KR20070034309A - Color filter substrate for liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter substrate for a liquid crystal display device and a method of manufacturing the same, capable of dispersing stresses imparted to a lower film of a column spacer.

The present invention is an insulating substrate; A column spacer formed on the insulating substrate; And a protrusion formed between the column spacer and the insulating substrate and protruding the lower layer to widen the contact area between the column spacer and the lower layer positioned below the column spacer.

Description

Color filter substrate for liquid crystal display device and manufacturing method therefor {COLOR FILTER SUBSTRATE FOR LIQUID CRYSTAL DISPLAY AND FABRICATING METHOD THEREOF}

1 is a plan view illustrating a color filter substrate for a liquid crystal display according to a first exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating the color filter substrate taken along the line "I-I '" in FIG.

3A and 3B are perspective views illustrating a surface area of a lower film in contact with a column spacer according to the present invention and the related art.

4A and 4B are cross-sectional views illustrating a pressure dispersion effect caused by a contact area between a column spacer and a bottom film according to the present invention and the prior art.

5A and 5B are plan and cross-sectional views illustrating a method of manufacturing the black matrix and the protrusions shown in FIGS. 1 and 2.

6A and 6B are cross-sectional views illustrating in detail a method of manufacturing the black matrix and the protrusions illustrated in FIGS. 5A and 5B.

7A and 7B are plan views and cross-sectional views illustrating a method of manufacturing the blue, green, and red color filters illustrated in FIGS. 1 and 2.

8A and 8B are plan and cross-sectional views illustrating a method of manufacturing the overcoat layer illustrated in FIGS. 1 and 2.

9A and 9B are plan and cross-sectional views illustrating a method of manufacturing the common electrode illustrated in FIGS. 1 and 2.

10A and 10B are plan views and cross-sectional views illustrating a method of manufacturing the column spacer shown in FIGS. 1 and 2.

11 is a cross-sectional view illustrating a color filter substrate for a liquid crystal display according to a second exemplary embodiment of the present invention.

12 is a cross-sectional view illustrating a color filter substrate for a liquid crystal display according to a third exemplary embodiment of the present invention.

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

111: substrate 140: black matrix

142: color filter 144: overcoat layer

146: common electrode 148: column spacer

150: projection

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter substrate for a liquid crystal display device and a method for manufacturing the same, and more particularly, to a color filter substrate for a liquid crystal display device and a method for manufacturing the same that can disperse a stress transferred to a lower layer of a column spacer.

The liquid crystal display device displays an image by adjusting the light transmittance of the liquid crystal using an electric field. The liquid crystal display includes a thin film transistor substrate and a color filter substrate which are bonded to each other with the liquid crystal interposed therebetween.

The thin film transistor substrate includes a thin film transistor array including a gate line and a data line formed to cross each other, a thin film transistor formed at an intersection thereof, a pixel electrode connected to the thin film transistor, and a lower alignment layer coated thereon for liquid crystal alignment. It is formed on the lower substrate.

The color filter substrate includes a color filter array including a black matrix for preventing light leakage, a color filter for realizing color, a common electrode forming a vertical electric field with the pixel electrode, and an upper alignment layer coated thereon for liquid crystal alignment on the upper substrate. Is formed.

A spacer for maintaining a liquid crystal cell gap is formed between the color filter substrate and the thin film transistor substrate. The spacer is divided into a ball spacer formed by a scattering method and a column spacer formed by a photolithography method. Recently, instead of the ball spacer formed up to the pixel region, a column spacer formed to overlap the black matrix except the pixel region to increase the light transmittance is mainly used.

However, the column spacer has a problem in that the elastic force is less than the ball spacer and the reliability of the external spacer is lowered. That is, when the column spacer is subjected to an external shock, the shock is transmitted to the black matrix, the color filter, the common electrode, etc., which are positioned under the column spacer, and thus, they are damaged.

Accordingly, an object of the present invention is to provide a color filter substrate for a liquid crystal display device and a method of manufacturing the same, which can disperse a stress transferred to a lower layer of a column spacer.

