Patent Publication Number: US-10310345-B2

Title: In-cell touch liquid crystal display apparatus, method of manufacturing the same, method of manufacturing thin film transistor array substrate, and method of manufacturing color filter array substrate

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Divisional Application of U.S. patent application Ser. No. 14/885,767 filed on Oct. 16, 2015, which claims priority under 35 U.S.C. § 119(a) of Republic of Korea Patent Application No. 10-2014-0150667 filed on Oct. 31, 2014, all of which are hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Field of the Invention 
     The disclosed embodiments relate to an in-cell touch liquid crystal display (LCD) device based on a twisted nematic (TN) mode, a method of manufacturing the same, a method of manufacturing a thin film transistor (TFT) array substrate, and a method of manufacturing a color filter array substrate. 
     Discussion of the Related Art 
     As portable electronic devices (e.g., mobile phones, tablet personal computers (PCs), notebook computers) and display devices (e.g., monitors, televisions (TVs)) advance, the demand for applicable flat panel display (FPD) devices is increasing. 
     FPD devices include liquid crystal display (LCD) devices, plasma display panels (PDPs), field emission display (FED) devices, and organic light emitting display devices, for example. 
     Among FPD devices, LCD devices are increasing in popularity because the LCD devices are easily manufactured due to the advance of manufacturing technology and because LCD devices have an easily-driven driver, low power consumption, high image quality, and a large screen. 
       FIG. 1  is a diagram schematically illustrating a related art LCD device based on a twisted nematic (TN) mode. In  FIG. 1 , a backlight unit and a driving circuit unit are not illustrated. 
     Referring to  FIG. 1 , the related art LCD device based on the TN mode includes a thin film transistor (TFT) array substrate  10 , a color filter array substrate  20 , and a TN liquid crystal layer  30  disposed between the TFT array substrate  10  and the color filter array substrate  20 . 
     The TFT array substrate  10  includes a TFT and a pixel  18 , which are disposed over a first glass substrate  11 . The TFT includes a gate electrode  12 , a gate insulation layer  13 , an active layer  14 , a source electrode  15 , and a drain electrode  16 . The pixel electrode  18  is electrically connected to the drain electrode  16  and is disposed on a passivation layer  17 . 
     The color filter array substrate  20  includes a second glass substrate  21 , a light shield layer (a black matrix)  22  defining a pixel area, red, green, and blue color filters  23 , an overcoat layer  24 , a common electrode  25 , and a color spacer  26 . 
     The color spacer  26  is formed on the common electrode  25  to protrude toward the TFT array substrate  10  and contacts an upper surface of the TFT. A cell gap between the TFT array substrate  10  and the color filter array substrate  20  is formed by the color spacer  26 . The liquid crystal layer  30  is disposed between the TFT array substrate  10  and the color filter array substrate  20 , and the TFT array substrate  10  is bonded to the color filter array substrate  20 . 
     Instead of using an input device such as a mouse, a keyboard, a keypad, or the like that is conventionally used with an LCD device or a portable electronic device, display devices may include a touch screen that enables a user to directly input information to the screen with a finger, pen, or other utensil. 
     A touch screen is applied to monitors of devices such as navigation devices, industrial terminals, notebook computers, automated teller machines (ATMs), game machines, portable devices (e.g., portable phones, MP3 players, personal digital assistants (PDAs), portable media players (PMPs), programmable signal processors (PSPs), portable game machines, digital media broadcasting (DMB) receivers, and tablet personal computers (PCs)), and home appliances (e.g., refrigerators, microwave ovens, and washing machines). Since all users can easily manipulate the touch screen, touch screens are increasing in popularity. 
     A touch screen may be classified based on the structure where the touch screen is coupled to a liquid crystal panel. The touch screen may an in-cell touch type in which the touch screen is built in a cell of a liquid crystal panel, an on-cell touch type in which the touch screen is disposed on a cell of a liquid crystal panel, an add-on type in which the touch screen is coupled to an outer portion of a display panel, or a one glass solution type in which a touch sensor is disposed on a window glass (or a cover glass) of a display device. Recently, because of its superior aesthetic appearance and reduced thickness, the in-cell touch type touch screen is increasing in popularity. 
     The in-cell touch type touch screen is used in LCD devices in an in-plane switching (IPS) mode or a fringe field switching (FFS) mode. However, there are many limitations in applying the in-cell touch type to LCD devices based on the TN mode. 
     Since the related art LCD device based on the TN mode has a structure where a common electrode is spread all over a color filter array substrate, it is difficult to apply the in-cell touch type to the LCD device based on the TN mode. LCD devices using TN mode are typically notebook PCs and PC monitors, but an in-cell touch LCD device based on the TN mode has not been developed. 
     SUMMARY 
     Accordingly, the disclosed embodiments describe an in-cell touch liquid crystal display (LCD) device based on a twisted nematic (TN) mode, a method of manufacturing the same, a method of manufacturing a thin film transistor (TFT) array substrate, and a method of manufacturing a color filter array substrate that substantially obviate one or more problems due to limitations and disadvantages of the related art. 
     The disclosed embodiments include an in-cell touch LCD device based on a TN mode. 
     The disclosed embodiments include a TFT array substrate configuring an in-cell touch LCD device based on a TN mode and a method of manufacturing the same. 
