KR20070000910A - Electrophoretic display device and method for fabricating the same - Google Patents

Abstract

An electrophoretic display device and a method for manufacturing the same are provided to suppress the deterioration of picture quality due to crosstalk or vibration of pixel voltage generated in an electronic paper, by forming an air gap in an insulating layer correspondingly to a gate line and a data line. A gate line is formed on a lower substrate(111). A gate insulating layer(117) and an active layer are formed on the resultant substrate including the gate line. A data line(121) is disposed on the gate insulating layer across the gate line. A source electrode and a drain electrode are disposed to face each other on the active layer. An insulating layer(125) is formed on the resultant substrate including the data line, the source electrode, and the drain electrode. The insulating layer has an air gap(129) at a region corresponding to the data line and the gate line. A pixel electrode(131) is formed on the insulating layer, and connected with the drain electrode. An electrophoretic film(135) is formed on the resultant substrate including the pixel electrode.

Description

Electrophoretic display and its manufacturing method {ELECTROPHORETIC DISPLAY DEVICE AND METHOD FOR FABRICATING THE SAME}

1 is a layout for schematically illustrating an electrophoretic display device according to the prior art.

2 is a cross-sectional view taken along the line II-II of FIG. 1 in the electrophoretic display device according to the prior art.

3 is a cross-sectional view taken along line III-III of FIG. 1 in the electrophoretic display device according to the prior art.

Figure 4 is a layout for schematically illustrating an electrophoretic display device according to the present invention.

5 is a cross-sectional view taken along the line VV of FIG. 4 in the electrophoretic display device according to the present invention.

6 is a cross-sectional view taken along line VI-VI of FIG. 4 in the electrophoretic display device according to the present invention.

-Code description of main parts of drawing-

111 substrate 113 gate wiring

113a: gate electrode 115: storage common wiring

117: gate insulating film 121: data wiring

121a: source electrode portion 123: drain electrode portion

125: insulating film 127: drain contact hole

129: air gap 131: pixel electrode 133: capsule 135: electrophoretic film 135a: white ink 135b: black ink 141: pixel area boundary

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 poor image quality caused by cross talk or vibration of pixel voltage generated from electronic paper. It relates to an electrophoretic display device and a method for manufacturing the same that can solve the problem.

Electrophoretic Display devices require no external light source, have excellent reflectivity, have excellent flexibility and portability, and have other characteristics such as light weight and electrophoresis. It is a kind of flat display using the phenomenon that particles move toward the anode or cathode.

The electrophoretic display device is a reflective display that drives an electrophoretic suspended particle by applying a transparent conductive film to a thin, bendable base film such as paper or plastic, and is the next generation of electric paper. It is a device that is expected to get the spotlight.

In this regard, the electrophoretic display device according to the related art will be described with reference to FIG. 1 as follows.

1 is a cross-sectional view for schematically illustrating an electrophoretic display device according to the prior art.

Referring to FIG. 1, the storage common wiring 15 is formed on the lower plate 11 with the gate wiring 13 in a horizontal direction and spaced apart by a predetermined interval in the same direction as the gate wiring 13.

In addition, the data wiring 21 is formed in a vertical direction crossing the gate wiring 13, and the drain electrode part 23 is formed to be spaced apart from the data wiring 21 by a predetermined interval. Here, the gate electrode 13a extends in the gate wiring 13 so as to overlap the source electrode 21a and the drain electrode 23 of the data wiring 21. In this case, the gate electrode 13a, the source electrode portion 21a, and the drain electrode portion 23 form a thin film transistor portion.

The pixel electrode 31 is overlapped in the pixel region 41 where the gate wiring 13 and the data wiring 21 are defined to be connected to the drain electrode part 23. The pixel electrode 31 overlaps the gate line 13 and the data line 21.

In addition, the electrophoretic display device is constructed by laminating an electrophoretic film on a lower plate applied to the electrophoretic display device configured as described above, and laminating transparent electrodes or other electrode material layers thereon.

A method of manufacturing an electrophoretic display device according to the related art, which is configured as described above, will be described below with reference to FIGS. 2 and 3.

2 is a cross-sectional view taken along the line II-II of FIG. 1 in the electrophoretic display device according to the prior art.

3 is a cross-sectional view taken along line III-III of FIG. 1 in the electrophoretic display device according to the prior art.