In order to achieve the above object, the color filter substrate according to the present invention and the insulating substrate; A column spacer formed on the insulating substrate; And a protrusion formed between the column spacer and the insulating substrate and protruding the lower layer to widen the contact area between the column spacer and the lower layer positioned below the column spacer.

In addition, the color filter substrate may include a black matrix formed on the insulating substrate to separate pixel areas; A color filter formed on the black matrix; An overcoat layer formed on the black matrix and the color filter; And a common electrode formed on the overcoat layer and a lower layer in contact with the column spacer.

The first embodiment of the protrusion is characterized in that formed on the black matrix and the same material as the black matrix.

A second embodiment of the protrusion is characterized in that formed on the black matrix of the same material as the color filter.

The third embodiment of the protrusion may include a first protrusion formed on the black matrix and made of the same material as the black matrix; And a second protrusion formed of the same material as the color filter on the first protrusion.

In order to achieve the above object, a method of manufacturing a color filter substrate including a column spacer to maintain a liquid crystal cell gap includes projecting the lower layer to widen the contact area between the column spacer and a lower layer positioned below the column filter. And forming a protrusion between the column spacer and the insulating substrate.

The method for manufacturing the color filter substrate may further include forming a black matrix on the insulating substrate; Forming a color filter in the pixel region separated by the black matrix; Forming an overcoat layer on the black matrix and the color filter; And forming a common electrode on the overcoat layer, which is a lower layer in contact with the column spacer.

The first embodiment of the step of forming the protrusions may include forming the protrusions of the same material as the black matrix on the black matrix simultaneously with forming the black matrix.

The second embodiment of forming the protrusions may include forming the protrusions of the same material as the color filter on the black matrix at the same time as the color filter is formed.

The third embodiment of forming the protrusion may include forming a first protrusion of the same material as the black matrix on the black matrix simultaneously with forming the black matrix; And forming a second protrusion of the same material as the color filter on the black matrix at the same time as the color filter is formed.

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

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 1 to 12.

FIG. 1 is a plan view illustrating a color filter substrate of a liquid crystal display panel according to a first exemplary embodiment of the present invention, and FIG. 2 is a view illustrating a color filter substrate of a liquid crystal display panel cut along a line "I-I '" in FIG. 1. It is a cross section.

The color filter substrate shown in FIGS. 1 and 2 includes a black matrix 140 for preventing light leakage, a color filter 142 for implementing color, and an overcoat layer 144 for compensating for the step by the color filter 142. ), A common electrode 146 forming a vertical electric field with the pixel electrode, and a column spacer 148 holding a cell gap.

The black matrix 140 is formed on the upper substrate 111 to distinguish the pixel region in which the color filter 142 is to be formed. To this end, the black matrix 142 is formed to overlap the gate line, the data line and the thin film transistor. The black matrix 140 prevents light leakage, reflection of external light, and light leakage current due to exposure of the channel portion of the thin film transistor to external light between the color filters 142.

On the black matrix 140, the protrusions 150 protruding at a predetermined height are formed of the same material as the black matrix 140. The protrusion 150 is formed at a height higher than that of the color filter 142 and protrudes between the color filters 142. For example, the protrusion 150 is formed to about 1 ~ 2㎛, preferably 1.5㎛.

The color filter 142 is formed in the pixel area provided by the black matrix 140. The color filter 142 is formed for each of R, G, and B to implement R, G, and B colors.

The overcoat layer 144 is formed of a transparent organic insulator such as an acrylic resin on the color filter 142 and the black matrix 140. The overcoat layer 144 protrudes in the region corresponding to the protrusion 150 along the protrusion 150 while providing a flat surface by compensating for the step between the color filter 142 and the black matrix 140.

The common electrode 146 is supplied with a common voltage for controlling the movement of the liquid crystal. The common electrode 146 is formed to protrude along the overcoat layer 144 formed to protrude from a region corresponding to the protrusion 150.

The column spacer 148 maintains a cell gap between the color filter substrate and the thin film transistor substrate. The column spacer 148 is formed on the common electrode 146 protruding from a region corresponding to the protrusion 150.

