KR20130051368A

KR20130051368A - Method of fabricating electrophoretic display device

Info

Publication number: KR20130051368A
Application number: KR1020110116665A
Authority: KR
Inventors: 김병걸; 김진욱; 민혜리; 김민지; 김성우; 유경열; 손영태
Original assignee: 엘지디스플레이 주식회사
Priority date: 2011-11-09
Filing date: 2011-11-09
Publication date: 2013-05-20

Abstract

The present invention includes forming a first electrode for each pixel region on a first substrate on which first, second, and third pixel regions are defined; Forming a partition on the boundary of the first, second, and third pixel areas over the first electrode; A first color electrophoretic particle having a first polarity, black electrophoretic particle having a second polarity opposite to the first polarity, a redispersibility enhancing agent, and a sacrificial solvent in the first pixel region surrounded by the partition wall; (A) forming a first color ink layer using color ink; Performing a heat treatment process to remove the sacrificial solvent included in the first color ink layer formed in the first pixel region to form a powder state of a first color; Step (A) using second and third color electrophoretic particles having a first polarity, black electrophoretic particles having a second polarity, second and third color inks comprising a redispersibility enhancing agent and a sacrificial solvent; Repeating steps (B) and (B) to achieve powder states of second and third colors in the second and third pixel areas, respectively; Injecting a fluid into the first, second, and third pixel areas in which the first, second, and third color ink layers have a powder state; A method of manufacturing an electrophoretic display device, the method comprising: placing a second substrate having an adhesive corresponding to the barrier rib and having a transparent counter electrode facing the first substrate on which the fluid is injected, and then bonding the fluid.

Description

Method of fabricating electrophoretic display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophoretic display, and more particularly, to a manufacturing method capable of manufacturing an electrophoretic display having excellent dispersibility without color intermixing between pixel regions and capable of realizing a full color image.

In general, liquid crystal displays, plasma displays, and organic light emitting displays have become mainstream display devices. However, recently, various types of display devices have been introduced to satisfy rapidly changing consumer demands.

In particular, with the advancement and portability of the information usage environment, the company is accelerating to realize light weight, thinness, and high efficiency. As a part of this, research on electrophoretic display devices combining only the advantages of paper and existing display devices is being actively conducted.

The electrophoretic display device is in the spotlight as a next generation display device having an advantage of ease of portability, and unlike a liquid crystal display device, it does not require a polarizing plate, a backlight unit, a liquid crystal layer, etc., thereby reducing manufacturing costs.

Hereinafter, a conventional electrophoretic display device will be described with reference to the accompanying drawings.

1 is a view briefly showing a structure of the electrophoretic display to explain the driving principle.

As shown, the conventional electrophoretic display device 1 includes first and second substrates 11 and 36, pixel electrodes 51 and common electrodes 55 facing each other, and the first and second electrodes. An ink layer 57 is interposed between the substrates 11 and 36. The ink layer 57 includes a plurality of capsules 63 filled with a plurality of white pigments 59 and black pigments 61 charged through a condensation polymerization reaction.

Meanwhile, a plurality of pixel electrodes 28 connected to a plurality of thin film transistors Tr are formed for each pixel region P in the first substrate 11. That is, the plurality of pixel electrodes 28 are selectively applied with a positive voltage or a negative voltage, respectively. In this case, when the size of the capsule 63 including the white pigment 59 and the black pigment 61 is not constant, only a capsule 63 having a predetermined size may be selectively used.

Applying a voltage of positive or negative polarity to the ink layer 57 described above causes the charged white pigment 59 and the black pigment 61 inside the capsule 63 to be drawn toward the opposite polarity. do. That is, when the black pigment 61 moves upward, black is displayed. When the white pigment 59 moves upward, white is displayed.

The electrophoretic display device 1 having such a configuration uses only the black pigment 61 and the white pigment 59, and thus, it is possible to realize a mono type text image by substantially implementing black and white.

In addition, an electrophoretic display device implementing full color by providing a red, green, and blue color filter layer (not shown) separately in the mono type electrophoretic display device 1 having the above-described configuration has also been proposed.

However, since the full color electrophoretic display is a reflective display device, if a separate color filter layer is provided, the brightness ratio is not good, and thus the contrast ratio is reduced.

