KR20080049346A - Liquid crystal display panel - Google Patents

Abstract

An LCD panel is provided to achieve equipotential of upper and lower array substrates, thereby removing a transparent electrode pattern forming process performed on the upper array substrate. An LCD(Liquid Crystal Display) panel comprises upper and lower array substrates(170,180) and at least one of a silver dot(145) and a conductive sealant. In the upper array substrate, a conductive black matrix(104) is formed in a non-display area(P2). In the lower array substrate, a conductive line is formed in an area corresponding to the conductive black matrix. At least one of the silver dot and the conductive sealant electrically connects the conductive black matrix with the conductive line. The conductive line is connected to the ground of an external driving unit.

Description

Liquid Crystal Display Panel

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

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

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

4 is a cross-sectional view taken along the line II ′ of FIG. 3.

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

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

3: transparent electrode pattern 18,118: common electrode

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

7,107: overcoat layer 145: silver dot

13,113: spacer 70,170: upper array substrate

80,180: lower array substrate 155: conductive sealant

156: contact hole 154: conductive ball

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel, and more particularly, to a liquid crystal display panel which can simplify the structure, reduce the cost, and reduce the thickness.

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.

Such liquid crystal displays are roughly classified into twisted nematic (TN) mode and in plan switch (IPS) mode using a vertical electric field according to the electric field driving the liquid crystal.

The TN mode is a mode in which a liquid crystal is driven by a vertical electric field between a pixel electrode and a common electrode arranged to face the upper substrate. The TN mode has an advantage that the aperture ratio is large while the viewing angle is folded. 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 a lower substrate, and has a large viewing angle, but a small aperture ratio.

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. An upper array substrate (or 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, Implanted into an inner space between the lower array substrate (or thin film transistor array substrate) 80 formed of the pixel electrode 16 and the lower alignment layer 38 and the upper array substrate 70 and the lower array substrate 80. The liquid crystal 51 is provided.

In the upper 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. Partition the cell area to be used. The black matrix 4 prevents light leakage and absorbs external light to increase 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 lower 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.

On the other hand, in the TN mode liquid crystal display panel, the liquid crystal is driven by the vertical electric field between the upper array substrate and the lower array substrate, so that an equipotential loop can be formed between the upper array substrate and the lower array substrate. Small and easy discharge of static electricity. 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 upper array substrate 70 and the lower array substrate 80 are electrically isolated from each other, and thus the amount of static electricity generated is relatively high. Emissions are also not easy.

In order to solve the problem of static electricity generation, the transparent electrode pattern 3 is formed on the rear surface of the upper array substrate 70 to discharge static electricity to the outside.

However, the conventional liquid crystal display panel 90 has a disadvantage in that the process and cost are increased by forming the transparent electrode pattern 3, and the liquid crystal display panel cannot be thinned as the transparent electrode pattern 3 is formed. have.

Accordingly, an object of the present invention is to provide a liquid crystal display panel and a method of manufacturing the same, which can simplify the structure, reduce the cost, and reduce the thickness.

In order to achieve the above object, a liquid crystal display panel according to an embodiment of the present invention includes an upper array substrate formed with a conductive black matrix in a non-display area; A lower array substrate having conductive lines formed in a region corresponding to the conductive black matrix; And at least one of a silver dot and a conductive sealant for electrically connecting the conductive black matrix and the conductive wiring.

Here, in the present invention, the conductive wiring is connected to the ground of the external driving unit.

The lower array substrate according to the present invention comprises: signal lines formed to cross each other;

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 conductive wire according to the present invention is characterized in that it is connected to the common electrode.

A gate insulating film and a protective film are further formed in the non-display area of the lower array substrate according to the present invention, and the conductive sealant contacts the conductive wire through a contact hole through the gate insulating film and the protective film to expose the conductive wire. It features.

The black matrix according to the invention is characterized in that it comprises chromium.

The conductive sealant according to the present invention is characterized by including conductive balls.

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

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 2 to 3.

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 has a structure substantially the same as that shown in FIG. 1. That is, an upper array substrate (or color filter) including a black matrix 104, a color filter 106, an overcoat layer 107, a spacer 113, and an upper alignment layer 108 sequentially formed on the upper substrate 102. Array substrate) 170, a lower array substrate (or thin film transistor array substrate) composed of a TFT 115, a common electrode 118, a pixel electrode 116, and a lower alignment layer 138 formed on the lower substrate 132; ) 180 and a liquid crystal (not shown) injected into an inner space between the upper array substrate 170 and the lower array substrate 180.

In the upper array substrate 170, 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 the color filter 106 is formed. Partition the cell area to be used. The black matrix 104 prevents light leakage and absorbs external light to increase contrast. The black matrix 104 is formed of a metal material such as chromium (Cr). As a result, the black matrix 104 becomes 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 lower 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 the gate insulating layer 144. Semiconductor layers 114 and 147 overlapping each other, and source / drain electrodes 140 and 142 formed together with 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, 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 black matrix 104 formed on the upper substrate 102 is positioned in the upper array substrate 170 in the non-display area P2, and the lower substrate 132 is grounded in the lower array substrate 180 in the lower array substrate 180. An electromotive voltage supply line 135 connected to the GND is formed. The electromotive voltage supply line 135 and the conductive black matrix 104 are electrically connected through the silver dot 145.

