KR101350669B1 - Liquid crystal display device and method of fabricating the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method of manufacturing the same, wherein the liquid crystal display device includes a first substrate having a pixel area, storage electrode parts disposed in the pixel area and spaced apart from each other, and disposed on the first substrate. An insulating film covering the insulating film, a pixel electrode having pixel electrode portions overlapping the storage electrode portions, a common electrode having common electrode portions disposed on the insulating layer and alternately arranged with each pixel electrode portion, and a pixel of the first substrate By including a second substrate facing the electrode and a liquid crystal layer interposed between the first substrate and the second substrate, it is possible to secure the aperture ratio and the charging capacity at the same time.

Charge capacity, aperture ratio, transverse electric field, storage electrode unit, pixel electrode

Description

Liquid crystal display and its manufacturing method {LIQUID CRYSTAL DISPLAY DEVICE AND METHOD OF FABRICATING THE SAME}

1A is a plan view of a liquid crystal display device according to a first embodiment of the present invention.

1B is a cross-sectional view taken along the line I-I 'shown in FIG. 1A.

2 is a cross-sectional view illustrating a cross-sectional view of a liquid crystal display according to a second exemplary embodiment of the present invention.

3A to 3D are plan views illustrating a method of manufacturing a liquid crystal display device according to a third embodiment of the present invention.

4A to 4D are cross-sectional views illustrating a method of manufacturing a liquid crystal display device according to a third embodiment of the present invention.

5A through 5C are cross-sectional views illustrating a method of manufacturing a liquid crystal display device according to a fourth embodiment of the present invention.

 DESCRIPTION OF THE REFERENCE NUMERALS (S)

 100: first substrate 110: pixel electrode

 110a: pixel electrode unit 110b: connection electrode

 120: common electrode 120a: first common electrode portion

 120b: second common electrode part 120c: third common electrode part

 130: storage electrode portion 140: gate insulating film

 150a, 150b: protective film 200: second substrate

 300: liquid crystal layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display and a method for manufacturing the same, which can improve an aperture ratio without reducing a charging capacity.

Today, a liquid crystal display device (LCD) is attracting attention as a next-generation advanced display device with low power consumption, high portability, and high value-added.

The driving principle of the liquid crystal display device is the optical and dielectric anisotropy of the liquid crystal. Since the liquid crystal has a long and thin structure, the liquid crystal has directivity in the arrangement of the molecules. can do.

Accordingly, if the molecular arrangement direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light is refracted in the molecular arrangement direction by optical anisotropy to express image information.

The liquid crystal display may be classified into various types such as twisted nematic mode, OCB mode, optically compensated birefringence mode, in-plane switching mode, and vertical alignment.

Among these, the transverse electric field type liquid crystal display device has appeared as a part for improving the viewing angle which may occur due to the characteristics of the liquid crystal. The liquid crystal of the transverse electric field type liquid crystal display device is driven by a transverse electric field generated between the pixel electrode and the common electrode which are alternately arranged in the pixel area. That is, the liquid crystal is oriented in the horizontal direction can improve the viewing angle problem.

However, such a transverse field type liquid crystal display device has a problem in that the aperture ratio of the transverse field type liquid crystal display device is lowered because the pixel electrode and the common electrode made of an opaque metal are disposed on one substrate in the pixel area. In addition, a capacitor electrode made of an opaque metal is further disposed in the pixel region to further reduce the aperture ratio of the transverse electric field type liquid crystal display device. Here, although the area of the capacitor electrode can be reduced to improve the aperture ratio, when the area of the capacitor electrode is reduced, it is impossible to effectively control the voltage variation of the pixel electrode. As a result, the transverse electric field type liquid crystal display may cause a problem of deterioration of image quality such as flicker on the screen.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device and a method for manufacturing the same, which can improve an aperture ratio without reducing a charging capacity.

