Liquid crystal display comprising a first dummy pattern formed alternately and apart from a second dummy pattern and method of manufacturing the same

This application claims the benefit of Korean Patent Application No. 102071/2005 filed in Korea on Oct. 28, 2005, which is hereby incorporated by reference.

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device conducting two substrates using a conductive thread pattern, and a method of manufacturing the same.

A liquid crystal display device (LCD) is one example of flat display devices. The LCD displays data through physical optics characteristics. Since the LCD has a lower power consumption compared to other display devices, takes advantages of lightweight and thin properties, and can be manufactured in various sizes, it has been widely used in diverse fields.

The LCD includes a thin film transistor (TFT) array substrate, a color filter array substrate, and a liquid crystal. The color filter array substrate is disposed opposite to the TFT array substrate. The liquid crystal is interposed between the TFT array substrate and the color filter array substrate. The TFT array substrate includes a plurality of signal lines, and a pixel electrode connected to the TFT transistor. Additionally, the color filter array substrate includes a color filter layer for color displaying, and common electrodes.

The common electrode disposed on the color filter array substrate is electrically connected to a conductive part, which is disposed on the outside of the TFT array substrate. A common voltage supplied from an external circuit through the conductive part is supplied to the common electrode.

The common electrode is electrically connected to the conductive part through a silver dot medium. The silver dot is manufactured by coating silver in a paste state through a dispenser, drying the resulted silver dot during a predetermined time, and attaching the two substrates by pressure. At this point, in case the two substrates are attached when a silver paste coated on the TFT is not dried completely, the silver of a low density is formed. Therefore, the area contacting the common electrode is reduced and also an appropriate voltage can not be supplied.

To overcome this problem, there is provided an LCD having the conductive part formed through a conductive ball of a high density without the silver paste.

FIGS. 1A and 1B are views of an LCD using a related art conductive thread pattern. FIG. 1A is a plan view when a second substrate of I-I′ portion is removed from the LCD. FIG. 1B is a sectional view taken along line II-II′ of FIG. 1A .

Referring to FIGS. 1A and 1B , the related art LCD includes a first substrate 10 and a second substrate 20 , which are defined by a display region A and a non-display region B. The first substrate 10 and the second substrate 20 are attached by a conductive thread pattern. A plurality of gate lines 40 and data lines 50 are crossing each other on the first substrate 10 corresponding to the display region A. Each crossing of the gate lines 40 and the data lines 50 includes at least one TFT, and a pixel electrode 60 electrically connected to the TFT.

A pad part is formed on the first substrate 100 corresponding to the non-display region B to connect to an external circuit. That is, at least two gate pad parts 70 are formed on one side of the first substrate 10 . The gate pad part 70 includes a predetermined region to which the end of each gate line 40 is gathered. Moreover, at least two data pad parts 80 are formed on another side of the first substrate 10 . The data pad part 60 includes a predetermined region to which the end of each data line is gathered. At this point, each of the pad parts is electrically connected to a printed circuit board (PCB) (not shown) through a tape automated bonding (TAB) 90 .

On the other hand, a conductive part 85 is disposed between the data pad parts 80 , and the conductive thread pattern 30 is disposed on the outside of the first substrate having the conductive part 85 . The conductive pattern 30 includes sealant 30 a and a conductive ball 30 b . The conductive thread pattern 30 attaches the first substrate 10 to the second substrate 20 . Additionally, the conductive thread pattern 30 connects the common electrode 22 in the second substrate 20 , and the conductive part 85 .

Thus, a common voltage is supplied from an external circuit to the conductive part 85 . The common voltage applied to the conductive part 85 is supplied to the common electrode 22 through the conductive thread pattern 30 .

The conductive part 85 includes a dummy pattern 85 a and a dummy pattern contact part 85 b . The dummy pattern 85 a is simultaneously formed when source/drain electrodes 45 a and 45 b of the TFT, and the data line 50 are formed. The dummy pattern contact part 58 b is simultaneously formed on the dummy pattern 85 a when the pixel electrode is formed.

