KR20070006485A - Method of manufacturing liquid crystal display and liquid crystal display manufactured thereby - Google Patents

Abstract

An LCD and a method for manufacturing the LCD are provided to minimize the step difference generated at color filters, thereby increasing the transmittance and brightness of an LCD panel, by improving the structure of a black matrix. A photosensitive resin is spread on a transparent insulating substrate(21). The photosensitive resin is pattern-etched using a slit mask, thereby forming a black matrix(22). The black matrix has a stepped structure, in which a lower portion is wider than an upper portion. Color filters(23) are formed on portions of the insulating substrate exposed by the black matrix. A common electrode(24) is formed above the color filters.

Description

Method of manufacturing liquid crystal display device and liquid crystal display device manufactured by the same

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

FIG. 2 is a process diagram of applying a photosensitive resin for a black matrix to a common electrode display panel of a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a flowchart illustrating a process of manufacturing a black matrix on a common electrode panel of a liquid crystal display according to an exemplary embodiment of the present invention.

4 is a process diagram of forming a red color filter on a common electrode display panel of a liquid crystal display according to an exemplary embodiment of the present invention.

5 is a process diagram of forming a green color filter on a common electrode display panel of a liquid crystal display according to an exemplary embodiment of the present invention.

6 is a process diagram of forming a blue color filter on a common electrode display panel of a liquid crystal display according to an exemplary embodiment of the present invention.

7 is a flowchart illustrating a step of forming a common electrode on a common electrode display panel of a liquid crystal display according to an exemplary embodiment of the present invention.

8 is a partial cross-sectional view of a common electrode display panel of a liquid crystal display according to another exemplary embodiment of the present invention.

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

100 liquid crystal display device 10 common electrode display plate

20: thin film transistor array panel 11, 21: insulating substrate

12 gate electrode 13 gate insulating film

14 active layer 15a source electrode

15b: drain electrode 16: insulating layer

17 pixel electrode 24 common electrode

22: black matrix 23: color filter

30: liquid crystal 40: slit mask

The present invention relates to a method for manufacturing a liquid crystal display device and a liquid crystal display device manufactured by the same, and more particularly, to a liquid crystal display device which can increase the transmittance and luminance of a liquid crystal panel by minimizing high steps generated in the pixel operation region. And a liquid crystal display device produced thereby.

Recently, as the modern society becomes the information socialization, the importance of the liquid crystal display device, which is one of the information display devices, is gradually increasing. Especially, due to its advantages such as miniaturization, light weight, and low power consumption, the liquid crystal display device As an alternative means to overcome the shortcomings of the Cathode Ray Tube (CRT), its use area is gradually expanding.

The liquid crystal display device is composed of a thin film transistor array panel in which thin film transistors, which are individual switching elements, are formed, and a common electrode display panel in which three color filter layers of red, green, and blue are repeatedly arranged to realize colorization. It is.

The common electrode display panel includes a black matrix formed of a metal such as chromium on a transparent insulating substrate, a color filter for realizing colorization, and a common electrode to which a voltage for driving a liquid crystal is applied.

The black matrix which prevents deterioration due to light and absorbs diffusely reflected light is deposited through a patterning process using a mask by depositing a metal thin film such as chromium on a transparent insulating substrate in a predetermined process. However, since the etchant that etches a metal thin film such as chromium adversely affects the environment, it is regulated to use a black matrix of chromium.

Due to these regulations, an organic black matrix using an organic compound has recently been used as an alternative to the chromium black matrix. However, the organic black matrix needs about 7.5 times the thickness of the chromium black matrix to obtain the same optical density effect as the chromium black matrix. This forms a high step in the color filter of the pixel active area, thereby reducing the transmittance and luminance of the liquid crystal panel. In addition, since the same black matrix process was performed twice to manufacture a double structured black matrix, there was a problem in that mass productivity was low due to an increase in manufacturing cost and an increase in time required for each process.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a method of manufacturing a liquid crystal display device capable of increasing transmittance and luminance of a liquid crystal panel by minimizing a high step generated in a color filter of a pixel operation region.

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

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

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, the method including applying a photosensitive resin for a black matrix on a transparent insulating substrate, and patterning the photosensitive resin for a black matrix using a slit mask. Manufacturing a black matrix integrally formed with a stepped structure having a lower width than an upper width thereof, forming a color filter on an insulating substrate exposed by the black matrix, and forming a common electrode on the color filter. Forming a step.