In order to achieve the above technical problem, an aspect of the present invention provides a liquid crystal display device. The liquid crystal display device includes a first substrate having a pixel region, storage electrode portions disposed in the pixel region and spaced apart from each other, an insulating layer disposed on the first substrate to cover the storage electrode portions, and disposed on the insulating layer. A pixel electrode having pixel electrode portions overlapping storage electrode portions, a common electrode disposed on the insulating layer and having common electrode portions alternately disposed with the pixel electrode portions, and a second electrode facing the pixel electrode of the first substrate; And a liquid crystal layer interposed between the second substrate and the first substrate and the second substrate.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device. The manufacturing method includes providing a first substrate having a pixel region, forming storage electrode portions spaced apart from each other on a first substrate of the pixel region, and insulating layers covering the storage electrode portions on the first substrate. Forming a common electrode having pixel electrode portions overlapping the storage electrode portions on the insulating layer, and a common electrode on the first substrate, the common electrode portions alternately arranged with the pixel electrode portions; And providing a second substrate facing the pixel electrode of the first substrate, and forming a liquid crystal layer between the first substrate and the second substrate.

Hereinafter, with reference to the drawings of the liquid crystal display according to the present invention will be described in detail. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the size and thickness of an apparatus may be exaggerated for convenience. Like numbers refer to like elements throughout.

Example  One

1A and 1B are diagrams for describing a liquid crystal display device according to a first embodiment of the present invention. 1A is a plan view of a liquid crystal display according to a first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line II ′ of FIG. 1A.

1A and 1B, the liquid crystal display of the present invention includes a liquid crystal layer interposed between the first substrate 100, the second substrate 200, and the first and second substrates 100 and 200 facing each other. 300.

The first substrate 100 has a plurality of pixel regions defined therein. The pixel area may be a minimum unit for displaying an image. The pixel region may be defined by the gate wiring 101 and the data wiring 102 crossing each other on the first substrate 100. That is, the plurality of gate lines 101 and the plurality of data lines 102 cross each other to form a plurality of cells. The pixel area may be each cell of the plurality of cells.

Each pixel region of the first substrate 100 includes a thin film transistor Tr, a pixel electrode 110 electrically connected to the thin film transistor Tr, and a common electrode 120 for forming a transverse electric field with the pixel electrode 110. This is arranged.

In addition, the storage electrode 130 overlapping at least a predetermined portion of the pixel electrode 110 is disposed. Here, as the storage electrode 130 and the pixel electrode 110 overlap with the insulating film interposed therebetween, a charge capacity is formed. Thereby, the image quality of the completed liquid crystal display device can be prevented from falling. In this case, the predetermined portion is an area that does not affect driving the liquid crystal of the liquid crystal layer 300. Here, the predetermined portion is a region that can transmit light, but may be a non-opening region because the liquid crystal is not driven. That is, the non-opening region may be defined as an inverse region in which the liquid crystal is not driven and thus the light transmittance is not controlled. Therefore, it is possible to secure a sufficient charging capacity that does not affect the aperture ratio of the liquid crystal display device and can prevent the fluctuation of the pixel electrode.

In detail, the gate wiring 101 and the gate electrode 112 branched from the gate wiring 101 are disposed on the first substrate 100. The common wiring 103 parallel to the gate wiring 101 is disposed on the first substrate 100. At least two storage electrode parts 130 spaced apart from each other on the first substrate 100. Here, each of the storage electrode units 130 is electrically connected to the common wiring 103. Therefore, the storage electrode units 130 are electrically connected to each other by the common wiring 103. In this case, the common wiring 103 and the storage electrode unit 130 may be integrally formed with each other. The gate wiring 101 may be formed of the same conductive material as the common wiring 103. Accordingly, the storage electrode units 130 may be formed of the same conductive material as the gate wiring 101.

In addition, the first common electrode part 120a disposed on the first substrate 100 adjacent to the data line 102 to be described later is disposed. Here, the first common electrode part 120a is electrically connected to the common wiring 103. In this case, the first common electrode part 120a may be integrally formed with the common wiring 103. As a result, the first common electrode part 120a not only forms a transverse electric field with the pixel electrode 110, which will be described later, but also serves as a light blocking member that prevents light from leaking around the data wire 102. .