Since the dummy pattern 85 a is simultaneously formed with the data line 50 and the source/drain electrodes 45 a and 45 b , there is no choice for selecting a conductive material of the dummy pattern 85 a . That is, the dummy pattern 85 a may be formed of a low resistance metal to minimize the loss of a common voltage supplied to the common electrode 22 . However, when considering simplicity of processes, the dummy pattern 85 a is formed of a conductive metal of the data line 50 and the source/drain electrodes 45 a and 45 b.

Additionally, when the dummy pattern 85 a , the data line 50 , and data pad 80 are formed on an identical layer, there is limitation in designing the dummy pattern 85 a.

An liquid crystal display (LCD) device includes first and second substrates defined by a display region and a non-display region, and spaced a predetermined interval apart from each other. The LCD further comprises a liquid crystal layer interposed between the first and second substrates, and a conductive part formed on at least one side of the first substrate corresponding to the non-display region. The conductive part has a first dummy pattern formed of metal identical to that of a gate line in the display region. The LCD then comprises a common electrode formed on the second substrate, and a conductive thread pattern that electrically connects the common electrode and the conductive part, and attaches the first and second substrates.

In another aspect of the present invention, an LCD includes a first substrate defined by a display region and a non-display region, a gate electrode disposed on the first substrate corresponding to the display region, and a dummy pattern disposed on the first substrate corresponding to the non-display region and formed on a layer identical to that of the gate electrode. The LCD further comprises a gate insulating layer formed on a surface of the first substrate that has the gate electrode and the first dummy pattern, source and drain electrodes formed spaced apart from each other on both sides of an active layer on the gate insulating layer corresponding to the gate electrode, and a pixel electrode electrically connected to the drain electrode.

In a further aspect of the present invention, an LCD includes a first substrate defined by a display region and a non-display region, a gate electrode disposed on the first substrate corresponding to the display region, and a dummy pattern disposed on the first substrate corresponding to the non-display region. The LCD further comprises a gate insulating layer formed on a surface of the first substrate that has the gate electrode and the first dummy pattern, source and drain electrodes formed spaced apart from each other on both sides of an active layer on the gate insulating layer corresponding to the gate electrode, a second dummy pattern disposed on the gate insulating layer corresponding to the non-display region, and a pixel electrode electrically connected to the drain electrode.

In still another aspect of the present invention, a method of manufacturing an LCD includes depositing a first conductive material on a first substrate, forming a gate electrode and a first dummy pattern through a patterning process on the first substrate, forming a gate insulating layer on a surface of the first substrate that includes the gate electrode and the first dummy pattern, and forming an active layer, and source and drain electrodes on the gate insulating layer. The method of manufacturing an LCD further comprises forming a protective layer on the surface of the first substrate that includes the active layer and the source and drain electrodes, forming first and second contact holes in the protective layer to expose the drain electrode and the first dummy pattern, and forming a pixel electrode connected to the drain electrode through the first contact hole.

In yet another aspect of the present invention, a method of manufacturing an LCD includes depositing a first conductive material on a first substrate, forming a gate electrode and a first dummy pattern through a patterning process on the first substrate, forming a gate insulating layer in a surface of the first substrate that includes the gate electrode and the first dummy pattern, and forming an active layer, source and drain electrodes, and a second dummy pattern on the gate insulating layer. The method of manufacturing an LCD further comprises forming a protective layer on the surface of the first substrate that includes the active layer, the source and drain electrodes, and the second dummy pattern, forming first and second contact holes in the protective layer to expose the drain electrode and the first dummy pattern, and forming a pixel electrode connected to the drain electrode through the first contact hole.

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIGS. 1A and 1B are views of an LCD using a related art conductive thread pattern;

FIGS. 2A-2C are views of an LCD according to an embodiment of the present invention;

FIG. 3 is a sectional view taken along line III-III′ of FIG. 2A ;

FIGS. 4A to 4E are views taken along line III-III′ of FIG. 2A to illustrate a method of manufacturing an LCD according to an embodiment of the present invention;

FIG. 5 is another sectional view taken along line III-III′ of FIG. 2A ; and

FIGS. 6A to 6E are views taken along line III-III′ of FIG. 2A to illustrate another method of manufacturing an LCD according to an embodiment of the present invention.

