KR101222973B1 - Liquid crystal display and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a multi-domain liquid crystal display device and a method of manufacturing the same. By forming a streamlined hole and rib that distorts a fringe electric field together with a color filter, a separate mask process is not required, thereby simplifying the manufacturing process and reducing manufacturing costs. Can be saved.

MVA, Rib, Color Filter, Hole, Slit

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal display device and a method of manufacturing the same,

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

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

3A to 3E are cross-sectional views for explaining stepwise a manufacturing method of the color filter substrate shown in FIG.

4 is a cross-sectional view of a liquid crystal display according to another exemplary embodiment of the present invention.

5A to 5D are cross-sectional views for explaining a method of manufacturing the color filter substrate shown in FIG. 4 step by step.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

10: color filter substrate 12, 22: insulating substrate

14 color filter 16, 17 hole

18 common electrode 24 pixel electrode

30: liquid crystal layer 32: liquid crystal molecules

50: rib 50A, 50B: protrusion

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a method of manufacturing the same that can simplify the manufacturing process for multi-domains.

A liquid crystal display device displays an image using electrical and optical characteristics of a liquid crystal. The liquid crystal display device includes a liquid crystal display panel for displaying an image through a pixel matrix using liquid crystal, a driving circuit for driving the liquid crystal display panel, and a backlight unit for supplying light to the liquid crystal display panel. The liquid crystal display is developing with a wide viewing angle technology in order to overcome a viewing angle limitation point in which an image is distorted depending on a position of a screen.

As a representative wide viewing angle technology of the liquid crystal display, a multi-domain VA (Multi-domain Vertical Alignment) mode is used. In the VA mode, liquid crystal molecules having negative dielectric anisotropy are vertically oriented and driven perpendicular to the electric field direction to adjust light transmittance. In the multi-domain VA mode, a wide viewing angle is obtained by dividing each sub-pixel into multi-domains in which the alignment directions of liquid crystal molecules are different so that the transmittance change is mutually compensated. For example, multi-domains are formed by being divided by dielectric ribs (or slits) formed in each sub-pixel. Dielectric ribs (or slits) cause liquid crystal molecules adjacent to them to be arranged at symmetrical pre-tilt angles around the ribs (or slits) and distort the fringe field adjacent to them when a driving voltage is applied. The molecules are driven symmetrically about the ribs (or slits) to form a multi-domain.

However, in order to form dielectric ribs (or slits) in each sub-pixel, a mask process including a deposition process, a photolithography process, an etching process, and the like must be added. Accordingly, the liquid crystal display of the multi-domain VA mode has a problem in that the manufacturing process is complicated and the manufacturing cost is increased.

Accordingly, an aspect of the present invention is to provide a liquid crystal display device and a method of manufacturing the same, which are designed to solve a conventional problem and can simplify a manufacturing process for a multi-domain.

To this end, the liquid crystal display according to the embodiment of the present invention is formed in each of the sub-pixels of the substrate, the color filter having a streamlined hole and rib on the surface; A black matrix formed between the substrate and the color filter to separate the sub pixels; And a common electrode formed on the front surface of the color filter including the hole and the rib, the common electrode having a streamlined surface along the hole and the rib, wherein the hole is formed in the color filter in the sub-pixel, and the rib is formed in the color filter. Peripheral portions of the color filters having different colors overlap with each other at the overlapping portion of the color filter and the black matrix to protrude.

The ribs may include a first protrusion having a thickness gradually decreasing as the periphery of the first color filter overlapping the black matrix toward the distal end, and a periphery of the second color filter different from the first color filter toward the distal end. The second protrusions, which gradually decrease in thickness, overlap each other.

