KR101323473B1 - Liquid crystal display panel of horizontal electronic field applying type and method for fabricating thereof - Google Patents

Abstract

The present invention relates to a horizontal field application type liquid crystal display panel and a method of manufacturing the same that can easily discharge and reduce the static electricity.

A horizontal field application liquid crystal display panel according to the present invention comprises: a color filter array substrate having a transparent metal layer formed in a display area and a non-display area; A thin film transistor array substrate having conductive wiring formed in a region corresponding to the transparent metal layer in the display region; And a conductive sealant for electrically connecting the transparent metal layer and the conductive metal line.

Description

Horizontal field-applied liquid crystal display panel and its manufacturing method {LIQUID CRYSTAL DISPLAY PANEL OF HORIZONTAL ELECTRONIC FIELD APPLYING TYPE AND METHOD FOR FABRICATING THEREOF}

1 is a cross-sectional view showing a conventional IPS liquid crystal display panel.

2 is a cross-sectional view illustrating an IPS liquid crystal display panel according to a first embodiment of the present invention.

3A to 3E are cross-sectional views illustrating a manufacturing process of the color filter array substrate of FIG. 2 step by step.

4 is a plan view illustrating an IPS liquid crystal display panel according to a second exemplary embodiment of the present invention.

5 is a plan view showing only the upper substrate and the transparent metal layer of FIG.

6A through 6E are cross-sectional views illustrating a manufacturing process of the color filter array substrate of FIG. 4 in stages.

<Explanation of symbols for the main parts of the drawings>

2,102: upper substrate 4,104: black matrix

3,103: transparent metal layer 18,118: common electrode

32,132: lower substrate 6,106: color filter

7,107: overcoat layer 145: conductive sealant

13,113: Spacer 70,170: color filter array substrate

80,180: thin film transistor array substrate

147: Challenge Ball

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a horizontal field applied liquid crystal display panel capable of discharging static electricity and a method of manufacturing the same.

In general, a liquid crystal display (LCD) displays an image corresponding to a video signal on a liquid crystal display panel in which liquid crystal cells are arranged in a matrix form by adjusting light transmittance of liquid crystal cells according to a video signal. To this end, the liquid crystal display device includes a liquid crystal display panel in which liquid crystal cells are arranged in an active matrix form, and driving circuits for driving the liquid crystal display panel.

The liquid crystal display device is roughly classified into a twisted nematic (TN) mode liquid crystal display device using a vertical electric field and a horizontal field plan type (IPS) liquid crystal display device using a horizontal electric field.

The liquid crystal display panel of the TN mode liquid crystal display device is a mode in which the liquid crystal is driven by a vertical electric field between the pixel electrode and the common electrode disposed opposite the upper substrate. The liquid crystal display panel of the IPS mode is a mode in which a liquid crystal is driven by a horizontal electric field between a pixel electrode and a common electrode arranged side by side on the lower substrate.

1 is a cross-sectional view showing a liquid crystal display panel of a conventional IPS mode.

Referring to FIG. 1, the liquid crystal display panel 90 in the IPS mode includes a black matrix 4, a color filter 6, a planarization layer 7, a spacer 13, and an upper part sequentially formed on the upper substrate 2. A color filter array substrate 70 composed of an alignment layer 8, a thin film transistor (hereinafter referred to as " TFT ") 15 formed on the lower substrate 32, a common electrode 18, a pixel electrode 16, and And a liquid crystal 51 injected into an inner space between the color filter array substrate 70 and the thin film transistor array substrate 80.

In the color filter array substrate 70, the black matrix 4 is formed to overlap the TFT 15 region of the lower substrate 2 and the region of gate lines and data lines not shown, and the color filter 6 is formed. The cell region to be formed is partitioned. The black matrix 4 prevents light leakage and absorbs external light to enhance the contrast. The color filter 6 is formed in the cell region separated by the black matrix 4. The color filter 6 is formed for each of R, G, and B to implement R, G, and B colors. The overcoat layer 7 is formed to cover the color filter 6 to planarize the upper substrate 2. The spacer 13 serves to maintain a cell gap between the upper substrate 2 and the lower substrate 32.