2 and 3, first, a conductive layer for forming a gate wiring is deposited on the lower plate 11, and then selectively patterned to form a gate wiring 13. At this time, when the conductive layer is patterned, the storage common wiring 15 is simultaneously formed in the same direction with the gate wiring 13 spaced apart from the gate wiring 13 by a predetermined interval.

Next, after the gate insulating layer 17 and the active layer (not shown) are stacked, a conductive layer is deposited and patterned thereon to form a data line 21 arranged to intersect the gate line 13. At this time, during the patterning of the conductive layer, the drain electrode part 23 is formed simultaneously with the data line 21 to be spaced apart from the data line 21 at a predetermined interval. In addition, the source electrode part 21a and the drain electrode part 23 extending from the data line 21 overlap the gate electrode 13a extending from the gate line 13 to form a thin film transistor part.

Subsequently, a thick film of the protective film 25 is deposited using an organic film or other insulating material over the entire lower plate, and then the patterned insulating film 25 is selectively patterned to expose the drain electrode part 23. And 27) of FIG. 1. In this case, the insulating layer 25 is formed by depositing a thick dielectric layer of about 2 to 3 μm on the overlapping structure of the electrodes, such as a low dielectric organic film, for example, photo acrylate.

Next, a transparent electrode material layer is deposited on the insulating layer 25 including the drain contact hole 27, and then patterned to form the pixel electrode part 31. In this case, the pixel electrode part 31 is connected to the drain electrode part 23 through the drain contact hole 27.

In addition, the pixel electrode part 31 overlaps the gate line 13 and the data line 21 in the pixel area 41 defined by the gate line 13 and the data line 21 intersecting each other. .

Subsequently, the electrophoretic film 33 is laminated on the lower plate 11 including the pixel electrode part 31. In this case, the electrophoretic film 33 is an electron ink forming a capsule 35 in a polymer binder, and the electron ink distributed in the capsule 35 includes a white ink 35a and a black ink ( 35b). In addition, the white ink 35a and the black ink 35b distributed in the electrophoretic film 33 have positive charge and negative charge characteristics, respectively. That is, the white ink 35a is charged with positive charge, and the black ink 35b is charged with negative charge.

Next, a common wiring 43 made of ITO, which is a transparent material, is formed on the electrophoretic film 33 to complete the electrophoretic display device.

According to the electrophoretic display device according to the related art configured as described above, the pixel electrode portion overlaps the gate wiring and the data wiring, which means that the electronic ink (e-ink) on the data wiring and the gate wiring is connected to the continuous drive signal. This is to prevent unnecessary driving and to make the image display uniform.

However, parasitic capacitors are formed by coupling the electrodes, that is, between the gate wiring and the pixel electrode, between the data wiring and the pixel electrode, which is a voltage between the source electrode and the pixel electrode, the gate electrode and the pixel electrode. The intervoltage is generated, making it difficult to apply the correct signal, and a phenomenon such as cross-talk appears.

In addition, in order to minimize the coupling (coupling), a low dielectric organic film, for example, a photo acrylate (for example, photo acrylate) on the overlapping structure of the electrodes were deposited thickly about 2 to 3 μm.

However, even when the organic film is thickly deposited, parasitic capacitors still exist due to the coupling between the gate wiring and the pixel electrode, and the data wiring and the pixel electrode, making it difficult to apply an accurate signal. Symptoms such as cross-talk continue to appear.

Accordingly, the present invention has been made to solve the above problems of the prior art, a problem of poor quality, deterioration caused by the cross talk (vibration) of the pixel voltage (cross talk) generated from the electronic paper An object of the present invention is to provide an electrophoretic display device and a method of manufacturing the same.

Electrophoretic display device according to the present invention for achieving the above object, the gate wiring formed on the lower plate; A gate insulating film and an active layer formed on the entire lower plate including the gate wiring; A source electrode portion and a drain electrode portion formed on the lower plate and disposed to intersect with the gate wiring and disposed to face each other from the active layer; An insulating film formed on the entire lower plate including the data line, the source electrode part, and the drain electrode part, and an air gap is formed in a portion on the data line and the gate line; A pixel electrode portion formed on the insulating film and connected to the drain electrode portion; And an electrophoretic film formed on a lower plate including the pixel electrode part.

