KR20060077724A - Liquid crystal display device and the fabrication method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display and a method of manufacturing the same, which are compact and simplify the manufacturing process.

In the manufacturing process of the array substrate of the liquid crystal panel according to the present invention, since the reactive liquid crystal substrate and the liquid crystal layer are formed at the same time by phase separation, the upper and lower substrates of the liquid crystal panel can be integrally formed to increase the manufacturing yield. Increase the simplicity and convenience of

In addition, in the reactive liquid crystal substrate of the liquid crystal panel according to the present invention, a partition wall is formed at the boundary of the pixel region to form an upper substrate. The partition wall maintains a constant thickness of the liquid crystal panel to make the image quality uniform, The panel does not need to include a separate retarder by simultaneously forming the upper substrate and the retarder, thereby achieving a compact product.

Reactive mesogen, retarder, polarizing film

Description

Liquid crystal display device and method for manufacturing same

1 is a view schematically showing a structure of a general liquid crystal display device.

2 is a partial cross-sectional view of a liquid crystal display according to a first embodiment of the present invention.

3A to 3E are process flowcharts illustrating a method for manufacturing a liquid crystal panel according to a first embodiment of the present invention.

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

5A to 5E are process flowcharts illustrating a method for manufacturing a liquid crystal panel according to a second embodiment of the present invention.

<Description of Signs of Major Parts of Drawings>

210, 310: substrate 211, 311: alignment film

230, 330: liquid crystal layer 231: lower retarder

232: reactive liquid crystal substrate 232a, 342a: partition wall

233, 333: liquid crystal 234, 334: reactive liquid crystal

241 and 341 lower polarizing film 242 upper polarizing film

342 polarizing substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display and a method of manufacturing the same, which are compact and simplify the manufacturing process.

Recently, with the rapid development of the information society, the necessity of a flat panel display having excellent characteristics such as thinning, light weight, and low power consumption has emerged.

In general, a liquid crystal display (LCD), which is one of flat panel display devices, has a better visibility than a cathode ray tube (CRT) and has a smaller average heat dissipation than a CRT of a screen size of the same size. Along with plasma display panels (PDPs) and field emission displays (FEDs), they have recently been in the spotlight as the next generation display devices for mobile phones, computer monitors and televisions.

In liquid crystal displays, two substrates each having an electric field generating electrode are disposed to face each other, and the liquid crystal material is injected between the two substrates, and then a voltage is applied to the two electrodes. By moving the liquid crystal molecules thereby to control the transmittance of the light is changed accordingly to represent the image.

In general, liquid crystals have anisotropy in their molecules, and the anisotropy of liquid crystal cells or films composed of the molecules is changed by the distribution of liquid crystal molecules and the degree of tilt angle with respect to the substrate.

In addition, this characteristic is an important factor to change the polarization of light depending on the viewing angle of the cell or film made of liquid crystal.

1 is a diagram schematically illustrating a structure of a general liquid crystal display device.

As shown therein, the liquid crystal display device includes: a lower plate 120 having a thin film transistor; An upper plate 130 having a color filter; A liquid crystal layer 140 filled between the upper plate 130 and the lower plate 120 and spaced apart from each other; A first polarizing plate 129 attached to a lower surface of the lower plate 120 to transmit natural light with linearly polarized light; It is attached to the upper surface of the top plate 130, and comprises a second polarizing plate 139 having a transmission axis perpendicular to the first polarizing plate 129.

In addition, the lower plate 120, the upper plate 130 and the liquid crystal layer 120 is provided in the lower portion of the liquid crystal panel, and further includes a backlight unit 110 for supplying light from the light source (111).

A gate wiring and a data wiring are formed on the lower plate 120 to be intersected on the transparent substrate 121, and a gate formed on the entire surface including the gate electrode 122 and the gate electrode 122. A thin film transistor TFT formed of an insulating film 123, a semiconductor layer 124 formed on the gate insulating film 123, and source / drain electrodes 125a and 125b formed on the semiconductor layer 124 is formed. The pixel electrode 127 connected to the drain electrode 125b of the thin film transistor is formed through the contact hole formed in the passivation layer 126.

