KR20030061106A - Liquid crystal display - Google Patents

Abstract

PURPOSE: A liquid crystal display is provided to increase the brightness and reduce the thickness by forming electro-luminescence area and liquid crystal area in one pixel area. CONSTITUTION: A first substrate has a plurality of pixel areas for displaying an image. A second substrate faces the first substrate. Electro-luminescence and liquid crystal areas are formed at the pixel areas respectively between the first substrate and the second substrate. The plurality of pixel areas are formed by crossing a plurality of gate lines(22) and a plurality of data lines(62). Switching elements and a pixel electrode(82) are formed at the plurality of pixel areas respectively to be electrically connected with the gate lines and the data lines. Black matrices(BM) formed on the second substrate are piled on the plurality of gate lines and the plurality of data lines. A plurality of red, green, and blue color filters(CF) are formed on the second substrate corresponding to the pixel areas respectively. A common electrode(120) and an electrode for electro-luminescence(122) are formed on the black matrices and the plurality of color filters.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY}

The present invention relates to a liquid crystal display device.

The liquid crystal display device is composed of upper and lower substrates on which electrodes are formed and liquid crystal materials injected therebetween. Such a liquid crystal display device displays an image by applying an electric field to the liquid crystal material injected between two substrates by using an electrode, and adjusting the intensity of the electric field to adjust the amount of light transmitted through the substrate.

Reflective liquid crystal display devices are advantageous in the bright outdoors, and the image can be viewed by turning on the front light indoors. However, there is a disadvantage that the contrast ratio is low and the brightness is low in a dark indoor.

The transmissive liquid crystal display can see an image brightly indoors by using a back light, but lacks visibility so that the image cannot be recognized in bright outdoors, and it is difficult to thin due to a back light system. .

The semi-transmissive liquid crystal display device combining the above two types has the advantage that it can be used indoors and outdoors. However, since the opening window and the reflection window are formed together, there is a limit to widening the opening window. However, even when the backlight is turned on when used indoors, there is a problem that the luminance is low due to the low transmittance. it's difficult.

The present invention seeks to increase the luminance while thinning the liquid crystal display.

1 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

2A is a cross-sectional view of a substrate in a first manufacturing step for manufacturing a lower substrate in a liquid crystal display according to an exemplary embodiment of the present invention;

FIG. 2B is a cross-sectional view of the substrate at the next stage of manufacture of FIG. 2A,

FIG. 2C is a cross-sectional view of the substrate at the next stage of manufacture of FIG. 2B,

FIG. 2D is a cross sectional view of the substrate at a subsequent fabrication step in FIG. 2C;

FIG. 2E is a cross sectional view of the substrate at a subsequent fabrication step in FIG. 2D;

3 is a cross-sectional view of the upper substrate in the liquid crystal display according to the exemplary embodiment of the present invention.

In order to solve the technical problem, the present invention forms an electroluminescent region and a liquid crystal region together in one pixel region.

Specifically, the liquid crystal display according to the present invention includes a first substrate on which a plurality of pixel regions are arranged to display an image, a second substrate facing the first substrate, and a pixel between the first substrate and the second substrate. An electroluminescent region and a liquid crystal region formed in each of the regions.

Here, a plurality of gate lines and a plurality of data lines intersect to define a plurality of pixel regions in the first substrate, and switching elements and pixel electrodes electrically connected to the gate lines and the data lines may be formed in the pixel regions, respectively. In this case, the pixel electrode may be formed of a metal material having reflective characteristics.

Here, the second substrate has a black matrix overlapping a plurality of gate lines and a plurality of data lines, and a plurality of red, green, and blue color filters facing each pixel area are formed, and a black mattress and The common electrode and the electroluminescent electrode may be formed on the plurality of color filters. In this case, the electroluminescent region may contact both the pixel electrode and the electroluminescent electrode.

In addition, the electroluminescent region may be formed of an organic light emitting material or an inorganic light emitting material.

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

1 is a schematic cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

First, the "lower substrate" of the liquid crystal display device will be described.

Gate wirings 22 and 24 having a thickness of 1000 to 3500 mW are formed on the insulating substrate 10 and a conductive material such as aluminum or an aluminum alloy, chromium or chromium alloy, molybdenum or molybdenum alloy, chromium nitride or molybdenum nitride.

