KR20060081280A - Display substrate - Google Patents

Abstract

A display substrate having improved reflectance is disclosed. The display substrate is a substrate, a thin film transistor formed on the substrate and having a drain electrode, formed in a stripe shape on the substrate, and crosses insulated from the gate signal line and the gate signal line electrically connected to the gate electrode of the thin film transistor, A gate signal line of an organic layer and an organic layer which are connected to a source electrode of the organic layer and an organic layer, wherein the organic signal and the organic layer have an embossed portion on the top surface of the stripe-shaped data signal line, the thin film transistor, the gate signal line, and the data signal line, the first curved portion having at least a portion thereof in plan view; And a pixel electrode formed in a region surrounded by the data signal line and disposed on the transparent electrode connected to the drain electrode and the transparent electrode, the pixel electrode having a reflective electrode having a first peripheral portion corresponding to the first curved portion when viewed in plan view. By forming a reflective electrode having a first peripheral portion corresponding to the first bent portion of the data signal line, the reflectance of the reflective electrode can be increased, and the parasitic capacitance formation can be suppressed because the reflective electrode and the data signal line do not overlap.

Description

Display board {DISPLAY SUBSTRATE}

1 is a plan view illustrating a display substrate according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of the display substrate illustrated in FIG. 1 taken along the line II ′.

3 is a plan view illustrating a display substrate according to another exemplary embodiment of the present invention.

4 is a cross-sectional view of the display substrate illustrated in FIG. 3 taken along the line II to II ′.

<Description of Symbols for Main Parts of Drawings>

100 display substrate 110 thin film transistor

120: gate signal line 130: data signal line

140 organic film 150 pixel electrode

151 transparent electrode 156 reflective electrode

The present invention relates to a display substrate. More specifically, the present invention relates to a display substrate capable of improving the display quality of an image by improving the reflectance.

In general, liquid crystal displays are classified into a transmissive type liquid crystal display device, a reflective type LCD, and a reflective-transmissive LCD according to a method of using light.

The transmissive liquid crystal display device displays an image by providing internal light generated from a lamp or the like to the liquid crystal, and the reflective liquid crystal display device displays an image by reflecting external light generated from the sun or a lamp to the liquid crystal. The reflection-transmissive liquid crystal display displays an image by providing internal or external light to the liquid crystal.

The reflection-transmissive liquid crystal display device includes a reflection electrode that reflects the external light to provide external light to the liquid crystal, and the reflective electrode is formed with irregularities for improving luminance uniformity by scattering and reflecting the external light.

In the reflective-transmissive liquid crystal display, a portion of the reflective electrode and a signal line disposed below the reflective electrode may be overlapped to increase the number of irregularities formed in the reflective electrode. As such, when a part of the reflective electrode and the signal line overlap each other, parasitic capacitance is generated by the reflective electrode and the signal line, and thus a driving signal for displaying an image is distorted or modulated.

Accordingly, it is an object of the present invention to substantially eliminate one or more problems and limitations of the prior art.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display substrate which improves the display quality of an image by improving reflectance and reducing parasitic capacitance.

According to an aspect of the present invention, a display substrate includes a thin film transistor having a drain electrode formed on the substrate and having a stripe shape on the substrate and electrically connected to a gate electrode of the thin film transistor. A stripe-shaped data signal line intersecting the gate signal line in an insulated state, connected to a source electrode of the thin film transistor, and having a first bent portion formed in at least a portion when viewed in plan view, the thin film transistor, the gate signal line, and the data An organic layer covering the signal line and having an embossed portion formed on an upper surface thereof, and formed on a region surrounded by the gate signal line and the data signal line among the organic layers and disposed on the transparent electrode and the transparent electrode connected to the drain electrode, 1st Oyster It includes a pixel electrode having a reflective electrode having a first peripheral portion and the corresponding portion.

According to such a display substrate, by forming a reflective electrode having a peripheral portion corresponding to the bent portion of the data signal line, the number of embossing patterns of the reflective electrode is increased to improve the reflectance, and further, parasitic capacitance between the data signal line, the reflective electrode and the organic film. It can suppress occurrence.

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

1 is a plan view illustrating a display substrate according to an exemplary embodiment of the present invention. FIG. 2 is a cross-sectional view of the display substrate illustrated in FIG. 1 taken along the line II ′.                     

1 and 2, the display substrate 100 includes a thin film transistor 110, a gate signal line 120, a data signal line 130, an organic layer 140, and a pixel electrode 150.

The thin film transistor 110 is disposed on the substrate 105 and outputs a designated drive signal at a specified timing. The thin film transistor 110 includes a gate electrode 112, a first insulating layer 125, a channel layer 127, a source electrode 113, and a drain electrode 115.

