KR20070020922A - Liquid crystal display and method of manufacturing for the same - Google Patents

Abstract

A liquid crystal display device and a manufacturing method thereof are provided. The liquid crystal display device includes a first display panel including a first field generating electrode formed on a first insulating substrate, a second display panel facing the first display panel and including a second field generating electrode formed on a second insulating substrate; A liquid crystal layer formed between the first display panel and the second display panel and an organic film formed on the second field generating electrode, wherein the organic film is positioned between the first display panel and the second display panel to maintain a distance from the first display panel at a predetermined interval. And a liquid crystal alignment guide portion having a cell gap holding portion and an inclined surface for pretilting the liquid crystal layer, and a height difference of 2 µm or more is formed between the uppermost end of the cell gap holding portion and the uppermost end of the liquid crystal alignment guide portion.

Patterned Vertical Alignment (PVA), Column Spacer, Slit Mask

Description

Liquid crystal display and its manufacturing method {Liquid crystal display and method of manufacturing for the same}

1A is a layout view illustrating a first display panel in a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 1B is a layout view illustrating a second display panel in a liquid crystal display according to an exemplary embodiment of the present invention. FIG.

FIG. 1C is a layout view of a liquid crystal display including the first display panel of FIG. 1A and the second display panel of FIG. 1B.

FIG. 2 is a cross-sectional view taken along the line II-II 'of FIG. 1C.

3A to 3E are cross-sectional views taken along line II-II ′ of FIG. 1C to illustrate a manufacturing process of a first display panel according to an exemplary embodiment of the present invention.

4A to 4I are cross-sectional views taken along line II-II ′ of FIG. 1C to illustrate a manufacturing process of a second display panel according to an exemplary embodiment of the present invention.

5A is a layout view of a first display panel in a liquid crystal display according to another exemplary embodiment of the present invention.

5B is a layout view of a second display panel in a liquid crystal display according to another exemplary embodiment of the present invention.

5C is a layout view of a liquid crystal display including the first display panel of FIG. 5A and the second display panel of FIG. 5B.

FIG. 6 is a cross-sectional view taken along the line VI-VI ′ of FIG. 5C.

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

1: first display panel 2: second display panel

3: liquid crystal layer 10, 20: insulating substrate

22: gate line 24: gate pad

26 gate electrode 27 sustain electrode line

28 sustain electrode 40 semiconductor layer

62: data line 65: source electrode

66, 66a, 66b: drain electrode 68: data pad

74, 76, 78: contact hole 80: pixel electrode

83: inter-pixel gap 84: auxiliary gate pad

88: auxiliary data pad 90: organic film

220: black matrix 230: color filter

240: planarization film 250: common electrode

251a, 251b, and 251c: cutout portion 260a: liquid crystal alignment guide portion

260b: cell gap holding part 362: data line

The present invention relates to a liquid crystal display device, and more particularly, to a vertical alignment mode liquid crystal display device, a liquid crystal display device capable of securing a space in which a liquid crystal layer can be interposed between a first display panel and a second display panel, and a It relates to a manufacturing method.

Liquid crystal display (LCD) is a display device that displays the image information by using the electrical and optical properties of the liquid crystal injected into the liquid crystal panel, compared to electronic products consisting of cathode ray tube (CRT) It has the advantages of low power consumption, light weight and small volume. Therefore, the liquid crystal display device has been widely applied to various fields such as a display device of a portable computer, a monitor of a desktop computer, and a monitor of a high definition image device.

The liquid crystal display may be classified into a horizontal field type liquid crystal display device and a vertical field type liquid crystal display device (In-Plane Switching: IPS) according to a driving method. The horizontal field type liquid crystal display controls horizontally the movement of liquid crystal molecules to control light transmission, and the vertical field type liquid crystal display controls the movement of liquid crystal molecules vertically to control the transmission of light.

Among them, a vertical alignment (VA) mode liquid crystal display device in which the long axis of the liquid crystal molecules is arranged perpendicular to the upper and lower display panels without an electric field applied thereto, has gained much attention due to its large contrast ratio and easy implementation of a wide reference viewing angle. .

As a means for implementing a wide viewing angle in the vertical alignment mode liquid crystal display, there is a method of forming a cutout in the field generating electrode. The incision formed in the field generating electrode divides one pixel into a plurality of domains and adjusts the direction of the electric field to determine the tilt direction of the liquid crystal molecules. Thus, the reference viewing angle is widened by dispersing the tilting direction of the liquid crystal molecules in various directions. Play a role.

Here, the direction of movement of the liquid crystal molecules by the cutout may be effective near the cutout, but the liquid crystal molecules far away from the cutout have relatively weak direction control effects. As a result, texture may not be able to tilt in the expected direction. In order to improve this, there is a method of pretilting the liquid crystal molecules to the alignment layer via the organic film inclined between the pixel electrode and the alignment layer and / or between the common electrode and the alignment layer. The organic layer is formed using a slit mask, and when forming the organic layer, a cell gap holding unit for maintaining a gap between the first display panel and the second display panel may be simultaneously formed to reduce the number of masks required for the process.

By the way, when forming a cell gap holding part and an organic film simultaneously using a slit mask, it is difficult to form a height difference more than a predetermined value between the top end of a cell gap holding part and the top end of an organic film conventionally. That is, it is difficult to secure enough space for the liquid crystal layer to be interposed between the first display panel and the second display panel.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a liquid crystal display device having a space where a liquid crystal may be interposed between a first display panel and a second display panel.