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

FIGS. 2A to 2C are views of an LCD according to an embodiment of the present invention. FIG. 2A is a plan view when I-I′ portion of a second substrate is removed from the LCD. FIGS. 2B and 2C are views of a conductive part 850 of FIG. 2A .

Referring to FIG. 2A , the LCD is defined by a display region A and a non-display region B. The LCD includes first and second substrates 100 and 200 with a predetermined cell gap therebetween, and a liquid crystal layer (not shown) interposed between the first and second substrates 100 and 200 .

A plurality of gate lines 400 and data lines 500 are crossed to define a plurality of unit pixels in the first substrate 100 corresponding to the display region A. Each of the unit pixels includes at least one thin film transistor (TFT), and a pixel electrode driven by the TFT. In one side of the first substrate 100 corresponding to the non-display region B, a gate pad part 700 is disposed on the ends of the gate lines 400 for connecting an external circuit part. In another side of the first substrate 100 , a data pad part 800 is disposed on the ends of the data lines 500 for connecting the external circuit part. Here, each pad part is connected to the external circuit part through a tape automated bonding (TAB) 900 using a tape carrier package (TCP) with a driving IC. Additionally, the second substrate 200 includes a color filter layer for displaying colors in a region corresponding to each unit pixel, and a common electrode on the color filter layer.

The first and second substrates 100 and 200 are attached to each other through a conductive thread pattern 300 in the outside of the first and second substrates 100 and 200 . The conductive thread pattern 300 attaches the first substrate 100 to the second substrates 200 , and also electrically connects the first substrate 100 and a predetermined portion of the second substrate 200 . The first substrate 100 includes a conductive part 850 disposed on a predetermined portion corresponding to the non-display region B. The conductive thread pattern 300 is formed on the conductive part 850 . Thus, the conductive part 850 receives a common voltage applied from the outside, and supplies the common voltage to the common electrode of the second substrate 200 through the conductive thread pattern 300 .

Referring to FIG. 2B , the conductive part 850 includes the data pad part 800 and a first dummy pattern 850 a on and between the data pad parts 800 . The first dummy pattern 850 a may be formed of metal identical to that of the gate line 400 of FIG. 2A . Here, since the gate line 400 and gate electrode are generally formed of metal of a low resistance, the first dummy pattern 850 a can be formed of metal of a low resistance. For example, the first dummy pattern 850 a can be formed of at least one selected from the group comprising of Ta, Al, Ti, Ni, and AlNd.

Furthermore, referring to FIG. 2C , the conductive part 850 further includes the second dummy pattern 850 c , which is alternately disposed with the first dummy pattern 850 a . The second dummy pattern 850 c is not directly connected to the conductive thread pattern 300 and serves to compensate an irregular cell gap generated from a step height between the dummy pattern 850 a and the data pad part. Additionally, the second dummy pattern 850 c may be formed of metal identical to that of the data line. Thus, a picture quality deterioration, which is generated by an irregular cell gap, can be reduced.

Referring to FIG. 2A , the conductive thread pattern 300 includes sealant and a conductive ball. The conductive ball can be formed of at least one selected from the group comprising of Ag, Au, Pb—Ag, and Pb—Sn. The conductive ball in the conductive thread pattern 300 serves to electrically connect the conductive part and the common electrode.

Therefore, when the conductive part 850 is formed of a low resistance metal identical to that of the gate line 400 and the gate electrode, a common voltage from the outside can be effectively supplied to the common electrode without loss.

The LCD of the present invention and a method of manufacturing the same will be described in more detail with reference to sectional views taken along line III-III′ of FIG. 2A .

FIG. 3 is a sectional view taken along line III-III′ of FIG. 2A .

Referring to FIG. 3 , a first substrate 100 is defined by a display region A and a non-display region B.