In the thin film transistor array substrate 80, the TFT 15 includes a gate electrode 9 formed on the lower substrate 32 together with a gate line (not shown), the gate electrode 9, and the gate insulating film 44. Semiconductor layers 14 and 47 overlapping each other, and source / drain electrodes 40 and 42 formed together with data lines (not shown) with semiconductor layers 14 and 47 interposed therebetween. . The TFT 15 supplies the pixel signal from the data line to the pixel electrode 16 in response to the scan signal from the gate line. The pixel electrode 16 is a transparent conductive material having a high light transmittance and is in contact with the drain electrode 42 of the TFT 15 with the protective film 50 interposed therebetween. The common electrode 18 is formed in a stripe shape so as to alternate with the pixel electrode 16. The common electrode 18 supplies a common voltage which is a reference when driving the liquid crystal. The liquid crystal rotates with respect to the horizontal direction by the horizontal electric field between the common voltage and the pixel voltage supplied to the pixel electrode 16.

The upper and lower alignment layers 8 and 38 for liquid crystal alignment are formed by applying an alignment material such as polyimide and then performing a rubbing process.

In the liquid crystal display panel of the TN mode, the liquid crystal is driven by a vertical electric field between the color filter array substrate and the thin film transistor array substrate, thereby enabling the formation of an equipotential loop between the color filter array substrate and the thin film transistor array substrate. It is much smaller than the mode and discharge of static electricity is also easy. On the other hand, the liquid crystal display panel 90 in the IPS mode is driven by the liquid crystal 51 by a horizontal electric field, so that the color filter array substrate 70 is electrically isolated, thereby preventing the discharge of static electricity.

In order to solve the problem of static electricity generation, the transparent metal layer 3 is formed on the rear surface of the color filter array substrate 70 to discharge static electricity to the outside.

However, the conventional liquid crystal display panel 90 has a problem that an etching process for thinning the liquid crystal display panel 90 cannot be performed as the transparent metal layer 3 is formed outside the liquid crystal display panel 90. That is, after the liquid crystal display panel 90 is formed, a process of partially etching the thicknesses of the upper and lower substrates 2 and 32 using a wet etching process is performed to thin the liquid crystal display panel 90. As the transparent metal layer 3 is formed on the outside of the liquid crystal display panel 90, the thinning process of the liquid crystal display panel 90 accompanying the deepening process in the etchant may not be performed.

In addition, as the transparent metal layer 3 is positioned outside the liquid crystal display panel 90, the static electricity generated inside the liquid crystal display panel 90 may not be easily discharged.

Accordingly, an object of the present invention is to provide a horizontal field application type liquid crystal display panel and a method of manufacturing the same that can easily discharge and reduce the static electricity.

In order to achieve the above object, a horizontal field applied liquid crystal display panel according to an embodiment of the present invention includes a color filter array substrate having a transparent metal layer formed in the display area and the non-display area; A thin film transistor array substrate having conductive wiring formed in a region corresponding to the transparent metal layer in the display region; It characterized in that it comprises a conductive sealant for electrically connecting the transparent metal layer and the conductive metal line.

The conductive metal line is connected to the ground of the external driver.

A black matrix formed on the transparent metal layer in the display area of the color filter array substrate; A color filter formed in a region partitioned by the black matrix; An overcoat layer formed on the color filter; And a spacer formed on the overcoat layer.

The transparent metal layer positioned in the display area is formed in a mesh shape and overlaps the black matrix.

The thin film transistor array substrate may include signal lines; A thin film transistor positioned at an intersection area of the signal line; A pixel electrode connected to the thin film transistor; A common electrode forming a horizontal electric field with the pixel electrode is provided.

The conductive sealant includes conductive balls.

A method of manufacturing a horizontal field application type liquid crystal display panel according to the present invention includes the steps of forming a color filter array substrate having a transparent metal layer formed in a display area and a non-display area; Forming a thin film transistor array substrate on which a conductive metal line is formed in a region corresponding to the transparent metal layer in the display region; And electrically connecting the transparent metal layer and the conductive metal line using a conductive sealant and bonding the color filter array substrate and the thin film transistor array substrate.

The conductive metal line is connected to the ground of the external driver.