Accordingly, there is a need for an electrophoretic display device that can realize brighter and full color, and recently, electrophoretic particles displaying red, green, and blue colors have been developed.

On the other hand, in the case of the black or white particles used in the electrophoretic display device having the above-described configuration usually uses any one type of particles of black or white, microcapsules in the preparation of the electrophoretic display small intestine having the above-described configuration Since the injection of black or white particles into the partition wall using a slit coating device or a syringe, etc. does not cause a big problem in the injection.

However, in order to implement a pixel area representing red, green, and blue to realize a color electrophoretic display device, red, green, and blue electrophoretic particles should be injected into a partition at a desired location. It is difficult to inject electrophoretic particles of each color at a desired position using a method of injecting particles, that is, a slit coating apparatus or a syringe, and since the injection is performed by ink formation, mixed color is generated between neighboring pixel areas, causing defects. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and manufactures an electrophoretic device capable of realizing a full color image without a separate color filter layer by injecting color electrophoretic particles without causing mixing of neighboring pixel regions. Its purpose is to provide a method.

According to one or more exemplary embodiments, a method of manufacturing an electrophoretic display device includes: forming a first electrode for each pixel area on a first substrate on which first, second, and third pixel areas are defined; Steps; Forming a partition on the boundary of the first, second, and third pixel areas over the first electrode; A first color electrophoretic particle having a first polarity, black electrophoretic particle having a second polarity opposite to the first polarity, a redispersibility enhancing agent, and a sacrificial solvent in the first pixel region surrounded by the partition wall; (A) forming a first color ink layer using color ink; Performing a heat treatment process to remove the sacrificial solvent included in the first color ink layer formed in the first pixel region to form a powder state of a first color; Step (A) using second and third color electrophoretic particles having a first polarity, black electrophoretic particles having a second polarity, second and third color inks comprising a redispersibility enhancing agent and a sacrificial solvent; Repeating steps (B) and (B) to achieve powder states of second and third colors in the second and third pixel areas, respectively; Injecting a fluid into the first, second, and third pixel areas in which the first, second, and third color ink layers have a powder state; And attaching the second substrate having an adhesive corresponding to the partition wall and facing the second substrate having a transparent counter electrode on the first substrate into which the fluid is injected.

In this case, the first, second, and third colors may be red, green, blue, or cyan, magenta, and yellow, respectively, and the fourth substrate may include a fourth pixel area, and the fourth pixel area may include the first color. Steps (A) and (B) are sequentially repeated using a fourth color ink comprising white electrophoretic particles having one polarity, black electrophoretic particles having the second polarity, a redispersibility enhancing agent and a sacrificial solvent. Thereby achieving a powder state of the fourth color.

The forming of the first, second, and third ink layers in the first, second, and third pixel areas may be performed by an ink manufacturing method using an inkjet device, or by a screen printing method using a screen mask and a squeegee. It is characterized by being.

When the first, second and third ink layers are formed by screen printing, the first, second and third inks have a viscosity of 5000 cps to 100000 cps.

In addition, the first, second, third color electrophoretic particles and the black electrophoretic particles are characterized in that the size (diameter) of 50nm to 1000nm, the first, second, third color and black electrophoretic particles are the first Surfactants are provided around particles showing 1, 2, and 3 colors, and the surfactants are made of polyisobutylene succinimide having a molecular weight of 1000 to 5000.

In addition, the agent is characterized by consisting of a polyisobutylene (polyisobutylene) -based material or mSPPG (mono succinate propylene glycol) having a molecular weight of about 300 to 2000, the sacrificial solvent is a tetra having a characteristic that is removed by the heat treatment It is characterized by consisting of detradecane.

In addition, the heat treatment is characterized in that for 30 minutes to 120 minutes at 60 ℃ to 80 ℃.

The fluid is characterized by injecting any one of H ₂ O, Isopar G, Halocarbor oil.

Before forming the first electrode, forming a gate line and a data line on the first substrate to define the pixel area by crossing each other; Forming a thin film transistor connected to the gate line and the data line in each pixel area; And forming a protective layer having a flat surface and exposing the drain electrode of the thin film transistor over the first substrate over the thin film transistor, wherein the first electrode is formed to contact the drain electrode.

The partition wall may be formed to overlap an edge of the pixel electrode formed in each pixel area.

