KR101686097B1 - Transflective type liquid crystal display device and method for fabricating the same - Google Patents

Abstract

The present invention relates to a transflective liquid crystal display device with improved color reproducibility and reflectance and a method of manufacturing the same. The transflective liquid crystal display device of the present invention comprises an embossing layer located on a first substrate and a reflection region on the first substrate, And a color filter layer located in a transmissive region different from the region.

Description

TECHNICAL FIELD [0001] The present invention relates to a transflective liquid crystal display device and a method of manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transflective liquid crystal display, and more particularly, to a transflective liquid crystal display device in which a color filter layer is formed in a transmissive region of a first substrate to improve a color reproduction rate and a reflectance, and a manufacturing method thereof.

(PDP), Electro Luminescent Display (ELD), Vacuum Fluorescent (VFD), and the like have been developed in recent years in response to the demand for display devices. Display) have been studied, and some of them have already been used as display devices in various devices.

Among them, liquid crystal display devices are mostly used in place of CRT (Cathode Ray Tube) for the purpose of portable image display devices because of their excellent image quality, light weight, thinness and low power consumption, But also various kinds of monitors such as a television and a computer monitor receiving and displaying a broadcast signal in addition to the use of the same mobile type.

Such a liquid crystal display device has a structure in which liquid crystal is filled between upper and lower substrates. The liquid crystal molecules are thin and long in structure and have a directionality in arrangement, so that the direction of alignment of the liquid crystal molecules can be controlled by applying an electric field to the liquid crystal layer.

When an electric field is applied to the liquid crystal display, the liquid crystal molecules move due to the electric field applied to the liquid crystal layer, and the light transmittance is changed, so that images and characters are expressed. Such a liquid crystal display device is excellent in image quality, light in weight, and low in power consumption, and has been attracting attention as a next-generation advanced display device.

The liquid crystal display device displays an image by light of a light source called a backlight located below the lower substrate. However, since the light incident on the backlight is lost in the process of passing through each cell of the liquid crystal display device, only about 7% is actually transmitted on the screen. Therefore, in a liquid crystal display device requiring a high brightness, power consumption for brightening the brightness of the backlight Big.

In order to solve such a problem, a reflection type liquid crystal display device which operates using external light without using a backlight has been developed. However, the reflection type liquid crystal display device can not be used in a place where external light is weak or absent, A semi-transmissive liquid crystal display device having the advantages of a reflective mode and a transmissive mode that can be selected and used has been developed.

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

1 is a cross-sectional view of a conventional transflective liquid crystal display device.

Referring to FIG. 1, a conventional transflective liquid crystal display device includes a liquid crystal layer between a first substrate 100 and a second substrate 180 opposed to each other with pixel regions, which are divided into a reflective region and a transmissive region, And a liquid crystal layer 155 formed by injection.

A gate electrode 105 formed of a conductive material such as metal is formed on the first substrate 100. The gate electrode 105 is formed on a gate line (not shown) formed on the first substrate 100 in one direction, As shown in Fig.

A gate insulating layer 110 is formed on the entire surface of the first substrate 100 including the gate electrode 105. A semiconductor layer 115 in which an active layer and an ohmic contact layer are sequentially stacked is formed at a position above the gate insulating film 110 to cover the gate electrode 105.

A source electrode 120s and a drain electrode 120d are formed on the semiconductor layer 115 at a predetermined distance from each other. The source electrode 120s is formed in a direction intersecting with the gate line (not shown) Line (not shown).

A channel exposing a part of the surface of the semiconductor layer 115 is formed in a spacing interval between the source electrode 120s and the drain electrode 120d. The gate electrode 105, the semiconductor layer 115, the source electrode 120s And the drain electrode 120d form a thin film transistor.

An inorganic insulating layer 125 is formed on the entire surface of the first substrate 100 including the thin film transistor, An emboss layer 130 having a concavo-convex surface on the inorganic insulating film 125 is formed.

At this time, the inorganic insulating layer 125 and the emboss layer 130 are formed only in the reflection region.

