KR101004453B1 - Fabrication method for LCD - Google Patents

Abstract

The present invention relates to a method for manufacturing a liquid crystal display device. According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, the method comprising: forming a color filter layer by sequentially patterning a first color layer, a second color layer, and a third color layer on a substrate at predetermined intervals; Coating a positive photoresist on the entire surface of the substrate on which the color filter layer is formed, and then exposing the substrate on a rear surface of the substrate; Developing and curing the back exposed positive photoresist; Depositing a black matrix material on the result of the development and curing of the positive photoresist; Lifting off a positive photoresist from the resultant on which the black matrix material is deposited to form a black matrix; It is characterized in that it comprises the step of forming a common electrode on the formed product.

In the method for manufacturing a liquid crystal display device according to the present invention, in the process of manufacturing a color filter substrate, by forming a black matrix without using a mask, the number of steps can be reduced to reduce manufacturing costs.

Black Matrix, Lift Off, Positive Photoresist

Description

Manufacturing method of liquid crystal display device {Fabrication method for LCD}

1 is a cross-sectional view schematically showing the structure of a general liquid crystal display device.

2A to 2F are diagrams showing a procedure of a conventional method for manufacturing a second substrate (color filter substrate).

3A to 3F are views illustrating a procedure for a method of manufacturing a color filter substrate of a liquid crystal display according to the present invention.

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

31 --- Substrate 32 --- Color Filter Layer

33 --- Positive Photoresist 34b --- Black Matrix

35 --- Common electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display, and in particular, in a process of manufacturing a color filter substrate, by forming a black matrix without using a mask, the number of processes can be reduced to reduce manufacturing costs. A method for manufacturing a liquid crystal display device.                         

Recently, with the rapid development of the information society, the necessity of flat panel displays having excellent characteristics such as thinning, light weight, and low power consumption has emerged. Among them, liquid crystal displays have been developed in terms of resolution, color display, and image quality. It is excellent and is actively applied to notebooks and desktop monitors.

In general, a liquid crystal display device arranges two substrates on which electrodes are formed so that the surfaces on which the two electrodes are formed face each other, injects a liquid crystal material between the two substrates, and applies a voltage to the two electrodes to generate an electric field. By moving the liquid crystal molecules, the image is expressed by the transmittance of light that varies accordingly.

1 is a cross-sectional view schematically illustrating a structure of a general liquid crystal display device. As shown in the drawing, the first substrate (thin film transistor substrate) 1 and the second substrate (color filter substrate) 3 are provided to face each other at a predetermined interval. The liquid crystal layer 2 is formed between the first substrate 1 and the second substrate 3.

In more detail with respect to the liquid crystal display, the first substrate 1 (thin film transistor substrate) has a gate wiring and a data wiring intersecting on the transparent substrate 16, and a gate electrode extending from the gate wiring. (4), a gate insulating film 5 formed on the entire surface including the gate electrode 4, a semiconductor layer 6 formed on the gate insulating film 5, and a source / formed on the semiconductor layer 6 A thin film transistor (TFT) including drain electrodes 7a and 7b is formed, and a pixel electrode 9 connected to the drain electrode 7b of the thin film transistor is formed through a contact hole formed in the passivation layer 8. Is formed.                         

The second substrate (color filter substrate) 3 on the other side facing the transparent substrate on which the plurality of pixel electrodes are formed is transparent substrate 15 to block light from being transmitted to an area except the pixel electrode 9. A black matrix 14 is formed on the black matrix, and a red, green, and blue color filter pattern 13 is formed on the black matrix 14, and a common electrode is formed on the color filter pattern 13. (12) is formed.

When voltage is applied to the gate bus line and the data bus line of the liquid crystal display device configured as described above, the TFT to which the voltage is applied is turned on, and charge is applied to the pixel electrode connected to the drain electrode of the on TFT. It is accumulated and displayed by changing the arrangement of liquid crystal molecules of the liquid crystal layer 2 between the common electrodes.