The forming of the color filter array substrate may include forming the transparent metal layer in a display area and a non-display area; Forming a black matrix on the transparent metal layer of the display area; Forming a color filter in a region partitioned by the black matrix; Forming an overcoat layer on the color filter; Forming a spacer on the overcoat layer.

The transparent metal layer positioned in the display area is formed in a mesh shape and overlaps the black matrix.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 2 to 6E.

2 is a view schematically showing a liquid crystal display panel in an IPS mode according to a first embodiment of the present invention.

The liquid crystal display panel of the IPS mode according to the present invention is divided into a display area P1 where an image is implemented and a non-display area P2 excluding the display area P1.

The display area P1 is formed of the transparent metal layer 103, the black matrix 104, the color filter 106, the overcoat layer 107, the spacer 113, and the upper alignment layer 108 sequentially formed on the upper substrate 102. A thin film transistor array substrate composed of a color filter array substrate 170 including a TFT, a TFT 115 formed on the lower substrate 132, a common electrode 118, a pixel electrode 116, and a lower alignment layer 138. 180 and a liquid crystal (not shown) injected into an inner space between the color filter array substrate 170 and the thin film transistor array substrate 180.

In the color filter array substrate 170, the transparent metal layer 103 is formed by depositing a transparent metal material by a deposition process such as sputtering. Transparent metal materials include indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO). Is used. Unlike the transparent metal layer 3 shown in FIG. 1, the transparent metal layer 103 is formed inside the liquid crystal display panel 90 to discharge static electricity.

The black matrix 14 is formed to overlap the TFT 115 region of the lower substrate 102 and the gate line and data line regions (not shown) and partitions a cell region in which the color filter 106 is to be formed. The black matrix 104 prevents light leakage and absorbs external light to increase contrast. Here, chromium (Cr) or the like has been conventionally used as the material of the black matrix 104, but heavy metals such as chromium (Cr) are increasingly restricted due to environmental regulations. Accordingly, black resin is used as the black matrix 104 material. As a result, the black matrix 104 is not conductive.

The color filter 106 is formed in the cell region separated by the black matrix 104. The color filter 106 is formed for each of R, G, and B to implement R, G, and B colors. It is formed to cover the overcoat layer 106 to planarize the upper substrate 102. The spacer 113 serves to maintain a cell gap between the upper substrate 102 and the lower substrate 132.

In the thin film transistor array substrate 180, the TFT 115 includes a gate electrode 109 formed on the lower substrate 132 along with a gate line (not shown), the gate electrode 109, and a gate insulating film ( The semiconductor layers 114 and 147 overlapping each other with the 144 interposed therebetween, and the source / drain electrodes 140 and 142 formed together with the data lines (not shown) with the semiconductor layers 114 and 147 interposed therebetween. The TFT 115 supplies a pixel signal from the data line to the pixel electrode 116 in response to a scan signal from the gate line. The pixel electrode 116 is a transparent conductive material having a high light transmittance and contacts the drain electrode 142 of the TFT 115 with the passivation layer 150 therebetween. The common electrode 118 is formed in a stripe shape so as to alternate with the pixel electrode 116. The common electrode 118 supplies a common voltage which is a reference when driving the liquid crystal. The liquid crystal rotates with respect to the horizontal direction by the horizontal electric field between the common voltage and the pixel voltage supplied to the pixel electrode 116.

The upper and lower alignment layers 108 and 138 for liquid crystal alignment are formed by applying an alignment material such as polyimide and then performing a rubbing process. Meanwhile, in the present invention, although the common electrode 118 is formed at the same time as the gate electrode 109 as the gate metal layer, the common electrode 118 may be formed of a transparent electrode material simultaneously with the pixel electrode 116 as necessary. When the pixel electrode 116 and the common electrode 118 are formed of a transparent electrode material, the common electrode 118 is positioned on the passivation layer 150 on the same plane as the pixel electrode 116 and the passivation layer 150. And a reference voltage to be connected to the common line through a separate through hole penetrating through the gate insulating layer 144.

Only the transparent metal layer 103 is positioned on the upper substrate 102 in the color filter array substrate 170 in the non-display area P2, and the external substrate is formed on the lower substrate 132 in the thin film transistor array substrate 180. A conductive metal line 135 connected to the ground GND of 195 is formed. Here, the conductive metal line 135 is electrically connected to the transparent metal layer 103 of the color filter array substrate 170 through the conductive sealant 145 including the plurality of conductive balls 147.