Specifically, the column spacer 148 according to the present invention is formed on the common electrode 146 protruding along the three-dimensional protrusion 150 as shown in FIG. 3A. In contrast, the conventional column spacer 48 is formed on the flat common electrode 46 as shown in FIG. 3B. For example, if the contact area of the conventional column spacer 48 and the common electrode 46 is a circle, the contact area of the column spacer 148 and the common electrode 146 according to the present invention becomes a sphere. . In this case, the contact area between the conventional column spacer 48 and the common electrode 46 is πr ² , whereas the contact area between the column spacer 148 and the common electrode 146 according to the present invention is 4πr ² . 4 times larger For example, if the diameter of the column spacers 48 and 148 is about 40 μm, the contact area between the conventional column spacers 48 and the common electrode 46 is 1256 μm ² , whereas the column spacers 148 and the column spacers 148 according to the present invention are used. The contact area with the common electrode 146 is 5024 µm ² .

As such, the column spacer 148 according to the present invention shown in FIG. 4A has a larger contact area with the common electrode 146 than the conventional column spacer 48 shown in FIG. 4B. In this case, the column spacer 148 according to the present invention can disperse the impact applied to the column spacer 48 in various directions as compared with the related art. This is because, when the column spacers 48 and 148 are impacted from the outside as shown in Equation 1, the stress? Transmitted to the lower layer under the column spacers 148 and 148 is inversely proportional to the contact area A. to be.

As such, when the contact area between the column spacer 148 and the common electrode 146 according to the present invention increases by n times or more, the stress transferred to the lower layer of the column spacer 148 is reduced by 1 / n times. do. Accordingly, the color filter substrate according to the present invention has a common electrode 146, an overcoat layer 144, a black matrix 140, and a color filter 142 positioned under the column spacer 148 when an impact from the outside is applied. ) And damage to at least one of the upper substrate 111 can be minimized.

In addition, since the column spacer 148 according to the present invention is formed on the common electrode 146 protruding along the protrusion 150, the height of the column spacer 148 itself may be lowered. That is, the liquid crystal display panel according to the present invention maintains the cell gap by the column spacer 148, the black matrix 140, the overcoat layer 144, and the common electrode 146 protruding from the bottom thereof. Accordingly, the color filter substrate according to the present invention can reduce the material cost of the column spacer 148 having a lower height than in the prior art.

A method of manufacturing the color filter substrate will be described in detail with reference to FIGS. 5A to 10B.

5A and 5B, the black matrix 140 and the protrusion 150 are formed on the upper substrate 101. This will be described in detail with reference to FIGS. 6A and 6B.

As shown in FIG. 6A, a black photosensitive resin 188 having a negative photoresist property is coated on the entire surface of the upper substrate 111. Then, the first photo mask 180, which is a partial exposure mask including a transflective mask or a diffraction mask, is aligned on the upper substrate 111 to which the black photosensitive resin 188 is applied. The first photo mask 180 includes a mask substrate 182 made of a transparent material, a blocking portion 184 formed in the blocking region S of the mask substrate 182, and a first partial exposure region of the mask substrate 182 ( And a semi-transmissive portion or slit 186 formed in P1) and second partial exposure region P2. Here, the region where the mask substrate 182 is exposed becomes the exposure region E. FIG. In the first partial exposure region P1, the slits 186 are spaced at equal intervals in the region where the black matrix 140 is to be formed. The interval between the second partial exposure region P2 and the slits 186 toward the exposure region E increases in the region where the protrusion 150 is to be formed.

The black photosensitive resin 188 having a negative photoresist property is exposed using the first photo mask 180 and then developed. Accordingly, as shown in FIG. 6B, the negative black photosensitive resin 188 corresponding to the blocking region S of the first photo mask 180 is removed. The black matrix 140 having a second height h2 lower than the first height h1 is formed on the upper substrate 111 to correspond to the first partial exposure area P1 of the first photo mask 180. The first height h1 is positioned on the upper substrate 111 and the second partial exposure area P2 of the first photo mask 180 corresponds to the exposure area E of the first photo mask 180. Correspondingly, the protrusion 150 extending from the second height h2 to the first height h1 is formed on the upper substrate 111. Here, since the side inclination angle of the protrusion 150 is lowered by the second partial exposure region P2, the step coverage of the upper layer formed on the protrusion 150, for example, the overcoat layer 144, is improved.