Another object of the present invention is to provide a method of manufacturing such a liquid crystal display.

However, the technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to an embodiment of the present invention, a liquid crystal display device includes: a first display panel including a first field generating electrode formed on a first insulating substrate; and the second display panel; A second display panel including a second field generating electrode formed on a substrate, a liquid crystal layer formed between the first display panel and the second display panel, and an organic film formed on the second field generating electrode, wherein the organic film is formed in the first display panel; A liquid crystal alignment guide part disposed between the display panel and the second display panel to maintain a distance from the first display panel at a predetermined interval, and a liquid crystal alignment guide part having an inclined surface for pretilting the liquid crystal layer; And a height difference of 2 μm or more is formed between the uppermost end of the liquid crystal alignment guide portion.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, including forming a first display panel on which a first field generating electrode is formed on a first insulating substrate, and forming a first display panel on the second insulating substrate. Forming a second field generating electrode, and including a liquid crystal alignment guide part having a cell gap holding part for maintaining a distance from the first display panel at a predetermined interval on the second field generating electrode and an inclined surface for pretilting liquid crystal molecules; And forming an organic film having a height difference of 2 μm or more between an uppermost end of the cell gap maintaining part and an uppermost end of the liquid crystal alignment guide part, and interposing a liquid crystal layer between the first display panel and the second display panel on which the organic film is formed. .

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout, and sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Examples of liquid crystal displays used in the present invention include a portable multimedia player (PMP), a personal digital assistant (PDA), a digital versatile disk (DVD) player, a cellular phone, a notebook computer, and a digital TV. It is not limited.

Hereinafter, a liquid crystal display and a manufacturing method thereof according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, a liquid crystal display device 100 according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1A to 2.

FIG. 1A is a layout view of a first display panel 1 for a liquid crystal display according to an exemplary embodiment, and FIG. 1B is a layout view of a second display panel 2 for a liquid crystal display according to an exemplary embodiment. FIG. 1C is a layout view of a liquid crystal display device 100 including the first display panel 1 of FIG. 1A and the second display panel 2 of FIG. 1B. 2 is a cross-sectional view taken along the line II-II 'of FIG. 1C.

The liquid crystal display device 100 is injected between the first display panel 1, the second display panel 2 facing each other, and the first display panel 1 and the second display panel 2, and is injected into the substrates 1 and 2. It consists of a liquid crystal layer 3 comprising liquid crystal molecules 5 which are oriented vertically.

In the first display panel 1, the gate line 22 is formed in the horizontal direction on the insulating substrate 10, and the gate electrode 26 formed in the form of a protrusion is formed on the gate line 22. At the end of the gate line 22, a gate pad 24 is formed to receive a gate signal from another layer or the outside and transmit the gate signal to the gate line 22. The gate pad 24 is connected to an external circuit. The width is extended. The gate line 22, the gate electrode 26, and the gate pad 24 are referred to as gate wirings 22, 24, and 26.

In addition, the storage electrode line 27 and the storage electrode 28 are formed on the insulating substrate 10. The storage electrode line 27 extends in the horizontal direction across the pixel region, and the storage electrode line 27 is formed with a storage electrode 28 having a wider width than the storage electrode line 27. Such storage electrode lines 27 and storage electrodes 28 are referred to as storage electrode wirings 27 and 28, and the shape and arrangement of the storage electrode wirings 27 and 28 may be modified in various forms.

The gate wirings 22, 24, and 26 and the sustain electrode wirings 27 and 28 include aluminum-based metals such as aluminum (Al) and aluminum alloys, silver-based metals such as silver (Ag) and silver alloys, and copper (Cu). And copper-based metals such as copper alloys, molybdenum-based metals such as molybdenum (Mo) and molybdenum alloys, and chromium (Cr), titanium (Ti), and tantalum (Ta). In addition, the gate wirings 22, 24, and 26 and the storage electrode wirings 27 and 28 may have a multilayer structure including two or more conductive films (not shown) having different physical properties. One of the conductive films is a low resistivity metal such as an aluminum-based metal or a silver-based metal so as to reduce the signal delay or voltage drop of the gate wirings 22, 24, and 26 and the sustain electrode wirings 27 and 28. It consists of a metal, a copper type metal, etc. In contrast, the other conductive film is made of a material having excellent contact properties with other materials, particularly indium tin oxide (ITO) and indium zinc oxide (IZO), such as molybdenum-based metals, chromium, titanium, tantalum, and the like. A good example of such a combination is a chromium bottom film and an aluminum top film and an aluminum bottom film and a molybdenum top film. However, the present invention is not limited thereto, and the gate wirings 22, 24, and 26 and the storage electrode wirings 27 and 28 may be made of various metals and conductors.

The gate insulating film 30 is formed on the gate wirings 22, 24, 26 and the sustain electrode wirings 27, 28.

On the gate insulating film 30, a semiconductor layer 40 made of hydrogenated amorphous silicon, polycrystalline silicon, or the like is formed. The semiconductor layer 40 may have various shapes such as an island shape and a linear shape. For example, the semiconductor layer 40 may be formed in an island shape on the gate electrode 26 as in the present embodiment. In addition, when the semiconductor layer 40 is linearly formed, the semiconductor layer 40 may be positioned below the data line 62 and extend to the upper portion of the gate electrode 26.

On the semiconductor layer 40, an island-type ohmic contact layer or a linear ohmic contact layer made of a material such as n + hydrogenated amorphous silicon doped with silicide or n-type impurities at a high concentration is formed. The ohmic contacts 55 and 56 of the present embodiment are island type ohmic contacts, and are positioned below the source electrode 65 and the drain electrodes 66a and 66b, respectively. In the case of the linear ohmic contact layer, it extends to the bottom of the data line 62.