A reflective electrode 145 is formed on the emboss layer 130. The surface of the emboss layer 130 has irregularities and the reflective electrode 145 is formed along the irregularities of the emboss layer 130.

A pixel electrode 150 is formed on the gate insulating layer 110 including the reflective electrode 145 and the pixel electrode 150 is connected to the drain electrode 120d through a contact hole 130H.

A color filter layer 170 is formed on the second substrate 180 and a common electrode 160 is formed on the color filter layer 170.

Also, although not shown, a black matrix (not shown) is formed on the second substrate 180, and the black matrix (not shown) is formed to correspond to the data line (not shown).

Since the transflective liquid crystal display device is divided into a reflective region and a transmissive region, the reflectivity is improved as the area of the reflective region is wider. However, since the transmissive region is relatively narrowed, A reflective region can not be formed.

In addition, since the color filter layer is formed on the second substrate, the path through which the light reflected by the reflective electrode passes is not one color but another color, and color mixing may occur.

Meanwhile, in order to improve the reflection performance, a method of forming a hole for removing a part of the color filter layer has been proposed. However, in this case, since the color does not pass through the color filter layer as much as the area of the hole, .

It is an object of the present invention to provide a transflective liquid crystal display device having improved color reproduction rate and reflectance by forming a color filter layer in a transmissive region of a first substrate and a method of manufacturing the same, .

According to an aspect of the present invention, there is provided a transflective liquid crystal display comprising: a first substrate including a pixel region divided into a reflective region and a transmissive region; A second substrate facing the first substrate; A thin film transistor positioned on the reflective region of the first substrate; An emboss layer located in the reflection region on the first substrate and covering the thin film transistor, the emboss layer having a concavo-convex surface; A reflective electrode positioned on the surface of the embossed layer; A color filter layer located on the first substrate only in the transmissive region; A pixel electrode connected to the thin film transistor and positioned on the color filter layer and the reflective electrode; And a liquid crystal layer disposed between the first substrate and the second substrate.

The embossed layer may include a contact hole exposing a predetermined region of the thin film transistor. The pixel electrode may extend along a surface of the contact hole of the emboss layer.

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The transflective liquid crystal display may further include a first protective layer disposed between the emboss layer and the reflective electrode, and a second protective layer disposed between the reflective electrode and the pixel electrode.

The transflective liquid crystal display may further include a common electrode disposed on the second substrate.

The thickness of the embossed layer may be 0.5 탆 to 3.0 탆.

The emboss layer may include a thermosetting resin.

The first passivation layer and the second passivation layer may include silicon nitride (SiNx).

The reflective electrode may include aluminum or an aluminum alloy.

The thickness of the color filter layer may be 0.5 mu m to 3.0 mu m.

The pixel electrode may include one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO).

According to another aspect of the present invention, there is provided a method of manufacturing a transflective liquid crystal display device including forming a thin film transistor on a reflective region of a first substrate including a pixel region divided into a reflective region and a transmissive region; Forming an emboss layer on the first substrate, the emboss layer having a concavo-convex surface, covering the thin film transistor; Etching the embossed layer formed on the transmissive region of the first substrate; Forming a reflective electrode on the surface of the embossed layer; Forming a color filter layer on the first substrate; Etching the color filter layer formed on the reflective region of the first substrate; Selectively removing the emboss layer to form a contact hole exposing the thin film transistor at a predetermined position; Forming a pixel electrode connected to the thin film transistor through the contact hole on the color filter layer and the reflective electrode; And forming a liquid crystal layer between the first substrate and the second substrate after preparing a second substrate facing the first substrate.

The method for fabricating a transflective liquid crystal display device includes: forming a first protective layer between the emboss layer and the reflective electrode; And forming a second protective layer between the reflective electrode and the pixel electrode.

The transflective liquid crystal display of the present invention has the following effects.

First, since the color filter layer exists only in the transmissive region of the first substrate, light reflected through the reflective electrode in the reflective mode is incident and reflected without passing through the color filter layer at the time of emergence.

Therefore, the light is incident on and reflected by the reflection region without loss of the light amount, and the reflectance is improved to realize high-reflectance monochrome.