A plurality of gate lines 400 of FIG. 2A and gate electrodes 410 are disposed on the first substrate 100 corresponding to the display region A. An extension line 520 of the gate line is disposed on the first substrate 100 corresponding to the non-display region B. A dummy pattern 850 a is disposed on a gate pad electrode (not shown) at the end of the gate line, and on another side having the gate pad electrode.

The first dummy pattern 850 a may be formed of metal of a low resistance. For example, the first dummy pattern 850 a can be formed of at least one selected from the group comprising of Ta, Al, Ti, Ni, and AlNd.

Since the gate electrode 410 is generally formed of a low resistance metal, the first dummy pattern 850 a can be formed of a conductive material identical to that of the gate electrode 410 . Thus, an additional process is unnecessary to form the first dummy pattern 850 a.

A gate insulating layer 110 is disposed on the first substrate 100 having the gate electrode 410 and the first dummy pattern 850 a.

An active layer 430 is formed on the gate insulating layer 110 corresponding to the gate electrode 410 , and source/drain electrodes 450 a and 450 b are spaced apart from each other on both sides of the active layer 430 . Additionally, an extension line 520 of the data line is disposed on the gate insulating layer 110 corresponding to the non-display region B. A data pad electrode (not shown) is disposed at the end of the extension line 520 of the data line.

A protective layer 120 is disposed on the gate insulating layer 110 having the source/drain electrodes 450 a and 450 b . The protective layer 120 includes a first contact hole P 1 exposing a portion of the drain electrode 450 b , and a second contact hole P 2 exposing a portion of the first dummy pattern 850 a.

A pixel electrode 600 is electrically connected to the drain electrode 450 b through the fist contact hole P 1 , and a first dummy pattern contact part 850 b is electrically connected to the first dummy pattern 850 a through the second contact hole P 2 .

The pixel electrode 600 can be formed of a conductive material identical to that of the fist dummy pattern contact part 850 b . Furthermore, the first dummy pattern contact part 850 b can be formed of indium-tin oxide (ITO) or indium-zinc oxide (IZO). Here, the first dummy pattern contact part 850 b can serve to prevent a corrosion of the first dummy pattern 850 a.

A first alignment layer (not shown) for an initial alignment of liquid crystal is disposed on the protective layer 120 of the display region A having the pixel electrode 600 .

On the other hand, a second substrate 200 is spaced a predetermined interval apart from the first substrate 100 . The second substrate 200 includes a color filter layer 210 in a region corresponding to each unit pixel of the first substrate 100 , and a common electrode 220 on the first substrate 100 having the color filter layer 210 . The common electrode 220 may be formed of a transparent conductive material such as ITO and IZO.

Additionally, a conductive thread pattern 300 is disposed on the outside of the first substrate 100 and the second substrate 200 . The conductive thread pattern 300 is disposed on the first dummy pattern 850 a of the first substrate 100 . The first dummy pattern 850 a is electrically connected to the common electrode 220 through the conductive thread pattern 300 . The conductive thread pattern 300 can include sealant 300 a and a conductive ball 300 b . The conductive ball 300 b can be formed of at least one selected from the group comprising of Ag, Au, Pb—Ag, and Pb—Sn. Thus, the first dummy pattern 850 a is electrically connected to the common electrode 220 through the conductive ball 300 b in the conductive thread pattern 300 .

Furthermore, the first dummy pattern 850 a is formed on the data pad part and between the data pad parts. Since the first dummy pattern 850 a is formed on the data pad part or a protective layer 120 on the extension line 520 of the data line, it does not contact the data pad part or the protective layer 120 . The first dummy pattern 850 a can be formed to be overlapped with the extension line 520 of the data line or the data pad part. Thus, when the first dummy pattern 850 a is formed, it can be designed without considering the data pad part or the extension line 520 of the data line.

The protective layer 120 may be formed of an insulation layer of a low dielectric constant. This can prevent a parasite capacity generated from overlapping the first dummy pattern 850 a with the data pad part or the extension line 520 of the data line.