A method of manufacturing a liquid crystal display according to an exemplary embodiment of the present invention may include forming a black matrix on a substrate to separate sub pixels; Sequentially forming a color filter having streamlined holes and ribs on a surface of each of the sub-pixels; And forming a common electrode having a streamlined surface along the hole and the rib in front of the color filter including the hole and the rib, wherein the hole is formed in the color filter in the sub-pixel. The protruding portion is formed by overlapping peripheral portions of the color filter having different colors in the overlapping portion of the color filter and the black matrix.

The ribs may include a first protrusion having a thickness gradually decreasing as the periphery of the first color filter overlapping the black matrix toward the distal end, and a periphery of the second color filter different from the first color filter toward the distal end. The second protrusions, which gradually decrease in thickness, overlap each other. Each of the first and second protrusions corresponds to an exposed portion of the mask and is overetched.

Other features and advantages of the present invention in addition to the features of the present invention will become apparent from the description of the preferred embodiment of the present invention with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 1 to 5D.

1 is a cross-sectional view schematically illustrating a part of one sub-pixel in a liquid crystal display of a multi-domain VA mode according to an exemplary embodiment of the present invention.

In one sub-pixel of the liquid crystal display shown in FIG. 1, the common electrode 18 of the color filter substrate 10 and the pixel electrode 24 of the thin film transistor substrate 20 face each other with the liquid crystal layer 30 interposed therebetween. Has a structure. The color filter substrate 10 includes a color filter 14 and a common electrode 18 stacked on the first insulating substrate 12, and the thin film transistor substrate 20 is a pixel formed on the second insulating substrate 22. An electrode 24 is provided. A black matrix (not shown) is further formed between the first insulating substrate 12 and the color filter 14 of the color filter substrate 10, and the second insulating substrate 20 and the pixel electrode of the thin film transistor substrate 20 are formed. A plurality of signal lines and insulating films are further formed between the 24 and the thin film transistors (not shown). In addition, an alignment layer for determining the alignment of the liquid crystal molecules 32 is further formed on one surface of each of the color filter substrate 10 and the thin film transistor substrate 20 in contact with the liquid crystal layer 30.

The color filter 14 is formed with a hole 16 having a concave streamlined surface, and the common electrode 18 is formed along the surface of the color filter 14 including the hole 16 and thus the hole of the color filter 14. It has a streamlined surface corresponding to (16). Liquid crystal molecules 32 adjacent to the hole 16 of the color filter 14 are arranged with a pre-tilt angle symmetric about the center of the hole 16. When a vertical electric field is formed between the common electrode 18 and the pixel electrode 24, the fringe electric field adjacent to the hole 16 of the color filter 14 is distorted in a direction perpendicular to an equipotential line parallel to the streamlined surface of the common electrode 18. do. The liquid crystal molecules 32 are driven symmetrically along the distorted fringe electric field in the pre-tilt direction, i.e., with respect to the hole 16 of the color filter 14, to form a multi-domain that can complement each other. do. The holes 16 of the color filters 14 that distinguish the multi-domains are elongated in the form of straight lines, diagonal lines or curves in each sub-pixel.

The holes 16 of the color filter 14 are formed together with the color filter 14 in a photolithography process in which a color photoresist is applied and patterned to form the color filter 14. Therefore, a separate mask process for forming the hole 16 distorting the fringe electric field is not required in each sub-pixel, thereby simplifying the manufacturing process of the liquid crystal display device.

2 is a cross-sectional view schematically illustrating a part of red, green, and blue sub-pixels in a liquid crystal display of a multi-domain VA mode according to another exemplary embodiment of the present invention.

The red (hereinafter R), green (hereinafter G), and blue (hereinafter B) sub-pixels of the liquid crystal display shown in FIG. 2 are pixels of the common electrode 18 of the color filter substrate 10 and the thin film transistor substrate 20. The electrode 24 has a structure in which the electrode 24 faces the liquid crystal layer 30 therebetween.