The data lines 62 and the drain electrodes 66a and 66b are formed on the ohmic contacts 55 and 56 and the gate insulating film 30. The data line 62 extends in the vertical direction and crosses the gate line 22 to define a pixel. A source electrode 65 extending from the data line 62 to the top of the ohmic contact layer 55 in a branch form is formed. At the end of the data line 62, a data pad 68 is formed to receive a data signal from another layer or the outside and transmit the data signal to the data line 62. The data pad 68 is connected to an external circuit. The width is extended. The drain electrodes 66a and 66b are separated from the source electrode 65 and positioned above the ohmic contact layer 56 opposite the source electrode 65 with respect to the gate electrode 26. Such data line 62, data pad 68, and source electrode 65 are referred to as data wirings.

Here, the data line 62 is formed such that the curved portion and the vertically extending portion appear repeatedly with the length of the pixel. At this time, the curved portion of the data line 62 is composed of two straight portions, one of these two straight portions forms 45 degrees with respect to the gate line 22, and the other portion is formed on the gate line 22. To -45 degrees. The source electrode 65 is connected to the vertically extending portion of the data line 62, and the portion intersects the gate line 22 and the storage electrode line 27.

At this time, the ratio of the lengths of the bent portion and the vertically extending portion of the data line 62 is between 1: 1 and 9: 1 (that is, the ratio of the bent portion of the data line 62 is between 50% and 90%). Is preferable.

Therefore, the pixel formed by the intersection of the gate line 22 and the data line 62 is formed in a band shape. As described above, the data line 62 may be formed by a combination of a straight line and a curved band like the shape of a pixel, but the present invention is not limited thereto. The data line 62 may be simply formed as a straight line or a curved band.

In addition, the drain electrodes 66a and 66b are formed to overlap with the storage electrode 28, thereby forming a storage capacitor by overlapping the storage electrode 28 with the gate insulating film 30 therebetween.

The data line 62, the source electrode 65, and the drain electrodes 66a and 66b are preferably made of refractory metals such as chromium, molybdenum-based metals, tantalum, and titanium, and include an underlayer (not shown) such as a refractory metal. It may have a multi-layer structure consisting of a low resistance material upper layer (not shown) disposed thereon. Examples of the multilayer film structure include a triple film of molybdenum film, aluminum film, and molybdenum film in addition to the above-described double film of chromium lower film and aluminum upper film or aluminum lower film and molybdenum upper film.

The source electrode 65 overlaps at least a portion of the semiconductor layer 40, and the drain electrodes 66a and 66b face the source electrode 65 around the gate electrode 26 and at least a portion of the semiconductor layer 40. This overlaps. Here, the ohmic contacts 55 and 56 are present between the semiconductor layer 40 below and the source electrode 65 and the drain electrodes 66a and 66b above and serve to lower the contact resistance.

A passivation layer 70 made of an organic insulating layer is formed on the data line 62, the drain electrodes 66a and 66b, and the exposed semiconductor layer 40. The protective film 70 is an inorganic material made of silicon nitride or silicon oxide, an organic material having excellent planarization characteristics and photosensitivity, or a-Si: C: O formed by plasma enhanced chemical vapor deposition (PECVD). low dielectric constant insulating materials such as a-Si: O: F and SiNx. In addition, the passivation layer 70 may have a double layer structure of the lower inorganic layer and the upper organic layer in order to protect the exposed portion of the semiconductor layer 40 while maintaining excellent characteristics of the organic layer.

In the passivation layer 70, contact holes 78 and 76 exposing the data pads 68 and the drain electrodes 66a and 66b are formed, respectively, and the passivation layer 70 and the gate insulating layer 30 are provided with gate pads. The contact hole 74 which exposes the 24 is formed. A band-shaped pixel electrode 80 electrically connected to the drain electrodes 66a and 66b through the contact hole 76 and bent along the shape of the pixel is formed.

In addition, an auxiliary gate pad 84 and an auxiliary data pad 88 connected to the gate pad 24 and the data pad 68 are formed on the passivation layer 70 through the contact holes 74 and 78, respectively. Here, the pixel electrode 80, the auxiliary gate pads, and the auxiliary data pads 84 and 88 are made of a transparent conductor such as ITO or IZO or a reflective conductor such as aluminum. The auxiliary gate pad and the auxiliary data pad 84 and 88 serve to bond the gate pad 24 and the data pad 68 to an external device.

The pixel electrode 80 is physically and electrically connected to the drain electrodes 66a and 66b through the contact hole 76 to receive a data voltage from the drain electrodes 66a and 66b.

The pixel electrode 80 to which the data voltage is applied generates a electric field together with the common electrode 240 of the common electrode display panel 2 to form liquid crystal molecules of the liquid crystal layer 3 between the pixel electrode 80 and the common electrode 240. Determine the arrangement of (5).

A cutout 81 is formed in the center of the pixel electrode 80 in a direction parallel to the gate line 22. Although not illustrated in the present exemplary embodiment, at least one cutout (not shown) may be formed in the pixel electrode 80 along the data line 62, and the pixel electrode 80 may be a cutout (not shown). ) Can be divided into multiple domains. Such cuts are referred to as domain dividing means. In the domain dividing means, not only the pixel electrode 80 but also the common electrode 240 of the common electrode display panel 2 may be divided into a plurality of domains by the domain dividing means. The arrangement of the liquid crystal molecules 5 of the liquid crystal layer 3 may be determined using a peripheral field formed by such domain dividing means.