According to another aspect of the present invention, there is provided a liquid crystal display device having a stepped structure having a transparent insulating substrate and a lower width than an upper width thereof, and having an upper portion and a lower portion integrally formed on the insulating substrate. And a black matrix formed, a color filter formed on the insulating substrate exposed by the black matrix, and a common electrode formed on the color filter.

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 may be embodied in various forms, and the present embodiments are merely provided to 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, the invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

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

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

As shown in FIG. 1, the liquid crystal display device 100 is formed between the thin film transistor array panel 10, the common electrode display panel 20, and the two display panels 10 and 20 and is oriented in a constant direction. The liquid crystal 30 is included.

The thin film transistor array panel 10 includes an insulating substrate 11 made of a transparent insulating material such as glass, a thin film transistor 18 and a pixel electrode 17 formed on the insulating substrate 11.

Here, the gate electrode 12 formed on the transparent insulating substrate 11 of the thin film transistor 18 may include aluminum-based metals such as aluminum (Al) and aluminum alloys, silver-based metals such as silver (Ag) and silver alloys, It may be made of copper-based metals such as copper (Cu) and copper alloys, molybdenum-based metals such as molybdenum (Mo) and molybdenum alloys, chromium (Cr), titanium (Ti), and tantalum (Ta).

In addition, the source electrode 15a and the drain electrode 15b are preferably made of a refractory metal such as chromium, molybdenum-based metals, tantalum, and titanium, and include a lower film (not shown) such as a refractory metal and a low resistance material disposed thereon. It may have a multi-layered film structure consisting of an upper film (not shown).

An insulating layer 16 for exposing the drain electrode 15b is formed on the thin film transistor 18.

On the insulating layer 16, the pixel electrode 17 in electrical contact with the drain electrode 15b is laminated with a uniform thickness. The pixel electrode 17 is made of indium tin oxide (ITO) or indium zinc oxide (IZO), which is a transparent conductive material.

A process of forming the thin film transistor array panel 10 will be described below.

First, aluminum-based metals such as aluminum (Al) and aluminum alloys, silver-based metals such as silver (Ag) and silver alloys, copper (Cu) and the like on a transparent insulating substrate 11 made of an insulating material such as glass or ceramics. Copper-based metals such as copper alloys, molybdenum-based metals such as molybdenum (Mo) and molybdenum alloys, metal films such as chromium (Cr), titanium (Ti), and tantalum (Ta) are deposited, and then the metal films are patterned to form gate lines. (Not shown) and a gate electrode 12 branching from the gate line are formed.

The gate line (not shown) may have a multi-layer structure including two conductive layers (not shown) having different physical properties. One of the conductive films is made of a low resistivity metal such as an aluminum-based metal, a silver-based metal, or a copper-based metal so as to reduce the signal delay or voltage drop of the gate line. 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 line may be made of various various metals and conductors.

Subsequently, silicon nitride is deposited on the entire surface of the transparent insulating substrate 11 including the gate electrode 12 to form the gate insulating layer 13.

An amorphous silicon film is formed on the gate insulating film 13 and then patterned to form an active layer 14 on the gate insulating film 13 above the gate electrode 12. Subsequently, after depositing a metal film such as chromium, molybdenum-based metal, tantalum and titanium on the entire surface of the resultant, the metal film is patterned to branch off from the data line (not shown) orthogonal to the gate line. The source electrode 15a and the drain electrode 15b are formed.

Through the above process, the thin film transistor 18 including the gate electrode 12, the active layer 14, the source electrode 15a, and the drain electrode 15b is completed. At this time, a gate insulating film 13 is interposed between the gate line and the data line to prevent the gate line from contacting the data line.

Subsequently, an insulating layer 16 is formed on the entire surface of the transparent insulating substrate 11 on which the thin film transistor 18 is formed. Then, a metal film, for example, a reflective conductive film or a transparent conductive film or a metal film in which the reflective conductive film and the transparent conductive film are laminated on the insulating layer 16 is deposited, and the metal film is patterned into a predetermined pixel shape to form a pixel electrode ( 17).

Subsequently, an alignment film (not shown) is formed on the pixel electrode 17 to pre-tilt the liquid crystal molecules in the liquid crystal layer at a selected angle by applying a resist and rubbing treatment or the like.

The alignment film should be deposited on the insulating substrate 11 with a uniform thickness, and rubbing should also be uniform. This rubbing is an important process for determining the initial alignment direction of the liquid crystal. The rubbing of the alignment layer enables normal driving of the liquid crystal and has uniform display characteristics.