The color filter substrate 10 includes R, G, and B color filters 14 and a common electrode 18 stacked on the first insulating substrate 12, and the first insulating substrate 12 and the R, G, and B substrates. A black matrix 13 formed between the color filters 14 is provided. The black matrix 13 is formed in a matrix form to distinguish the R, G, and B sub pixel areas while preventing external light reflection and light leakage. The R, G, and B color filters 14 are formed in the sub-pixel area so that when the white light is incident, the R, G, and B color filters are transmitted. The common electrode 18 supplies a common voltage, which is a reference for driving the liquid crystal, to the R, G, and B sub pixels in common.

The thin film transistor substrate 20 includes a pixel electrode 24 formed on the second insulating substrate 22, and a plurality of thin film transistors (not shown) are disposed between the second insulating substrate 20 and the pixel electrode 24. Signal lines and insulating films (not shown) are further formed. For example, the thin film transistor substrate 20 may include a gate line and a data line intersecting on the second insulating substrate 22, a pixel electrode 24 formed in each sub pixel region divided by the intersection of the gate line and the data line, A thin film transistor connected between the gate line and the data line and the pixel electrode 24 is provided. The thin film transistor supplies the data signal from the data line to the pixel electrode 24 in response to the scan signal from the gate line.

On one surface of each of the color filter substrate 10 and the thin film transistor substrate 20 in contact with the liquid crystal layer 30, an alignment layer for determining the alignment of the liquid crystal molecules 32 is further formed. For example, the liquid crystal molecules 32 are oriented in the vertical direction to be driven in VA mode. In addition, a spacer (not shown) is formed between the color filter substrate 10 and the thin film transistor substrate 20 to form a cell gap in which the liquid crystal layer 30 is formed.

Each of the R, G, and B sub-pixels charges a pixel voltage which is a difference voltage between a common voltage supplied to the common electrode 18 and a data signal supplied to the pixel electrode 24, and has liquid crystal molecules 32 having dielectric anisotropy. ) Is driven according to the pixel voltage to adjust the light transmittance to realize gradation. Accordingly, a color of each pixel is realized by a combination of red, green, and blue sub-pixels representing gray levels according to data signals, and the liquid crystal display displays an image by the combination of each pixel.

Further, in each of the R, G, and B color filters 14 of the R, G, and B sub pixels, a first hole 16 having a concave streamlined surface is formed to form a multi-domain. In addition, the periphery of the R, G, B sub-pixels, that is, the periphery of the R, G, B color filters 14 overlapping the black matrix 13 is formed in each of the periphery of two adjacent color filters 14 and is concave, streamlined. The second hole 17 forming the surface is provided. The second hole 17 is symmetrically formed in two adjacent color filters 14 in the portion overlapping with the black matrix 13. Since the common electrode 18 is formed along the surface of the color filter 14 including the first and second holes 16 and 17, the common electrode 18 also includes the first and second holes of the color filter 14. 16, 17) has a streamlined surface. The liquid crystal molecules 32 adjacent to the first and second holes 16, 17 of the color filter 14 have a pre-tilt angle symmetric about the center of the first and second holes 16, 17. Are arranged. When a vertical electric field is formed between the common electrode 18 and the pixel electrode 24, the fringe field adjacent to the first and second holes 16 and 17 of the color filter 14 is parallel to the streamlined surface of the common electrode 18. It is distorted in the direction orthogonal to the equipotential lines. The liquid crystal molecules 32 are driven symmetrically in the pre-tilt direction along the distorted fringe electric field, i.e., relative to the first and second holes 16 and 17 of the color filter 14 to complement each other. To form multi-domains. The first hole 16 of the color filter 14 is formed long in a straight line, diagonal line, or curved line in each sub-pixel. The second hole 17 of the color filter 14 is formed long in a straight line, diagonal line, or curved line along the black matrix 13 overlapping the boundary of each sub-pixel.