The present invention has the effect of providing a full color electrophoretic display device having improved luminance characteristics by manufacturing using color electrophoretic particles without forming a separate color filter layer.

Further, in order to prevent color mixing between neighboring pixel regions of the color electrophoretic particles, an ink including electrophoretic particles of each color is made using a sacrificial solvent, and then, using the same, an ink layer having a desired color is formed in a desired pixel region. By removing the sacrificial solvent, there is an effect of minimizing the occurrence of color mixing with the ink layer formed next.

In addition, the color ink according to the present invention improves the redispersibility of the color electrophoretic particles in the fluid by removing the sacrificial solvent, and including an agent for improving the dispersibility of the electrophoretic particles in the fluid when the fluid is injected It is effective to have an excellent electrophoretic ability.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram illustrating a structure of a driving principle of an electrophoretic display.
2A to 2M are cross-sectional views of steps in manufacturing an electrophoretic display device according to an exemplary embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described for the electrophoretic display particle and the method of manufacturing the same according to the present invention.

2A to 2M illustrate four pixel areas as process steps of manufacturing an electrophoretic display device according to an exemplary embodiment of the present invention, and a thin film transistor which is a switching element for only one pixel area is illustrated for convenience. In addition, for convenience of description, an area in which the thin film transistor Tr, which is a switching element, is formed is defined as a switching area TrA.

First, as shown in FIG. 2A, any one of a first metal material such as aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, and chromium (Cr) on the transparent substrate 101 is shown. Or by depositing two or more materials to form a first metal layer (not shown).

Thereafter, a gate wiring (not shown) extending in one direction is formed by patterning the first metal layer (not shown), and the gate electrode 105 connected to the gate wiring (not shown) is formed in each switching region TrA. Form.

Next, an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is deposited on the entire surface of the gate line (not shown) and the gate electrode 105 to form the gate insulating layer 110 on the entire surface.

In addition, a pure amorphous silicon layer (not shown), an impurity amorphous silicon layer (not shown), and a second metal material layer (not shown) are formed on the gate insulating layer 110, and these include diffraction exposure or halftone exposure. Patterning the second metal layer (not shown) and the impurity and pure amorphous silicon layer (not shown) respectively by patterning at the same time through one mask process or by performing two mask processes, respectively. A semiconductor layer made of a pure amorphous silicon active layer 120a and an ohmic contact layer 120b of impurity amorphous silicon spaced apart from each other over the active layer 120a in correspondence with the gate electrode 105 in P3 and P4. 120 and source and drain electrodes 133 and 136 spaced apart from each other on the ohmic contact layer 120b.

At this time, a source spaced apart from the gate electrode 110, the gate insulating layer 118, and the semiconductor layer 120 sequentially stacked in the switching region TrA in each pixel region P1, P2, P3, and P4 in this step. The drain electrodes 133 and 136 form a thin film transistor Tr, which is a switching element.

At the same time, a data line 130 is formed on the gate insulating layer 118 to define the pixel regions P1, P2, P3, and P4 by crossing the gate line (not shown).

Meanwhile, in the embodiment of the present invention, the second metal layer (not shown) and the impurity and pure amorphous silicon layer (not shown) are formed by performing one mask process including halftone exposure or diffraction exposure. In this process, the semiconductor pattern 121 including the first and second patterns 121a and 121b may be formed of the same material forming the active layer 120a and the ohmic contact layer 120b under the data line 130. It is forming.

However, the semiconductor layer 120 is formed by first patterning the impurity and pure amorphous silicon layer (not shown) by first masking, and then forming a second metal layer (not shown) on the semiconductor layer 120. When the patterning process is performed by performing two mask processes after forming the semiconductor layer, the semiconductor pattern 121 formed under the data line 130 is omitted.

Next, a first protective layer having a flat surface on the front surface is coated with an organic insulating material, for example, photo acryl or benzocyclobutene (BCB), over the data line 130 and the thin film transistor Tr. 140 is formed.

Thereafter, a mask process is performed on the protective layer 140 to form a drain contact hole 143 exposing the drain electrode 136.

In this case, before forming the first protective layer 140 made of the organic insulating material, an inorganic insulating material such as silicon oxide or silicon nitride may be deposited to further form a second protective layer (not shown). The formation of the second protective layer (not shown) made of the inorganic insulating material is to prevent the active layer 120a in which the channel of the thin film transistor Tr is formed from being contaminated by contact with the organic material.