When the first and second substrates 100 and 200 are conducted through the conductive ball 300 b , the first dummy pattern 850 a can be formed with a more enlarged size compared to a related art by forming the first dummy pattern 850 a on a layer identical to that of the gate electrode 410 and the gate line. The first dummy pattern 850 a supplies a common voltage to the second substrate 200 . Additionally, the first dummy pattern 850 a can be formed of a low resistance metal, and thus more efficiently supplies the common voltage to the common electrode 220 .

FIGS. 4A to 4E are views taken along line III-III′ of FIG. 2A to illustrate a method of manufacturing an LCD according to an embodiment of the present invention.

Referring to FIG. 4A , a first substrate 100 is defined by a display region A and a non-display region B. Here, the first substrate 100 can be formed of glass or plastic.

A first conductive material is deposited on the first substrate 100 . The first conductive material can be a low resistance metal. The first conductive material can be formed of at least one selected from the group comprising of Ta, Al, Ti, Ni, and AlNd.

Next, a plurality of gate lines and a gate electrode 410 protruded toward a direction different from that of the gate line are formed by patterning the first conductive material. Additionally, an extension line of the gate line, and a gate pad electrode and a first dummy pattern 850 a disposed at the end of the extension line of the gate line are formed on a region corresponding to the non-display region B.

Next, a gate insulating layer 110 is formed on an entire surface of the first substrate 100 having the gate electrode 410 and the first dummy pattern 850 a . The gate insulating layer 110 can be formed by depositing silicon nitride or silicon oxide through a chemical vapor deposition (CVD) process.

Referring to FIG. 4B , an amorphous silicon and an amorphous silicon doped with impurity are sequentially deposited on the gate insulating layer 110 . Then, an active layer 430 is formed on a region corresponding to the gate electrode 410 by patterning the amorphous silicon layer and the amorphous silicon layer doped with impurity.

Next, a second conductive material is deposited on the gate insulating layer 110 having the active layer 430 , and then patterned. Then, source/drain electrodes 450 a and 450 b are formed spaced apart from each other on the both sides of the active layer 430 . Each data line is formed to be crossed with the gate line. At this point, a unit pixel is defined in the display region A through the gate line and the data line. On the other hand, an extension line 520 of the data line, and a data pad electrode at the end of the extension line 520 of the data line are formed on the gate insulating layer 110 corresponding to the non-display region B.

The active layer 430 and the source/drain electrodes 450 a and 450 b are formed using another mask process, but the present invention is not limited to this. Thus, the active layer 430 and the source/drain electrodes 450 a and 450 b can be formed using an identical mask process. An amorphous silicon layer and an amorphous silicon layer doped with impurity can be disposed on the bottom of the data line and the data pad electrode.

Next, a protective layer 120 is formed on the gate insulating layer 110 having the source/drain electrodes 450 a and 450 b . The protective layer 120 can be formed of silicon oxide or silicon nitride using a CVD process. The protective layer 120 may be formed of benzo-cyclo-butene (BCB) of a low dielectric constant. This allows the protective layer 120 to be interposed between the first dummy pattern 850 a and the extension line 520 of the data line or the data pad part. When the first dummy pattern 850 a is designed with a more enlarged size, the first dummy pattern 850 a can be formed to be overlapped with the extension line 520 of the data line or the data pad part. However, since a parasite capacity can be generated in a region where the first dummy pattern 850 a is overlapped with the extension line 520 of the data line or the data pad part, the protective layer 120 may be formed of an insulation layer of a low dielectric constant.

Referring to FIG. 4C , a first contact hole P 1 is formed on the protective layer 120 to expose a portion of the drain electrode 450 b . At this point, a second contact hole P 2 may be simultaneously formed to expose a portion of the first dummy pattern 850 a . The second contact hole P 2 can be formed by etching the protective layer 120 and the gate insulating layer 100 collectively.