The gate lines 22 and 24 include a gate line 22 extending in the horizontal direction and a gate electrode 24 extending to the gate line 22.

At this time, the gate wirings 22 and 24 can be formed in a structure having a double layer or more, in which case, at least one layer is preferably formed of a metal material having low resistance characteristics.

On the insulating substrate 10, a gate insulating film 30 having a thickness of 3500 to 4500 kV made of an insulating material such as silicon nitride or silicon oxide covers the gate wirings 22 and 24.

On the gate insulating film 30, a semiconductor pattern 42 of 800-1500 Å thickness is formed which overlaps the gate electrode 24 and is made of amorphous silicon or the like. On the semiconductor pattern 42, ohmic contact layers 55 and 56 having a thickness of 500 to 800 Å made of amorphous silicon doped with conductive impurities are formed.

Over the ohmic contact layers 55 and 56 and the gate insulating layer 30, a data line 62 having a thickness of 1500 to 3500 Å made of a conductive material such as aluminum or an aluminum alloy, chromium or chromium alloy, molybdenum or molybdenum alloy, chromium nitride or molybdenum nitride, etc. 65, 66) are formed.

The data lines 62, 65, and 66 extend in the vertical direction, intersect the gate line 22, protrude from the data line 62, and the data line 62 to define the pixel area, and one ohmic contact layer 55. The source electrode 65 extending up to the top and the opposite electrode of the source electrode 65 and the drain electrode 66 extending from the other ohmic contact layer 56 to the gate insulating film 30 inside the pixel region. It includes.

The data lines 62, 65, and 66 can be formed in a double layer or more structure. In this case, at least one layer is preferably formed of a metal material having low resistance.

Here, the gate electrode 24, the source electrode 64, the drain electrode 66, and the semiconductor pattern 42 constitute a thin film transistor electrically connected to the gate line 33 and the data line 62 in the pixel region. It becomes a switching element.

The data lines 62, 65, 66 and the semiconductor pattern 42 are covered with a protective film 70 having a thickness of 1500 to 2500 Å made of an insulating material such as silicon nitride or silicon oxide.

In the passivation layer 70, a contact hole 72 exposing the drain electrode 66 is formed. A pixel electrode 82 connected to the drain electrode 66 through the contact hole 72 is formed on the protective film 70. Here, the pixel electrode 82 is advantageously made of a metal material having excellent reflection characteristics such as aluminum or an aluminum alloy.

A first alignment layer 90 made of an alignment material such as polyimide is formed on the passivation layer 70 and the pixel electrode 82. In this case, a first opening pattern 92 exposing a part of the pixel electrode 82 is formed in the first alignment layer 90.

The "upper substrate" corresponding to the "lower substrate" of the liquid crystal display will be described below.

The black matrix BM overlapping the gate line 22, the data line 62, and the thin film transistor TFT of the thin film transistor substrate is formed on the second insulating substrate 100.

In addition, on the second insulating substrate 100, a color filter CF positioned between two neighboring black matrices BM is formed in a line shape. At this time, the color filters CF are formed alternately with red, green, and blue color filters (in the drawings, red, green, and blue color filters are not distinguished and displayed).

The overcoat layer 110 made of an organic insulating material is flatly covered on the entire surface of the color filter CF and the black matrix BM, and the common electrode 120 made of ITO or Izo and the electrons are formed on the overcoat layer 110. The light emitting electrode 122 is formed. Here, the common electrode 120 and the electroluminescent electrode 122 are separated from each other, and the electroluminescent electrode 122 is connected to a separate wiring to receive a voltage from the outside.

A second alignment layer 130 made of an alignment material such as polyimide is formed on the common electrode 120 and the electroluminescent electrode 122 to determine the alignment of the liquid crystal. In this case, a second opening pattern 132 exposing a part of the electroluminescent electrode 122 is formed in the second alignment layer 130.

The liquid crystal region LC filled with liquid crystal and the electroluminescent region EL filled with an electroluminescent material are formed between the "upper substrate" of the liquid crystal display and the "lower substrate" of the liquid crystal display described above. Here, the electroluminescent region EL is formed of a polymer, a low molecular organic light emitting material, or an inorganic light emitting material.