The black matrix 132 is formed on the transparent substrate 131 to block light from being transmitted to an area except the pixel electrode 127 in the upper plate 130, and the color is formed on the black matrix 132. Red, green, and blue color filter patterns 133 are formed to be expressed, and a common electrode 134 is formed on the color filter patterns 133.

The first and second polarizing plates 129 and 139 are formed on the outer surfaces of the lower plate 120 and the upper plate 130 so that their transmission axes intersect with each other by 90 degrees, and the incident natural light is divided into polarization components. Only one side passes through to absorb or disperse the other components.

In other words, light is an electron pie, and its vibration direction is perpendicular to the traveling direction. Polarization is light that is biased in the direction of vibration. That is, the light vibrates strongly in a specific direction among the directions perpendicular to the advancing direction.

Therefore, the light emitted from the backlight unit 110 provided under the liquid crystal panel has a probability that the vibration direction is the same in all directions. In this case, the first and second polarizing plates 129 and 139 transmit only light that vibrates in the same direction as the polarization axis among these lights, and light that vibrates in the other directions is absorbed or reflected by using a suitable medium to be identified in one specific direction. It creates a vibrating light.

Since the first and second polarizing plates 129 and 139 are attached to the lower plate and the upper plate so that the polarization axes are perpendicular to each other above and below the liquid crystal layer 140, according to the degree of rotation of the polarization axis during the liquid crystal layer 140. The intensity of the transmitted light is adjusted to enable gray representation between black and white.

However, the polarized light transmitted by the first polarizing plate 129 attached to the lower plate of the liquid crystal panel generates unpolarized light while passing through the inside of the liquid crystal panel.

This is caused by scattering of light due to the stepped portion formed on the lower plate 120 and the color filter layer 133 formed on the upper plate 130, thereby changing to unpolarized light.

Therefore, the light transmittance of the liquid crystal display device is very small due to the generated unpolarized light, resulting in a problem of low contrast ratio.

The present invention is an innovative liquid crystal display in which a production yield is improved by forming an upper substrate and a polarizing film or a compensation film integrally and forming a liquid crystal layer using phase separation when forming an array substrate in a liquid crystal display device including a polarizing film or a compensation film. It is an object to provide an apparatus and a method of manufacturing the same.

In order to achieve the above object, a liquid crystal display according to the present invention comprises: a first substrate defined by a plurality of pixel regions; An alignment film formed on the first substrate; A second polymer-polymerized substrate including the reactive liquid crystal; And a liquid crystal layer formed in a pixel region partitioned by the second substrate.

In addition, in order to achieve the above object, a method of manufacturing a liquid crystal display device according to the present invention comprises the steps of forming an array element on a substrate by separating the pixel region; Forming a polymer mixture including a liquid crystal and a reactive mesogen on the substrate; Exposing a boundary portion of the pixel region to cure the polymer mixture to form a partition wall; And exposing the entire surface of the substrate to form a top plate separated from the liquid crystal.

Hereinafter, a liquid crystal display according to the present invention will be described with reference to the accompanying drawings.

2 is a partial cross-sectional view of a liquid crystal display according to a first exemplary embodiment of the present invention.

In the liquid crystal display according to the present invention, an alignment layer 211 is formed on the array substrate 210, and an array element is formed between the array substrate 210 and the alignment layer 211, but is not specifically illustrated.

2, an alignment layer 211 is formed on an array substrate 210, and a reactive liquid crystal substrate 232 is formed for each pixel region on the array substrate 210, and the reactive liquid crystal substrate 232 is formed. The liquid crystal layer 233 is formed between the array substrate 210 and the array substrate 210.

The reactive liquid crystal substrate 232 faces the array substrate 210 at a predetermined interval, and includes a reactive mesogen 234 and a binder monomer (not shown).

The reactive liquid crystal substrate 232 has a structure separated by the partition wall 232a for each pixel area.

In this case, the partition wall 232a may be applied to various structures such as stripes, squares, diamonds, triangles, etc. according to the pixel structures of red, blue, and green.

The reactive liquid crystal substrate 232 serves as a retarder.