The gate electrode 112 is formed on the substrate 105. The gate driving signal is applied to the gate electrode, and the gate driving signal is applied through the gate signal line 120.

The first insulating layer 125 covers the gate electrode 112 and is formed over the entire surface of the substrate 105. Examples of the material forming the first insulating layer 125 may include an insulating material such as silicon nitride (SiNx) through which light is transmitted and silicon oxide (SiOx) through which light is transmitted.

The channel layer 127 is disposed on the first insulating layer 125. The channel layer 127 is formed corresponding to the gate electrode 112. The channel layer 127 may include a first semiconductor layer including an amorphous silicon film. Alternatively, the channel layer 127 may include a first semiconductor layer and a second semiconductor layer disposed on the first semiconductor layer. The first semiconductor layer may be, for example, an amorphous silicon film, and the second semiconductor layer may include an n + amorphous silicon thin film including conductive impurities. The pair of second semiconductor layers disposed on the first semiconductor layer is spaced apart from each other.

The source electrode 113 is disposed on the first insulating layer 125. A portion of the source electrode 113 is electrically connected on the channel layer 127.                     

The drain electrode 115 is disposed on the first insulating layer 125. A portion of the drain electrode 115 is electrically connected on the channel layer 127. The drain electrode 115 and the source electrode 113 are spaced apart from each other by a predetermined interval. Examples of the material forming the source electrode 113 and the drain electrode 115 include conductive metals such as chromium (Cr), aluminum (Al), copper (Cu), molybdenum (Mo), tungsten (W), and alloys thereof. Can be mentioned.

The gate signal line 120 is disposed on the substrate 105. The gate signal line 120 is electrically connected to the gate electrode 112, and provides a gate driving signal to the gate electrode 112.

In the present embodiment, the gate signal line 120 electrically connected to the gate electrode 112 is disposed on the same plane as the gate electrode 112 and has a stripe shape. Hereinafter, the direction in which the gate signal line 120 extends is defined as the first direction. In the planar view of the gate signal line 120, the bent portion 129 is formed at least in part. In this case, it is preferable that the planar area of the bent portion 129 of the gate signal line 120 and the planar area of the portion of the gate signal line 120 where the bent portion 129 is not formed are substantially the same.

The data signal line 130 having a stripe shape is disposed on the first insulating layer 125. The data signal line 130 intersects the gate signal line 120 disposed under the first insulating layer 125.

In the present embodiment, the data signal line 130 extends in the second direction substantially perpendicular to the first direction. The curved portion 137 is formed in the data signal line 130 at least in part when viewed in a plane.                     

Hereinafter, an area surrounded by a pair of adjacent data signal lines 130 and a pair of adjacent gate signal lines 120 will be defined as a pixel area.

The organic layer 140 is disposed on the first insulating layer 125 to cover the thin film transistor 110, the gate signal line 120, and the data signal line 130. An embossed portion having a concave portion 141 and a convex portion 143 is formed on an upper surface of the organic layer 140, and a first opening 145 exposing the drain electrode 115 is formed in the organic layer 140.

For the organic layer 143, an organic material having a low dielectric constant such as benzocyclobutene (BCB), polyethylene terephthalate (PET), or photo acrylic resin is preferably used.

The pixel electrode 150 is disposed on the organic layer 140, and the pixel electrode 150 is disposed within the defined pixel area. The pixel electrode 150 includes a transparent electrode 151 and a reflective electrode 156 disposed on the transparent electrode 151.

The transparent electrode 151 is electrically connected to the drain electrode 115 exposed by the first opening 145. The data signal is applied to the transparent electrode 151 electrically connected to the drain electrode 115 through the data signal line 130. Examples of the material forming the transparent electrode 151 include a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), and zinc oxide (ZO). have.

The reflective electrode 156 is disposed in a predetermined region on the transparent electrode, for example. Alternatively, the reflective electrode 156 may be interposed between the transparent electrode 151 and the organic layer 140. The reflective electrode is formed in a part of the pixel region, hereinafter, a region in which the reflective electrode 156 is formed among the pixel regions will be defined as a reflective region. In addition, the remaining region except the reflective region will be defined as a transmission region.

Examples of the material forming the reflective electrode 156 include metals such as aluminum (Al), aluminum alloys (Al alloys), silver (Ag), and silver alloys.

The reflective electrode 156 has unevenness corresponding to the uneven shape of the embossed portion formed on the organic film 140. The uneven reflective electrode 156 scatters or diffuses incident light incident from the outside to further improve the luminance uniformity of the light reflected from the reflective electrode 156. It also has an improved reflectance for. Further, the light reflectance at the reflective electrode having a shape substantially the same as that of the embossed portion is higher than the light reflectance of the reflective electrode having a shape that is not the same as the embossed portion. Accordingly, the shape of the reflective electrode 156 preferably has the same shape as the embossed portion. In the plan view, when the shape of the periphery of the reflective electrode is the same as the embossed portion, the periphery of the reflective electrode 157 has an uneven shape.