Typically, the electron emission region EL has a lamination structure of an electron generation layer (or electron transfer layer), a light emitting layer, and a hole generation layer (or hole transfer layer). The electron generating layer contacts an electrode to be used as a cathode, for example, an electrode 122 for electroluminescence, and the hole generating layer contacts an electrode to be used as an anode, for example, a pixel electrode 82. In this case, the electroluminescent region EL is made to emit light by using a voltage applied between the two electrodes 82 and 122. At this time, a light emitting material constituting the electroluminescent region EL is appropriately selected to emit a predetermined wavelength, and in this embodiment, it is advantageous to emit white light. On the other hand, the electroluminescent region EL may be formed by different light emitting materials so as to emit red, green, and blue light. In this case, the color filter CF may be formed only in a region corresponding to the liquid crystal region of the pixel region. Form. At this time, the color of the light emitted from the electroluminescent region EL and the color of the color filter CF in the electroluminescent region EL and the color filter CF included in one pixel region must match.

The liquid crystal region LC fills the entire region between the two substrates except the electroluminescent region EL. Here, the liquid crystal region LC is in contact with the first alignment layer 90 and the second alignment layer 130 and is twisted in an appropriate direction according to the alignment directions of the alignment layers 90 and 130.

As described above, the liquid crystal display according to the present invention simultaneously has the liquid crystal region LC and the electroluminescent region EL in one pixel region.

Here, the ratio of the area occupied by the electroluminescent region EL and the liquid crystal region LC in one pixel region may be appropriately set according to the material or structure of the liquid crystal display. In this case, the area ratio of the electric feet and the area EL may be different for each line of each pixel area facing the color filters of red, green, and blue.

In the liquid crystal display device according to the present invention as described above, when displaying an image, the light reflected by the pixel electrode and the bright light emitted from the electroluminescent region is used. Therefore, a bright image can be displayed even in a bright place or a dark place, and brightness can be raised. In addition, since the pixel electrode is used for light reflection, it does not require a backlight system, thereby making it thinner.

Next, a method of manufacturing a liquid crystal display device according to an exemplary embodiment of the present invention will be described.

First, a method of manufacturing a thin film transistor substrate will be described with reference to FIGS. 2A to 2E and 3 and FIG. 1.

As shown in FIG. 2A, a gate wiring metal layer is deposited on the insulating substrate 10, and then the metal layer is patterned by a photolithography process to form gate wirings 22 and 24. The gate wirings 22 and 24 include a gate line 22 and a gate electrode 24.

Next, as shown in FIG. 2B, a gate insulating film 30 made of an insulating material such as silicon nitride is deposited on the insulating substrate 10 to cover the gate wirings 22 and 24.

Subsequently, an amorphous silicon layer and an amorphous silicon layer doped with a conductive impurity are sequentially formed on the gate insulating layer 30, and then the two silicon layers are patterned by a photolithography process to form a semiconductor pattern 42 and an ohmic contact layer pattern ( 52).

Next, as shown in FIG. 2C, after depositing a metal layer for data wiring on the exposed front surface of the substrate, the metal layer is patterned by a photolithography process to form data lines 62, 65, and 66. The data lines 62, 65, 66 include a data line 62, a source electrode 65, and a drain electrode 66. Here, the data line 62 crosses the gate line 22 to define a plurality of pixel areas.

Subsequently, the ohmic contact layer pattern 52 is etched using the source electrode 65 and the drain electrode 66 as a mask to contact the ohmic contact layer 55 and the drain electrode 66 contacting the source electrode 65. The resistive contact layer 56 is separated.

Next, as shown in FIG. 2D, the protective film 70 is formed of silicon nitride, silicon oxide, or the like on the entire surface of the substrate including the data lines 62, 65, 66, and the semiconductor pattern 42. Next, the protective film 70 and the gate insulating film 30 are patterned by a photolithography process to form a contact hole 72 exposing the drain electrode.