In addition to the negative black photosensitive resin, the projections and the black matrix may be formed using the positive black photosensitive resin. In this case, the positive black photosensitive resin is removed in the area corresponding to the exposure area of the photomask, remains in the area corresponding to the blocking area, and remains lower than the blocking area in the area corresponding to the partial exposure area.

7A and 7B, the color filter 142 is formed on the upper substrate 111 on which the black matrix 140 including the protrusions 150 is formed.

First, a blue resin layer is formed on the upper substrate 111 on which the black matrix 140 is formed. The blue resin layer is patterned by a photolithography process using a second photo mask to form a blue (B) color filter 142 in the pixel region. Then, a green resin layer is formed on the upper substrate 111 on which the blue (B) color filter 142 is formed. The green resin layer is patterned by a photolithography process using a third photo mask to form a green (G) color filter 142 in the pixel region. Thereafter, a red resin layer is formed on the upper substrate 111 on which the green (G) color filter 142 is formed. The red resin layer is patterned by a photolithography process using a fourth photo mask to form a red (R) color filter 142 in the pixel region.

8A and 8B, an overcoat layer 144 is formed on the upper substrate 111 on which the color filter 142 is formed.

The overcoat layer 144 is formed by coating an entire surface of an organic insulating material such as an acrylic resin on the upper substrate 111 on which the color filter 142 is formed. The overcoat layer 144 protrudes from an area overlapping the protrusion 150 and is formed flat in the remaining area.

9A and 9B, a common electrode 146 is formed on the overcoat layer 144.

The common electrode 146 is formed by depositing a transparent conductive layer on the overcoat layer 144 through a deposition method such as sputtering. As the transparent conductive layer, a transparent conductive material such as indium tin oxide is used.

The common electrode 146 protrudes from an area overlapping the protrusion 150 and is formed flat in the remaining area.

10A and 10B, a column spacer 148 is formed on the upper substrate 111 on which the common electrode 146 is formed.

An organic insulating film such as photoacryl is coated on the entire surface of the upper substrate 111 on which the common electrode 146 is formed. The organic insulating film is patterned by a photolithography process to form column spacers 148. The column spacer 148 is formed to contact the common electrode 146 protruding in three dimensions along the protrusion 150.

11 is a cross-sectional view illustrating a color filter substrate according to a second embodiment of the present invention.

Referring to FIG. 11, the color filter substrate according to the second embodiment of the present invention has the same components except that the protrusions 150 are formed as color filters as compared to the color filter substrate illustrated in FIG. 2. . Accordingly, detailed description of the same components will be omitted.

The protrusion 150 is formed of the same material as the color filter 142 on the black matrix 140 overlapping the column spacer 148. The protrusion 150 is formed by any one of the R, G, and B color filters 142 or at least two color filters 142 are stacked. These protrusions 150 are formed at a relatively higher height than the color filters 142 and protrude between the color filters 142.

The overcoat layer 144 and the common electrode 146 protrude from a region corresponding to the protrusion 150.

The column spacer 148 is formed on the common electrode 146 protruding from a region corresponding to the protrusion 150. The column spacer 148 has a larger contact area with the common electrode 146 than the conventional column spacer 48. In this case, the column spacer 148 according to the present invention can disperse the impact applied to the column spacer 48 in various directions as compared with the related art.

Accordingly, the color filter substrate according to the present invention has a common electrode 146, an overcoat layer 144, a black matrix 140, and a color filter 142 positioned under the column spacer 148 when an impact from the outside is applied. ) And damage to at least one of the upper substrate 111 can be minimized.

12 is a cross-sectional view illustrating a color filter substrate according to a third embodiment of the present invention.

Referring to FIG. 12, the color filter substrate according to the third embodiment of the present invention is stacked on the first protrusion 150a formed of the same material as the black matrix 140 as compared to the color filter substrate illustrated in FIG. 2. The same components are provided except that the second protrusion 150b is further provided. Accordingly, detailed description of the same components will be omitted.