On the pixel electrode 80, an organic film 90 having an inclined surface for pretilting the liquid crystal molecules 5 is formed. The organic layer 90 is relatively thick in the pixel gap 83, and the thickness becomes relatively thin as the pixel gap 83 gets closer to the center of the pixel electrode 80. That is, the region corresponding to the pixel gap 83 becomes the organic film floor located relatively high. At this time, it is preferable that the organic film floor forms an angle equal to or greater than the threshold value in order to prevent an afterimage from occurring later.

The photoresist, which is a material of the organic layer 90, may be formed of a solvent that plays a role of viscosity adjustment, a photoactive compound that causes photosensitivity, a resin that is a chemical bonding material, and the like. It consists of. The organic composition is a novolak based resin-based positive type photosensitive organic composition in which a region exposed to a light source reacts with a developer to dissolve, or an acrylic resin in which a non-exposure region is dissolved in a developer. It may be composed of a series of negative type photosensitive organic composition. Hereinafter, in the embodiment of the present invention will be described by taking the case of using a positive organic composition as an example.

Although not shown in the drawing, an alignment film for orienting the liquid crystal molecules 5 is formed on the organic film 90 inclined in both directions. The alignment film is formed in a conformal shape with the organic film 90 to have a pretilt structure. Accordingly, the liquid crystal molecules 5 have a fringe field due to the pixel gap 83 and the cutout 81, the tilted alignment force induced by the pretilt structure of the alignment layer, and the thickness of the organic layer 90. Due to the change in the equipotential line due to the cell gap difference caused by the above, the pretilt angle is laid down in the direction in which the domain is divided, and when a voltage is applied to the common electrode and the pixel electrode 80 which will be described later, The direction in which the non-adjacent liquid crystal molecules 5 also lie down is determined. Therefore, as a whole, the liquid crystal molecules 5 are driven fast, thereby increasing the response speed. If the organic layer 90 has an alignment characteristic with respect to the liquid crystal, the alignment layer may not be formed on the organic layer 90.

On the other hand, the second display panel 2 has a black mattress 220 formed on the lower surface of the insulating substrate 10 along the circumference of the pixel area.

Red, green, and blue color filters 230R, 230G, and 230B are formed on the black mattress 220. The color filters 230R, 230G, and 230B selectively transmit only light having a predetermined wavelength. The color filters 230R, 230G, and 230B may be formed, for example, in a stripe type, a mosaic type, or the like according to an arrangement method. For example, when the color filters 230R, 230G, and 230B are arranged in a stripe shape, the color filters 230R, 230G, and 230B are vertically elongated along the pixel column partitioned by the black mattress 220. It is periodically bent along the shape of the pixel. In the present embodiment, the color filters 230R, 230G, and 230B have been described using an example formed on the second display panel 2. However, the present invention is not limited thereto, and the color filters 230R, 230G, and 230B may be the first display panel. It may be formed on (1).

A planarization film 240 is formed on the color filters 230R, 230G, and 230B to planarize the steps formed by the color filters 230R, 230G, and 230B. The planarization layer 240 may be made of an organic material.

The common electrode 250 facing the pixel electrode 80 is formed on the planarization layer 240. The common electrode 250 is made of a transparent conductive material such as crystalline or amorphous ITO or IZO. The common electrode 240 has diagonal cuts 251a and 251c which are formed to be inclined at about 45 degrees or −45 degrees with respect to the gate line 22, and a horizontal cut which is formed in parallel with the gate line 22 ( 251b) is formed. The cutouts 251a, 251b, and 251c act as domain dividing means as described above.

On the common electrode 240, the liquid crystal alignment guide part 260a having an inclined surface for pretilting the liquid crystal molecules 5 is disposed between the first display panel 1 and the second display panel 2 and the first display panel 1. Organic layers 260a and 260b including cell gap holding parts 260b for maintaining a constant cell gap between the second display panels 2 are formed.

Here, the liquid crystal alignment guide part 260a is formed to be inclined in both directions with respect to the cutouts 251a and 251c in the diagonal direction in the common electrode 240. That is, the liquid crystal alignment guide portion 260a is relatively thick at the cutouts 251a and 251c in the oblique direction, and becomes thinner as it moves away from these cutouts 251a and 251c. That is, the area corresponding to the cutouts 251a, 251b, and 251c in the diagonal direction is an organic film floor located relatively high. The organic layers 260a and 260b may be formed of the same material as the organic layer 90 formed on the pixel electrode 80 of the first display panel 1.

As described above, an alignment film (not shown) for orienting the liquid crystal molecules 5 is formed on the liquid crystal alignment guide portion 260a that is inclined at a predetermined angle. The alignment layer is formed in a conformal shape with the liquid crystal alignment guide portion 260a to have a pretilt structure. This pretilt structure increases the response speed of the liquid crystal molecules 5 as described in the alignment layer of the pixel electrode 80. If the organic layers 260a and 260b have alignment characteristics with respect to the liquid crystal, the alignment layers may not be formed.

On the other hand, the cell gap holding part 260b includes an area overlapping with the gate wiring and / or data wiring of the first display panel 1, for example, an area where the thin film transistor is formed and the black matrix 220 of the second display panel 2 so as to maintain the aperture ratio. ) Is formed between the formed regions. The cell gap maintaining part 260b is made of the same material as the liquid crystal alignment guide part 260a and may be formed simultaneously with the liquid crystal alignment guide part 260a.