     The disclosed embodiments include a color filter array substrate configuring an in-cell touch LCD device based on a TN mode and a method of manufacturing the same. 
     Additional advantages and features of the invention will be set forth in part in the description which follows, in part will become apparent to those having ordinary skill in the art upon examination of the following, and may be learned in part from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these and other advantages, as embodied and broadly described herein, an in-cell touch liquid crystal display (LCD) device includes: a thin film transistor (TFT) array substrate including a gate line and a data line that intersect each other to define a pixel area on a first glass substrate, a TFT disposed in the pixel area, a conductive line disposed on the TFT, and a transparent conductive layer disposed above the conductive line and in electrical contact with the conductive line; a color filter array substrate including: a light shield layer and a color filter disposed on a second glass substrate, an overcoat layer covering the light shield layer and the color filter, a column spacer disposed on the overcoat layer to horizontally overlap with the light shield layer, and a common electrode disposed on the overcoat layer and the column spacer, the conductive line configured to supply the common electrode with a common voltage or a touch driving signal through the transparent conductive layer in electrical contact with the common electrode; and a liquid crystal layer disposed between the TFT array substrate and the color filter array substrate. 
     In another aspect, a method of manufacturing a thin film transistor (TFT) array substrate includes: forming a data line and a TFT on a first glass substrate; forming a first passivation layer to cover the TFT; forming a conductive line above the first passivation layer in a region horizontally overlapping with the data line; forming a second passivation layer on the conductive line; forming a pixel electrode above the first passivation layer and in electrical contact with the TFT; and forming a transparent conductive layer on the conductive line and in electrical contact with the conductive line. 
     In another aspect, a method of manufacturing a color filter array substrate includes: forming a light shield layer and a color filter on a second glass substrate; forming an overcoat layer to cover the light shield layer and the color filter; forming a column spacer on the overcoat layer to horizontally overlap with the light shield layer; forming a common electrode on the overcoat layer and the column spacer; and patterning the common electrode as a plurality of blocks to form a plurality of touch electrodes. 
     In another aspect, a method of manufacturing an in-cell touch liquid crystal display device includes: providing a liquid crystal layer between the TFT array substrate and the color filter array substrate; and bonding the thin film transistor array substrate to the color filter array substrate to bring the conductive line formed on the TFT array substrate into electrical contact with the touch electrode formed on the color filter array substrate. 
     It is to be understood that both the foregoing general description and the following detailed description provide examples embodiments that are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the disclosed embodiments and are incorporated in and constitute a part of this application, illustrate the disclosed embodiments and together with the description serve to explain the principles of the disclosed embodiments. In the drawings: 
         FIG. 1  is a diagram schematically illustrating a related art LCD device based on a TN mode; 
         FIG. 2  is a diagram illustrating an in-cell touch LCD device according to an embodiment; 
         FIG. 3  is a diagram illustrating a touch electrode provided by patterning a common electrode of a color filter array substrate according to an embodiment; 
         FIG. 4  is a diagram illustrating a plan layout of a TFT array substrate according to an embodiment; 
         FIG. 5  is a cross-sectional view illustrating a cross-sectional structure of a liquid crystal panel configured as an in-cell touch LCD device according to an embodiment and illustrates a view of a TFT array substrate and a color filter array substrate along path A 1 -A 2  of  FIG. 4 ; 
         FIG. 6  is a table describing six masks used to manufacture a TFT array substrate and a layer formed by a mask process corresponding to each mask according to an embodiment; 
         FIGS. 7 to 12  are diagrams illustrating a method of manufacturing a TFT array substrate according to an embodiment; 
         FIG. 13  is a table describing six masks used to manufacture a color filter array substrate according to an embodiment and a layer formed by a mask process corresponding to each mask; 
         FIGS. 14 to 19  are diagrams illustrating a method of manufacturing a color filter array substrate according to an embodiment; and 
         FIG. 20  is a diagram illustrating that a conductive line is electrically connected to a touch electrode by bonding a TFT array substrate to a color filter array substrate according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the example embodiments that 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. 
     Advantages and features of the present invention, and implementation methods thereof will be clarified through the following embodiments described with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough, and will fully convey the scope of the present invention to those skilled in the art. Furthermore, the present invention is defined by the scope of the claims. 
     Any shape, size, ratio, angle, or number disclosed in the drawings for describing an embodiment is merely an example, and thus, the present invention is not limited to the illustrated details. Like reference numerals refer to like elements throughout. In the following description, when the detailed description of the relevant known function or configuration unnecessarily obscures the features of the disclosed embodiment, such detailed description is omitted. Where the present specification uses “comprise,” “have,” or “include,” another part may be added unless “only” is used. A reference to an element in singular form includes a plurality of that element unless otherwise stated. 
     In construing an element, the element should be construed as including an error range even when there is no explicit description of an error range. 
     In describing a positional relationship, for example, when a positional relation between two parts is described as “on,” “over,” “under,” or “next to,” one or more other parts may be disposed between the two parts unless “just” or “directly” is used. 
     In describing a time relationship, for example, when the temporal order of a step is described as “after,” “subsequent,” “next,” or “before,” another step, one or more further steps may be included between the step and the other step unless “just” or “direct” is used. 