When the peripheral portion 157 of the reflective electrode 156 overlaps the data signal line 130, parasitic capacitance may be generated between the reflective electrode and the data signal line 130, so that the bent portion 137 of the curved portion 137 of the data signal line 130 may be formed. It is preferable that the shape and the shape of the unevenness of the reflective electrode substantially coincide. By forming the peripheral portion 157 and the bent portion 137 so as not to overlap each other, the generation of parasite capacitance between the data signal line 130, the reflective electrode 156, and the organic layer 140 may be greatly reduced. Can be.

In addition, the reflective electrode 156 has a peripheral portion 159 corresponding to the bent portion 129 of the gate signal line 120. By forming the peripheral portion 159 of the reflective electrode 156 and the bent portion 129 of the data signal line 130 so as not to overlap each other, parasitic capacitance is formed between the gate signal line 120, the reflective electrode 156, and the organic layer 140. can greatly reduce the occurrence of (parasite capacitance).

3 is a plan view illustrating a display substrate according to another exemplary embodiment of the present invention. 4 is a cross-sectional view of the display substrate illustrated in FIG. 3 taken along the line II to II ′. The same reference numerals and names will be given to the same components as the display substrates shown in FIGS. 1 and 2 among the display substrates according to the present exemplary embodiment.

3 and 4, the display substrate 100 includes a thin film transistor 110, a gate signal line 120, a data signal line 130, an organic layer 140, and a pixel electrode 150.

The thin film transistor 110 is disposed on the substrate 105. The thin film transistor 110 outputs a driving signal at a specified timing. The thin film transistor 110 includes a gate electrode 112, a first insulating layer 125, a channel layer 127, a source electrode 113, and a drain electrode 115.

The gate electrode 112 is formed on the substrate 105. The gate driving signal is applied to the gate electrode 112, and the gate driving signal is applied through the gate signal line 120.

The first insulating layer 125 covers the gate electrode 112 and is formed over the entire surface of the substrate 105. Examples of the material forming the first insulating layer 125 may include an insulator such as silicon nitride (SiNx) and silicon oxide (SiOx) that may transmit light.

The channel layer 127 is disposed on the first insulating layer 125. The channel layer 127 is formed corresponding to the gate electrode 112. The channel layer 127 includes a first semiconductor layer. The first semiconductor layer is, for example, an amorphous silicon film. Alternatively, the channel layer 127 may include a first semiconductor layer and a second semiconductor layer disposed on the first semiconductor layer. The first semiconductor layer is, for example, an amorphous silicon film. The material constituting the second semiconductor layer may include amorphous silicon and conductive impurities. The pair of second semiconductor layers is spaced apart from each other.

The source electrode 113 is disposed on the first insulating layer 125. A portion of the source electrode 113 is electrically connected on the channel layer 127.

The drain electrode 115 is disposed on the first insulating layer 125. A portion of the drain electrode 115 is electrically connected to the channel layer 127. The drain electrode 115 and the source electrode 113 are spaced apart from each other by a predetermined interval. Examples of the material forming the source electrode 113 and the drain electrode 115 include conductive metals such as chromium (Cr), aluminum (Al), copper (Cu), molybdenum (Mo), tungsten (W), and alloys thereof. Can be mentioned.

The gate signal line 120 is disposed on the substrate 105. The gate signal line 120 is electrically connected to the gate electrode 112, and applies the gate signal to the gate electrode 112.

In this embodiment, the gate signal line 120 electrically connected to the gate electrode 112 is disposed on the same plane as the gate electrode 112 and has a stripe shape. The gate electrode having a stripe shape extends in the first direction. The bent part 129 is formed in the gate signal line 120 in at least one part when viewed on a plane.

The data signal line 130 having a stripe shape is disposed on the first insulating layer 125. The data signal line 130 crosses the gate signal line 120 disposed under the first insulating layer.

In the present embodiment, the data signal line 130 extends in the second direction. The bent part 139 is formed in the whole data signal line 130 in planar view.

The organic layer 140 is disposed on the first insulating layer 125 to cover the thin film transistor 110, the gate signal line 120, and the data signal line 130. An embossed portion having a concave portion 141 and a convex portion 143 is formed on an upper surface of the organic layer 140, and a first opening 145 is formed in the organic layer 140 to expose the drain electrode 115.

For the organic layer 143, an organic material having a low dielectric constant such as benzocyclobutene (BCB), polyethylene terephthalate (PET), or photo acrylic resin is preferably used.