First, a method of manufacturing the first substrate (thin film transistor) 1 will be described. A gate electrode 4 is formed on the transparent substrate 16, and a Plasma Enhanced Chemical Vapor (PECVD) is formed on the gate electrode 4. The gate insulating film 5 is grown by deposition.

Next, an amorphous silicon layer doped with amorphous silicon and phosphorus is patterned by deposition after photolithography to form a channel layer with an active layer 6 and an ohmic contact layer (not shown).

In addition, a predetermined metal is deposited on the channel layer including the active layer 6 and the ohmic contact layer (not shown), and the source / drain electrodes 7a and 7b are formed as shown through a photolithography process.

Subsequently, a passivation layer 8 is formed using an inorganic layer, and a pixel electrode 9 is formed of indium titan oxide (ITO) on the passivation layer 8.                         

Meanwhile, the second substrate 3 is disposed on the first substrate 1 at regular intervals from the first substrate 1, and the black matrix 14 is formed on the inner surface of the second substrate 3. It is formed at a position corresponding to the transistor T.

The color filter 13 corresponding to the pixel electrode 9 is formed on the black matrix 14. An overcoat layer (not shown) may be selectively formed on the color filter 13 to protect the color filter 13 and to eliminate a step caused by the color filter 13. In addition, a common electrode 12 made of a transparent conductive material is formed below.

In addition, alignment layers 10 and 11 are formed on the pixel electrode 9 and the common electrode 12, respectively, and a liquid crystal layer 2 is injected between the alignment layers 10 and 11.

2A to 2F are diagrams showing a procedure of a conventional method for manufacturing a second substrate (color filter). Here, the manufacturing method of the second substrate (color filter) includes a dyeing method, a dye dispersion method, a pigment dispersion method, an electrodeposition method and the like, but the pigment deposition method will be described as an example.

First, as shown in FIG. 2A, after cleaning the glass substrate 21, a chromium or carbon based organic material used as the black matrix 22 material is deposited by sputtering, and then a mask is used. After patterning, the black matrix 22 is formed.

After the black matrix 22 is formed, a color filter layer is formed using a color resist to implement color.                         

That is, as shown in FIG. 2B, the first color resist 23 colored in red is applied to the entire surface including the black matrix 22 so as to completely cover the black matrix 22.

Next, as shown in FIG. 2C, after exposing only a specific region on the first color resist 23 applied using the mask 24, partial exposure is performed.

Next, as shown in FIG. 2D, the first color resist 23 whose photochemical structure is changed by exposure is immersed in a developing solution to develop a first color layer pattern 23, and the developed photoresist film is cured to give a red color. (Hereinafter referred to as R color) 23 is formed.

In general, the color resist has the characteristics of a negative resist, so that an unexposed part is removed.

Then, the processes shown in FIGS. 2B to 2D are repeatedly performed to form second and third colored layer patterns 24 and 25 colored in green and blue, respectively, as shown in FIG. 2E. .

Subsequently, as shown in FIG. 2F, indium tin oxide (ITO), which is a transparent electrode material having good permeability and conductivity and excellent chemical and thermal stability, is deposited on the entire surface including the colored pattern by sputtering. ITO as the common electrode 27 does not form a separate pattern.

For reference, in order to protect and planarize the colored pattern before the common electrode 27 is formed, a planarization layer (overcoat layer) is formed by spin coating using an acrylic resin or a polyimide resin. In some cases, it may be omitted to reduce the manufacturing process cost.

However, as described above, in forming the color filter layer and the black matrix, one mask process is patterned through photo resist coating, exposure, development, and etching processes. Therefore, the above process must be repeatedly performed to form one pattern, which raises a problem of increasing manufacturing cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a liquid crystal display device, which can reduce the number of processes and reduce manufacturing costs by forming a black matrix without using a mask in the process of manufacturing a color filter substrate.