The upper array substrate 170 and the lower array substrate 180 may form an equipotential structure through the silver dot 145. Accordingly, the static electricity generated in the upper array substrate 170 of the liquid crystal display panel 90 may be discharged to the outside through the ground GND of the driving unit via the silver dot 145 and the electromotive voltage supply line 135. Will be. Instead of the silver dot 145, a conductive ball used for the conductive sealant 155 may be used.

As described above, the liquid crystal display panel 90 according to the first exemplary embodiment of the present invention electrically connects the conductive black matrix 104 with the electromotive voltage supply line 135 of the upper array substrate 170 to discharge static electricity to the outside. You can do it. As a result, as the transparent electrode pattern 3 is not required, the structure can be simplified, the cost can be reduced, and the thickness can be reduced.

2 and 3 show a liquid crystal display panel according to a second embodiment of the present invention. FIG. 2 is a plan view schematically illustrating a liquid crystal display panel, and FIG. 3 is a cross-sectional view taken along line II ′ of FIG. 2.

The liquid crystal display panel shown in FIGS. 2 and 3 has a display area P1 instead of the electromotive voltage supply line 135 in the non-display area P2 of the lower array substrate 180 compared to the liquid crystal display panel shown in FIG. 2. The upper array substrate 170 and the lower array substrate 180 may be disposed through the conductive sealant 155 including the conductive balls 154 instead of the silver dot 145. Except for the equipotential, the same components as those of the liquid crystal display panel shown in FIG. 2 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.

The extended common electrode 118 in the display area P1 may be located in the non-display area P2 of the lower array substrate 180 in FIG. 3, or the electromotive voltage supply line 135 is positioned as shown in FIG. 2. You may. For example, when the liquid crystal display panel 190 is driven by a line inversion or frame inversion method, one of the common electrode 118 and the electromotive voltage supply line 135 is formed. In the case of the dot inversion method, it is more effective that the electromotive voltage supply line 135 is formed.

The common electrode 118 is also connected to the external driver so that the static electricity generated in the upper array substrate 170 can be discharged to the outside via the conductive sealant 155.

The sealant 155 serves to bond the upper array substrate 170 and the lower array substrate 180 as shown in FIG. 3. As the conductive balls 154 are added to the sealant 155, the black matrix 104 of the upper array substrate 170 may be attached to the lower array substrate as well as the upper array substrate 170 and the lower array substrate 180 may be bonded to each other. Electrically connected to the common electrode 118 or the electromotive voltage supply line 135 of 180.

Meanwhile, in the structure in which the gate insulating layer 144 and the passivation layer 150 are formed in the non-display area P2 of the lower array substrate 180, the common electrode 118 passes through the gate insulating layer 144 and the passivation layer 150. Or a contact hole 156 exposing the electromotive voltage supply line 135 is formed. In this case, the conductive sealant 155 may be in contact with the common electrode 118 or the electromotive voltage supply line 135 through the contact hole 156.

Meanwhile, the process of forming the contact hole 156 may be simultaneously performed in the process of forming the gate pad portion and the data pad portion of the lower array substrate 180, so that the contact hole 156 may be formed without a separate mask addition process.

As described above, the liquid crystal display panel according to the embodiment of the present invention forms a black matrix in the non-display area of the upper array substrate with a conductive metal and is connected to the ground GND of the external driver in the non-display area of the lower array substrate. A common electrode or electromotive voltage supply line is formed. At the same time, the upper array substrate and the lower array substrate are equipotential as the conductive black matrix and the common electrode or the electromotive voltage supply line are electrically connected through silver dots or conductive sealants. Accordingly, as the transparent electrode pattern forming process formed on the upper array substrate is removed, the liquid crystal display panel can be thinned, the manufacturing process is simplified, and the cost is reduced.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present 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 (7)

An upper array substrate having a conductive black matrix formed in the non-display area; A lower array substrate having conductive lines formed in a region corresponding to the conductive black matrix; And at least one of a silver dot and a conductive sealant for electrically connecting the conductive black matrix and the conductive wiring. The method of claim 1, The conductive line is connected to the ground of the external driving unit, the liquid crystal display panel. The method of claim 2, The lower array substrate Signal lines formed to cross each other; 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 3, wherein And the conductive line is connected to the common electrode. The method of claim 3, wherein A gate insulating film and a protective film are further formed in the non-display area of the lower array substrate. And the conductive sealant is in contact with the conductive wire through a contact hole through the gate insulating film and the protective film to expose the conductive wire. The method of claim 1, And the black matrix comprises chromium. The method of claim 1, And the conductive sealant comprises conductive balls.

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