Second, since the reflected light is reflected without passing through the color filter layer, the light efficiency is improved, so that the low power operation can be performed even when the backlight is off in the reflection mode, and the lifetime is extended.

Thirdly, in the transmissive mode, light incident on the transmissive region passes through the color filter layer before being transmitted through the liquid crystal layer, so that color mixture can be prevented, holes are not formed in the color filter layer, The color reproducibility of light is improved.

1 is a cross-sectional view of a general transflective liquid crystal display device.
2 is a plan view of a transflective liquid crystal display device of the present invention.
3 is a cross-sectional view taken along the line I-I 'of Fig.
FIGS. 4 to 11 are cross-sectional views illustrating a method of manufacturing the transflective liquid crystal display device of the present invention.

Hereinafter, the transflective liquid crystal display device of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a plan view of a transflective liquid crystal display device of the present invention, and FIG. 3 is a cross-sectional view taken along the line I-I 'of FIG.

2 and 3, the transflective liquid crystal display of the present invention includes a first substrate 200 in which pixel regions, which are divided into a reflective region and a transmissive region, are arranged in a matrix, A plurality of gate lines (not shown) and data lines (not shown) that divide the pixel regions and intersect each other on the first substrate 200, a plurality of gate lines A thin film transistor (not shown) formed at an intersection of a line (not shown) and a data line (not shown), an emboss layer (not shown) A reflective electrode 240 formed on the emboss layer 230, a color filter layer 270 formed on the transmissive region, and a thin film transistor (not shown) A pixel electrode 250 formed on the pixel electrode 240, A liquid crystal layer 255 formed between the first substrate 100 and second substrate 280 comprise.

As shown in FIG. 2, the reflection region is defined to include the formation region of the thin film transistor, and the transmission region occupies a larger area of the pixel region than the reflection region.

A contact hole 230H is further formed in the emboss layer 240 to connect the thin film transistor (not shown) and the pixel electrode 250. A first passivation layer 235 and a second protective film 245.

The first passivation layer 235 is formed on the emboss layer 230 and the second passivation layer 245 is disposed under the pixel electrode 250.

An inorganic insulating film 225 is further formed on the first substrate 200 including the thin film transistor (not shown) below the emboss layer 230. A common electrode 260 ).

The inorganic insulating film 225 is formed of an inorganic insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx), and may be formed only in the reflection region, As shown in FIG.

The thickness of the embossed layer 230 is in the range of 0.5 탆 to 3.0 탆, and is made of a thermosetting resin. For example, the thermosetting resin may include photo acrylic resin or PMMA (Polymethylmethacrylate) resin.

The first protective layer 235 and the second protective layer 245 are made of silicon nitride (SiNx), and the reflective electrode 240 is made of aluminum or an aluminum alloy.

The first and second protective layers 235 and 245 may be omitted in order to simplify the manufacturing process. The first protective layer 235 improves adhesion between the emboss layer 230 and the reflective electrode 240, The second protective layer 245 preferably has an advantage of improving adhesion between the reflective electrode 240 and the pixel electrode 250.

The pixel electrodes 250 formed on the first and second protective layers 235 and 245 and the reflective electrode 240 are formed along the irregularities of the emboss layer 230. When the external light is incident, And is reflected by the projections and depressions of the reflective electrode 240. Thus, scattered light can be scattered along the uneven surface, and the reflection efficiency can be increased.

The color filter layer 270 is formed to have a thickness of 0.5 to 3.0 탆 and a thickness similar to that of the embossed layer 230. Therefore, the surface of the pixel region divided into the transmissive region and the reflective region has a uniform height as a whole.

The pixel electrode 250 is formed of one of ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), and ITZO (Indium Tin Zinc Oxide). The pixel electrode 250 is connected to the drain electrode 220d of the thin film transistor and is formed on the surface of the second protective film 245 of the reflective region and the color filter layer 270 of the transmissive region.

Hereinafter, a method of manufacturing the transflective liquid crystal display device of the present invention will be described.

4 to 11 are cross-sectional views illustrating a method of manufacturing a transflective liquid crystal display device according to the present invention.