The gate insulating layer 140 is disposed on the first substrate 100 including the gate electrode 112 and the storage electrode units 130. The gate insulating layer 140 may be an inorganic insulating layer. For example, the gate insulating layer 140 may be a silicon oxide film, a silicon nitride film, or a stacked film thereof.

The semiconductor layer 122 is disposed on the gate insulating layer 140 corresponding to the gate electrode 112. The semiconductor layer 122 may include a stacked amorphous silicon layer 122a and an amorphous silicon layer 122b containing impurities. Here, the amorphous silicon layer 122b doped with impurities is disposed between the amorphous silicon layer 122a and the source electrode 132 which will be described later, and between the amorphous silicon layer 122a and the drain electrode 142 which will be described later.

The data line 102 intersecting with the gate line 101 is disposed on the gate insulating layer 140. In addition, a source electrode 132 branched from the data line 102 is disposed on the semiconductor layer 122. The source electrode 132 may have a 'U' shape in order to improve characteristics of the thin film transistor Tr. However, in the embodiment of the present invention, the shape of the source electrode 132 is not limited. In addition, the drain electrode 142 is disposed on the semiconductor layer 122 and spaced apart from the source electrode 132. In this case, the source electrode 132 is wrapped around the drain electrode 142.

Accordingly, the thin film transistor Tr including the gate electrode 112, the semiconductor layer 122, the source electrode 132, and the drain electrode 142 is disposed on the first substrate 100.

The passivation layer 150a is disposed on the first substrate 100 including the thin film transistor Tr. In this case, the passivation layer 150a includes a contact hole exposing at least a portion of the drain electrode 142.

The pixel electrode 110 and the common electrode 120 forming a transverse electric field are disposed on the passivation layer 150a corresponding to the pixel region.

The pixel electrode 110 includes at least two pixel electrode parts 110a spaced apart from each other and a connection electrode 110b electrically connecting the pixel electrode parts 110a to each other. The connection electrode 110b is electrically connected to the drain electrode 142 exposed through the contact hole. Thus, the pixel electrode 110 is electrically connected to the drain electrode 142.

In addition, the pixel electrode unit 110a overlaps the storage electrode units 130. That is, the pixel electrode unit 110a has a shape corresponding to that of the story electrode unit 130. Here, an insulating film, that is, a gate insulating film 140 and a passivation film 150a, is interposed between the pixel electrode part 110a and the storage electrode part 130 to prevent a change in pixel voltage of the pixel electrode 110. Capacity is formed. In this case, a transverse electric field for driving the liquid crystal is not generated in correspondence with the central portion of the pixel electrode part 110a. That is, the center portion of the pixel electrode portion 110a is a non-opening region that does not affect the aperture ratio of the liquid crystal display device. Therefore, the storage electrode unit 130 corresponds to the center portion of the pixel electrode unit 110a. In this case, the width of the storage electrode 130 is smaller than the width of the pixel electrode 110a, thereby preventing the opening ratio from being lowered by the storage electrode 130.

The common electrode 120 includes at least two second common electrode parts 120b spaced apart from each other and third common electrode parts 120c electrically connecting the second common electrode parts 120b to each other. Here, the second common electrode part 120b adjacent to the data line 102 among the second common electrode parts 120b may partially overlap the first common electrode part 120a. In this case, the third common electrode part 120c is electrically connected to the common wiring 103. In addition, the second and third common electrode parts 120b and 120c may be integrally formed.

Here, the second and third common electrode parts 120b and 120c may be made of a transparent conductive material to secure the aperture ratio of the liquid crystal display. In addition, the second and third common electrode parts 120b and 120c may be made of the same conductive material as the pixel electrode 110. For example, the second and third common electrode units 120b and 120c may be ITO or IZO.

The second substrate 200 may include a black matrix 220 having an opening and a color filter layer provided in the opening. Here, the black matrix 220 corresponds to the gate wiring 101, the data wiring 102, and the thin film transistor Tr of the first substrate 100.