Next, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is deposited on the entire surface of the first passivation layer 140 and patterned by a mask process. The pixel electrode 150 in contact with the drain electrode 136 is formed in the P1, P2, P3, and P4 through the drain contact hole 143.

Next, as shown in FIG. 2B, a resin or a polymer material is coated on the pixel electrode 150 to have a thickness of about 20 μm to about 40 μm, and patterned by performing a mask process. The partition wall is formed in a form surrounding the regions P1, P2, P3, and P4.

In this case, although the barrier ribs 155 are formed in the drawing to correspond to the boundaries of the pixel regions P1, P2, P3, and P4, they do not overlap with the edges of the pixel electrode 150. The thin film transistors Tr may be formed to overlap the edges of the pixel electrodes 150 formed in the regions P1, P2, P3, and P4. Furthermore, the thin film transistors Tr provided in the pixel regions P1, P2, P3, and P4 may be formed. It may be formed to overlap with.

Next, as shown in FIG. 2C, electrophoretic particles having any one of red, green, blue, and white colors are disposed on the pixel electrode 150 on the substrate 101 on which the partition wall 155 is formed. Red electrophoretic particles 159R), black electrophoretic particles 159B, and a high viscosity ink 180R, which is one of the most characteristic constitutions of the present invention in which a sacrificial solvent and a redispersibility enhancing agent are properly mixed. The ink layer 160R is formed by screen printing in correspondence with the pixel region P1 that should be red. For convenience of explanation, the pixel areas P1, P2, P3, and P4 representing red, green, blue, and white are defined as first, second, third, and fourth pixel areas P1, P2, P3, and P4, respectively. .

Meanwhile, the screen printing method includes a screen mask 190, a high viscosity ink 180R, and a squeegee (not shown) having an opening formed in a portion to be printed and a region other than that. It is a patterning method for printing the high viscosity ink 180R to a desired portion by using.

First, the screen mask 190 is positioned on a substrate on which the high-viscosity ink 180R is to be formed, and the screen is positioned so that an opening op corresponds to a portion where an ink layer on the substrate 101 is to be formed. Align mask 190 well.

Subsequently, an appropriate amount of high viscosity ink 180R is applied onto the screen mask 190 and the high viscosity ink 180R is moved using the squeegee (not shown) to open the opening op of the screen mask 190. The ink layer 160R is formed only in a portion corresponding to the opening op of the screen mask 190.

At this time, the high viscosity ink 180R preferably has a high viscosity of about 5000cp to about 100000cp. Using the high viscosity ink 180R when the screen printing is performed has a viscosity lower than 5000 cps when the ink layer 160R is formed on the substrate 101 through an opening of the screen mask 190. In the case of the material, spreading occurs directly on the substrate 101, and the amount of the ink layer 160R formed through the opening op has a large difference by position, or the ink 180R passes through the opening op. Is spread between the substrate 101 and the screen mask 190, so that color mixture between neighboring pixel regions P1, P2, P3, and P4 occurs, so that the high-viscosity ink 180R as described above is used to prevent this. will be.

On the other hand, looking at the configuration of the high viscosity ink 180R, which is one of the characteristic features of the present invention, the high viscosity ink 180R has red, green, blue, and white color with positive (+) or negative (-) polarity. Electrophoretic particles of any color of electrophoretic particles (red electrophoretic particles 159R in the drawing), black electrophoretic particles 159BL having a polarity opposite to the color electrophoretic particles, a sacrificial solvent (not shown) and ash A dispersibility enhancing agent (hereinafter referred to as an agent (hereinafter referred to as 168 in FIG. 2J)) is properly mixed to have a viscosity of about 5000 cps to 100000 cps.

At this time, in the embodiment of the present invention, the electrophoretic display device includes pixel areas P1, P2, P3, and P4 displaying four colors of red, green, blue, and white, thereby providing the high viscosity ink 180R (Fig. 180G of 2e, 180B of FIG. 2G, and 180W of FIG. 2i) use electrophoretic particles (180R, not shown) and black electrophoretic particles (159BL) in red, green, blue, and white colors, but are full color. In this case, even if the pixel area including magenta, cyan, and yellow is provided, full color can be realized. Therefore, in this case, electrophoretic particles having a magenta, cyan or yellow color may be used, and when the pixel area displaying black or white color is selectively provided to improve contrast ratio, the electrophoretic particles of black or white color may be used. It may be.