     The term “at least one” should be understood as including any and all combinations of one or more of the associated listed items. For example, the meaning of “at least one of a first item, a second item, and a third item” denotes any combination or subset of the items, such as two or more of the first item, the second item, and the third item as well as the first item, the second item, or the third item. 
     It will be understood that, although the terms “first,” “second,” and other ordinal terms may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. 
     Features of various embodiments may be partially or completely coupled to or combined with each other, and may be variously inter-operated with each other and driven technically as those skilled in the art may understand. The embodiments of the present invention may be carried out independently from each other, or may be carried out together in co-dependent relationship. 
     Before providing a detailed description with reference to the drawings, LCD devices have been variously developed in a twisted nematic (TN) mode, a vertical alignment (VA) mode, an in-plane switching (IPS) mode, and a fringe field switching (FFS) mode according to a scheme of adjusting the alignment of liquid crystals. An LCD device including a TFT array substrate and a color filter array substrate according to an embodiment may be applied to the VA mode as well as the TN mode. 
     Hereinafter, an in-cell touch LCD device based on a TN mode, a method of manufacturing the same, a method of manufacturing a thin film transistor (TFT) array substrate, and a method of manufacturing a color filter array substrate, according to various embodiments will be described in detail with reference to the accompanying drawings. 
       FIG. 2  is a diagram illustrating an in-cell touch LCD device according to an embodiment. 
     Referring to  FIG. 2 , the in-cell touch LCD device according to an embodiment may include a liquid crystal panel  1 , a driving circuit unit  2 , a backlight unit  3 , and a power supply (not shown). The driving circuit unit  2  may include a timing controller, a data driver, a gate driver, a touch driver, and a backlight driver. 
     The gate driver may be integrated on a TFT array substrate of the liquid crystal panel  1  in an amorphous silicon gate (ASG) type or a gate-in panel (GIP) type. Also, the gate driver, the timing controller, the data driver, and the touch driver may each be manufactured as a separate integrated circuit (IC) chip or may all be implemented as one IC chip. A method of driving each of the timing controller, the data driver, the gate driver, the touch driver, and the backlight driver is irrelevant to the disclosed embodiments, and thus, the elements of the driving circuit unit  2  and a method of driving the driving circuit unit  2  are not described. 
     The liquid crystal panel  1  may include a color filter array substrate (an upper substrate), a TFT array substrate (a lower substrate), and a liquid crystal layer disposed between two the substrates. The liquid crystal panel  1  may be configured to operate in the TN mode, a pixel electrode may be formed in each of a plurality of pixel areas in the TFT array substrate of the liquid crystal panel  1 , and a common electrode  260  may be formed on the color filter array substrate. Hereinabove, it has been described above that the liquid crystal panel  1  is configured to operate in the TN mode, but the liquid crystal panel  1  is not limited thereto. In other embodiments, the liquid crystal panel  1  may be configured to operate in the VA mode. 
     An alignment of the liquid crystal layer may be adjusted according to a vertical electric field generated between the pixel electrode formed on the TFT array substrate and the common electrode  260  formed on the color filter array substrate, and a transmittance of light emitted from the backlight unit  3  may be adjusted according to an alignment of liquid crystal, thereby displaying an image. 
     In the liquid crystal panel  1 , a plurality of pixels for displaying an image and a plurality of touch sensors for detecting a touch may be implemented in one body. By temporally dividing display driving and touch sensing driving, an image may be displayed, and touch may be sensed. In a display period, a data voltage based on image data may be supplied to the pixel electrode of each of the plurality of pixels, and a common voltage (Vcom) may be supplied to the common electrode, thereby displaying an image. In a non-display period (a touch period), a touch driving signal may be supplied to the common electrode (i.e., a plurality of touch electrodes), and then, capacitances of the touch electrodes may be sensed, thereby determining whether there is a touch and detecting a touched position. 
       FIG. 3  is a diagram illustrating a touch electrode provided by patterning a common electrode of a color filter array substrate according to an embodiment. 
     Referring to  FIG. 3 , the common electrode  260  formed on the color filter array substrate may be patterned as a plurality of touch blocks, and each of the plurality of touch blocks may become a touch electrode  262 . One touch block  262  may be formed to correspond to a plurality of pixels. The number of pixels corresponding to each touch block  262  may be changed depending on a size of the liquid crystal panel  1  and a size of each pixel, but for example, each of the plurality of touch blocks  262  may be configured to correspond to twenty horizontal pixels and twelve vertical pixels (20×12). 
     Here, a plurality of conductive lines  160  and each of the touch electrodes  262  formed on the TFT array substrate may be selectively connected to each other, and thus, the common voltage and the touch driving signal may be applied to the connected touch electrode  262 . Each of the touch blocks  262  may operate separately, and thus is not short-circuited when a touch driving signal is applied to another touch block  262 . To this end, one conductive line  160  may be connected to one touch block  262 . A minimum of one contact part CNT connects a touch block  262  to a corresponding conductive line  160 . A contact part CNT may connect a conductive line  160  to the corresponding touch block  262  at every pixel corresponding to the touch block  262  or to only a subset of the pixels corresponding to the touch block  262 .  FIG. 3  illustrates an example where one touch block  262  is connected to one conductive line  160  by three contact parts CNT. A structure where the touch blocks  262  are connected to the conductive lines  160  will be described in detail with reference to  FIGS. 4 and 5 . 