The thin film transistor array panel 10 including the gate electrode 12, the gate insulating layer 13, the active layer 14, the source electrode 15a, and the drain electrode 15b is completed by the above-described process.

Next, the common electrode display panel 20 will be described in detail.

The common electrode display panel 20 includes an insulating substrate 21 made of a transparent insulating material such as glass, a black matrix 22 that prevents deterioration due to light formed on the insulating substrate 21 and absorbs diffusely reflected light; The color filter 23 formed on the insulating substrate 21 exposed by the black matrix 22 and the common electrode 24 positioned on the color filter 23 are included.

Here, the black matrix 22 is integrally formed with a lower portion 22a of the flat plate structure and an upper portion 22b positioned on the lower portion 22a and narrower than the width of the lower portion 22a, and having both inclined sides between 0 and 90. It is formed.

The black matrix 22 having such a structure causes the color filter 23 applied on the black matrix 22 to flow down to the pixel active region by both inclined sides of the upper portion 22b. The step difference formed in the color filter of the pixel operation region is minimized, and only the black matrix 22 is formed.

Here, when the inclined side surface of the upper portion 22b of the black matrix 22 is z, the amount Q of the fluid flowing in the z direction may be defined by Equation 1.

Where W is the width of the fluid, δ is the thickness of the fluid, μ is the viscosity of the fluid, and α is the angle formed by the inclined side of the top.

)에 비례한다. As described above, the quantity Q of the fluid flowing down in the z-direction by Equation 1 is applied to the angle? Thickness of

Is proportional to).

In addition, since the thickness to which the color filter 23 is applied is fixed according to the color reproducibility standard required by the user, the thickness of the color filter 23 flowing down to the pixel operation region through the inclined surface of the top 22b of the black matrix 22 is increased. The amount Q is determined by the angle α formed by the inclined side of the upper portion 22b of the black matrix 22.

Accordingly, by optimizing the angles α between the upper and lower portions 22b and 22a of the black matrix 22, the amount of fluid flowing into the pixel operation region is increased, thereby minimizing the level difference of the color filter 23. The process of forming the black matrix 22 will be described later in detail.

The color filter 23 is formed on the transparent insulating substrate 21 exposed by the black matrix 22 and is composed of red, green, and blue.

The color filter 23 is formed to have a predetermined thickness, and is applied by a printing method, a pigment dispersion method, a polymer electrodeposition method, or the like and formed by a photo process. In the present embodiment, the color filter 23 is described using an example formed on the common electrode display panel 20, but the present invention is not limited thereto, and the color filter 23 may be formed on the thin film transistor array panel 10. have.

The common electrode 24 is stacked on the color filter 23 formed as above in a uniform thickness. Here, the common electrode 24 is made of ITO, IZO, or the like, which is a transparent conductive material.

An alignment film (not shown) is stacked on the common electrode 24. This alignment film is formed on the thin film transistor array panel 10 and the common electrode display panel 20, whereby the liquid crystal molecules in the liquid crystal layer 30 interposed therebetween are pre-tilted at a selected angle. do.

The common electrode display panel 20 including the color filter 23, the black matrix 22, and the common electrode 24 is completed by performing the above-described process.

Here, an overcoat layer made of an organic material for planarization may be formed between the color filter 23 and the common electrode 24.

A manufacturing process of the common electrode display panel will be described in more detail with reference to FIGS. 2 to 7.

As shown in FIG. 2, the photosensitive resin 31 for black matrix is applied onto the transparent insulating substrate 21.

Here, the photosensitive resin 31 for black matrix is coated on the transparent insulating substrate 21 with a predetermined thickness by an optical density rule, and a spin coating method or a coating method using a slit may be used.

For example, in the case of the black matrix photosensitive resin 31, the thickness applied is approximately 1.5 µm or more, and the thickness thereof may be thinner according to the kind of the black matrix photosensitive resin 31.

As illustrated in FIG. 3, the black matrix 22 is manufactured by exposing the photosensitive resin 31 for black matrix applied through one exposure process using the slit mask 40.

The slit mask 40 includes a first region 47 through which ultraviolet rays are transmitted, a second region 45 having a diffraction pattern configured to transmit only a predetermined amount of ultraviolet rays, and a third region 43 blocking ultraviolet rays. The second region 45 of the slit mask 40 is positioned to correspond to the lower side 22b of the black matrix 22 and the side surface of the upper side 22a.