At this time, in each of the color inks 180R, 180G in FIG. 2E, 180B in FIG. 2G, and 180W in FIG. 2I, the black electrophoretic particles 159BL have the same polarity, that is, positive polarity or negative polarity. Each of the color electrophoretic particles 159R, 159G in FIG. 2E, 159B in FIG. 2G, and 159W in FIG. 2I, which are mixed with the electrophoretic particles 159BL, has a polarity opposite to that of the black electrophoretic particles 159BL. .

On the other hand, since the black electrophoretic particles 159BL should be basically mixed due to the ink characteristics representing the color of the electrophoretic display device, the ink containing the red electrophoretic particles 159R and the black electrophoretic particles 159BL is red ink 180R. Inks containing green, blue, and white electrophoretic particles (159G in FIG. 2E, 159B in FIG. 2G, 159W in FIG. 2I) and black electrophoretic particles 159BL, respectively, may also be used. 180G of 2e, 180B of FIG. 2G, and 180W of FIG. 2I).

The electrophoretic particles 159R of each color, 159G of FIG. 2E, 159B of FIG. 2G, and 159W of FIG. 2I are characterized in that their size (diameter) is 50 nm to 1000 nm.

In addition, the electrophoretic particles 159R of each color, 159G of FIG. 2E, 159B of FIG. 2G, and 159W of FIG. 2I have a structure in which the main particle which displays each color, and surfactant are provided in the circumference | surroundings. In this case, the surfactant is for suppressing the aggregation between the particles, characterized in that made of polyisobutylene succinimide having a molecular weight of about 1000 to 5000.

In addition, the agent for improving redispersibility (168 of FIG. 2J) is a surfactant that is a component of the electrophoretic particles 159R of each color, 159G of FIG. 2E, 159B of FIG. 2G, and 159W of FIG. 2I. It has the same or similar backbone), for example, is characterized by consisting of a polyisobutylene (polyisobutylene) -based material or mSPPG (mono succinate propylene glycol) having a molecular weight of about 300 to 2000.

The agent (168 of FIG. 2J) made of such polyisobutylene or mSPPG has a bandelvans between adjacent particles upon injection of a fluid (170 of FIG. 2K) after drying of the sacrificial solvent (not shown). By suppressing the van der Waals force serves to improve the redispersibility of the electrophoretic particles.

When the agent (168 in FIG. 2J) is not included among the elements constituting the high viscosity ink 180R, 180G in FIG. 2E, 180B in FIG. 2G, and 180W in FIG. 2I, the ink layer 160R (FIG. When the sacrificial solvent (not shown) included in 160G of FIG. 2E, 160B of FIG. 2G and 160W of FIG. 2I is volatilized and removed, the copper copper particles 159R, 159G of FIG. 2E, 159B of FIG. 2G, and FIG. 159W) agglomeration of particles is caused by the interaction of van der Waals force (van der Waals force) and the particles are not sprayed even if the fluid is injected to realize the electrophoretic phenomenon by applying an electric field By keeping them together, they do not do the desired drive.

Therefore, in order to overcome this phenomenon, in the manufacture of a full color electrophoretic display device according to an exemplary embodiment of the present invention, a high viscosity ink 180R (see FIG. 2J) of polyisobutylene or mSPPG is added. 180G, 180B in FIG. 2G, 180W in FIG. 2I).

On the other hand, the sacrificial solvent (not shown) provided in the high-viscosity ink is a tetradecane (tetradecane) is an example of a liquid having a characteristic that is easily volatilized almost easily by heat treatment for a specific time.

Hereinafter, a method of manufacturing a full color electrophoretic display device according to an exemplary embodiment of the present invention will be described again.

Next, as shown in FIG. 2D, an oven or furnace is used as an example of a heat treatment apparatus (not shown) for the substrate 101 on which the red high-viscosity ink layer (180R of FIG. 2C) is formed in the first pixel region P1. After placing it inside, a heat treatment was performed for 30 minutes to 120 minutes in a temperature atmosphere of about 60 ° C. to 80 ° C. to provide a sacrificial solvent included in the ink layer (180R of FIG. 2C) provided in the first pixel region P1. Completely volatize and remove (not shown).

