380 and the protective layer 324 are formed by this etching.
Thereafter, as illustrated in FIG. 5E, the pixel electrode 318 is formed on the protective layer 324 and on the sidewall of the partition wall 380 to be electrically connected to the drain electrode 316 through the contact hole 317. Thereafter, an electrophoretic material is filled in the pixels between the partitions 380 to form the electrophoretic layer 360. Subsequently, after sealing the electrophoretic layer 360 by the sealing layer 368, the second substrate 340 on which the common electrode 342 is formed is attached to the first substrate 320 by the sealing layer 368 or an adhesive. The electrophoretic display device is completed by adhering to the electrophoretic display device. In this case, a color filter layer 369 may be formed on the sealing layer 368.
At this time, the formation of the electrophoretic layer 360 and the bonding of the substrates 220 and 240 proceed in the same manner as in the first embodiment shown in FIGS. 2F and 2G.
Meanwhile, the partition wall may be formed by stacking an insulating layer and then applying pressure to the insulating layer by a mold or may be formed by an imprint method. After the barrier rib and the protective layer are formed in the same manner as described above, a contact hole is formed in the protective layer to expose the drain electrode to the outside.

In the above description, the structure of the electrophoretic display device is limited to a specific structure, but the electrophoretic display device of the present invention is not limited to the specific structure. In particular, various electrophoretic layers currently used as electrophoretic layers may be applied. That is, it may be applied to the electrophoretic layer of any structure that can be formed on the first substrate.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

Therefore, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also within the scope of the present invention.

120, 140: substrate 111: gate electrode
113: semiconductor layer 115: source electrode
116: drain electrode 118: pixel electrode
124: protective layer 142: common electrode
160: electrophoresis layer 164: white particles
165 black particles 168 sealing layer

Claims (21)

A first substrate comprising an image display region in which a plurality of pixels are arranged and a non display region outside the image display region, and a second substrate corresponding to the first substrate. step;
Forming a thin film transistor for each pixel on the first substrate;
Forming a barrier layer on the first substrate on which the thin film transistor is formed and defining a plurality of pixels on the passivation layer;
Forming a transparent conductive layer on sidewalls of the protective layer and the partition wall;
Etching the transparent conductive layer to form pixel electrodes integrally connected to the sidewalls of the protective layer and the barrier rib at once;
Forming an electrophoretic layer by filling an electrophoretic material in unit pixels between the barrier ribs on the protective layer;
Forming a common electrode on the second substrate; And
And bonding the first substrate and the second substrate to each other. The method of claim 1, further comprising forming a sealing layer for sealing the electrophoretic layer after filling the electrophoretic material in a unit pixel. The method of claim 2, wherein the sealing layer is formed over the entire image display area. The method of claim 2, wherein the sealing layer is formed on the partition wall. The method of claim 1, wherein the bonding of the first substrate to the second substrate comprises forming an adhesive layer on at least one of the first substrate and the second substrate. The method of claim 1, wherein the electrophoretic material comprises charged white particles and black particles. The method of claim 1, wherein the electrophoretic material comprises charged color particles. The method of claim 6, wherein the electrophoretic material further comprises a dispersion medium. The method of claim 1, wherein the forming of the protective layer and the partition wall,
Stacking an insulating layer on the first substrate to form a protective layer; And
Forming a partition on the protective layer, characterized in that the electrophoretic display device manufacturing method. The method of claim 9, wherein the forming of the partition wall comprises:
Forming an insulating layer on the protective layer; And
And removing a portion of the insulating layer by one of a photolithography process, a mold process, and an imprint process. The method of claim 1, wherein the forming of the protective layer and the partition wall,
Stacking an insulating layer on the first substrate; And
And removing a portion of the insulating layer by one of a photolithography process, a mold process, and an imprint process to form a protective layer and a partition wall. The method of claim 1, wherein the forming of the electrophoretic layer is performed by using one of a dropping method, a squeeze method, a casting printing method, a bar coating printing method, a screen printing method, and a mold printing method. Electrophoretic display device manufacturing method comprising the step of filling the electrophoretic material. The method of claim 1, wherein the forming of the thin film transistor comprises:
Forming a gate electrode on the first substrate;
Forming a semiconductor layer on the gate electrode;
Forming a source electrode and a drain electrode on the semiconductor layer. A first substrate including an image display region in which a plurality of pixels are arranged and a non-display region outside the image display region, and a second substrate corresponding to the first substrate;
A thin film transistor formed for each pixel on the first substrate;
A protective layer on the first substrate on which the thin film transistor is formed;
Barrier ribs formed on the passivation layer to define unit pixels;
A pixel electrode integrally formed on the sidewalls of the protective layer and the partition wall;
An electrophoretic material formed on a pixel between partition walls in a unit pixel and in contact with the pixel electrode; And
An electrophoretic display device comprising a common electrode formed on a second substrate. The method of claim 14, wherein the thin film transistor,
A gate electrode formed on the first substrate;
A semiconductor layer formed on the gate electrode; And
And a source electrode and a drain electrode formed on the semiconductor layer. 15. The electrophoretic display device of claim 14, wherein the electrophoretic material comprises charged white particles and black particles. 15. The electrophoretic display device of claim 14, wherein the electrophoretic material comprises charged color particles. 18. The electrophoretic display device of claim 16 or 17, wherein the electrophoretic material further comprises a dispersion medium. 15. The electrophoretic display device of claim 14, further comprising a sealing layer formed on the electrophoretic material to seal the electrophoretic material. The electrophoretic display device of claim 14, wherein the protective layer and the partition wall are made of the same material. The electrophoretic display device of claim 14, wherein the protective layer and the partition wall are made of different materials.

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