It is preferable that a predetermined height difference d2 is formed between the top end of the cell gap holding part 260b and the top end of the liquid crystal alignment guide part 260a. For example, it is preferable that a height difference d2 of 2 µm or more is formed between the top end of the cell gap holding part 260b and the top end of the liquid crystal alignment guide part 260a. A method of forming a predetermined height difference d2 between the top end of the cell gap holding part 260b and the top end of the liquid crystal alignment guide part 260a will be described later with reference to FIGS. 4A to 4I.

When the first display panel 1 and the second display panel 2 having the above structure are aligned and combined, and the liquid crystal layer 3 is formed therebetween and is vertically aligned, as shown in FIGS. 1C and 2, A basic structure of the liquid crystal display device 100 manufactured according to an embodiment is achieved.

That is, the first display panel 1 and the common electrode display panel 2 are aligned such that the pixel electrodes 80 accurately overlap the color filters 230R, 230G, and 230B. As a result, the pixel is divided into a plurality of domains by the cutouts 251a, 251b, and 251c of the common electrode 240 and the inter-pixel gap 83. In this case, the pixels are divided left and right by diagonal cutouts 251a and 251c and the inter-pixel gap 83, but the alignment directions of the liquid crystals are different from each other in the upper and lower directions with respect to the bent portion of the pixel. Divided into. That is, when an electric field is applied to the liquid crystal layer 3, the pixel is divided into four kinds of domains according to the direction in which the main directors of the liquid crystal molecules 5 included in the liquid crystal layer 3 are arranged. However, the present invention is not limited thereto and may be divided into a plurality of domains by the domain dividing means formed in the common electrode 240 and the pixel electrode 80 and the inter-pixel gap 83.

The liquid crystal display device 100 is formed by disposing elements such as a polarizing plate (not shown) and a backlight (not shown) in this basic structure. In this case, one polarizing plate (not shown) may be disposed on both sides of the basic structure, and the transmission axis thereof may be arranged such that one of the two is parallel to the gate line 22 and the other is perpendicular to the gate line 22.

When the liquid crystal display device 100 is formed as described above, when an electric field is applied to the liquid crystal, the liquid crystal in each domain is inclined in a direction perpendicular to the long side of the domain. However, since the direction is perpendicular to the data line 62, the liquid crystal is inclined by a lateral field formed between two adjacent pixel electrodes 80 with the data line 62 therebetween. By coinciding with the direction, the lateral electric field assists the liquid crystal alignment of each domain.

The liquid crystal display 100 generally uses various inversion driving methods such as point inversion driving, thermal inversion driving, and two-point inversion driving to apply voltages having opposite polarities to pixel electrodes positioned on both sides of the data line 62. Lateral electric fields almost always occur and the direction becomes the direction that helps the liquid crystal orientation of the domain.

In addition, since the transmission axis of the polarizing plate (not shown) is arranged in the direction perpendicular to or parallel to the gate line 22, the polarizing plate can be manufactured at low cost, but the alignment direction of the liquid crystal is 45 degrees with the transmission axis of the polarizing plate in all domains. The highest luminance can be obtained.

Next, a method of manufacturing the liquid crystal display device 100 according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 3A to 4I.

First, a method of manufacturing the first display panel 1 for a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to FIGS. 3A to 3E. 3A to 3E are cross-sectional views taken along line II-II 'of FIG. 1C to show a process sequence of the first display panel 1 for a liquid crystal display according to the exemplary embodiment of the present invention.

A conductive material such as aluminum, copper, silver, or an alloy thereof is deposited and patterned on the insulating substrate 10 to form a gate wiring including the gate electrode 26 as shown in FIG. 3A. If necessary, the gate wirings may have a multilayer structure of two or more layers.

Subsequently, silicon nitride or the like is deposited on the entire surface of the first insulating substrate 10 on which the gate wirings are formed to form the gate insulating layer 30. Subsequently, n + hydrogenated amorphous silicon doped with a high concentration of hydrogenated amorphous silicon and n-type impurities is sequentially deposited and patterned on the gate insulating layer 30 to form the channel portion of the thin film transistor as shown in FIG. 3B. An n + hydrogenated amorphous silicon layer 50 is formed over the layer 40.

Next, a data line (not shown), a source electrode 65 connected to the data line, and a source are deposited on the n + hydrogenated amorphous silicon layer 50 and by depositing and patterning a conductive material such as aluminum, copper, silver, or an alloy thereof. A data line including drain electrodes 66a and 66b which are spaced apart from the electrode 65 by a predetermined distance is formed. Next, the n + hydrogenated amorphous silicon layer 50 between the source electrode 65 and the drain electrodes 66a and 66b is removed to complete the ohmic contacts 55 and 56 as shown in FIG. 3C.

Subsequently, an inorganic material, such as an organic material, a low dielectric constant insulating material, or silicon nitride, which has excellent planarization characteristics and photosensitivity, is stacked and patterned on the ohmic contact layers 55 and 56 to have a plurality of contact holes as shown in FIG. 3D. The protective film 70 is formed. 3D shows a contact hole 76 exposing drain electrodes 66a and 66b.