 The shape of the first and second holes 16, 17 of the color filter 14 determines the pre-tilt angle and driving direction of the liquid crystal molecules 32, so that a predetermined angled surface for uniform arrangement and control of the liquid crystal molecules It is preferable to have a streamlined surface than when having. In addition, the size (width) of the first and second holes 16 and 17, that is, the diameter determines the aperture ratio and the response speed of the liquid crystal molecules 32 so that they are appropriately set. For example, the diameter of the first hole 16 is set in the range of 5 µm to 15 µm in order to ensure an appropriate response speed while ensuring an opening ratio. The diameter of the second hole 17 is set smaller than the line width of the black matrix 13 so as to completely overlap the black matrix 13 in order to secure the aperture ratio. The first and second holes 16, 17 of the color filter 14 are formed together with the color filter 14 in a photolithography process for forming the R, G, B color filters 14.

Specifically, FIGS. 3A to 3E are cross-sectional views for explaining a method of manufacturing the color filter substrate 10 shown in FIG. 2 step by step.

Referring to FIG. 3A, a black matrix 13 is formed on one surface of the first insulating substrate 10. The black matrix 13 is formed by depositing a black matrix material such as chromium (Cr) or black resin on one surface of the first insulating substrate 10 and then patterning the same using a mask process. For example, when chromium is used, the mask process includes a photolithography process and an etching process, and when black resin is used, only a photolithography process is used.

Referring to FIG. 3B, an R color filter 14 including a part of the first hole 16 and the second hole 17 in a corresponding sub pixel area of the first insulating substrate 10 on which the black matrix 13 is formed. Is formed. The R color filter 14 is formed by depositing an R photoresist containing a red pigment and then patterning it by a photolithography process using a mask, and at the same time, the first hole 16 in each sub pixel and both ends of each sub pixel. A part of the second hole 17 located is formed. In general, the color photoresist is negatively insoluble, and only the R photoresist in the region exposed to ultraviolet rays is insolubilized to form an R color filter 14, and the R photoresist in the region where the ultraviolet rays are blocked is removed by a developer. . In other words, the R color filter 14 is formed corresponding to the exposed portion of the mask, and a part of the first hole 16 and the second hole 17 at both ends of the R color filter 14 is a blocking portion of the mask. It is formed correspondingly. Particularly, a part of the second hole 17 is formed to overlap the black matrix 13 by extending the masking portion adjacent to the edge of the black matrix 13 on the R color filter 14 side. Here, the development conditions such as the development time and the composition ratio of the developer are appropriately adjusted so that a part of the first hole 16 and the second hole 17 can have a streamlined surface.

3C and 3D, the photolithography process using G photoresist and the photolithography process using B photoresist are repeated as described above to form G and B color filters 14 in each of the corresponding sub-pixel regions, respectively. do. At this time, each of the G and B color filters 14 is formed with a part of the first hole 16 and the second hole 17 corresponding to the blocking portion of the mask, and a part of the second hole 17 has another adjacent color. Combined with a portion of the second hole 17 of the filter 14 to form a streamlined surface similar to the first hole 16.

Referring to FIG. 3E, a common electrode 18 is formed by depositing a transparent conductive material on the color filter 14. The common electrode 18 is formed with a uniform thickness along the surface of the color filter 14 having the first and second holes 16, 17, so that the streamlined surface corresponding to the first and second holes 16, 17 is provided. Has

As described above, in the method of manufacturing the liquid crystal display according to the present invention, the manufacturing process may be simplified by forming the first and second holes 16 and 17 which distort the fringe electric field together with the color filter 14.

4 is a cross-sectional view schematically illustrating a part of red, green, and blue sub-pixels in a liquid crystal display of a multi-domain VA mode according to another exemplary embodiment of the present invention.

In the liquid crystal display shown in FIG. 4, in contrast to the liquid crystal display shown in FIG. 2, instead of the second hole 17 of the color filter 14 shown in FIG. Since the streamlined rib 50 of the structure has the same components except that the structure is overlapped with the black matrix 13, the description of the overlapping components will be omitted.