If the sacrificial solvent (not shown) is left, it becomes an element that hinders the movement of the electrophoretic particles (159R, 159BL) when an electric field is applied to the electrophoretic particles (159R, 159BL), so it is generated in the drive more than 99.9% It is desirable to remove.

In the case of the high-viscosity ink (180R of FIG. 2C, 180G of FIG. 2E, 180B of FIG. 2G, 180W of FIG. 2I) using such tetradecane as a sacrificial solvent (not shown) to maintain high viscosity, the high-viscosity ink (180R of FIG. 2C) , The content ratio and molecular weight of the surfactant (not shown) and the agent (168 in FIG. 2J) included in the electrophoretic particles 159R and 159BL, which are the main components of 180G in FIG. 2E, 180B in FIG. 2G, and 180W in FIG. 2I). Although there is a slight time difference, when the heat treatment for 30 minutes to 120 minutes in an oven having a temperature atmosphere of about 60 ℃ to 80 ℃, it was confirmed that the sacrificial solvent (not shown) is removed 99.9% or more.

Meanwhile, after the red ink layer (160R of FIG. 2C) is formed on the substrate 101 using the red high viscosity ink (180R of FIG. 2C), it is possible to remove the sacrificial solvent (not shown) through heat treatment immediately. This is to prevent mixing with other ink layers (160R of FIG. 2C, 160G of FIG. 2E, 160B of FIG. 2G, and 160W of FIG. 2I) to be formed in neighboring pixel areas P1, P2, P3, and P4. .

The ink layer (160R of FIG. 2C, 160G of FIG. 2E, 160B of FIG. 2G, 160W of FIG. 2I) is a solution or colloidal state no matter how high it is, so when another solution is injected by the partition wall 155. Even if separated, mixing may occur at the upper portion of the partition wall 155 due to the difference in the amount of ink to be aligned and injected. In this case, the ink layers (160R in FIG. 2C, 160G in FIG. 2E, 160B in FIG. 2G, and 160W in FIG. 2I) that are mixed on the partition 155 are interspersed with each pixel region P1, P2, P3, and P4 by diffusion. Since color mixing may occur, an ink layer (180R in FIG. 2C, 180G in FIG. 2E, 180B in FIG. 2G, 180W in FIG. 2I) of a desired color is formed at a desired position on the substrate 101 to prevent this from occurring. Then, electrophoretic particles 159BL by directly removing the sacrificial solvent (not shown) contained in the ink layer (160R of FIG. 2C, 160G of FIG. 2E, 160B of FIG. 2G, and 160W of FIG. 2I) through heat treatment. , 159R) and an agent (168 in FIG. 2J) to achieve a powder 165R state.

On the other hand, by the heat treatment process, red and black electrophoretic particles 159R and 159BL remain in the powder 165R state, including a small amount of the agent (168 in FIG. 2J) inside the first pixel region P1.

Next, as shown in FIGS. 2E and 2F, a high viscosity green ink including green and black electrophoretic particles 159G and 159BL having opposite polarities, a sacrificial solvent (not shown), and an agent (168 in FIG. 2J). Screen printing using the screen mask 190 is performed at 180G to form the green ink layer 180G in the second pixel region P2. After the heat treatment, the sacrificial solvent (not shown) remaining in the green ink layer 180G is volatilized and removed to remove the green and black electrophoretic particles 159G and 159BL and a small amount of the agent in the second pixel region P. Only the powder 165G (only 168 of FIG. 2J) remains.

Next, as shown in Figs. 2G to 2J, the blue and white ink 180B and 180W and the screen mask 190 respectively correspond to the third and fourth pixel areas P3 and P4 by performing the same method described above. Screen printing using the s) and the heat treatment sequentially, the powder 165B including the blue and black electrophoretic particles 159B and 159BL and the agent (168 in FIG. 2J) in the third pixel region P3, and the fourth In the pixel region P4, only the powder 165W including the white and black electrophoretic particles 159W and 159BL and the agent (168 of FIG. 2J) remains.