Next, ITO, IZO, or the like is stacked and patterned on the passivation layer 70 to form the pixel electrode 80. Thereafter, an organic film 90 inclined in both directions is formed on the pixel electrode 80 using a slit mask (not shown). In this case, the thickness of the organic layer 90 is formed relatively thick in the pixel gap 83, and the thickness of the organic layer 90 becomes relatively thin as it approaches the center of the pixel electrode 80 in the pixel gap 83. That is, the region corresponding to the pixel gap 83 becomes the organic film floor located relatively high. At this time, it is preferable that the organic film floor is at a predetermined angle in order to prevent an afterimage from occurring later. As a result, the first display panel 1 of the liquid crystal display 100 according to the exemplary embodiment of the present invention is completed.

Next, a method of manufacturing the second display panel 2 according to an exemplary embodiment of the present invention will be described with reference to FIGS. 4A to 4I. 4A to 4I are cross-sectional views taken along line II-II ′ of FIG. 1C to illustrate a process sequence of the second display panel 2 according to an exemplary embodiment of the present invention.

First, a black matrix 21 is formed on the second insulating substrate 20 by forming and patterning a layer made of an opaque material such as chromium. Here, the black matrix 21 may be made of an organic material or an inorganic material in addition to a metal material such as chromium.

Subsequently, a photosensitive red resist is coated on the entire surface of the second insulating substrate 20, and exposed and developed to form a red color filter 230R as shown in FIG. 4B. Although not shown in the figure, a photosensitive green resist is coated on the entire surface of the second insulating substrate 20, and exposed and developed to form a green color filter. Then, a photosensitive blue resist is coated on the entire surface of the second insulating substrate 20, and exposed and developed to form a blue color filter 210B as shown in FIG. 4C. This completes the color filters 230R, 230B of red (R), green (G), and blue (B) colors.

Herein, a photosensitive resin is used as a material constituting the color filters 230R and 230B. However, a photosensitive resin may be used. In this case, the photoresist is used after the color resin is coated. Moreover, although the order of red, green, and blue was illustrated as a formation order of a color filter, it can be formed in another order, of course.

Thereafter, the organic material and ITO or IZO, etc. are sequentially stacked on the entire surface of the second insulating substrate 20 on which the color filters 230R and 230B are formed, and the planarization film 240 and the common electrode 250 are sequentially stacked as shown in FIG. 4D. To form. Then, the common electrode 250 is patterned to form the cutout 251a as shown in FIG. 4E.

Next, as shown in FIG. 4F, the organic layer is coated on the common electrode 250 to form an organic layer 261. At this time, the organic composition is coated in a dissolved state in an organic solvent, and the thickness of the coated organic layer 261 is substantially the cell gap between the first display panel 1 and the second display panel 2. Make it the same. Thereafter, the organic film layer 261 is soft baked to evaporate the solvent remaining in the organic composition.

Subsequently, as shown in FIG. 4G, the mask 300 having the first region m1 having the light blocking pattern 310 and the second region m2 having the slit pattern 320 is aligned with the second display panel 2. do. When the mask 300 is aligned, the first region m1 of the mask 300 may be aligned to correspond to the black matrix 210 of the second display panel 2. Next, the mask 300 is exposed to light.

Here, referring to the mask 300, the first region m1 of the mask 300 is completely covered to form the cell gap retaining portion 260b, and is different from the second region m2 of the mask 300. Slit patterns 320 having a resolution are formed. More specifically, the narrower the slit patterns 320 are formed so that a smaller amount of light can pass through the closer to the cutout 251a of the common electrode 250, the greater the distance away from the cutout 251a. Wide slit patterns 320 are formed to allow light to pass through.

When the organic layer 261 exposed using the mask 300 is developed using a water-soluble alkaline developer, the liquid crystal inclined in both directions about the cutout 251a of the common electrode 250 as shown in FIG. 4H. Organic films 260a and 260b including the alignment guide part 260a and the cell gap holding part 260b are formed.

More specifically, since the region corresponding to the light blocking pattern 310 of the first region m1 is not exposed, most of the organic layer 261 remains. On the contrary, in the second region m2, light incident by the slit patterns 320 causes diffraction, thereby decreasing the intensity of light incident toward the insulating substrate 20. At this time, since the wide portion of the slit pattern is exposed more than the narrow portion of the slit pattern, most of the organic film layer 261 is removed during development, and the thin portion remains. For example, the thickness remains at a thickness of 100 kPa to 1000 kPa. As a result, as shown in FIG. 4H, the organic layer 260a including the cell gap maintaining part 260b and the liquid crystal alignment guide part 260a inclined in both directions about the cutout 251a of the common electrode 250. , 260b) is formed.

In the present exemplary embodiment, the slit patterns 320 are formed in the second region m2 of the mask 300 to leave a part of the organic layer 261. A half-tone mask (not shown) in which a film is formed may be used.

Through such a process, when the organic films 260a and 260b including the cell gap maintaining part 260b and the liquid crystal alignment guide part 260a are formed, the second display panel 2 is formed on the glass of the organic films 260a and 260b. The heat treatment is performed for a predetermined time above the glass transition temperature (Tg). For example, the second display panel 2 is heat treated at a temperature of 180 ° C. to 230 ° C. for about 30 minutes to 1 hour. At this time, the heat treatment process is performed for a short time as the temperature is higher. For example, the heat treatment process is performed for about 1 hour at a temperature of 220 ℃, or the heat treatment process for a time within 1 hour at a temperature of 220 ℃ or more.

When the heat treatment step is performed under such conditions, the liquid crystal alignment guide portion 260a is reflowed to reduce the height of the uppermost end of the liquid crystal alignment guide portion 260a. As a result, as shown in FIG. 4I, a predetermined height difference d2, for example, a height difference d2 of 2 μm or more is formed between the top end of the cell gap holding part 260b and the top end of the liquid crystal alignment guide part 260a.