The lower polarizing film 241 is formed under the array substrate 210, and the upper polarizing film 242 is formed on the reactive liquid crystal substrate 232.

The lower retarder 231 is formed between the array substrate 210 and the lower polarizing film 242.

In addition, since the reactive liquid crystal substrate 232 is simultaneously formed by the liquid crystal layer 233 and phase separation on the array substrate 210, the liquid crystal panel may be completed while manufacturing the array substrate 210, thereby simplifying manufacturing yield and process. Increase convenience

A method of manufacturing a liquid crystal panel having such a configuration will be described in detail with reference to FIGS. 3A to 3E.

Here, the thin film transistor process described above will be omitted, and the liquid crystal layer and the reactive liquid crystal substrate forming process will be described in detail.

Although not shown, gate wirings and data wirings intersected on the substrate are formed, a gate electrode extending with the gate wiring, a gate insulating film formed on the entire surface including the gate electrode, and a semiconductor layer formed on the gate insulating film. And a thin film transistor (TFT) including a source / drain electrode formed on the semiconductor layer, and a pixel electrode connected to the drain electrode of the thin film transistor through a contact hole formed in the passivation layer.

An alignment layer 211 is formed on the passivation layer.

3B, a UV curable reactive mesogen 234, a binder monomer (not shown), and a liquid crystal (LC) 233a are disposed on the array substrate 210. Is applied to the liquid crystal mixture (230).

The reactive liquid crystal 234 is cured with a polymer upon UV irradiation to form a reactive liquid crystal substrate 232 serving as a support layer monomer and an upper substrate.                     

Subsequently, as shown in FIG. 3C, a mask 250 is covered on the array substrate 210 and the boundary portion of the pixel region P is first exposed.

The mask 250 includes a transmissive portion 250a and a blocking portion 250b, and the transmissive portion 250a is formed to correspond to a boundary portion of the pixel region P on the array substrate 210.

Therefore, when UV is irradiated on the mask 250, the UV passing through the transmissive part 250a hardens the reactive liquid crystal 234 and the support layer monomer of the liquid crystal mixture 230 to seed the polymer partition wall 232a as a seed. ).

In this case, the partition wall 232a may be applied to various structures such as stripes, squares, diamonds, triangles, etc. according to the pixel structures of red, blue, and green.

As shown in FIG. 3D, UV is irradiated on the entire surface of the array substrate 210 on which the partition wall 232a is formed.

In this case, since the UV cures the reactive liquid crystal 234 and the support layer monomer of the liquid crystal mixture 230, a polymer grows from the barrier rib 232a to phase-separate the liquid crystal 233a to form the reactive liquid crystal substrate 232. do.

That is, since the liquid crystal 233a and the polymer are phase-separated by polymerizing the reactive liquid crystal 234 and the support layer monomer by photocuring, the reactive liquid crystal substrate 232 that is the upper substrate is formed from the partition wall 232a.

Accordingly, the liquid crystal layer 233 and the reactive liquid crystal substrate 232 are formed over the array substrate 210.                     

Here, the reactive liquid crystal substrate 232 also serves as a retarder, and if the thickness of the reactive liquid crystal substrate 232 is d, the retardation (retardation value) is Δnd (Δn is reactive). Birefringence of the liquid crystal).

3E, an upper polarizing film 242 is attached to the reactive liquid crystal substrate 232, and a lower polarizing film 241 is attached to the lower portion of the array substrate 210 to complete the liquid crystal panel. .

As described above, since the reactive liquid crystal substrate 232 and the liquid crystal layer 233 serving as a retarder are simultaneously formed by phase separation in the array substrate manufacturing process of the liquid crystal panel, the upper and lower substrates of the liquid crystal panel may be integrally formed. It is an innovative invention that can increase the manufacturing yield and increase the simplicity and convenience of the process.

In addition, since the reactive liquid crystal substrate 232 is simultaneously formed by the liquid crystal layer 233 and phase separation on the array substrate 210, the liquid crystal panel may be completed while manufacturing the array substrate 210, thereby simplifying manufacturing yield and process. Increase convenience

In addition, in the reactive liquid crystal substrate of the liquid crystal panel according to the present invention, a partition wall is formed at a boundary of a pixel region to form an upper substrate, and the partition wall may serve as a spacer of the upper substrate.