In addition, the electrophoretic display device manufacturing method according to the present invention for achieving the above object comprises the steps of forming a gate wiring on the lower plate; Forming a gate insulating film and an active layer on the entire lower plate including the gate wiring; Forming a data line disposed on the lower plate to cross the gate line, and a source electrode part and a drain electrode part disposed to face each other from the active layer; Forming an insulating film on the entire lower plate including the data line, the source electrode part, and the drain electrode part; Forming an air gap in an insulating portion located on the data and gate lines; Forming a pixel electrode portion connected to the drain electrode portion on the insulating film; And forming an electrophoretic film on the lower plate including the pixel electrode part.

Hereinafter, an electrophoretic display device and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a layout for schematically illustrating an electrophoretic display device according to the present invention.

Referring to FIG. 4, the electrophoretic display device according to the present invention is spaced apart by a predetermined interval in the same direction as the gate wiring 113 along with the gate wiring 113 in a horizontal direction on the lower plate 111. 115 is formed.

In addition, the data wiring 121 is formed in a vertical direction crossing the gate wiring 113, and the drain electrode part 123 is formed to be spaced apart from the data wiring 121 by a predetermined interval. The gate electrode 113a extends in the gate wiring 113 so as to overlap the source electrode portion 121a and the drain electrode portion 123 of the data wiring 121. In this case, the gate electrode 113a, the source electrode portion 121a and the drain electrode portion 123 form a thin film transistor portion.

The pixel electrode 131 overlaps the pixel electrode 131 in the pixel region 141 defined by the gate wiring 113 and the data wiring 121 intersecting and connected to the drain electrode part 123. Here, the pixel electrode 131 overlaps with each other in the pixel area where the gate wiring 113 and the data wiring 121 cross each other. That is, the pixel electrode 113 does not overlap with the gate wiring 113 and the data wiring 121 differently from the conventional method. However, the pixel electrode 13 overlaps the gate electrode 113a and the source electrode 121a.

In addition, although not shown in the drawings, an electrophoretic film (not shown) is laminated on a lower plate (not shown) applied to the electrophoretic display device configured as described above, and is composed of a transparent electrode or other electrode material layer thereon. Top plates (not shown) are stacked to form an electrophoretic display device.

Meanwhile, a method of manufacturing the electrophoretic display device according to the present invention configured as described above will be described with reference to FIGS. 5 and 6.

5 is a cross-sectional view taken along the line VV of FIG. 4 in the electrophoretic display device according to the present invention.

6 is a cross-sectional view taken along line VI-VI of FIG. 4 in the electrophoretic display device according to the present invention.

Referring to FIGS. 5 and 6, first, a conductive layer for forming a gate wiring is deposited on the lower plate 111, and then selectively patterned to form a gate wiring 113. At this time, when the conductive layer is patterned, the storage common wiring 115 is simultaneously formed in the same direction with the gate wiring 113 spaced apart from the gate wiring 113 at a predetermined interval.

Next, the gate insulating layer 117 and the active layer (not shown) are sequentially stacked, and a conductive layer is deposited thereon and patterned to form a data line 121 arranged to intersect the gate line 113. At this time, during the patterning of the conductive layer, the drain electrode part 123 is formed simultaneously with the data line 121 to be spaced apart from the data line 121 at a predetermined interval. In addition, the data line 121 extends from the source electrode 121a to overlap the gate electrode 113a extending from the gate line 113 together with the drain electrode 123 to form a thin film transistor.

Subsequently, an insulating film 125 for a passivation layer is deposited on the entire lower plate 111 using an organic film or other insulating material, and then the insulating film 125 is selectively patterned to form the drain electrode part 123. A drain contact hole (not shown) 127 of FIG. 4 is formed to be exposed. At this time, when the insulating layer 125 is patterned, the air gap 127a is simultaneously formed by etching the thickness of the insulating layer 125 located above the gate line 113 and the data line 121 together with forming the drain contact hole. Form.

Next, a transparent electrode material layer such as ITO is deposited on the insulating layer 125 including the drain contact hole 127 and then patterned to form the pixel electrode part 131. In this case, the pixel electrode part 131 is connected to the drain electrode part 123 through the drain contact hole 127. In addition, the pixel electrode unit 131 is positioned inside the pixel region 141 where the gate wiring 113 and the data wiring 121 intersect with each other.