       FIG. 4  is a diagram illustrating a plan layout of a TFT array substrate according to an embodiment. In  FIG. 4 , a plan layout and a cross-sectional structure of one of a plurality of pixels are illustrated. 
     Referring to  FIG. 4 , a gate line may be disposed in a first direction (for example, a horizontal direction) on a substrate, and a data line may be disposed in a second direction (for example, a vertical direction) to intersect the gate line. A pixel area may be defined around an intersection of the gate line and the data line. A TFT  120 , a pixel electrode  180 , and a storage capacitor which are switching elements may be included in the pixel area. The pixel electrode  180  is formed in a display area of the pixel area. 
     A conductive line  160  may be disposed on the data line, and a transparent conductive layer  190  may be disposed on the conductive line  160  to horizontally overlap with the conductive line  160  with a passivation layer of an insulating material therebetween. A contact hole H 2  may be formed by removing the passivation layer in order for the conductive line  160  to be exposed, and the conductive line  160  may be electrically connected to the transparent conductive layer  190  through the contact hole H 2 . A column spacer may be disposed on a color filter array substrate to horizontally overlap with the transparent conductive layer  190 , and a common electrode (a touch electrode) disposed on the color filter array substrate may be electrically connected to the transparent conductive layer  190 . 
     Although not shown, a black light shield pattern (BLSP) for blocking light emitted from a backlight unit may be included in each of a plurality of pixel areas. The black light shield pattern may surround an opening of each of the pixel areas and may be disposed on the same layer as the gate line. 
       FIG. 5  is a cross-sectional view illustrating a cross-sectional structure of a liquid crystal panel configured as an in-cell touch LCD device according to an embodiment and illustrates a view of a TFT array substrate and a color filter array substrate along path A 1 -A 2  of  FIG. 4 . In  FIG. 5 , a plan layout and a cross-sectional structure of one of a plurality of pixels are illustrated. 
     Referring to  FIG. 5 , the in-cell touch LCD device according to an embodiment may include a TFT array substrate  100 , a color filter array substrate  200 , and a liquid crystal layer LC disposed between the TFT array substrate  100  and the color filter array substrate  200 . The TFT array substrate  100  and the color filter array substrate  200  may be bonded to each other and may be sealed by a sealant. A lower polarizing film POL 1  may be disposed under the TFT array substrate  100 , and an upper polarizing film POL 2  may be disposed on the color filter array substrate  200 . 
     First, elements and a structure of the TFT array substrate  100  will now be described. 
     The TFT array substrate  100  may include a first glass substrate  110 , a TFT  120 , a first buffer layer  130 , a first passivation layer (PAS 1 )  140 , a second buffer layer  150 , a conductive line  160 , a second passivation layer (PAS 2 )  170 , a pixel electrode  180 , and a transparent conductive layer  190 . 
     The TFT  120  may be disposed in each of a plurality of pixel areas included on the TFT array substrate  100 , and may have a bottom gate structure. The TFT  120  may include a gate electrode  121  disposed under a gate insulation layer  122 , an active layer  123 , a source electrode  124 , and a drain electrode  125 . The active layer  123 , the source electrode  124 , and the drain electrode  125  may be disposed on the gate insulation layer  122 . Although not shown, a storage capacitor may be formed in each of the pixel areas. In  FIG. 5 , the TFT  120  is illustrated as having a bottom gate structure, but it is not limited thereto. In other embodiments, the TFT  120  may have a top gate structure. 
     The gate electrode  121  may be formed on the first glass substrate  110 . The gate electrode  121  may branch from the gate line illustrated in  FIG. 4 , and metal of a gate electrode in a TFT area may be the gate electrode  121 . In this case, the gate electrode  121  may be formed of copper (Cu), aluminum (Al), molybdenum (Mo), titanium (Ti), Mo—Ti, other metals, other alloys, or other conductors and may have a thickness of 2,000 Å to 3,000 Å. 
     The gate insulation layer  122  may be formed to cover the gate line and the gate electrode  121 . The gate insulation layer  122  may be formed of silicon oxide (SiO 2 ) or nitride silicon (SiNx) and may have a thickness of 1,000 Å to 3,000 Å. As another example, the gate insulation layer  122  may be formed in a multi-layer structure where a SiO 2  layer and a SiNx layer are stacked. The gate insulation layer  122  may be formed by depositing tetra ethyl ortho silicate (TEOS) or middle temperature oxide (MTO) in a chemical vapor deposition (CVD) process. 
     The active layer  123  may be formed on the gate insulation layer  122  to horizontally overlap with the gate electrode  121 . The active layer  123  may have a thickness of 500 Å to 1,500 Å. The active layer  123  may be formed of amorphous silicon, poly silicon, low temperature poly silicon (LTPS), oxide, and/or the like. 
     The source electrode  124  may be formed on one side of an upper surface of the active layer  123 , and the drain electrode  125  may be formed on the other side. Each of the source electrode  124  and the drain electrode  125  may be formed of copper (Cu), aluminum (Al), molybdenum (Mo), titanium (Ti), Mo—Ti, other metals, other alloys, or other conductors and may have a thickness of 2,000 Å to 3,000 Å. The TFT  120  may be configured with the gate electrode  121 , the gate insulation layer  122 , the active layer  123 , the source electrode  124 , and the drain electrode  125 . 