In addition, the liquid crystal panel according to the present invention has a compact advantage because it is not necessary to provide a separate retarder by simultaneously forming the upper substrate and the retarder.

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

As described above, an array element in which a thin film transistor is formed in a matrix form on the array substrate 310 is configured.

An alignment layer is formed on the array substrate 310.

In addition, as illustrated in FIG. 4, a polarization substrate 342 is formed for each pixel area on the array substrate 310, and the liquid crystal layer 333 is between the polarization substrate 342 and the array substrate 310. ) Is formed.

The polarizing substrate 342 faces the array substrate 310 at a predetermined interval, and includes a reactive mesogen 334 and a binder monomer (not shown).

The reactive liquid crystal 334 is a smetic series liquid crystal monomer, and in particular, the smear A phase liquid crystal 333a is preferable.

The polarizing substrate 342 has a structure separated by the partition wall 342a for each pixel region.

In this case, the partition wall 342a may be applied to various structures such as stripes, squares, diamonds, triangles, etc. according to the pixel structures of red, blue, and green.

The polarizing substrate 342 is an upper substrate and serves as a polarizer film.

In addition, since the polarizing substrate 342 is simultaneously formed by the liquid crystal layer 333 and phase separation on the array substrate 310, the liquid crystal panel may be completed while manufacturing the array substrate 310, thereby simplifying and convenient manufacturing yield and process. Increase sex

In addition, in the reactive liquid crystal substrate of the liquid crystal panel according to the present invention, a partition wall is formed at a boundary of a pixel region to form an upper substrate, and the partition wall may serve as a spacer of the upper substrate.

In addition, the liquid crystal panel according to the present invention has a compact advantage because it does not need to be provided with a separate retarder by simultaneously forming the upper substrate and the retarder.

The manufacturing method of the liquid crystal panel having such a configuration will be described in detail with reference to FIGS. 5A to 5E.

Here, the thin film transistor process described above is omitted, and the liquid crystal layer and the polarizing upper plate forming process will be described in detail.

First, as shown in FIG. 5A, an alignment layer 311 is formed on the array substrate 310.

As shown in FIG. 5B, a liquid crystal mixture 330 of a reactive mesogen 334, a support layer monomer, and a liquid crystal (LC) 333a is coated on the array substrate 310. do.

Here, the reactive liquid crystal 334 is a smetic phase series.

The reactive liquid crystal 334 polymerizes with a polymer upon UV irradiation to form a polarizing substrate 342 serving as a support layer monomer and an upper substrate.

In this case, the liquid crystal mixture 330 may include a black dye.

In this case, the liquid crystal 333a and the black dye are aligned by the alignment layer 311.

Subsequently, as shown in FIG. 5C, a mask 350 is covered on the array substrate 310, and the boundary of the pixel area is exposed first.                     

The mask 350 includes a transmissive portion 350a and a blocking portion 350b, and the transmissive portion 350a is formed to correspond to a boundary portion of the pixel region P on the array substrate 310.

Therefore, when UV is irradiated on the mask 350, the UV passing through the transmission part 350a may photopolymerize the reactive liquid crystal 334 and the support layer monomer of the liquid crystal mixture 330 to seed the polymer barrier 342a as a seed. ).

In this case, the partition wall 342a may be applied to various structures such as stripes, squares, diamonds, triangles, etc. according to the pixel structures of red, blue, and green.

As shown in FIG. 5D, UV is irradiated on the entire surface of the array substrate 310 on which the partition wall 342a is formed.

In this case, since the UV cures the reactive liquid crystal 334 and the support layer monomer of the liquid crystal mixture 330, a polymer grows from the barrier rib 342a to form a polarization substrate 342 by phase separation from the liquid crystal 333a. .

That is, since the liquid crystal 333a and the polymer are phase-separated by polymerizing the reactive liquid crystal 334 and the support layer monomer by photocuring, the polarizing substrate 342 serving as a polarizing film is formed from the barrier rib 342a as an upper substrate. do.