Here, with reference to <Table 1>, the change in the thickness H2 of the uppermost end of the liquid crystal alignment guide portion 260a according to the heat treatment temperature will be described. Table 1 shows measured values of the thickness H1 of the cell gap holding part 260b and the thickness H2 of the top end of the liquid crystal alignment guide part 260a before and after the heat treatment process, and the top end of the cell gap holding part 260b and the liquid crystal. The height difference d2 between the uppermost ends of the orientation guide portions 260a is shown for each temperature of the heat treatment step.

 Cell gap holding part thickness (H1)  Thickness of Organic Film Top (H2) H1-H2 (before heat treatment: d1, after heat treatment: d2)  Experimental Example 1 Before heat treatment 5.21 4.7 0.51 After heat treatment 5.86 2.46 3.4  Experimental Example 2 Before heat treatment 5.21 4.55 0.66 After heat treatment 5.88 2.75 3.13  Experimental Example 3 Before heat treatment 5.21 4.69 0.52 After heat treatment 5.57 3.15 2.42

(Unit: μm)

In Table 1, Experimental Example 1, Experimental Example 2 and Experimental Example 3 show the respective measured values when heat-treated at a temperature of 230 ° C, 200 ° C and 180 ° C, respectively. Referring to Table 1, when the second display panel 2 is heat treated at a temperature of 180 ° C. to 230 ° C., the thickness H2 of the uppermost end of the liquid crystal alignment guide part 260a is reduced by about half compared to before the heat treatment. You can see that. As a result, it can be seen that a height difference d2 of 2 μm or more is formed between the top end of the cell gap holding part 260b and the top end of the liquid crystal alignment guide part 260a. That is, it can be seen that a space in which the liquid crystal layer 3 can be interposed between the first display panel 1 and the second display panel 2 is secured.

Through this process, the second display panel 2 is completed. In the above-described process, since the cell gap maintaining part 260b and the liquid crystal alignment guide part 260a are formed at the same time, the manufacturing process is simple.

Next, the liquid crystal display 110 according to the second exemplary embodiment of the present invention will be described with reference to FIGS. 5A to 6. FIG. 5A is a layout view of a first display panel 1 for a liquid crystal display according to a second embodiment of the present invention, and FIG. 5B is a layout view of a second display panel 2 for a liquid crystal display according to a second embodiment of the present invention. 5C is a layout view of the liquid crystal display 110 according to the second embodiment of the present invention. 6 is a cross-sectional view taken along the line VI-VI 'of FIG. 5C. For convenience of description, members having the same functions as the members shown in the drawings of the above embodiment are denoted by the same reference numerals, and thus description thereof is omitted.

As shown in FIGS. 5A to 6, the liquid crystal display 110 of the present exemplary embodiment has the same structure as the liquid crystal display 100 of the exemplary embodiment except for the following.

First, in the first display panel 1, the storage electrode line 27 is formed to be parallel to the gate line 22, and the storage electrodes 28a, 28b, 28c, and 28d are connected to the gate line 22 at the edge of the pixel area. It is connected to the storage electrode line 27 extended side by side. The storage electrodes 28a, 28b, 28c, and 28d overlap with the vertical portions 28a and 28b connected to the storage electrode lines 27 and the cutouts 81a, 81b, and 81c of the pixel electrode 80. And diagonal lines 28c and 28d connecting the vertical portions 28a and 28b.

In addition, the data line 362 has no bent portion and is composed only of vertically extending portions. Therefore, the pixel defined by the intersection of the data line 362 and the gate line 22 is formed in a rectangle. In this case, as compared with the data line 62 of the first embodiment, the data line 362 reduces the length of the wiring, thereby reducing the resistance and load of the wiring, thereby reducing signal distortion. In addition, new stripes due to coupling between the data line 362 and the pixel electrode 80 can be prevented.

The connection member 85 is formed on the passivation layer 70 to connect the storage electrodes 28a and the storage electrode lines 27 that are adjacent to each other up and down through the contact holes 71 and 72.

In addition, a pixel electrode 80, which is electrically connected to the drain electrode 66 and positioned in the pixel, is formed on the passivation layer 70 through the contact hole 76. Cutouts 81a, 81b, and 81c are formed in the pixel electrode 80 to distort an electric field to control a direction of movement of the liquid crystal molecules 5. The cutouts 81a, 81b, and 81c are recessed in the left direction at positions halfway up and down the pixel electrode 80, and the horizontal cutouts 81b and the horizontal cutouts 81b in which the entrances are symmetrically extended. Diagonal cutouts 81a and 81c which are formed in diagonal directions in the upper and lower portions of the pixel electrode 80, which are divided by half. The diagonal cuts 81a and 81c are formed perpendicular to each other to evenly distribute the fringe fields in four directions. The cutouts 81a, 81b, 81c of the pixel electrode 80 serve as domain division means for splitting and aligning the liquid crystal molecules 5 together with the cutout of the upper common electrode.

Meanwhile, in the second display panel, the common electrodes 250 include cutouts 251a and 251b for distorting an electric field together with cutouts 81a, 81b and 81c of the pixel electrode 80 to control the movement direction of the liquid crystal molecules 5. , 251c is formed. The cutouts 251a, 251b, and 251c are alternately arranged with the diagonal cutouts 81a and 81c of the pixel electrode 80 so as to be parallel to the cutouts 251a and 251b and the common electrode 250. And a central cutout 251b formed at a position that is half-vertical. The center cutout 81b divides the common electrode 250 from the left half and extends in parallel with the diagonal cutouts 251a and 251b.