Subsequently, the electrophoretic film 133 is laminated on the lower plate 111 including the pixel electrode part 131. In this case, the electrophoretic film 133 is an electronic ink forming a capsule 135 in a polymer binder, the electronic ink distributed in the capsule 135 is a white ink (135a) and a black ink ( 135b). In addition, the white ink 135a and the black ink 135b distributed in the electrophoretic film 133 have positive charge and negative charge characteristics, respectively. That is, the white ink 135a is charged with positive charge, and the black ink 135b is charged with negative charge. In addition, the electrophoretic film 133 is integrally stacked on the lower plate 111 by an adhesive layer (not shown). Therefore, even after patterning, since there exists a sufficient area with the pixel electrode part which is the uppermost layer, there is no big difficulty for the electrophoretic film to adhere.

On the other hand, when the pixel electrode portion is patterned to be spaced apart from the data wiring and the gate wiring by a predetermined interval, the pixel voltage can be fundamentally protected from the parasitic capacitor loss, thereby providing accurate driving ( driving is possible.

Next, although not shown in the figure, the electrophoretic display device is completed by forming a common wiring (not shown) or other electrode material made of ITO, which is a transparent material, on the electrophoretic film 133.

As described above, according to the present invention, an electrophoretic display device and a method of manufacturing the same according to the present invention provide a method of preventing organic electrode coupling, in which organically deposited gate wiring, data wiring, and pixel electrode portions are thickly deposited on portions overlapping each other. The film, ie, the insulating film, is etched to a certain thickness to form an air gap, which is generated from the crosstalk or pixel voltage vibration generated in the electronic paper. It can solve the problem of poor quality and poor image quality.

In addition, in the electronic paper pattern structure, the organic film portions overlapping with the gate wiring and the data wiring are etched to form an air gap so as to be spaced apart from each other, thereby protecting the pixel voltage from the loss of the parasitic capacitor.

On the other hand, while described above with reference to a preferred embodiment of the present invention, those skilled in the art various modifications of the present invention without departing from the spirit and scope of the invention described in the claims below And can be changed.

Claims (11)

A gate wiring formed on the lower plate; A gate insulating film and an active layer formed on the entire lower plate including the gate wiring; A source electrode portion and a drain electrode portion formed on the lower plate and disposed to cross the gate line and face each other from the active layer; An insulating film formed on the entire lower plate including the data line, the source electrode part, and the drain electrode part, and an air gap is formed in a portion located on the data line and the gate line; A pixel electrode portion formed on the insulating film and connected to the drain electrode portion; And And an electrophoretic film formed on the lower plate including the pixel electrode part. The electrophoretic display device of claim 1, wherein the pixel electrode part is positioned in an area formed between the gate line and the data line. The electrophoretic display device of claim 1, wherein the pixel electrode part is spaced apart from the gate line and the data line. The electrophoretic display device according to claim 1, wherein the insulating film is formed of an organic film or a protective film material. The electrophoretic display device of claim 1, wherein a storage common wiring is formed on the lower plate to be spaced apart from the gate wiring at a predetermined interval. Forming a gate wiring on the lower plate; Forming a gate insulating film and an active layer on the entire lower plate including the gate wiring; Forming a data line disposed on the lower plate to cross the gate line, and a source electrode part and a drain electrode part disposed to face each other from the active layer; Forming an insulating film on the entire lower plate including the data line, the source electrode part, and the drain electrode part; Forming an air gap in an insulating portion located on the data and gate lines; Forming a pixel electrode portion connected to the drain electrode portion on the insulating film; And Forming an electrophoretic film on the lower plate including the pixel electrode portion; Electrophoretic display device manufacturing method comprising a. The method of claim 6, wherein the pixel electrode part is positioned in an area formed between the gate line and the data line. The method of claim 6, wherein the pixel electrode part is spaced apart from the gate wiring and the data wiring. The method of claim 6, wherein the insulating film is formed of an organic film or a protective film material. The method of claim 6, wherein the storage common wiring is formed to be spaced apart from the gate wiring at a predetermined interval when the gate wiring is formed. The method of claim 6, further comprising forming a drain contact hole on the insulating layer to connect the pixel electrode part to the drain electrode part.

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