In each of the R, G, and B color filters 14 of the R, G, and B subpixels, holes 16 having a streamlined surface are formed to form a multi-domain. In addition, ribs 50 having convex, streamlined surfaces are formed at both ends of the color filters 14 of different colors adjacent to each other where the black matrix 13 is positioned between the R, G, and B subpixels. In particular, the rib 50 of the color filter 14 is formed convexly so that both ends of each of the R, G, and B color filters 14 overlap the black matrix 13, and the thickness gradually decreases (or increases) in the opposite direction. The two protrusions 50A and 50B overlap each other. For example, the first protrusion 50A gradually decreases in thickness from one edge of the black matrix 13 to the other edge to have a streamlined surface, and the second protrusion 50B overlapping the first protrusion 50A. The thickness gradually decreases in a direction opposite to the first protrusion 50A to have a streamlined surface. Thus, the rib 50 has a streamlined surface that is uniformly convex in a combination of the first and second protrusions 50A, 50B. The hole 16 of the color filter 14 has a diameter in the range of 5 μm to 15 μm in consideration of the aperture ratio and the response speed, and the rib 50 is completely overlapped with the black matrix 13 or the black matrix ( It has a diameter that does not deviate greatly to the outside of 13). The holes 16 and ribs 50 of the color filter 14 are formed together with the color filter 14 in a photolithography process for forming the R, G, and B color filters 14.

The common electrode 18 is formed along the surface of the color filter 14 including the hole 16 and the rib 50 so that the concave streamlined surface corresponding to the hole 16 of the color filter 14 and the rib 50 are formed. ) And the corresponding convex streamlined surface. The liquid crystal molecules 32 adjacent the holes 16 and ribs 50 of the color filter 14 are arranged with symmetrical pre-tilt angles about the center of each of the grooves 16 and ribs 50. When a vertical electric field is formed between the common electrode 18 and the pixel electrode 24, the fringe electric field adjacent to the hole 16 and the rib 50 of the color filter 14 may have an equipotential line parallel to the streamlined surface of the common electrode 18. It is distorted in the orthogonal direction. The liquid crystal molecules 32 are driven symmetrically in the pre-tilt direction along the distorted fringe electric field, that is, with respect to the holes 16 and the ribs 50 of the color filter 14 to complement each other. Forms a multi-domain. The hole 16 of the color filter 14 is formed long in a straight line, diagonal line, or curved shape in each sub-pixel. The rib 50 of the color filter 14 is formed long in a straight line, diagonal line, or curved shape along the black matrix 13 overlapping the boundary of each sub-pixel.

Specifically, FIGS. 5A to 5D are cross-sectional views for explaining stepwise a method of manufacturing the color filter substrate 10 shown in FIG. 4.

Referring to FIG. 5A, a black matrix 13 is formed on one surface of the first insulating substrate 10. The black matrix 13 is formed by depositing a black matrix material such as chromium (Cr) or black resin on one surface of the first insulating substrate 10 and then patterning the same using a mask process. For example, when chromium is used, the mask process includes a photolithography process and an etching process, and when black resin is used, only a photolithography process is used.

In addition, an R color filter 14 including a hole 16 and a protrusion 50A is formed in a corresponding sub pixel area of the first insulating substrate 10 on which the black matrix 13 is formed. The R color filter 14 is formed by depositing an R photoresist containing a red pigment and then patterning it by a photolithography process using a mask, and at the same time, a black matrix (at both ends of the subpixels and holes 16 in each subpixel) Overlaid with 13), a protruding portion 50A is formed. In particular, the protrusion 50A of the R color filter 14 gradually decreases in thickness from the inner (relative to the R color filter) edge to the outer (relative to the R color filter) edge of the black matrix 13 to have a streamlined surface. do. In general, the color photoresist is of a negative type and the R color filter 14 is formed corresponding to the exposed portion of the mask, and the hole 16 in the R color filter 14 is formed corresponding to the blocking portion of the mask. Here, the development conditions such as the development time and the composition ratio of the developer are appropriately adjusted so that the holes 16 and the protrusions 50A have a streamlined surface. For example, both ends of the R color filter 14 superimposed with the black matrix 13 correspond to the exposed portion of the mask, but are overetched due to an increase in development time, thereby gradually increasing from the inner edge to the outer edge of the black matrix 13. The thickness is reduced to have a streamlined surface.

