JP2009092881A - Color filter substrate, liquid crystal display panel, liquid crystal display device, and method for manufacturing color filter substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter substrate capable of suppressing the occurrence of light leakage during black display and the degradation in contrast in spite of formation of a resin BM, and to provide a liquid crystal display panel, a liquid crystal display device, and a method for manufacturing a color filter substrate. <P>SOLUTION: The color filter substrate is provided with a substrate, a plurality of colored layers arrayed in correspondence to pixels on one major face side of the substrate, and a light shielding layer provided in the boundary regions of the plurality of the colored layers. The light shielding layer partially varies in film thickness within one pixel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a color filter substrate, a liquid crystal display panel, a liquid crystal display device, and a method for manufacturing a color filter substrate. More specifically, the present invention relates to a color filter substrate on which a resin BM is formed, a liquid crystal display panel, a liquid crystal display device, and a method for manufacturing a color filter substrate.

2. Description of the Related Art In recent years, liquid crystal display devices having great advantages such as thin and light weight and low power consumption have been actively used as display devices for personal office automation equipment such as Japanese word processors and desktop personal computers.

In a color filter substrate for a liquid crystal display device, a colored layer is formed in a region to be a pixel on the substrate, and a light shielding layer having a certain width is provided in a boundary region of each pixel in order to increase display contrast. This light shielding layer is a black matrix (BM).

The BM is usually formed as a metal thin film with a minute pattern on a glass substrate. As the material of the metal thin film, chromium, nickel, aluminum or the like is adopted, and as a film forming method, a vapor deposition method, a sputtering method, or a vacuum film forming is generally used. Patterning of the metal thin film is performed by applying a photoresist on the metal thin film, drying, irradiating ultraviolet rays through a photomask, dissolving the unexposed portion with a developer to form a resist pattern, etching the metal, This is performed by a resist stripping process. However, this method increases the manufacturing cost due to the complexity of the process, and thus increases the cost of the color filter substrate itself. In addition, when a color filter substrate having a BM formed of this metal thin film is mounted on a liquid crystal display device, the reflectance of the surface of the metal thin film is high, so that when strong external light is irradiated, the reflected light is strong. The display quality may be remarkably deteriorated. Therefore, BM formed using resin as a material other than the metal thin film has been proposed.

Resin BM is configured by dispersing a black pigment typified by carbon black or a mixed color black pigment obtained by mixing a pigment such as red, green, blue, yellow, and purple alone or in a mixture with an alkali-soluble negative resist. Is used. As described above, the resin BM requires a thickness as compared with the metal BM because the resin BM is obtained with a black pigment containing a light shielding property in the component. As a method for forming the resin BM, first, a photosensitive resin, which is a negative resist, is applied and dried on a transparent substrate. Next, the photosensitive resin is exposed to ultraviolet rays through a photomask having a desired pattern as a black matrix. In the negative resist, the exposed portion undergoes a crosslinking reaction with light energy and is photocured, so that the solubility in the developing solution is lower than that in the unexposed portion. Pattern formation is performed using this difference in solubility. That is, after a non-exposed portion is selectively dissolved and removed using a dilute alkaline developer such as sodium carbonate, a desired pattern is formed by washing the developer. As described above, the patterning of the resin BM is only a normal photolithography process, and the pattern can be formed simply and inexpensively compared with the metal BM.

As a technique using the resin BM, one layer of BM is formed in the display area of the liquid crystal display element, two layers of BM are formed in the peripheral portion, and the sum of the BM film thickness in the peripheral portion is displayed. A liquid crystal display device in which the film thickness of the color filter in the region is formed to be substantially the same is disclosed (for example, see Patent Document 1).

Further, in a color filter having a resin BM and a colored portion provided between the resins BM on a transparent substrate, the film thickness of the resin BM in the non-display portion on the outer periphery of the display pixel region portion is the display pixel region portion. A color filter formed to be thinner than the film thickness of the resin BM is disclosed (for example, see Patent Document 2).