     The first buffer layer  130  may be formed over the first glass substrate  110  to cover the TFT  120 . The first buffer layer  130  may be formed of SiO 2 , SiNx, and/or the like and may have a thickness of 1,000 Å to 2,000 Å. 
     The first passivation layer  140  may be formed to cover the first buffer layer  130 . The first passivation layer  140  may be formed of photo acryl and may have a thickness of 2.0 μm to 3.0 μm. Accordingly, the first passivation layer  140  is thicker than the TFT  120  (between about 1.9 and 5.5 times thicker). The first passivation layer  140  may be thickly formed for reducing a parasitic capacitance between the conductive line  160  and the TFT  120  and a parasitic capacitance between lower metal layers. 
     The second buffer layer  150  may be formed to cover the first passivation layer  140 . The second buffer layer  150  may be formed of SiO 2 , SiNx, and/or the like and may have a thickness of 1,000 Å to 2,000 Å. 
     The conductive line  160  may be formed on a portion of an upper surface of the second buffer layer  150  horizontally overlapping the data line. In  FIG. 4 , a position at which the conductive line  160  is formed is illustrated. The conductive line  160  may transfer a common voltage (Vcom) and a touch driving signal to a common electrode (a touch electrode) and may be connected to an output channel of a driving circuit unit. In a display period, the common voltage (Vcom) may be supplied to the common electrode through the conductive line  160 , thereby displaying an image. In a non-display period, the touch driving signal may be supplied to the conductive line  160 , and thus, a touch may be sensed. 
     The conductive line  160  may have a line width which is the same as or broader than that of the data line. The conductive line  160  may be formed of copper (Cu), aluminum (Al), molybdenum (Mo), titanium (Ti), Mo—Ti, other metals, other alloys, or other conductors and may have a thickness of 1,000 Å to 2,000 Å. The conductive line  160  may be formed in a multi-layer structure where a Cu layer, a Mo layer, an Al layer, and a Mo layer are stacked. 
     The second passivation layer  170  may be formed to cover a portion of the conductive line  160  and the second buffer layer  150 . The second passivation layer  170  may be formed of SiO 2 , SiNx, and/or the like and may have a thickness of 1,000 Å to 2,000 Å. 
     A first contact hole H 1  exposing a top of the drain electrode  125  of the TFT  120  may be formed by removing a portion of each of the first buffer layer  130 , the first passivation layer  140 , the second buffer layer  150 , and the second passivation layer  170  corresponding to a portion which horizontally overlaps with the drain electrode  125  of the TFT  120 . Also, a second contact hole H 2  exposing a top of the conductive line  160  may be formed by removing a portion of the second passivation layer  170  corresponding to a portion which horizontally overlaps with the conductive line  160 . 
     The pixel electrode  180  may be formed on a portion of an upper surface of the second passivation layer  170  around the opening of the first contact hole  180 . The pixel electrode  180  may be formed in the first contact hole H 1  and may be electrically connected to the drain electrode  125  of the TFT  120 . The pixel electrode  180  may be formed of a transparent conductive material such as indium-tin-oxide (ITO), indium-zinc-oxide (IZO), indium tin zinc oxide (ITZO), and/or the like and may have a thickness of 700 Å to 1,500 Å. 
     The transparent conductive layer  190  may be formed on a portion of an upper surface of the second passivation layer  170  horizontally overlapping with the conductive line  160 . An upper surface of the conductive line  160  may be exposed by the second contact hole H 2 , and thus, the conductive line  160  may be electrically connected to the transparent conductive layer  190 . The transparent conductive layer  190  may be formed of a transparent conductive material such as indium-tin-oxide (ITO), indium-zinc-oxide (IZO), indium tin zinc oxide (ITZO), and/or the like and may have a thickness of 700 Å to 1,500 Å. 
     Here, the pixel electrode  180  and the transparent conductive layer  190  may be formed of the same material through the same manufacturing process. In  FIGS. 4 and 5 , the pixel electrode  180  is formed in a plate shape in a pixel area, but the present embodiment is not limited thereto. In other embodiments, the pixel electrode  180  may be patterned and formed in a finger shape. 
     The TFT array substrate  100  according to an embodiment may be configured with the above-described elements. 
     Hereinafter, elements and a structure of the color filter array substrate  200  will be described. 
     The color filter array substrate  200  may include a second glass substrate  210 , a light shield layer (a black matrix)  220 , red (R), green (G), and blue (B) color filters (hereinafter referred to as a color filter)  230 , an overcoat layer  240 , a column spacer  250 , and a common electrode  260 . 
     The light shield layer (the black matrix)  220  may be formed on the second glass substrate  210 . The light shield layer (the black matrix)  220  may be included an opaque material to define a plurality of pixel areas. The R, G, and B color filters  230  may be respectively formed in the plurality of pixel areas defined by the light shield layer (the black matrix)  220 . The light shield layer (the black matrix)  220  may be disposed to correspond to a light shield area, and the color filter  230  may be disposed to correspond to an opening area. 