Here, since the black matrix 22 has a negative photoresist property, the black matrix 22 positioned corresponding to the third region 43 of the slit mask 40 is not cured by ultraviolet rays and thus is removed. The black matrix 22 positioned corresponding to the second region 45 is cured and removed by a predetermined thickness by diffraction exposure of ultraviolet rays, so that the side surface is inclined.

In addition, when the black matrix 22 has a positive photo resist property, the third region 43 of the slit mask 40 is positioned corresponding to the portion of the black matrix 22 to be unremoved. This is because the positive photoresist has a property of removing the exposed portion.

The black matrix 22 thus formed includes a lower portion 22b of the flat plate structure and an upper portion 22a positioned above the lower portion 22b and having a width narrower than that of the lower portion 22b.

In addition, the upper part 22a and the lower part 22b of the black matrix 22 are integrally formed, and both sides of the upper part 22a are formed to be inclined between 0 and 90 degrees. Here, the cross section of the upper portion 22a may have a trapezoidal shape. Here, the inclined side surface of the upper portion 22a of the black matrix 22 increases the amount of the color filter photosensitive resin applied on the black matrix 22 to flow into the pixel operation region. Therefore, the amount of the photosensitive resin material for the color filter remaining on the black matrix 22 is minimized, and the level difference generated in the pixel operation area is minimized to improve the light transmittance.

In addition, the thickness from the transparent insulating substrate 21 to the lower portion 22b of the black matrix 22 is 1.0 to 1.3 μm, and the thickness from the lower portion 22b to the upper portion 22a is formed to be 0.2 to 0.5 μm. This has the effect that the color filters are laminated on the lower part 22b of the black matrix 22 and the light transmittance is reduced by the stacked color filters, thereby satisfying a predetermined optical density specification.

4 to 6, color filters 25, 27, and 29 are formed on the transparent insulating substrate 21 exposed by the black matrix 22 formed by the above-described process.

The color filters 25, 27, and 29 are composed of three colors of red, green, and blue, and use a photosensitive resin in which pigments are dispersed.

Referring to FIG. 4, the red color filter 25 has a predetermined uniformity such that the black matrix 22 is superposed on the transparent insulating substrate 21 on the photosensitive resin material 51 in which the pigment having red spectral characteristics is dispersed. Apply to thickness. The photosensitive resin material 51 thus applied is soft bakered on a hot plate at 80 to 110 ° for 5 minutes, then selectively exposed using a photo mask 55, and then developed for 2 to 3 minutes with a developer. Through the red color filter 25 is formed.

Next, as shown in FIG. 5, the green color filter 27 uses the black matrix 22 and the red color on the transparent insulating substrate 21 to disperse the photosensitive resin material 61 in which the pigment having green spectral characteristics is dispersed. Applying a predetermined uniform thickness to overlap the color filter 25, soft baker for 5 minutes on a hot plate of 80 to 110 °, and then using a photo mask 65 so as not to overlap with the red color filter 25 To form.

Subsequently, as shown in FIG. 6, the blue color filter 29 uses a red and green color filter 25 on the transparent insulating substrate 21 to place a photosensitive resin 71 in which a pigment having blue spectral characteristics is dispersed. 27) and a predetermined uniform thickness so that the black matrix 22 overlaps, soft baker for 5 minutes on a hot plate of 80 to 110 °, and then the photo so as not to overlap with the red and green color filters 25, 27 It forms in the process using the mask 75. In the present exemplary embodiment, an example in which the red color filter 25 is formed first is described. However, the present invention is not limited thereto, and the order in which the red filters are formed may be arbitrarily determined.

In addition, the photosensitive resins 51, 61, and 71 for color filters may be formed of photopolymerizable photosensitive compositions such as photopolymerization initiators, monomers, and binders, and organic pigments having red, blue, green, or similar colors. Consists of. In addition, the photosensitive resins 51, 61, and 71 may be applied by a printing method, a dyeing method, a polymer electrodeposition method, a pigment dispersion method, or the like.

Through the above-described process, red, green, and blue color filters 25, 27, and 29 are formed, and the color filters 25, 27, and 29 have a region overlapping a portion of the adjacent black matrix 22. do.

In addition, an overcoat film (not shown) may be formed on the transparent insulating substrate 21 on which the color filters 25, 27, and 29 are formed by applying a transparent resin having insulating properties for planarization.

As shown in FIG. 7, a common electrode 24 is formed on the formed color filters 25, 27, and 29.