Therefore, in the exemplary embodiment of the present invention, since the non-opening region of the pixel electrode part 110a and the storage electrode part 130 are overlapped, the capacitance can be secured without affecting the aperture ratio.

Example  2

2 is a cross-sectional view illustrating a cross-sectional view of a liquid crystal display according to a second exemplary embodiment of the present invention. The second embodiment of the present invention has the same configuration as the liquid crystal display device of the first embodiment described above except for the protective film. Therefore, redundant description of the same constituent elements will be omitted, and the same names and reference numerals will be given to the same constituent elements.

Referring to FIG. 2, the liquid crystal display includes a first substrate 100, a second substrate 200, and a liquid crystal layer 300 interposed between the first and second substrates 100 and 200. .

The first substrate 100 includes a plurality of pixel regions. The thin film transistor Tr including the gate electrode 112, the semiconductor layer 122, the source electrode 132, and the drain electrode 142 is disposed in the pixel region. In addition, spaced storage electrode units 130 are disposed in the pixel area.

The passivation layer 150b is disposed on the first substrate 100 including the storage electrode units 130 and the thin film transistor Tr. The passivation layer 150b includes a contact hole exposing the drain electrode of the thin film transistor Tr and an opening exposing the gate insulating layer 140 corresponding to the pixel region. The pixel electrode 110 and the common electrode 120 for forming a transverse electric field are disposed in the opening. That is, the pixel electrode 110 and the common electrode 120 are disposed on the gate insulating layer 140.

In this case, the pixel electrode part 110a of the pixel electrode 110 overlaps the storage electrode part 130 with the gate insulating layer 140 interposed therebetween. Accordingly, an insulating film, that is, a gate insulating film 140, is interposed between the pixel electrode part 110a and the storage electrode part 130 to form a charging capacity to minimize the pixel voltage variation of the pixel electrode 110.

Therefore, in the exemplary embodiment of the present invention, the charging capacity may be improved by interposing the gate insulating layer 140 between the pixel electrode part 110a and the storage electrode part 130. This is because the charge capacity is inversely proportional to the thickness of the insulating film interposed between the two electrodes. As a result, the aperture ratio of the completed liquid crystal display device can be ensured, and a further improved charging capacity can be obtained.

Example  3

3A to 3D are plan views illustrating a method of manufacturing a liquid crystal display device according to a third embodiment of the present invention.

4A to 4D are cross-sectional views illustrating a method of manufacturing a liquid crystal display device according to a third embodiment of the present invention.

 3A and 4A, in order to manufacture a liquid crystal display, first, a first substrate 100 in which a pixel region is defined is provided.

A conductive film is formed by depositing a conductive material on the first substrate 100. Thereafter, the conductive film is patterned to form a common wiring 103 in parallel with the gate wiring 101 and the gate wiring 101. Here, the gate electrode 112 branched from the gate wiring 101 may be further formed when the conductive film is patterned. In addition, the first common electrode part 120a connected to the common line 103 and adjacent to the formation area of the data line 102 to be described later may be formed. That is, the first common electrode part 120a is formed at both sides of the pixel area.

In addition, the storage electrode units 130 spaced apart from each other are formed in the pixel region. In this case, the story electrode units 130 are electrically connected to the common wiring 103.

Thereafter, a gate insulating layer 140 is formed on the first substrate 100 including the gate electrode and the storage electrode units 130. In this case, the gate insulating layer 140 may be formed through chemical vapor deposition. The gate insulating layer 140 may be an inorganic insulating layer. For example, the gate insulating layer 140 may be a silicon nitride film, a silicon oxide film, or a stacked film thereof.

3B and 4B, after forming the gate insulating layer 140, the semiconductor layer 122 is formed on the gate insulating layer 140 corresponding to the gate electrode 112. In order to form the semiconductor layer 122, amorphous silicon and amorphous silicon containing impurities are sequentially deposited on the gate insulating layer 140, and then patterned to form the amorphous silicon layer 122a and the doped amorphous silicon layer ( 122b).