In order to achieve the above object, a method of manufacturing a liquid crystal display device according to the present invention,

Forming a color filter layer by sequentially patterning each of the first colored layer, the second colored layer, and the third colored layer on the substrate at predetermined intervals;

Coating a positive photoresist on the entire surface of the substrate on which the color filter layer is formed, and then exposing the substrate on a rear surface of the substrate;

Developing and curing the back exposed positive photoresist;

Depositing a black matrix material on the result of the development and curing of the positive photoresist;

Lifting off a positive photoresist from the resultant on which the black matrix material is deposited to form a black matrix;                     

It is characterized in that it comprises the step of forming a common electrode on the formed product.

In particular, the coated positive photoresist is removed between the first color layer, the second color layer, and the third color layer at predetermined intervals, in particular in the developing and curing of the positive photoresist. have.

In particular, the black matrix material is characterized in that it is formed using a chromium (Cr), chromium oxide (CrOx), a carbon-based organic material or a photosensitive resin material.

Here, in particular, in the step of lifting off the positive photoresist to form a black matrix, the positive photoresist is melted by injecting a remover into the side of the positive photoresist.

In particular, an overcoat layer is formed by using an acrylic resin or a polyimide resin to protect and planarize the colored pattern before forming the common electrode.

According to this invention, in the process of manufacturing a color filter substrate, by forming a black matrix without using a mask, the number of processes can be reduced and manufacturing cost can be reduced.

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

3A to 3F are views illustrating a procedure for a method of manufacturing a color filter substrate of a liquid crystal display according to the present invention. Here, the manufacturing method of the color filter substrate includes a dyeing method, a dye dispersion method, a pigment dispersion method, an electrodeposition method and the like.

First, as shown in FIG. 3A, after the glass substrate 31 is cleaned, the color filter layer 32 is formed using a color resist to implement color.

That is, a color resist colored in red is applied to the entire surface of the substrate. Then, after exposing only a specific region over the color resist applied using a mask, partial exposure is performed.

At this time, the color resist whose photochemical structure is changed by partial exposure is immersed in a developing solution to develop a colored layer pattern, and the developed photosensitive film is cured to form a red color (hereinafter referred to as R color).

Here, in general, the color resist has the characteristics of a negative resist, so the unexposed portions are removed.

In addition, the processes shown in the process of forming the first colored layer pattern 32a colored in red are repeated to sequentially perform the second and third colored layer patterns 32b colored in green and blue, respectively. 32c).

At this time, the first color layer pattern 32a, the second color layer pattern 32b, and the third color layer pattern 32c of the color filter layer 32 formed as described above are formed at predetermined intervals, respectively.

Subsequently, as illustrated in FIG. 3B, a positive photoresist 33 is coated on the entire surface of the color filter layer 32 spaced apart by the predetermined intervals, and then back exposure is performed.

As shown in FIG. 3C, after the back exposure is performed, a pattern is formed through a developing and curing process.

In more detail, the portion of the positive photoresist 33 that is exposed is removed, and the portion that is not exposed remains.

That is, when the positive photoresist 33 is exposed on the back side of the coated substrate, the positive photoresist 33 applied on the respective first, second and third colored layer patterns 32a, 32b, and 32c may be formed. The first, second and third colored layer patterns 32a, 32b, and 32c do not cause photoreaction and remain intact, and the positive photoresist coated between the spaced spaces of the respective colored layer patterns. Only 33 will react. However, the positive photoresist 33 reacts to a part of both edge regions of the colored layer patterns due to the diffraction phenomenon of the exposed light. As a result, the width of the positive photoresist 33 formed on the colored layer patterns has a width slightly smaller than that of the complex layer pattern.

In this case, when the exposed positive photoresist 33 is developed and cured, the exposed portion may be removed.

Therefore, after the positive photoresist 33 is coated by the above-described method, the back exposure is performed, thereby forming a pattern without a separate mask.