     The overcoat layer  240  may be formed to cover the light shield layer (the black matrix)  220  and the color filter  230 . An upper surface of the second glass substrate  210  may be planarized by the overcoat layer  240 . In  FIG. 5 , one of the plurality of pixel areas is illustrated, and the red color filter of the R, G, and B color filters  230  is illustrated as an example. 
     A plurality of column spacers  250  may be formed in a region of an upper surface of the overcoat layer  240  corresponding to the light shield layer (the black matrix)  220 . To describe a position of the column spacer  250  with reference to  FIGS. 4 and 5 , the column spacers  250  may be formed on the overcoat layer  240  to horizontally overlap with the conductive line  160  and the transparent conductive layer  190  which are formed on the TFT array substrate  100 . Since the conductive line  160  and the column spacers  250  are formed to horizontally overlap with the data line, an aperture ratio of each of a plurality of pixels is preserved when an in-cell touch structure is applied to a display device. That is, the conductive line  160  and the column spacers  250  may be aligned in one row on a cross-sectional surface, and thus, a separate structure for electrically connecting the conductive line  160  to the touch electrode  262  is not formed, which would reduce the aperture ratio. 
     The plurality of column spacers  250  may maintain a cell gap between the TFT array substrate  100  and the color filter array substrate  200 . Each of the column spacers  250  may be formed in, for example, a circular shape or a bar shape when seen from above. 
     In  FIG. 5 , one of the plurality of pixel areas is illustrated, and one of the plurality of column spacers  250  is illustrated. Although not shown, a plurality of push spacers may be formed in order for a certain portion of the color filter array substrate  200  to be pressed when pressure is applied to the color filter array substrate  200 . 
     The common electrode  260  may be formed to cover the overcoat layer  240  and the column spacers  250 . The common electrode  260  may be formed of a transparent conductive material such as indium-tin-oxide (ITO), indium-zinc-oxide (IZO), indium tin zinc oxide (ITZO), and/or the like and may have a thickness of 700 Å to 1,500 Å. 
     To provide a description with reference to  FIGS. 3 and 5 , the in-cell touch LCD device according to an embodiment may use the common electrode  260 , formed on the color filter array substrate  200 , as the touch electrode. To this end, the common electrode  260  may be patterned as a plurality of blocks, and each of the blocks of the patterned common electrode  260  may be a separate touch electrode  262 . 
     The color filter array substrate  200  according to an embodiment may be configured with the above-described elements. 
     When the TFT array substrate  100  is bonded to the color filter array substrate  200 , the common electrode (the touch electrode)  260  formed on the column spacer  250  may electrically contact the transparent conductive layer  190  formed on the TFT array substrate  100 . 
     Here, since the transparent conductive layer  190  electrically contacts the conductive line  160  through the second contact hole H 2 , the touch electrode  262  formed on the color filter array substrate  200  may electrically contact the conductive line  160  formed on the TFT array substrate  100  by using a protruding form of the column spacer  250 . The in-cell touch LCD device including the above-described elements according to an embodiment enables an in-cell touch type to be applied to the TN mode. 
     In the display period, the data driver may supply the common voltage to the conductive line  160  to allow all touch electrodes  262  to act as the common electrode  260 , thereby displaying an image. Also, in the non-display period, the touch driver may supply the touch driving signal to the conductive line  160  in a self-touch sensing type and then may sense a capacitance of each of the touch electrodes  262 , thereby allowing a touch to be sensed. 
       FIG. 6  is a table describing six masks used to manufacture a TFT array substrate according to an embodiment and a layer formed by a mask process corresponding to each mask, and  FIGS. 7 to 12  are diagrams illustrating a method of manufacturing a TFT array substrate according to an embodiment. 
     Hereinafter, a method of manufacturing the TFT array substrate  100  according to an embodiment will be described with reference to  FIGS. 6 to 12 . 
     As illustrated in  FIG. 6 , the TFT array substrate  100  according to an embodiment may be manufactured through a 6-mask manufacturing process. 
     Referring to  FIG. 7 , a gate metal layer may be formed by coating a conductor such as Cu, Al, Mo, Ti, Mo/Ti, and/or the like on the first glass substrate  110 . Subsequently, the gate line (not shown) and the gate electrode  121  may be formed by performing a photolithography process and an etching process using a first mask. In this case, the gate line and the gate electrode  121  may have a thickness of 2,000 Å to 3,000 Å. 
     Referring to  FIG. 8 , the gate insulation layer  122  may be formed by coating SiO 2 , SiNx, and/or the like on a whole surface of the first glass substrate to cover the gate line and the gate electrode  121 . The gate insulation layer  122  may have a thickness of 1,000 Å to 3,000 Å. 
     As another example, the gate insulation layer  122  may be formed in a multi-layer structure where a SiO 2  layer and a SiNx layer are stacked. The gate insulation layer  122  may be formed by depositing tetra ethyl ortho silicate (TEOS) or middle temperature oxide (MTO) in a chemical vapor deposition (CVD) process. 
     Subsequently, a semiconductor layer may be formed by coating amorphous silicon, poly silicon, low temperature poly silicon (LTPS), oxide, and/or the like to cover the gate electrode  121 . 
     Subsequently, a source/drain metal layer may be formed by coating a conductor such as Cu, Al, Mo, Ti, Mo/Ti, and/or the like on the semiconductor layer. 