5B and 5C, the photolithography process using G photoresist and the photolithography process using B photoresist are repeated as described above, whereby G and B color filters 14 are formed in each of the corresponding sub-pixel regions, respectively. do. At this time, each of the G and B color filters 14 is provided with a hole 16 corresponding to the blocking portion of the mask. In addition, both sides of each of the G and B color filters 14 overlapping the black matrix 13 are overetched so that the thickness gradually decreases from the inner edge to the outer edge of the black matrix 13. Thus having a streamlined surface by the overlap of R and G protrusions 50A, 50B, the overlap of G and B protrusions 50A, 50B, and the overlap of B and R protrusions 50A, 50B, respectively. Ribs 50 are formed.

Referring to FIG. 5D, a common electrode 18 is formed by depositing a transparent conductive material on the color filter 14. The common electrode 18 is formed to have a uniform thickness along the surface of the color filter 14 having the holes 16 and the ribs 50 and thus has a streamlined surface corresponding to the holes 16 and the ribs 50.

As described above, the manufacturing method of the liquid crystal display according to the present invention may be simplified by forming the holes 16 and the ribs 17 that distort the fringe electric field together with the color filter 14.

As described above, the liquid crystal display and the manufacturing method thereof according to the present invention simplify the manufacturing process by forming a streamlined hole or streamlined hole and rib that distorts the fringe electric field together with the color filter, thereby eliminating a separate mask process. can do. Therefore, manufacturing cost can be reduced.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the 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 (18)

A color filter formed in each of the sub-pixels of the substrate and having a streamlined hole and a rib on its surface; A black matrix formed between the substrate and the color filter to separate the sub pixels; And A common electrode formed on a front surface of the color filter including the holes and ribs, the common electrode having a streamlined surface along the holes and ribs; And the hole is formed in the color filter in the sub-pixel, and the rib is formed by overlapping peripheral portions of the color filter having different colors at the overlapping portion of the color filter and the black matrix. delete delete delete delete delete delete The method of claim 1, The rib is The first protrusion that gradually decreases in thickness as the periphery of the first color filter overlapping the black matrix toward the end, and the periphery of the second color filter, which is different in color from the first color filter, gradually increase toward the end. And a second protrusion having a reduced thickness overlapping each other. Forming a black matrix on the substrate to separate the sub pixels; Sequentially forming a color filter having streamlined holes and ribs on a surface of each of the sub-pixels; And Forming a common electrode having a streamlined surface along the holes and ribs in front of the color filter including the holes and ribs, Wherein the hole is formed in the color filter in the sub-pixel, and the rib is formed so that a peripheral portion of the color filter having a different color overlaps and protrudes from an overlapping portion of the color filter and the black matrix. Manufacturing method. delete delete delete delete The method of claim 9, And the color filter corresponds to the exposed portion of the mask and the streamlined hole corresponds to the cutoff portion of the mask. delete delete The method of claim 9, The rib is The first protrusion that gradually decreases in thickness as the periphery of the first color filter overlapping the black matrix toward the end, and the periphery of the second color filter, which is different in color from the first color filter, gradually increase toward the end. And a second protrusion having a reduced thickness is formed to overlap each other. The method of claim 17, Wherein each of the first and second protrusions corresponds to an exposed portion of the mask and is overetched to form the liquid crystal display device.

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