After the semiconductor layer 122 is formed, a conductive film is formed on the gate insulating layer 140, and then the conductive film is patterned to form a data wire 102 crossing the gate wiring 101. In this case, a source electrode 132 branched from the data wire 102 and disposed on the semiconductor layer 122 may be formed. In addition, a drain electrode 142 disposed on the semiconductor layer 122 and spaced apart from the source electrode 132 may be further formed. As a result, the thin film transistor Tr may be formed on the first substrate 100.

3C and 4C, after forming the thin film transistor Tr, the passivation layer 150a is formed on the first substrate 100 including the thin film transistor Tr. The passivation layer 150a may be formed through chemical vapor deposition. In this case, the passivation layer 150a may be an inorganic insulating layer. For example, the protective film 150a may be a silicon oxide film, a silicon nitride film, or a stacked film thereof.

Thereafter, a first contact hole C1 partially exposing the drain electrode 142 and a second contact hole C2 exposing the common wiring 103 are formed in the passivation layer 150a.

3D and 4D, after forming the passivation layer 150a including the first and second contact holes C1 and C2, the pixel electrode 110 may be formed on the passivation layer 150a corresponding to the pixel region. The common electrode 120 is formed.

In order to form the pixel electrode 110 and the common electrode 120, a transparent conductive film is formed on the passivation layer 150a, and then the transparent conductive film is patterned. Here, the pixel electrode 110 forms a pixel electrode part 110a having a shape corresponding to the storage electrode part 130 and a connection electrode 110b electrically connecting the pixel electrode part 110a to each other. The connection electrode 110 b is electrically connected to the drain electrode 142 exposed by the first contact hole C1. In this case, the pixel electrode parts 110a and the connection electrode 110b are integrally formed. Thus, the pixel electrode 110 is electrically connected to the thin film transistor Tr.

In addition, the storage electrode 130 and the pixel electrode 110a overlap each other. In this case, in order not to affect the aperture ratio of the completed liquid crystal display, the storage electrode 130 is formed smaller than the width of the pixel electrode 110a.

 The common electrode 120 electrically connects the second common electrode portions 120b and the second common electrode portions 120b, which are alternately disposed with the pixel electrode portions 110a, and the second contact hole C1. To form a third common electrode part 120c electrically connected to the common wiring 103. In this case, the second and third common electrode parts 120b and 120c may be integrally formed.

The pixel electrode 110 and the second and third common electrode parts 120b and 120c may be made of the same conductive material. In this case, in order to secure the aperture ratio of the completed liquid crystal display, the conductive material may be a transparent conductive material. For example, the pixel electrode 110 and the second and third common electrode parts 120b and 120c may be formed of ITO or IZO.

Thereafter, the second substrate 200 may be bonded to face the first substrate 100, and a liquid crystal layer may be formed between the first and second substrates 100 and 200 to manufacture a liquid crystal display device.

Therefore, in the exemplary embodiment of the present invention, by overlapping the non-opening portion of the pixel electrode portion 110a and the storage electrode portion 130, the liquid crystal display device which can secure the aperture ratio and the charging capacity at the same time can be manufactured.

Example  4

5A through 5C are cross-sectional views illustrating a method of manufacturing a liquid crystal display device according to a fourth embodiment of the present invention. The fourth embodiment of the present invention has the same manufacturing method of the liquid crystal display device of the third embodiment described above except for the protective film. Therefore, duplicate description of the same manufacturing method will be omitted, and the same components and the same reference numerals will be given for the same components.

Referring to FIG. 5A, a first substrate 100 in which pixel regions are defined for manufacturing a liquid crystal display is provided. The storage electrode parts 130 spaced apart from each other are formed on the first substrate 100 of the pixel region. In addition, a thin film transistor is formed on the first substrate 100.

Thereafter, the preliminary passivation layer 160 is formed on the first substrate 100 including the storage electrode 130 and the thin film transistor Tr.