Subsequently, after depositing a metal layer having excellent light reflection characteristics such as aluminum or an aluminum alloy on the exposed front surface of the substrate, the metal layer is patterned by a photolithography process and connected to the drain electrode 66 through the contact hole 72. An electrode 82 is formed.

Next, as shown in FIG. 2E, after forming the first alignment layer 90 covering the passivation layer 70 and the entire surface of the pixel electrode 82, and performing a rubbing process on the first alignment layer 90, the pixel electrode ( A first opening pattern 92 exposing a portion of 82 is formed.

Subsequently, after the electroluminescent material layer is formed on the entire surface of the substrate, the electroluminescent material layer is patterned by a photolithography process to contact the pixel electrode 82 through the first opening pattern 92. Form. Here, the electroluminescent material layer is formed by a lamination structure of an electron generating layer (electron transporting layer), a light emitting layer, and a hole generating layer (hole transporting layer), and these layer structures may be formed by spin coating a polymer organic light emitting material, The low molecular weight organic light emitting material or the inorganic light emitting material may be formed through a deposition technique.

Next, the "upper substrate" of the liquid crystal display device is produced through a normal manufacturing process.

As illustrated in FIG. 3, an opaque metal layer or an opaque insulating material layer is deposited on the second insulating substrate 100, and then patterned by a photolithography process to form a black matrix BM.

Subsequently, a process of applying a resin having a predetermined color to the entire surface of the second insulating substrate 100 and the black matrix BM and patterning the photo by etching is performed for each color to perform a color filter CF of red, green, and blue. Form.

Subsequently, the entire surface of the substrate including the black matrix BM and the color filter CF may be covered with the overcoat layer 110 made of an insulating material. Next, a transparent conductive layer made of ITO or IZO is deposited on the overcoat layer 110, and then the transparent conductive layer is patterned by a photolithography process to form a common electrode 120 and an electroluminescent electrode 122.

Subsequently, after forming the second alignment layer 130 covering the common electrode 120 and the electrode 122 for electroluminescence, and performing a rubbing process on the second alignment layer 130, a part of the electrode 122 for electroluminescence is formed. To form a second opening pattern 132 to reveal.

1, the "upper substrate" of the liquid crystal display device is bonded to the "lower substrate" of the liquid crystal display device described above. At this time, the electroluminescent electrode 120 of the "upper substrate" and the pixel electrode 82 of the "lower substrate" are brought into contact with the electroluminescent region EL. In this case, the electroluminescent region EL is formed of two substrates. It is functioning as a spacer to maintain the interval of.

Next, the liquid crystal is injected between the two bonded substrates to fill the space between the two substrates except the electroluminescent region EL with the liquid crystal LC. As a result, the electroluminescent region EL and the liquid crystal region LC exist simultaneously in one pixel region.

In the liquid crystal display according to the present invention, since the light reflected by the pixel electrode is used to display an image and the bright light emitted from the electroluminescent region formed in a part of the pixel region is used, the liquid crystal display device can increase the luminance and requires a backlight system. It can be thinned because it is not.

Claims (7)

A first substrate on which a plurality of pixel regions are arranged to display an image, A second substrate facing the first substrate, An electroluminescence region and a liquid crystal region formed in each of the pixel regions between the first substrate and the second substrate Liquid crystal display comprising a. In claim 1, In the first substrate, a plurality of gate lines and a plurality of data lines intersect to define the plurality of pixel regions, and each of the pixel regions includes a switching element and a pixel electrode electrically connected to the gate line and the data line. Liquid crystal display. In claim 1, The pixel electrode is formed of a metallic material having reflective characteristics. In claim 2, A black matrix overlapping the plurality of gate lines and the plurality of data lines is formed on the second substrate, and a plurality of red, green, and blue color filters corresponding to the pixel area are formed, and the black mattress and the A liquid crystal display device in which a common electrode and an electroluminescence electrode are formed on a plurality of color filters. In claim 4, And the electroluminescent region is in contact with both the pixel electrode and the electroluminescent electrode. In claim 4, And the color filter is formed only in a region corresponding to the liquid crystal region of the pixel region, and the electroluminescent region of the pixel region emits red, green, and blue light corresponding to the color of the color filter. In claim 1, The electroluminescent region is formed of an organic light emitting material or an inorganic light emitting material.