Referring to FIG. 4D , a transparent conductive material is deposited on the protective layer 120 , and then patterned. Thus, a pixel electrode 600 connected electrically to the drain electrode 450 b is formed through the first contact hole P 1 . The transparent conductive material can be ITO or IZO. On the other hand, the first dummy pattern contact part 850 b is simultaneously formed, which is electrically connected to the first dummy pattern 850 a exposed through the second contact hole P 2 . Since the outside of the first dummy pattern 850 a can be prevented from corroding, reliability of the LCD can be achieved. A first alignment layer (not shown) can be further formed on the pixel electrode 600 .

Referring to FIG. 4E , a conductive thread pattern 300 having sealant 300 a and a conductive ball 300 b is formed on the first substrate 100 having the first dummy pattern 850 a . The conductive ball can be formed of at least one selected from the group comprising of Ag, Au, Pb—Ag, and Pb—Sn. Additionally, the conductive thread pattern 300 can be formed on a second substrate.

Next, the second substrate 200 is disposed on the first substrate 100 . The first and second substrates 100 and 200 are coupled by pressure. Here, the second substrate 200 includes a color filter layer 210 and a common electrode 220 on a region corresponding to a unit pixel of the first substrate 100 . Additionally, an alignment layer (not shown) can be further formed on the common electrode 220 .

The first and second substrates 100 and 200 are coupled together through the conductive thread pattern 300 . The first dummy pattern 850 a of the first substrate 100 is electrically connected to the common electrode 220 of the second substrate 200 .

Therefore, a common voltage supplied to the first dummy pattern 300 is supplied to the common electrode 220 through the conductive ball 300 b of the conductive thread pattern 300 .

FIG. 5 is another sectional view taken along line III-III′ of FIG. 2A .

Here, except for adding a second dummy pattern 850 c , like reference numerals in the drawings denote like elements.

Referring to FIG. 5 , a first substrate 100 is defined by a display region A and a non-display region B. A plurality of gate lines and gate electrodes 410 are disposed on the first substrate 100 corresponding to the display region A. An extension line 520 of the gate line is disposed on the first substrate 100 corresponding to the non-display region B. A dummy pattern 850 a is disposed on a gate pad electrode (not shown) at the end of the gate line, and on another side having the gate pad electrode. The first dummy pattern 850 a may be formed of metal of a low resistance. For example, the first dummy pattern 850 a can be formed of at least one selected from the group comprising of Ta, Al, Ti, Ni, and AlNd.

Since the gate electrode 410 is formed of a low resistance metal, the first dummy pattern 850 a can be formed of a conductive material identical to that of the gate electrode 410 . Thus, an additional process is unnecessary to form the first dummy pattern 850 a.

A gate insulating layer 110 is disposed on the first substrate 100 having the gate electrode 410 and the first dummy pattern 850 a.

An active layer 430 is formed on the gate insulating layer 110 corresponding to the gate electrode 410 , and source/drain electrodes 450 a and 450 b are spaced apart from each other on both sides of the active layer 430 . Additionally, a second dummy pattern 850 c is disposed on the gate insulating layer 110 corresponding to the non-display region B.

The second dummy pattern 850 c and the first dummy pattern 850 a are disposed alternately. Since a step height between the first dummy pattern 850 a and the extension line of the data line or the data pad part can be overcome, a picture quality deterioration, which is generated by an irregular cell gap, can be reduced.

A protective layer 120 is disposed on the gate insulating layer 110 having the source/drain electrodes 450 a and 450 b . The protective layer 120 includes a first contact hole P 1 exposing a portion of the drain electrode 450 b , and a second contact hole P 2 exposing a portion of the first dummy pattern 850 a.

A pixel electrode 600 is disposed and electrically connected to the drain electrode 450 b through the fist contact hole P 1 . A first dummy pattern contact part 850 b is disposed and electrically connected to the first dummy pattern 850 a through the second contact hole P 2 . Here, the area where the first dummy pattern contact part 850 b contacts a conductive thread pattern 300 increases through the second dummy pattern 850 c . Thus, a common voltage can be easily supplied to a common electrode in the second substrate 200 . Additionally, since the area contacting the conductive thresh pattern increases, an adhesive strength between the first substrate 100 and the second substrate 200 can be improved.