Here, the common electrode 24 is a portion to which a voltage for driving the liquid crystal is applied, and uses ITO or IZO, which is a transparent conductive material, and has a uniform thickness of about 500 to 1300 1 on the color filters 25, 27, and 29. It is formed by a sputtering method or the like.

In addition, an alignment layer (not shown) may be coated on the common electrode 24 to align the liquid crystal molecules.

Hereinafter, another embodiment of the present invention will be described with reference to FIG. 8. For convenience of description, members having the same functions as the members shown in the drawings of the embodiments described with reference to FIGS. 2 to 7 are denoted by the same reference numerals, and thus description thereof is omitted.

As shown in Fig. 8, the common electrode display panel of this embodiment has a basically identical structure except for the following. That is, as shown in FIG. 8, the common electrode display panel 800 according to the present exemplary embodiment includes a black matrix 810 having a triangular cross section at an upper portion thereof.

Here, as shown in FIGS. 2 and 3, the black matrix 810 having a triangular cross section at the top is coated with a photosensitive resin for the black matrix 810 on the transparent insulating substrate 21, thereby using a slit mask. It is formed by an exposure process.

The slit mask is composed of a first region that transmits ultraviolet rays, a second region having a diffraction pattern that transmits only a predetermined amount of ultraviolet rays, and a third region that blocks ultraviolet rays. The width is adjusted to expose the black matrix 810 at a corresponding position, thereby forming a black matrix 810 including an upper portion having a triangular cross section.

The color filters 25, 27, and 29 are formed on the transparent insulating substrate 21 exposed by the black matrix 810 thus formed, and the common electrode 24 is formed on the color filters 25, 27 and 29. do.

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, the embodiments described above are to be understood in all respects as illustrative and not restrictive.

As mentioned above, according to the manufacturing method of the liquid crystal display device of this invention, and the liquid crystal display device manufactured by it, there exist one or more of the following effects.

First, there is an advantage of increasing the transmittance and brightness by manufacturing a black matrix that minimizes the high step generated in the color filter of the pixel operation region.

Secondly, the black matrix is manufactured by one exposure process, thereby reducing the manufacturing cost and processing time.

Claims (14)

Applying the photosensitive resin for the black matrix onto the transparent insulating substrate; Patterning the photosensitive resin for the black matrix using a slit mask to have a step width structure wider than a width of an upper part thereof to produce a black matrix in which the upper part and the lower part are integrally formed; Forming a color filter on the insulating substrate exposed by the black matrix; And And forming a common electrode on the color filter. The method of claim 1, wherein the slit mask, A first region corresponding to an upper portion of the black matrix and transmitting ultraviolet rays; A second region corresponding to the inclined surfaces of the lower portion and the upper portion of the black matrix and positioned next to the first region and having slits formed to transmit ultraviolet rays by a predetermined amount; And And a third region corresponding to a region other than the black matrix and positioned next to the second region and blocking ultraviolet rays. The method of claim 2, The manufacturing method of the liquid crystal display device which manufactures the said black matrix in one exposure process using the said slit mask. According to claim 1, The lower part of the black matrix is a flat plate structure, An upper portion of the black matrix is disposed above the lower portion, and is narrower than the width of the lower portion, and has a side surface inclined between 0 ° and 90 °. The method of claim 4, wherein The lower part has a thickness of 1.0 to 1.3㎛ manufacturing method of the liquid crystal display device. The method of claim 4, wherein The upper part has a thickness of 0.2 ~ 0.5㎛ manufacturing method of the liquid crystal display device. The method of claim 4, wherein The upper part has a trapezoidal cross section. The method of claim 4, wherein The upper portion has a triangular cross-section of the liquid crystal display device manufacturing method. Transparent insulating substrates; A black matrix having a step width structure wider than a width of an upper portion of the upper portion, wherein the upper and lower portions are integrally formed on the insulating substrate; A color filter formed on the insulating substrate exposed by the black matrix; And And a common electrode formed on the color filter. The method of claim 9, The lower part of the black matrix is a flat plate structure, An upper portion of the black matrix is disposed above the lower portion, and is narrower than the width of the lower portion, and has two inclined side surfaces between 0 ° and 90 °. The method of claim 10, The lower portion of the liquid crystal display device having a thickness of 1.0 ~ 1.3㎛. The method of claim 10, The upper portion has a thickness of 0.2 ~ 0.5㎛ liquid crystal display device. The method of claim 10, The upper portion has a trapezoidal cross section. The method of claim 10, The upper portion of the liquid crystal display device having a triangular cross section.

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