The protrusion 150 includes first and second protrusions 150a and 150b sequentially stacked on the black matrix 140 overlapping the column spacer 148.

The first protrusion 150a is formed on the black matrix 140 with the same material as the black matrix 140. The second protrusion 150b is formed of the same material as the color filter 142 on the first protrusion 150a. The second protrusion 150b may be formed of any one of the R, G, and B color filters 142, or may be formed by stacking at least two color filters 142. The protrusions 150 may be formed at a height higher than those of the protrusions illustrated in FIGS. 2 and 11.

The overcoat layer 144 and the common electrode 146 protrude from a region corresponding to the protrusion 150.

The column spacer 148 is formed on the common electrode 146 protruding from a region corresponding to the protrusion 150. The column spacer 148 has a larger contact area with the common electrode 146 than the conventional column spacer 48. In this case, the column spacer 148 according to the present invention can disperse the impact applied to the column spacer 48 in various directions as compared with the related art.

Accordingly, the color filter substrate according to the present invention has a common electrode 146, an overcoat layer 144, a black matrix 140, and a color filter 142 positioned under the column spacer 148 when an impact from the outside is applied. ) And damage to at least one of the upper substrate 111 can be minimized.

Meanwhile, the color filter substrate according to the present invention can be applied to not only a vertical field type liquid crystal display panel but also a vertical alignment type liquid crystal display panel and a horizontal field type liquid crystal display panel.

As described above, the color filter substrate for a liquid crystal display according to the present invention includes protrusions formed on a black matrix in a region overlapping with the column spacer. This projection increases the contact area between the column spacer and the lower film, so that the impact can be dispersed in various directions during an external impact. Accordingly, the color filter substrate for the liquid crystal display according to the present invention can minimize damage to at least one of the common electrode, the overcoat layer, the black matrix, the color filter, and the upper substrate disposed under the column spacer.

In addition, the color filter substrate for a liquid crystal display device according to the present invention can lower the height of the column spacer holding the liquid crystal cell gap by the projections as compared with the prior art. Accordingly, the color filter substrate for the liquid crystal display according to the present invention can reduce the material cost of the column spacer.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (10)

An insulating substrate; A column spacer formed on the insulating substrate; And a protrusion formed between the column spacer and the insulating substrate and protruding the lower layer to widen the contact area between the column spacer and the lower layer positioned below the column spacer. The method of claim 1, A black matrix formed on the insulating substrate to separate pixel regions; A color filter formed on the black matrix; An overcoat layer formed on the black matrix and the color filter; And a common electrode formed on the overcoat layer, the common electrode being in contact with the column spacer. The method of claim 2, The projection is a color filter substrate, characterized in that formed on the black matrix and the same material as the black matrix. The method of claim 2, The projection is a color filter substrate, characterized in that formed on the black matrix and the same material as the color filter. The method of claim 2, The projections A first protrusion formed on the black matrix and made of the same material as the black matrix; And a second protrusion formed on the first protrusion of the same material as the color filter. In the manufacturing method of the color filter substrate including a column spacer to maintain a liquid crystal cell gap, And forming a projection between the column spacer and the insulating substrate to protrude the lower layer so as to widen the contact area between the column spacer and the lower layer positioned below the column spacer. The method of claim 6, Forming a black matrix on the insulating substrate; Forming a color filter in the pixel region separated by the black matrix; Forming an overcoat layer on the black matrix and the color filter; And forming a common electrode on the overcoat layer, the common electrode being in contact with the column spacer. The method of claim 7, wherein Forming the protrusions And forming the protrusions of the same material as the black matrix on the black matrix at the same time as the black matrix is formed. The method of claim 7, wherein Forming the protrusions And forming the protrusions of the same material as the color filter on the black matrix at the same time as the color filter is formed. The method of claim 7, wherein Forming the protrusions Simultaneously forming the black matrix and forming a first protrusion of the same material as the black matrix on the black matrix; And forming a second protrusion of the same material as the color filter on the black matrix at the same time as the color filter is formed.

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