Accordingly, the color filter array substrate 170 and the thin film transistor array substrate 180 may have an equipotential structure through the conductive sealant 145. Accordingly, the static electricity generated in the color filter array substrate 170 of the liquid crystal display panel 190 is transferred to the outside through the ground GND of the driving unit 195 via the conductive sealant 145 and the conductive metal line 135. Can be discharged.

As described above, the liquid crystal display panel 190 according to the first exemplary embodiment of the present invention proposes a structure in which the transparent metal layer 103 may not be formed outside the liquid crystal display panel 190. That is, the transparent metal layer 103 of the present invention can be formed inside the liquid crystal display panel 190 unlike the conventional one formed on the rear surface of the color filter array substrate 170. Accordingly, the wet etching process for reducing the thickness of the upper substrate 102 and the lower substrate 132 of the liquid crystal display panel 190 can be performed, thereby making it possible to thin the liquid crystal display panel 190.

In addition, since the transparent metal layer 103 is formed inside the liquid crystal display panel 190 in which static electricity is substantially concentrated, static electricity may be more easily discharged to the outside than in the related art.

3A to 3E are cross-sectional views illustrating a manufacturing process of the color filter array substrate 170 illustrated in FIG.

First, as the transparent metal material is deposited on the upper substrate 102 in a deposition process such as sputtering, the transparent metal layer 103 is formed in the display area P1 and the non-display area P2 as shown in FIG. 3A.

Transparent metal materials include indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO). Is used.

After the opaque resin is formed on the upper substrate 102 on which the transparent metal layer 103 is formed by a printing, coating or coating process, the opaque material is patterned by a photolithography process and an etching process using a mask. As a result, a black matrix 104 is formed as shown in FIG. 3B.

After the red resin is deposited on the upper substrate 102 on which the black matrix 104 is formed, the red resin is patterned by a photolithography process using an mask, an etching process and a baking for curing, thereby red color filter (R). ) Is formed.

After the green resin is deposited on the upper substrate 102 on which the red color filter R is formed, the green color filter G is formed by patterning the green resin by a photolithography process, an etching process, and baking using a mask.

After the blue resin is deposited on the upper substrate 102 on which the green color filter G is formed, the blue resin is patterned by photolithography, etching, and baking using a mask to form the blue color filter B. Accordingly, the red, green, and blue color filters 106 are formed as shown in FIG. 3C.

In this way, the overcoat material is entirely deposited on the upper substrate 102 on which the red, green, and blue color filters 106 are formed, thereby forming the overcoat layer 107 as shown in FIG. 3D.

After the organic insulating material is deposited on the upper substrate 102 on which the overcoat layer 7 is formed, the organic insulating material is patterned by a photolithography process and an etching process using a mask. ) And a pattern spacer 113 overlapping each other is formed.

4 is a cross-sectional view illustrating an IPS liquid crystal display panel according to a second embodiment of the present invention.

The liquid crystal display panel shown in FIG. 4 has the liquid crystal display panel shown in FIG. 2 except that the transparent metal layer 103 is formed in a mesh shape in the display area P1 compared to the liquid crystal display panel shown in FIG. 2. The same components as the display panel 190 are provided. Therefore, components having the same configuration as those of FIG. 2 are given the same numerals and detailed description thereof will be omitted.

In FIG. 4, the transparent metal layer of FIG. 2 is patterned by a photolithography process and an etching process to form a mesh in the display area P1. That is, as shown in FIG. 5, a transparent metal layer 105 having a mesh shape is formed on the upper substrate 102.

In addition, the transparent metal layer 105 in the display area P1 is positioned to overlap the black matrix 104. That is, the transparent metal layer 105 in the display area P1 is formed to have the same shape as the black matrix 104.

As a result, the liquid crystal display panel 190 according to the second embodiment of the present invention includes the effects of electrostatic discharge and thinning of the liquid crystal display panel 190 in the first embodiment and is more advantageous in terms of luminance.

That is, as the transparent metal layer 103 is formed only in the region overlapping the black matrix 104 in the display region P1, the transparent metal layer 105 is not positioned in the region where the backlight light is transmitted, as compared with the first embodiment. The transmittance of light emitted from the backlight can be improved.