The polarizing substrate 342 forms a polarization absorption grating by forming a book shelf structure of the smectic liquid crystal (Smatic A phase), which is the reactive liquid crystal 334.

Therefore, the polarizing substrate 342 in which the upper substrate and the upper polarizing film are integrated by the polymerization as described above is phase-separated from the liquid crystal layer 333 and formed at the same time.                     

In this case, since the thickness of the polarizing substrate 342 may be sufficiently thick, sufficient optical density (OD) may be ensured.

Therefore, the liquid crystal layer 333 and the polarizing substrate 342 are formed on the entire surface of the array substrate 310.

5E, a lower polarizing film 341 is formed under the array substrate 310.

As described above, in the present invention, since the polarizing substrate and the liquid crystal layer serving as the polarizing film are simultaneously formed by phase separation in the array substrate manufacturing process of the liquid crystal panel, the upper and lower substrates of the liquid crystal panel can be integrally formed, thereby increasing the production yield. Simplification and convenience of the process can be increased.

In addition, since the liquid crystal panel according to the present invention has a polarizing effect in the polarizing substrate, there is no need to provide a separate upper polarizing film, which has a compact advantage.

As described above, the liquid crystal display device and the manufacturing method thereof according to the present invention are not limited to the above embodiments, and modifications and improvements are possible by those skilled in the art within the technical idea of the present invention. This is obvious.

According to the present invention, since the reactive liquid crystal substrate and the liquid crystal layer, which act as a retarder in the array substrate manufacturing process of the liquid crystal panel, are formed at the same time by phase separation, the upper and lower substrates of the liquid crystal panel can be integrally formed, thereby increasing the manufacturing yield. This has the effect of increasing simplicity and convenience.                     

In addition, the reactive liquid crystal substrate of the liquid crystal panel according to the present invention forms a barrier rib at a pixel region boundary to form an upper substrate. The barrier rib has an effect of maintaining a constant thickness of the liquid crystal panel to uniform the image quality.

In addition, the liquid crystal panel according to the present invention does not need to have a separate retarder by simultaneously forming the upper substrate and the retarder has the effect of implementing a compact (compact) product.

Claims (20)

A first substrate defined by a plurality of pixel regions; An alignment film formed on the first substrate; A second polymer-polymerized substrate including the reactive liquid crystal; And a liquid crystal layer formed in a pixel region partitioned by the second substrate. The method of claim 1, And the second substrate comprises a nematic liquid crystal. The method of claim 1, And the second substrate comprises a smectic liquid crystal. The method of claim 1, And the second substrate comprises a smetic A-phase liquid crystal. The method of claim 1, And the second substrate comprises a support layer monomer. The method of claim 1, And liquid crystal layers formed in the pixel region are separated from each other. The method of claim 1, And a polymer barrier rib formed at a boundary of the pixel region. The method of claim 1, And the second substrate transmits polarized light. The method of claim 1, And the second substrate delays the phase of light. The method of claim 1, And the second substrate comprises a black dye. The method of claim 10, And the black dye is oriented by an alignment layer. Forming an array element by dividing pixel regions on a substrate; Forming a polymer mixture including a liquid crystal and a reactive mesogen on the substrate; Exposing a boundary portion of the pixel region to cure the polymer mixture to form a partition wall; Exposing the entire surface of the substrate to form a top plate separated from the liquid crystal. The method of claim 12, And the upper plate is polymerized from the partition wall to form the liquid crystal display device. The method of claim 12, The top plate includes the reactive liquid crystal. The method of claim 12, Wherein the polymer mixture comprises a black dye. The method of claim 12, And the polymer mixture comprises a support layer monomer. The method of claim 12, The top plate has a phase delay value, characterized in that the manufacturing method of the liquid crystal display device. The method of claim 12, The top plate is a method of manufacturing a liquid crystal display device, characterized in that passing the polarized light. The method of claim 12, And said reactive liquid crystal is a nematic liquid crystal. The method of claim 12, The said reactive liquid crystal is a smectic liquid crystal, The manufacturing method of the liquid crystal display device characterized by the above-mentioned.

Images