As shown in FIG. 4, a plurality of gate lines (not shown) and a plurality of data lines (not shown) are formed on the first substrate 200 on which pixel regions are divided into a reflective region and a transmissive region, (Not shown).

A gate electrode 205 made of a conductive material such as metal is formed on the first substrate 200. The gate electrode 205 is protruded from one side of a gate line (not shown) formed in one direction on the first substrate 200.

A gate insulating layer 210 is formed on the entire surface of the first substrate 200 including the gate electrode 205 and an active layer and an ohmic contact layer are formed in a position covering the gate electrode 205 above the gate insulating layer 210, And a semiconductor layer 215 in which layers are sequentially stacked.

A source electrode 220s and a drain electrode 220d are formed on the semiconductor layer 215. The source electrode 220s and the drain electrode 220d are spaced apart from each other by a portion of the ohmic contact layer, The electrode 220s is protruded from a data line (not shown) formed in a direction crossing the gate line (not shown).

Here, the gate line (not shown) and the data line (not shown) intersect each other to define a pixel region, and the pixel region is divided into a reflective region and a transmissive region.

The gate electrode 205, the semiconductor layer 215, the source electrode 220s and the drain electrode 220d constitute a thin film transistor and an inorganic insulating film pattern 225a ) Can be further formed.

The inorganic insulating film 225 is formed as shown in FIG. 5 by etching the inorganic insulating film pattern 225a while leaving only the portion corresponding to the transmitting region. In some cases, the inorganic insulating film 225 may be omitted.

6, a thermosetting resin having a thickness of 0.5 mu m to 3.0 mu m is coated on the gate insulating film 210 including the inorganic insulating film 225. Next, as shown in Fig. Then, an emboss pattern 230a is formed on the surface of the thermosetting resin through heat treatment to form an embossed pattern 230a, and etching is performed leaving only a portion corresponding to the reflection area.

A reflective electrode pattern 240a is formed on the embossed layer pattern 230a and the reflective electrode pattern 240a is etched while leaving only a portion corresponding to the reflective region like the embossed pattern 230a.

The first protective film pattern 235a and the second protective film pattern 245a may be formed on the lower and upper portions of the reflective electrode pattern 240a. 230a and the reflective electrode pattern 240a and the second protective film pattern 245a is formed on the reflective electrode pattern 240a.

7, a contact hole 230H exposing the drain electrode 220d is formed.

8, a color filter pattern 270a is formed on the entire surface of the gate insulating layer 210 including the second protective layer 245 and is etched so as to remain only in the transmissive region as shown in FIG. 9 to form a color filter layer 270 do.

For example, when the color filter layer 270 is divided into R, G, and B color filters, color filter layers of different colors may be formed in the corresponding pixel regions. In some cases, a color filter of an intermediate color may be included in addition to the R, G, and B color filters.

When the color filter layer 270 of the corresponding color is formed in the entire pixel region, the emboss layer 230, the first protective layer 235, the reflective electrode 240, and the second protective layer 245 of the reflective region The surface of the pixel region divided by the reflective region and the transmissive region has a uniform height as a whole with a uniform height with the color filter layer 270 in the transmissive region.

As shown in FIG. 10, a pixel electrode 250 is formed on the second passivation layer 245 including the color filter layer 270 and the contact hole 230H.

11, a common electrode 260 is formed on the second substrate 280. The common electrode 280 is formed on the second substrate 280 in a TN mode (twisted nematic mode) And may be formed on the first substrate 200 and alternately disposed with the pixel electrode 250, such as an IPS mode (In-Plane Switching Mode).

In addition, although not shown, a black matrix (not shown) is formed on the second substrate 280, and the black matrix (not shown) is formed to correspond to the data line (not shown).

Next, a liquid crystal layer 255 is formed by injecting liquid crystal between the first substrate 200 and the second substrate 280.

In the transflective liquid crystal display of the present invention as described above, light incident on the reflective region is reflected by the reflective electrode via the liquid crystal layer and then emitted to the outside via the liquid crystal layer, The light of the backlight which is transmitted through the color filter layer first passes through the liquid crystal layer and is emitted to the outside.