The pixel electrode 600 can be formed of a conductive material identical to that of the fist dummy pattern contact part 850 b . Furthermore, the first dummy pattern contact part 850 b can be formed of ITO or IZO. Here, the first dummy pattern contact part 850 b can serve to reduce a corrosion of the first dummy pattern 850 a.

A first alignment layer (not shown) for an initial alignment of liquid crystal is disposed on the protective layer 120 of the display region A having the pixel electrode 600 .

On the other hand, a second substrate 200 is spaced a predetermined interval apart from the first substrate 100 . The second substrate 200 includes a color filter layer 210 in a region corresponding to each unit pixel of the first substrate 100 , and a common electrode 220 on the first substrate 100 having the color filter layer 210 . The common electrode 200 may be formed of a transparent conductive material such as ITO and IZO.

Additionally, a conductive thread pattern 300 is disposed on the outside of the first substrate 100 and the second substrate 200 . The conductive thread pattern 300 is disposed on the first dummy pattern 850 a and the second dummy pattern 850 b of the first substrate 100 . The first dummy pattern 850 a is electrically connected to the common electrode 220 through the conductive thread pattern 300 . The conductive thread pattern 300 can include sealant 300 a and a conductive ball 300 b . The conductive ball 300 b can be formed of at least one selected from the group comprising of Ag, Au, Pb—Ag, and Pb—Sn. Thus, the first dummy pattern 850 a is electrically connected to the common electrode 220 through the conductive ball 300 b in the conductive thread pattern 300 . Additionally, the second dummy pattern 850 c serves to overcome a step height between the extension line 520 of the data line or the data pad part, and also increase the area contacting the conductive thread pattern 300 . Thus, an adhesive strength and a voltage mobility can be improved.

As described above, since the first dummy pattern 850 a is formed on the data pad part, and between the data pad parts, it is formed on the protective layer 120 on the data pad part or the extension line 520 of the data line. Thus, when the first dummy pattern 850 a is formed, it can be designed without considering the data pad part or the extension line 520 of the data line. Additionally, when the first and second substrates 100 and 200 are conducted through the conductive ball 300 b , the first dummy pattern 850 a is formed on a layer identical to that of the gate electrode 410 . The first dummy pattern 850 a is a conductive part for supplying a common voltage to the second substrate 200 . Thus, the first dummy pattern 850 a can be formed with a more enlarged size compared to a related art. Additionally, since the first dummy pattern 850 a can be formed of a low resistance metal, a common voltage can be more efficiently supplied to the common electrode 220 .

FIGS. 6A to 6E are views taken along line III-III′ of FIG. 2A to illustrate another method of manufacturing an LCD according to an embodiment of the present invention. Except for the additional second dummy pattern 850 c , like reference numerals in the drawings denote like elements.

Referring to FIG. 6A , a first substrate 100 is defined by a display region A and a non-display region B. Here, the first substrate 100 can be formed of glass or plastic.

A first conductive material is deposited on the first substrate 100 . The first conductive material can be a low resistance metal. The first conductive material can be formed of at least one selected from the group comprising of Ta, Al, Ti, Ni, and AlNd.

Next, a plurality of gate lines, and a gate electrode 410 protruded toward a direction different from that of the gate line are formed by patterning the first conductive material. Additionally, an extension line of the gate line, and a gate pad electrode and a first dummy pattern 850 a disposed on the end of the extension line of the gate line are formed on a region corresponding to the display region B.

Next, a gate insulating layer 110 is formed on an entire surface of the first substrate having the gate electrode 410 and the first dummy pattern 850 a . The gate insulating layer 110 can be formed by depositing silicon nitride or silicon oxide through the CVD process.

Referring to FIG. 6B , an amorphous silicon and an amorphous silicon doped with impurity are sequentially deposited on the gate insulating layer 110 . Then, an active layer 430 is formed on a region corresponding to the gate electrode 410 by patterning the amorphous silicon layer and the amorphous silicon layer doped with impurity.