On the other hand, in the embodiment of the present invention, the screen using a high-viscosity red, green, blue and white ink (18R in Fig. 2c, 180G in Fig. 2e, 180B in Fig. 2g, 180W in Fig. 2i) and the screen mask 190 A printing method is performed on the red, green, blue, and white ink layers (160R in FIG. 2C, 160G in FIG. 2E, and 160B in FIG. 2G) in the first, second, third, and fourth pixel areas P1, P2, P3, and P4. 2W is shown as an example, the color ink layer may be formed in each pixel region by an ink jet method using an ink jet apparatus in addition to the screen printing.

Even when the ink jet method is performed, after the red ink layer is formed in the first pixel region, heat treatment is performed to remove the sacrificial solvent (not shown), and then the green ink layer is formed in the second pixel region. It is characterized by being.

Next, as shown in FIG. 2K, a powder-formed substrate composed of only electrophoretic particles of red, green, blue, and black colors and an agent (168 in FIG. 2J) is formed in the first, second, third, and fourth pixel areas, respectively. In the fluid, a fluid 170 is injected into the first, second, third, and fourth pixel areas P1, P2, P3, and P4. In this case, the fluid is to create an environment in which the color electrophoretic particles 159R, 159G, 159B, 159W, and 159BL can be moved when an electric field is applied to each pixel region P1, P2, P3, and P4. It is a necessary element to generate the phenomena. The fluid 170 is made of any one of H ₂ O, Isopar G, Halocarbor oil, for example.

When the fluid 170 is injected into each of the color electrophoretic particles P1, P2, P3, and P4 and the agent (168 of FIG. 2J) in the form of powder (165R, 165B, 165B, and 165W of FIG. 2J), Repulsion is applied between each of the color electrophoretic particles 159R, 159G, 159B, 159W, and 159BL by the agent (168 in FIG. 2J), and the electrophoretic particles 159R, 159G, 159B, 159W, Reducing the vandalvane force between 159BL) suppresses the aggregation of particles and thereby facilitates redispersion in the fluid.

Next, as shown in FIGS. 2L and 2M, an adhesive pattern corresponding to the partition wall 155 over the fluid and the partition wall 155 in a state in which fluid is injected into each pixel region P1, P2, P3, and P4. (Not shown) is provided and the opposing substrate 182 made of a transparent film including an opposing electrode 184 made of a transparent conductive material and the pixel electrode 150 and the opposing electrode 184 facing each other The substrate 101 and the opposing substrate 182 are bonded to each other to complete the full color electrophoretic display 100 according to the exemplary embodiment of the present invention.

In this case, the opposing substrate 182 is completely bonded to the upper part of the partition wall 155 to prevent color mixing due to the movement of the fluid 170 between the pixel areas P1, P2, P3, and P4 representing each color. to be.

The electrophoretic display device 100 according to the exemplary embodiment of the present invention manufactured in the above-described manner may implement different colors for each of the first, second, third, and fourth pixel areas P1, P2, P3, and P4. An image can be realized and a sacrificial solvent (not shown) is used to inject each color ink into the pixel areas P1, P2, P3, and P4 having different colors, and the sacrificial solvent (not shown) is removed through heat treatment. Through the process, color mixing between neighboring pixel areas P1, P2, P3, and P4 is prevented during injection of each color ink.

Furthermore, since a small amount of agent (168 in FIG. 2J) is included in the high-viscosity color ink, the redispersing ability is improved, so that even when the fluid is injected in a state in which the sacrificial solvent (not shown) is removed to form a powder, interparticle repulsion is generated. By preventing agglomeration, there is an advantage that excellent electrophoretic driving is possible by being at a level similar to that of a mono type electrophoretic display without a conventional sacrificial solvent.

The electrophoretic display device 100 manufactured by the method according to the exemplary embodiment of the present invention uses external light including natural light or room light as a light source, and is positive (+) polarity or negative (-) by the thin film transistor Tr. The plurality of pixel electrodes 150 selectively applied with polarities have opposite polarities in the fluid 170 provided in the first, second, third and fourth pixel regions P1, P2, P3, and P4. The change in position of the electrophoretic particles 159R, 159B, 159C, and 159W representing each color of the electrophoretic particles 159BL and the plurality of blacks is induced to realize a full color image.

The present invention is not limited to the above-described embodiments, and it will be apparent that various changes and modifications can be made without departing from the spirit and spirit of the present invention.