The organic layers 260a and 260b including the liquid crystal alignment guide portion 260a and the cell gap maintaining portion 260b are formed on the common electrode 250. Here, the liquid crystal alignment guide portion 260a has a structure inclined in both directions about the cutouts 251a, 251b, and 251c. That is, the thickness of the liquid crystal alignment guide portion 260a is relatively thick at the cutouts 251a, 251b, and 251c, and becomes thinner as it moves away from the cutouts 251a, 251b, and 251c. The cell gap maintaining part 260b is formed at the same time as the liquid crystal alignment guide part 260a.

Although not shown in the drawing, an alignment layer for orienting the liquid crystal molecules 5 is formed on the organic layers 260a and 260b. The alignment layer covers the organic layers 260a and 260b and is conformally formed according to the shapes of the organic layers 260a and 260b to have a pretilt structure. This pretilted structure increases the response speed of the liquid crystal molecules (5).

The manufacturing process of the liquid crystal display according to the second embodiment of the present invention is the same as the manufacturing method of the liquid crystal display according to the first embodiment described above. However, unlike the first embodiment, in the manufacture of the first display panel, an organic layer forming process for pretilting the liquid crystal molecules 5 on the pixel electrode 80 is omitted.

In the above-described exemplary embodiments, the organic layers 90 and 260a are formed only on the first display panel 1 and the second display panel 2 or the second display panel 2 as the second embodiment. Instead, the first display panel 1 may be formed only. In addition, in the present exemplary embodiment, the cell gap holding part 260b and the liquid crystal alignment guide part 260a are simultaneously formed on the second display panel 2, but the cell gap holding part 260b and the liquid crystal alignment guide part ( 260a may be simultaneously formed on the first display panel 1.

Although the organic films 90, 260a, and 260b are formed to be inclined preliminarily, they may have other structures or shapes. The organic films 90, 260a and 260b may have different structures or shapes. As long as 90, 260a, 260b) is formed, it can apply similarly. The same applies to the case where no cutout is formed in the pixel electrode 80 and / or the common electrode 250.

In addition, the liquid crystal display according to the exemplary embodiment of the present invention may be equally applicable to a transflective liquid crystal display device as well as a transmissive liquid crystal display device, but is not limited thereto. In the present embodiment, the case where the black matrix and / or the color filter is formed on the second display panel is illustrated, but the present invention is not limited thereto.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

As described above, according to the liquid crystal display according to the present invention and a method of manufacturing the same, when the liquid crystal alignment guide portion for pretilting the liquid crystal layer and the cell gap holding portion are simultaneously formed, the liquid crystal alignment guide portion is formed between the top end of the liquid crystal alignment guide portion and the top end of the cell gap holding portion. By forming a height difference of 占 퐉 or more, it is possible to secure a space in which the liquid crystal layer can be interposed between the first display panel and the second display panel.

Claims (12)

A first display panel including a first field generating electrode formed on the first insulating substrate; A second display panel facing the first display panel and including a second field generating electrode formed on a second insulating substrate; A liquid crystal layer formed between the first display panel and the second display panel; And An organic film formed on the second field generating electrode; The organic layer may include a liquid crystal alignment guide part disposed between the first display panel and the second display panel to maintain a distance from the first display panel at a predetermined interval and an inclined surface to pretilt the liquid crystal layer. , And a height difference of 2 μm or more is formed between an uppermost end of the cell gap holding unit and an uppermost end of the liquid crystal alignment guide unit. The method of claim 1, The second display panel is a common electrode display panel, and the second field generating electrode is a common electrode. The method of claim 1, The second display panel is a thin film transistor array panel, and the second field generating electrode is a pixel electrode formed for each pixel. The method of claim 1, The liquid crystal display of claim 2, wherein the liquid crystal alignment guide portion is inclined in both directions with respect to the cut portion formed in the second field generating electrode. The method of claim 4, wherein And a thickness of the liquid crystal alignment guide portion becomes thinner as it moves away from the cutout portion. The method of claim 1, And an alignment layer for aligning the liquid crystal layer on the organic layer. Forming a first display panel on which a first field generating electrode is formed, on the first insulating substrate; Forming a second field generating electrode on the second insulating substrate; A liquid crystal alignment guide portion having a cell gap holding portion for maintaining a distance from the first display panel at a predetermined interval on the second field generating electrode and an inclined surface for pretilting liquid crystal molecules, the uppermost end of the cell gap holding portion and the liquid crystal; Forming an organic film having a height difference of 2 μm or more between the top ends of the alignment guide parts; And And a liquid crystal layer interposed between the first display panel and the second display panel on which the organic layer is formed. The method of claim 7, wherein The forming of the organic layer may include applying an organic composition on the second field generating electrode; Exposing and developing the second insulating substrate using a mask having a first region and a second region; And And manufacturing the second insulating substrate. The method of claim 8, The heat treating of the second insulating substrate may include heat treating the second insulating substrate at a temperature of 180 ° C. to 230 ° C. for 30 minutes to 1 hour. The method of claim 7, wherein And forming an alignment layer for aligning the liquid crystal layer on the organic layer after forming the organic layer. The method of claim 7, wherein The second display panel is a common electrode display panel, and the second field generating electrode is a common electrode. The method of claim 7, wherein The second display panel is a thin film transistor array panel, and the second field generating electrode is a pixel electrode formed for each pixel.

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