6A through 6E are cross-sectional views illustrating manufacturing steps of the color filter array substrate 170 illustrated in FIG. 4.

First, the transparent metal material is deposited on the upper substrate 102 in a deposition process such as sputtering, followed by a photolithography process and an etching process, thereby forming the transparent metal layer 105 as illustrated in FIG. 6A. Transparent metal materials include indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO). Is used.

Subsequent processes are performed in the same manner as the manufacturing process of the color filter array substrate 170 of the liquid crystal display panel according to the first embodiment of the present invention. Accordingly, only a schematic description will be given with reference to the drawings.

That is, after the opaque resin is formed, the black matrix 104 is formed as shown in FIG. 6B by a photolithography process and an etching process using a mask. The black matrix 104 is formed to overlap the transparent metal layer 105 of the display area P1. Thus, the black matrix 104 also has a mesh structure.

Then, the red, green, and blue color filters 106 are formed as shown in FIG. 6C, and the overcoat layer 107 is formed as shown in FIG. 3D, and then the black matrix 104 is shown in FIG. 6E. ) And a pattern spacer 113 overlapping each other is formed.

In this way, the color filter array substrate 170 formed by the method of FIGS. 3A to 3E and 6A to 6E is formed.

The thin film transistor array substrate 180 is formed by a separate process. In the display area P1 of the thin film transistor array substrate 180, thin film patterns such as thin film transistors, gate lines and data lines, common electrodes, and pixel electrodes are formed. The conductive metal line 135 is formed in the non-display area P2.

Thereafter, the conductive metal line 135 and the transparent metal layer 103 are electrically connected by using the conductive sealant 145, and the color filter array substrate 170 and the thin film transistor array substrate 180 are bonded to each other.

As described above, the horizontal field application type liquid crystal display panel and the manufacturing method thereof according to the embodiment of the present invention can be formed inside the liquid crystal display panel unlike the conventional case where the transparent metal layer is formed on the back of the color filter array substrate. . Accordingly, the wet etching process for reducing the thickness of the upper substrate and the lower substrate of the liquid crystal display panel can be performed, thereby making it possible to thin the liquid crystal display panel. In addition, since the transparent metal layer is formed inside the liquid crystal display panel in which static electricity is concentrated, static electricity may be more easily discharged to the outside than in the related art.

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. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

Claims (11)

A color filter array substrate having a transparent metal layer formed on the display area and the non-display area; A thin film transistor array substrate having conductive metal lines formed in a non-display area; A conductive sealant electrically connecting the transparent metal layer and the conductive metal line, In the display area of the color filter array substrate A black matrix formed on the transparent metal layer; A color filter formed in a region partitioned by the black matrix; The overcoat layer formed on the color filter is further provided, And wherein the transparent metal layer positioned in the display area is formed in a mesh shape and overlaps the black matrix. The method of claim 1, And the conductive metal line is connected to the ground of an external driving unit. The method of claim 1, In the display area of the color filter array substrate And a spacer formed on the overcoat layer. delete The method of claim 1, The thin film transistor array substrate Signal lines; A thin film transistor positioned at an intersection area of the signal line; A pixel electrode connected to the thin film transistor; And a common electrode forming a horizontal electric field with the pixel electrode. The method of claim 1, And wherein the conductive sealant comprises conductive balls. Forming a color filter array substrate having a transparent metal layer formed on the display area and the non-display area; Forming a thin film transistor array substrate having conductive metal lines formed in the non-display area; Electrically connecting the transparent metal layer and the conductive metal line using a conductive sealant and bonding the color filter array substrate and the thin film transistor array substrate to each other; Forming the color filter array substrate Forming a black matrix on the transparent metal layer of the display area; Forming a color filter in a region partitioned by the black matrix; Forming an overcoat layer on the color filter; The transparent metal layer positioned in the display area is formed in a mesh form and overlaps with the black matrix. The method of claim 7, wherein And wherein the conductive metal line is connected to the ground of an external driving unit. The method of claim 7, wherein Forming the color filter array substrate And forming a spacer on the overcoat layer. delete The method of claim 7, wherein And the conductive sealant comprises conductive balls.

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