101 substrate 105 gate electrode
110 gate insulating film 120 semiconductor layer
120a: active layer 120b: ohmic contact layer
121: dummy pattern 121a, 121b: first and second dummy patterns
130: data wiring 133: source electrode
136: drain electrode 140: first protective layer
143: drain contact hole 150: pixel electrode
155: bulkhead 159BL: black electrophoretic particles
159R, 159G: Red and green electrophoretic particles 160G: Green ink layer
165R: Powder 180: Green Ink
190: screen mask
P1, P2, P3, and P4: first, second, third and fourth pixel areas
Tr: Thin Film Transistor TrA: Switching Area

Claims

Forming a first electrode for each pixel region on a first substrate on which first, second, and third pixel regions are defined;
Forming a partition on the boundary of the first, second, and third pixel areas over the first electrode;
A first color electrophoretic particle having a first polarity, black electrophoretic particle having a second polarity opposite to the first polarity, a redispersibility enhancing agent, and a sacrificial solvent in the first pixel region surrounded by the partition wall; (A) forming a first color ink layer using color ink;
Performing a heat treatment process to remove the sacrificial solvent included in the first color ink layer formed in the first pixel region to form a powder state of a first color;
Step (A) using second and third color electrophoretic particles having a first polarity, black electrophoretic particles having a second polarity, second and third color inks comprising a redispersibility enhancing agent and a sacrificial solvent. Repeating steps (B) and (B) to achieve powder states of second and third colors in the second and third pixel areas, respectively;
Injecting a fluid into the first, second, and third pixel areas in which the first, second, and third color ink layers have a powder state;
Attaching and then bonding the second substrate having the transparent counter electrode with an adhesive corresponding to the partition wall on the first substrate into which the fluid is injected;
Method of manufacturing an electrophoretic display device comprising a.

The method of claim 1,
And the first, second, and third colors are red, green, blue, or cyan, magenta, and yellow, respectively.

The method of claim 2,
The first substrate is provided with a fourth pixel region, and in the fourth pixel region, white electrophoretic particles having the first polarity, black electrophoretic particles having the second polarity, a redispersibility enhancing agent, and a sacrificial solvent are provided. And repeating steps (A) and (B) to sequentially form a powder of a fourth color by using the fourth color ink.

The method of claim 1,
The forming of the first, second, and third ink layers in the first, second, and third pixel areas may be performed by an ink manufacturing method using an inkjet device, or by a screen printing method using a screen mask and a squeegee. Characterized by a method of manufacturing an electrophoretic display.

The method of claim 1,
When the first, second and third ink layers are formed by screen printing, the first, second and third inks have a viscosity of 5000 cps to 100000 cps.

The method of claim 1,
The first, second and third color electrophoretic particles and the black electrophoretic particles have a size (diameter) of 50nm to 1000nm manufacturing method of an electrophoretic display device.

The method of claim 5, wherein
The first, second, third and black electrophoretic particles are provided with particles around the particles representing the first, second, and third colors, and the surfactant is polyisobutylene succinate having a molecular weight of 1000 to 5000. Method for producing an electrophoretic display characterized in that the imide (polyisobutylene succinimide).

The method according to claim 6,
The agent is a method of manufacturing an electrophoretic display, characterized in that the molecular weight is made of polyisobutylene (polyisobutylene) -based material or mSPPG (mono succinate propylene glycol).

The method of claim 7, wherein
And the sacrificial solvent is made of tetradecane having a property of being removed by the heat treatment.

The method of claim 8,
The heat treatment is performed for 30 minutes to 120 minutes at 60 ℃ to 80 ℃ manufacturing method of an electrophoretic display device.

The method of claim 7, wherein
The fluid is a method of manufacturing an electrophoretic display, characterized in that any one of H ₂ O, Isopar G, Halocarbor oil is injected.

The method of claim 1,
Forming a gate line and a data line on the first substrate to define the pixel area on the first substrate before forming the first electrode;
Forming a thin film transistor connected to the gate line and the data line in each pixel area;
Forming a protective layer having a flat surface and exposing the drain electrode of the thin film transistor over the first substrate over the thin film transistor;
Wherein the first electrode is in contact with the drain electrode.

The method of claim 1,
And the partition wall is formed to overlap an edge of the pixel electrode formed in each pixel area.