Next, a second conductive material is deposited on the gate insulating layer 110 having the active layer 430 , and then patterned. Then, source/drain electrodes 450 a and 450 b are formed spaced apart from each other on the both sides of the active layer 430 . Each data line is formed to be crossed with the gate line. At this point, a plurality of unit pixels is defined in the display region A by the gate lines and the data lines. On the other hand, an extension line 520 of the data line, and a data pad electrode and the second dummy pattern 850 c at the end of the extension line 520 of the data line are formed on the gate insulating layer 110 corresponding to the non-display region B. At this point, the second dummy pattern 850 c and the first dummy pattern 850 a are formed to be disposed alternately.

Here, the active layer 430 and the source/drain electrodes 450 a and 450 b are formed using another mask process, but the present invention is not limited thereto. Thus, the active layer 430 and the source/drain electrodes 450 a and 450 b can be formed using an identical mask process. An amorphous silicon layer and an amorphous silicon layer doped with impurity can be disposed on the bottom of the data line and the data pad electrode.

Next, a protective layer 120 is formed on the gate insulating layer 110 having the source/drain electrodes 450 a and 450 b . The protective layer 120 can be formed of silicon oxide or silicon nitride using a CVD process. The protective layer 120 may be formed of benzo-cyclo-butene (BCB) of a low dielectric constant. A parasite capacity can be generated in a region where the first dummy pattern 850 a is overlapped with the extension line 520 of the data line or the data pad part.

Referring to FIG. 6C , a first contact hole P 1 is formed on the protective layer 120 to expose a portion of the drain electrode 450 b . At this point, a second contact hole P 2 may be simultaneously formed to expose a portion of the first dummy pattern 850 a . The second contact hole P 2 can be formed by etching the protective layer 120 and the gate insulating layer 110 collectively.

Referring to FIG. 6D , a transparent conductive material is deposited on the protective layer 120 , and then patterned. Thus, a pixel electrode 600 connected electrically to the drain electrode 450 b is formed through the first contact hole P 1 . The transparent conductive material can be ITO or IZO. On the other hand, the first dummy pattern contact part 850 b is simultaneously formed, which is electrically connected to the first dummy pattern 850 a exposed through the second contact hole P 2 . Since the outside of the first dummy pattern 850 a can be prevented from corroding, reliability of the LCD can be achieved. A first alignment layer (not shown) can be further formed on the pixel electrode 600 .

Referring to FIG. 6E , a conductive thread pattern 300 having sealant 300 a and a conductive ball 300 b is formed on the first substrate 100 having the first dummy pattern 850 a . The conductive ball can be formed of at least one selected from the group comprising of Ag, Au, Pb—Ag, and Pb—Sn.

Next, the second substrate 200 is disposed on the first substrate 100 . The first and second substrates 100 and 200 are coupled by pressure. Here, the second substrate includes a color filter layer 210 and a common electrode 220 on a region corresponding to a unit pixel of the first substrate 100 . Additionally, a second alignment layer (not shown) can be further formed on the common electrode 220 .

The first and second substrates 100 and 200 are coupled together by the conductive thread pattern 300 . The first dummy pattern 850 a of the first substrate 100 is electrically connected to the common electrode 220 of the second substrate 200 .

Therefore, a common voltage supplied to the first dummy pattern 300 is supplied to the common electrode 220 through the conductive ball 300 b of the conductive thread pattern 300 .

According to the present invention, since the first substrate is conducted to the second substrate through the conductive thread pattern having a high-density conductive ball, the LCD with an improved conductivity can be manufactured.

Additionally, since the first dummy pattern, which is the conductive part of the first substrate, can be formed using a low resistance gate metal, a common voltage supplied from the external circuit part can be efficiently supplied to the common electrode of the second substrate.

Additionally, since the first dummy pattern, which is a conductive part of the first substrate, can be designed to be overlapped with the extension line of the data line or the data pad electrode, the design margin area of the first dummy pattern can be enlarged.

Moreover, since the first dummy pattern and the second dummy pattern are disposed alternately to overcome a step height between the first dummy pattern and the data pad, an irregular cell gap between the first and second substrates can be prevented.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.