Subsequently, as shown in FIG. 3D, chromium (Cr), chromium oxide (CrOx), or carbon (used as a black matrix material) is formed on the resultant product of the positive photoresist 33 formed on the respective colored layer patterns. Carbon) organic material is deposited by sputtering.

Here, a photosensitive resin material may be used as the material of the black matrix. A black matrix material is formed on the entire surface of the glass substrate 31, and the black matrix formed on the photoresist 33 is called the first black matrix 34a, and both edge regions and both sides of the upper surfaces of the color layer patterns are formed. And the black matrix formed on the glass substrate 31 exposed between them is called the second black matrix 34b.

As shown in FIG. 3E, a lift haute is performed to remove the positive photoresist 33 remaining on the respective colored layer patterns and the first black matrix 34a material formed thereon.

In more detail, the lift off is a method for removing the positive photoresist 33 and the first black matrix 34a material deposited thereon, and the side surface of the positive photoresist 33 formed first. The positive photoresist 33 is melted by penetrating the photoresist remover.

In this case, when the positive photoresist 33 is removed, only the first black matrix 34a material deposited thereon remains, and since there is no material capable of supporting the positive photoresist 33, the material is broken at the edge portion.

Thus, the first black matrix 34a material deposited on the portion where the positive photoresist 33 is formed is easily removed. Then, as shown in the figure, the second black matrix 34b is formed on the glass substrate 31 along the side of the colored layer pattern from both edge regions of the upper surface of the colored layer patterns.

Finally, as shown in FIG. 3F, the second black matrix 34b formed between each of the colored layer patterns spaced at a predetermined interval and the transmissivity and conductivity on the entire surface of the color filter layer 32 including the colored patterns. Indium Tin Oxide (ITO), which is a transparent electrode material having good chemical and thermal stability, is deposited by sputtering to form a common electrode 35. At this time, the ITO as the common electrode 35 does not form a separate pattern. However, in some cases, the patterning process may be performed to form the common electrode 35.

For reference, in order to protect and planarize the colored pattern before the common electrode 35 is formed, a planarization film (overcoat layer) (not coated) is formed by using a spin coating method using an acrylic resin or a polyimide resin. In some cases, it may be omitted to reduce the manufacturing process cost.                     

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the manufacturing method of the liquid crystal display device according to the present invention can reduce the number of processes by forming a black matrix without using a mask in the process of manufacturing a color filter substrate, thereby reducing the manufacturing cost.

Claims (5)

Forming a color filter layer by sequentially forming a first color layer pattern, a second color layer pattern, and a third color layer pattern on the substrate so as to be spaced apart from each other by a predetermined interval; Coating a positive photoresist on the entire surface of the substrate on which the color filter layer is formed, and then exposing the substrate on a rear surface of the substrate; Developing and curing the back exposed positive photoresist to form a positive photoresist on each of the first, second and third colored layer patterns; Depositing a black matrix material on the result of the development and curing of the positive photoresist; Lifting off a positive photoresist from the resultant on which the black matrix material is deposited to form a black matrix; Forming a common electrode on the formed result; The positive photoresist formed on the first, second and third colored layer patterns has a width narrower than the width of each colored layer pattern, and the formed black matrix is formed from both side edges of the top surface of the colored layer pattern. A method of manufacturing a liquid crystal display device, characterized in that formed on the substrate along the side. The method of claim 1, In the developing and curing of the positive photoresist, the coated positive photoresist is removed between the first color layer, the second color layer, and the third color layer at predetermined intervals. Manufacturing method. The method of claim 1, The black matrix material is formed using a chromium (Cr), chromium oxide (CrOx), a carbon-based organic material or a photosensitive resin material. The method of claim 1, And removing the positive photoresist by dissolving the positive photoresist in a side of the positive photoresist to lift off the positive photoresist to form a black matrix. The method of claim 1, An overcoat layer is formed using an acrylic resin or a polyimide resin to protect and planarize the colored pattern before forming the common electrode.

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