In this case, since the color filter layer exists only in the transmissive region of the first substrate, it is omitted in the reflective region, so that light incident on the reflective region is incident and reflected without passing through the color filter layer, Thereby realizing black and white of reflectance.

Further, since the light is reflected without passing through the color filter layer, the layer that causes light absorption in the reflection region is omitted to improve the light efficiency, and in the reflection mode, low power driving is possible even when the backlight is off.

In addition, in the transmissive mode, light incident on the transmissive region passes through the color filter layer before being transmitted through the liquid crystal layer. Thus, color mixture can be prevented, and the color filter layer can be transparent The color reproducibility is improved as compared with the structure in which holes are formed in the color filter layer.

Therefore, in the transflective liquid crystal display device of the present invention, since the light incident on the reflective region does not pass through the color filter layer, the amount of light is not lost and the black and white are clearly realized. Thus, low power driving is possible even when the backlight is off in the reflective mode, . Further, in the transmissive mode, the light of the backlight passes through the color filter layer in which holes are not formed, thereby improving the color reproduction rate.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

200: first substrate 205: gate electrode
210: gate insulating film 215: semiconductor layer
220s: source electrode 220d: drain electrode
225: inorganic insulating film 230: emboss layer
230H: Contact hole 235: First protective film
240: reflective electrode 245: second protective film
250: pixel electrode 255: liquid crystal layer
260: common electrode 270: color filter layer
280: second substrate

Claims (13)

A first substrate including a pixel region divided into a reflective region and a transmissive region;
A second substrate facing the first substrate;
A thin film transistor positioned on the reflective region of the first substrate;
An emboss layer located in the reflection region on the first substrate and covering the thin film transistor, the emboss layer having a concavo-convex surface;
A reflective electrode positioned on the surface of the embossed layer;
A color filter layer located on the first substrate only in the transmissive region;
A pixel electrode connected to the thin film transistor and positioned on the color filter layer and the reflective electrode; And
And a liquid crystal layer disposed between the first substrate and the second substrate. The method according to claim 1,
Wherein the emboss layer includes a contact hole exposing a predetermined portion of the thin film transistor, and the pixel electrode extends along a surface of the contact hole of the emboss layer. The method according to claim 1,
A first protective layer disposed between the emboss layer and the reflective electrode, and a second protective layer disposed between the reflective electrode and the pixel electrode. delete The method according to claim 1,
And a common electrode disposed on the second substrate. The method according to claim 1,
Wherein the emboss layer has a thickness of 0.5 탆 to 3.0 탆. The method according to claim 1,
Wherein the emboss layer comprises a thermosetting resin. The method of claim 3,
Wherein the first passivation layer and the second passivation layer comprise silicon nitride (SiNx). The method according to claim 1,
Wherein the reflective electrode comprises aluminum or an aluminum alloy. The method according to claim 1,
Wherein the thickness of the color filter layer is 0.5 mu m to 3.0 mu m. The method according to claim 1,
Wherein the pixel electrode comprises one of ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), and ITZO (Indium Tin Zinc Oxide). Forming a thin film transistor on the reflective region of the first substrate including a pixel region divided into a reflective region and a transmissive region;
Forming an emboss layer on the first substrate, the emboss layer having a concavo-convex surface, covering the thin film transistor;
Etching the embossed layer formed on the transmissive region of the first substrate;
Forming a reflective electrode on the surface of the embossed layer;
Forming a color filter layer on the first substrate;
Etching a color filter layer formed on the reflective region of the first substrate;
Selectively removing the emboss layer to form a contact hole exposing a predetermined portion of the thin film transistor;
Forming a pixel electrode connected to the thin film transistor through the contact hole on the color filter layer and the reflective electrode; And
And forming a liquid crystal layer between the first substrate and the second substrate after preparing a second substrate facing the first substrate. 13. The method of claim 12,
Forming a first protective layer between the emboss layer and the reflective electrode; And
And forming a second protective layer between the reflective electrode and the pixel electrode.

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