     Subsequently, the semiconductor layer and the source/drain metal layer may be patterned by performing a photolithography process and an etching process using a second mask (a halftone mask). 
     Therefore, the active layer  123  may be formed to horizontally overlap with the gate electrode  121 , and the data line intersecting the gate line may be formed. Also, the source electrode  124  may be formed on one side of an upper surface of the active layer  123 , and the drain electrode  125  may be formed on the other side. The active layer  123  may have a thickness of 500 Å to 1,500 Å, and the source electrode  124  and the drain electrode  125  may each have a thickness of 2,000 Å to 3,000 Å. 
     The TFT  120  having the bottom gate structure may be configured with the gate electrode  121 , the gate insulation layer  122 , the active layer  123 , the source electrode  124 , and the drain electrode  125 . In  FIG. 8 , the TFT  120  is illustrated as having the bottom gate structure, but is not limited thereto. In other embodiments, the TFT  120  may be formed in the top gate structure. 
     Referring to  FIG. 9 , by performing a photolithography process and an etching process using a third mask, the first buffer layer  130  may be formed by coating SiO 2 , SiNx, and/or the like on a whole surface of the first glass substrate  110  to cover the TFT  120 . The first buffer layer  130  may have a thickness of 1,000 Å to 2,000 Å. 
     Subsequently, the first passivation layer  140  may be formed by coating photo acryl to cover the first buffer layer  130 . The first passivation layer  140  may have a thickness of 2.0 μm to 3.0 μm. 
     Referring to  FIG. 10 , the second buffer layer  150  may be formed by coating SiO 2 , SiNx, and/or the like to cover the first passivation layer  140 . The second buffer layer  150  may have a thickness of 1,000 Å to 2,000 Å. 
     Subsequently, a conductive metal layer may be formed by coating a conductor such as Cu, Al, Mo, Ti, M—Ti, and/or the like on the second glass substrate  110 . 
     Subsequently, by performing a photolithography process and an etching process using a fourth mask, the conductive line  160  may be formed on a portion of an upper surface of the second buffer layer  150  which horizontally overlaps with the data line and the source electrode  124 . The conductive line  160  may have a line width which is the same as or broader than that of the data line, and may have a thickness of 1,000 Å to 2,000 Å. The conductive line  160  may be formed in a multi-layer structure where a Cu layer, a Mo layer, an Al layer, and a Mo layer are stacked. 
     The conductive line  160  may transfer the common voltage (Vcom) and the touch driving signal to the common electrode (the touch electrode) and may be connected to an output channel of a driving circuit unit. In the display period, the common voltage (Vcom) may be supplied to the common electrode through the conductive line  160 , thereby displaying an image. In the non-display period, the touch driving signal may be supplied to the conductive line  160 , and thus, a touch may be sensed. 
     Referring to  FIG. 11 , the second passivation layer  170  may be formed by coating SiO 2 , SiNx, and/or the like to cover the second buffer layer  150  and the conductive line  160 . The second passivation layer  170  may have a thickness of 1,000 Å to 2,000 Å. 
     Subsequently, a portion of each of the first buffer layer  130 , the first passivation layer  140 , the second buffer layer  150 , and the second passivation layer  170  corresponding to the drain electrode  125  may be removed by performing a photolithography process and an etching process using a fifth mask. Since the portion of each of the first buffer layer  130 , the first passivation layer  140 , the second buffer layer  150 , and the second passivation layer  170  is removed, the first contact hole H 1  exposing the top of the drain electrode  125  may be formed. 
     Simultaneously, a portion of the second passivation layer  170  horizontally overlapping with the conductive line  160  may be removed. Since the portion of the second passivation layer  170  is removed, the second contact hole H 2  exposing the top of the conductive line  160  may be formed. The first contact hole H 1  and the second contact hole H 2  may be simultaneously formed through the same mask process, and thus, the number of detailed processes is reduced, and manufacturing efficiency is enhanced. 
     Referring to  FIG. 12 , a transparent conductive material such as ITO, IZO, ITZO, and/or the like may be coated to cover the second passivation layer  170 . 
     Subsequently, by patterning a transparent conductive material layer through a photolithography process and an etching process using a sixth mask, the pixel electrode  180  may be formed on a portion of an upper surface of the second passivation layer  170  corresponding to an opening area. The pixel electrode  180  may have a thickness of 700 Å to 1,500 Å. In this case, the pixel electrode  180  may be formed in the first contact hole H 1 , and thus, the drain electrode  125  of the TFT  120  may electrically contact the pixel electrode  180 . The pixel electrode  180  is formed in a plate shape in a pixel area, or may be patterned and formed in a finger shape. 
     Simultaneously, the transparent conductive layer  190  may be formed of a transparent conductive material, such as ITO, IZO, ITZO, and/or the like, in a region of an upper surface of the second passivation layer  170  overlapping with the conductive line  160 . The transparent conductive layer  190  may have a thickness of 700 Å to 1,500 Å. The pixel electrode  180  and the transparent conductive layer  190  may be simultaneously formed through the same mask process, and thus, the number of detailed processes is reduced, and manufacturing efficiency is enhanced. 
     The transparent conductive layer  190  may be formed with an upper surface of the conductive line  160  being exposed by the second contact hole H 2 , and thus may electrically contact the conductive line  160 . 