Referring to FIG. 5B, after forming the preliminary passivation layer 160, the preliminary passivation layer 160 is patterned to form a first contact hole C1 exposing the drain electrode 142 of the thin film transistor Tr. At the same time, an opening for exposing the gate insulating film corresponding to the pixel region is formed.

Referring to FIG. 5C, the pixel electrode 110 and the second and third common electrode portions 120b and 120c are formed on the gate insulating layer exposed to the opening. As a result, the gate insulating layer 140 is interposed between the pixel electrode unit 110a and the storage electrode unit 130 of the pixel electrode 110.

Therefore, in the embodiment of the present invention, a liquid crystal display device having further improved aperture ratio and filling capacity can be manufactured without adding a separate process.

As described above, the liquid crystal display according to the present invention can simultaneously improve the aperture ratio and the charging capacity of the liquid crystal display by overlapping the non-opening region of the pixel electrode with the storage electrode.

In addition, by forming an opening corresponding to the pixel region in the passivation layer and forming a pixel electrode in the opening, the thickness of the insulating layer interposed between the pixel electrode and the storage electrode can be reduced, thereby further improving the charging capacity.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It can be understood that.

Claims (17)

A first substrate having a pixel region; A gate wiring formed on the first substrate; A common wiring spaced apart from the gate wiring; Storage electrode parts disposed in the pixel area and branched from the common line and spaced apart from each other; An insulating layer disposed on the first substrate to cover the storage electrode portions; A pixel electrode disposed on the insulating layer, the pixel electrode having a connection electrode electrically connected to the thin film transistor, and pixel electrode portions branched from the connection electrode and spaced apart from each other; A common electrode disposed on the insulating layer and having upper common electrode portions alternately disposed with the pixel electrode portions; A second substrate facing the pixel electrode of the first substrate; And And a liquid crystal layer interposed between the first substrate and the second substrate, The storage electrode parts and the pixel electrode parts of the pixel electrode have a shape corresponding to each other and overlap each other. And the storage electrode parts are formed of the same conductive material as the gate electrode of the thin film transistor. delete The method of claim 1, And the width of the storage electrode portion is smaller than the width of the pixel electrode portion. The method of claim 1, The upper common electrode part is formed of a transparent conductive material. delete delete The method of claim 1, And the insulating film includes a gate insulating film interposed between the gate electrode and the semiconductor layer of the thin film transistor. The method of claim 7, wherein The insulating film further comprises a protective film provided on the gate insulating film. The method of claim 1, And the pixel electrode and the common electrode are made of the same conductive material. Providing a first substrate having a pixel region; Forming a gate wiring, a common wiring spaced apart from the gate wiring, and storage electrode portions spaced apart from the common wiring on the first substrate of the pixel region; Forming an insulating layer covering the storage electrode portions on the first substrate; Forming a common electrode having a connecting electrode connected to the thin film transistor, a pixel electrode having pixel electrode portions branched from the connecting electrode, and spaced apart from each other, and upper common electrode portions alternately arranged with the pixel electrode portions; step; Providing a second substrate facing the pixel electrode of the first substrate; And Forming a liquid crystal layer between the first substrate and the second substrate, wherein the storage electrode portions and the pixel electrode portions of the pixel electrode have a shape corresponding to each other and overlap each other; And the storage electrode part is formed at the same time as the gate electrode of the thin film transistor. delete 11. The method of claim 10, The width of the storage electrode portion is smaller than the width of the pixel electrode portion manufacturing method of the liquid crystal display device. 11. The method of claim 10, The upper common electrode part and the pixel electrode part are formed by performing a photo process using the same mask. 11. The method of claim 10, And the storage electrode parts are electrically connected to the upper common electrode parts. 15. The method of claim 14, The forming of the storage electrode parts, wherein the lower common electrode part disposed adjacent to the data line formation area on both sides of the pixel area is integrally formed with the storage electrode parts. The method of claim 1, And the storage electrode parts are electrically connected to the upper common electrode parts. 17. The method of claim 16, And a lower common electrode unit formed integrally with the storage electrode units and disposed adjacent to the data line forming region on both sides of the pixel region.

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