The pixel electrode 150 is disposed on the organic layer, and the pixel electrode 150 is disposed in each defined pixel area. The pixel electrode 150 includes a transparent electrode 151 and a reflective electrode 156 disposed on the transparent electrode 151.

The transparent electrode 151 is electrically connected to the drain electrode 115 exposed by the first opening 145. The data signal is applied to the transparent electrode 151 electrically connected to the drain electrode 115 through the data signal line 130. The transparent electrode 151 is formed in an embossed pattern having convex portions and concave portions corresponding to the embossed pattern of the organic film 143.

Examples of the material forming the transparent electrode 151 include a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), and zinc oxide (ZO). have.

The reflective electrode is disposed on the transparent electrode 151. Alternatively, the reflective electrode 156 may be interposed between the transparent electrode 151 and the organic layer 140. The reflective electrode has a mesh shape. Examples of the material forming the reflective electrode include metals such as aluminum (Al), aluminum alloys (Al alloys), silver (Ag), and silver alloys.

In this embodiment, the reflective electrode 156 is formed in the recess of the transparent electrode. Accordingly, the reflective electrode 156 formed in the concave portion of the transparent electrode 151 is incident from the outside to reflect external light, and the convex portion of the transparent electrode 151 transmits the internal light incident from the rear surface of the substrate 105. .

Alternatively, the reflective electrode 156 may be formed in the convex portion of the transparent electrode 151. Accordingly, the reflective electrode 156 formed on the convex portion of the transparent electrode 151 reflects external light incident from the outside, and the concave portion of the transparent electrode 151 transmits internal light incident from the rear surface of the display substrate 100. Let

The reflectance of the closed mesh shaped reflective electrode is higher than that of the open mesh shaped reflective electrode. Thus, in order to form the reflective electrode 156 having a closed mesh shape at the periphery of the pixel region, the reflective electrode 156 has a non-uniform periphery 157 in plan view.

When the peripheral portion 157 of the reflective electrode 156 overlaps with the data signal line 130, parasitic capacitance may be generated between the reflective electrode 156 and the data signal line 130, so that the bent portion of the data signal line 130 may be formed. It is preferable that the shape of the reflective electrode and the shape of the reflective electrode substantially match 137. The peripheral portion 157 and the bent portion 137 are formed so as not to overlap each other, whereby the data signal line 130, the reflective electrode 156 and the organic film 140 Generation of parasite capacitance is suppressed between

In addition, the reflective electrode 156 has a peripheral portion 159 corresponding to the bent portion 129 of the gate signal line 120. By forming the peripheral portion 129 and the bent portion 159 so as not to overlap each other, generation of parasitic capacitance between the gate signal line 120, the reflective electrode 156, and the organic layer 140 is suppressed.

As described in detail above, according to the present invention, by forming a data signal line having a reflective electrode having a perfect shape and a bent portion corresponding to the periphery of the reflective electrode, the reflectance of incident light incident from the outside is improved, and the reflective electrode is further improved. And parasitic capacitance between the data signal lines is suppressed to improve display quality of the image.

Although the detailed description of the present invention has been described with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art will have the idea of the present invention described in the claims to be described below. It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (6)

A thin film transistor formed on the substrate and having a drain electrode; A gate signal line formed in a stripe shape on the substrate and electrically connected to a gate electrode of the thin film transistor; A stripe-shaped data signal line intersecting the gate signal line in an insulated state, connected to a source electrode of the thin film transistor, and having a first bent portion formed at least in part when viewed in plan view; An organic layer covering the thin film transistor, the gate signal line, and the data signal line, and having an embossed portion formed on an upper surface thereof; And A reflection formed in a region surrounded by the gate signal line and the data signal line of the organic layer and disposed on the transparent electrode connected to the drain electrode and the transparent electrode, and having a first peripheral portion corresponding to the first curved portion when viewed in plan view A display substrate comprising a pixel electrode having an electrode. The method of claim 1, wherein a second bent portion is formed in a portion of the gate signal line corresponding to the reflective electrode, and a second peripheral portion corresponding to the second bent portion is formed in the reflective electrode corresponding to the second curved portion. Display substrate. The display substrate of claim 1, wherein the pixel electrode has one reflective electrode. The display substrate of claim 1, wherein the reflective electrode has a mesh structure for forming a plurality of transmission windows. The display substrate of claim 4, wherein the first curved portion is formed over the entire data signal line. The method of claim 4, wherein a second bent portion is formed in a portion of the gate signal line that corresponds to the reflective electrode, and a second peripheral portion corresponding to the second bent portion is formed in the reflective electrode corresponding to the second bent portion. Display substrate.

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