     The TFT array substrate  100  according to an embodiment may be manufactured by the above-described manufacturing process. 
       FIG. 13  is a table describing six masks used to manufacture a color filter array substrate according to an embodiment and a layer formed by a mask process corresponding to each mask, and  FIGS. 14 to 19  are diagrams illustrating a method of manufacturing a color filter array substrate according to an embodiment. 
     Hereinafter, a method of manufacturing the color filter array substrate  200  according to an embodiment will be described with reference to  FIGS. 13 to 19 . 
     As illustrated in  FIG. 13 , the color filter array substrate  200  according to an embodiment may be manufactured through a 6-mask manufacturing process. 
     Referring to  FIG. 14 , a resin or a black resin containing a light blocking pigment may be coated on the second glass substrate  210 , and then, the light shield layer (the black matrix)  220  may be formed by performing a photolithography process and an etching process using a first mask. An opening of each of the plurality of pixel areas may be defined by the light shield layer (the black matrix)  220 . The light shield layer (the black matrix)  220  may be formed of a conductive metal material, such as Cr, Mo, Ti, Cr-Oxide, and/or the like, or a carbon-based organic material. 
     Although not shown, the light shield layer (the black matrix)  220  may be formed in a bezel area of a liquid crystal panel to cover a non-display area and a plurality of signal lines which are routed at an edge of the TFT array substrate  100 . 
     Referring to  FIG. 15 , the R, G, and B color filters  230  may be sequentially disposed in a pixel area defined by the light shield layer (the black matrix)  220  by sequentially performing a photolithography process and an etching process using a second mask. In  FIG. 15 , one of the plurality of pixel areas is illustrated, and the red color filter of the R, G, and B color filters  230  is illustrated as an example. 
     Referring to  FIG. 16 , an overcoat material may be coated to cover the light shield layer (the black matrix)  220  and the color filter  230 . Subsequently, the overcoat layer  240  may be formed by performing a photolithography process and an etching process using a third mask. An upper surface of the second glass substrate  210  may be planarized by the overcoat layer  240 . 
     Referring to  FIG. 17 , an organic layer or an inorganic layer may be formed by coating an organic material or an inorganic material on a region of an upper surface of the overcoat layer  240  corresponding to the light shield layer (the black matrix)  220 . Subsequently, the column spacer  250  may be formed by patterning the organic layer or the inorganic layer through a photolithography process and an etching process using a fourth mask. 
     To describe a position of the column spacer  250  with further reference to  FIG. 4 , the column spacer  250  may be formed on the overcoat layer  240  to horizontally overlap with the conductive line  160  and the transparent conductive line  190  which are formed on the TFT array substrate  100 . The plurality of column spacers  250  may maintain a cell gap between the TFT array substrate  100  and the color filter array substrate  200 . Each of the column spacers  250  may be formed in a circular shape or a bar shape when seen from above. 
     Referring to  FIG. 18 , a transparent conductive material such as ITO, IZO, ITZO, and/or the like may be coated to cover the overcoat layer  240  and the column spacer  250 . 
     Subsequently, the common electrode  260  may be formed on the overcoat layer  240  and the column spacer  250  by patterning a transparent conductive material layer through a photolithography process and an etching process using a fifth mask. The common electrode  260  may have a thickness of 700 Å to 1,500 Å. 
     Referring to  FIG. 19 , the in-cell touch LCD device according to an embodiment may use the common electrode  260 , formed on the color filter array substrate  200 , as the touch electrode. To this end, the common electrode  260  may be patterned as a plurality of blocks by performing the photolithography process and the etching process using the sixth mask, and each of the blocks of the patterned common electrode  260  may be a separate touch electrode  262 . 
     The color filter array substrate  200  according to an embodiment may be manufactured by the above-described manufacturing process. 
       FIG. 20  is a diagram illustrating that a conductive line is electrically connected to a touch electrode by bonding a TFT array substrate to a color filter array substrate. 
     Referring to  FIG. 20 , the liquid crystal layer LC may be disposed in the cell gap between the TFT array substrate  100  and the color filter array substrate  200 , and the TFT array substrate  100  may be bonded to the color filter array substrate  200  by the sealant. 
     When the TFT array substrate  100  is bonded to the color filter array substrate  200 , the common electrode (the touch electrode)  260  formed on the column spacer  250  may electrically contact the transparent conductive layer  190  formed on the TFT array substrate  100 . Here, since the transparent conductive layer  190  electrically contacts the conductive line  160  through the second contact hole H 2 , the touch electrode  262  formed on the color filter array substrate  200  may electrically contact the conductive line  160  formed on the TFT array substrate  100  by using a protruding form of the column spacer  250 . 
     The in-cell touch LCD device according to an embodiment may be manufactured by the above-described manufacturing process. 
     The above embodiments describe an in-cell touch LCD device based on the TN mode; a TFT array substrate configuring the in-cell touch LCD device based on the TN mode and the method of manufacturing the same; and a color filter array substrate configuring the in-cell touch LCD device based on the TN mode and the method of manufacturing the same. 
     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 its spirit or scope. Thus, it is intended that the present invention covers modifications and variations of this invention that come within the scope of the appended claims and their equivalents.