Then, a first step of patterning a first rib for forming a light shielding layer on the base layer by a photolithography method and a second rib having a height smaller than the first rib, and an inkjet technique A second step of dropping a translucent material in a region defined by the first rib and the second rib to form a step forming layer; and after forming the step forming layer, the first rib is formed by inkjet technology. Has disclosed a method for producing a color filter having a third step of forming a colored layer by dropping a photochromic material into a region defined by (see, for example, Patent Document 3).
JP-A-11-52351 JP 2004-69984 A JP 2006-30650 A

However, in the liquid crystal display device on which the resin BM is formed, light leakage may occur in the vicinity of the resin BM during black display, or the contrast may be lowered. More specifically, for example, in a VA (Vertical Alignment) mode liquid crystal display device in which the resin BM is formed, light leakage occurs near the end of the BM during black display. In addition, in an ECB (Electrically Controlled Birefringence) mode liquid crystal display device in which the resin BM is formed, a region that is shaded by the resin BM in the rubbing progress direction may shine white and the contrast may decrease.

The present invention has been made in view of the above situation, and even when the resin BM is formed, a color filter substrate, a liquid crystal capable of suppressing the occurrence of light leakage and a decrease in contrast during black display An object of the present invention is to provide a method for manufacturing a display panel, a liquid crystal display device, and a color filter substrate.

The present inventors have provided a color filter substrate, a liquid crystal display panel, a liquid crystal display device, and a color filter capable of suppressing the occurrence of light leakage during black display and the reduction in contrast even when the resin BM is formed. As a result of various studies on the substrate manufacturing method, attention was paid to the BM and the alignment film formed above the BM. Since the film thickness of the conventional resin BM is large and uniform, the alignment film in the region corresponding to the end portion of the resin BM has a large step, and as a result, in the vicinity of the end portion of the resin BM. They found that the alignment of liquid crystal molecules was disturbed.

Here, with reference to FIGS. 6 and 7, the cause of the occurrence of light leakage or a decrease in contrast in the vicinity of the resin BM during black display will be described in more detail. FIG. 6 is a schematic diagram showing a configuration and a display state in an active area on the color filter substrate side of a conventional VA mode liquid crystal display device during black display, (a) is a plan view, (b) These are sectional drawings in the P1-P2 line in (a). In FIG. 6, the brightness of the pixel opening is represented by gray shades. FIG. 7 is a schematic diagram showing a configuration in an active area on the color filter substrate side of a conventional ECB mode liquid crystal display device, (a) is a plan view, and (b) is Q1 in (a). It is sectional drawing in the -Q2 line.

In the VA mode, during black display, the liquid crystal molecules 115 are usually aligned perpendicular to the main surface of the transparent substrate 111 at the center of the pixel, as shown in FIG. On the other hand, the vertical alignment film 114 has a large step at the end of the resin BM 112 due to the thickness of the resin BM 112. That is, the vertical alignment film 114 is largely inclined near the end of the resin BM112. Accordingly, the liquid crystal molecules 115 are oriented obliquely with respect to the main surface of the transparent substrate 111 in the vicinity of the end portion of the resin BM112, that is, oriented in a tilted state. As a result, as shown in FIG. As shown, light leakage occurred.

On the other hand, in the ECB mode, the alignment of the liquid crystal is controlled by rubbing the alignment film. However, the alignment film 224 has a step due to the thickness of the resin BM 222 as shown in FIG. In the rubbing progress direction (the direction of the white arrow in FIG. 7), the shadowed area of the resin BM 222 (the white area in FIG. 7A and the alignment film 224 in FIG. 7B). In this region, the rubbing was not sufficiently performed, and the alignment of the liquid crystal molecules was disturbed in this region. Therefore, as shown in FIG. 7B, the shadow area of the resin BM 222 shines white, and the contrast is lowered.

Therefore, as a result of further investigation, the alignment film formed above the light shielding layer is flattened by partially changing the film thickness of the BM (light shielding layer provided in the boundary region of the colored layer) within one pixel. As a result, it was found that the alignment state of liquid crystal molecules in the vicinity of the edge of the light shielding layer, that is, the edge of the pixel was improved, and as a result, the occurrence of light leakage and the decrease in contrast could be suppressed. The inventors have arrived at the present invention by conceiving that the problem can be solved.

That is, the present invention provides a color comprising a substrate, a plurality of colored layers arranged in correspondence with pixels on one main surface side of the substrate, and a light shielding layer provided in a boundary region of the plurality of colored layers. In the filter substrate, the light shielding layer is a color filter substrate having partially different film thicknesses within one pixel. Thereby, the film thickness of the light shielding layer can be appropriately changed so that the flatness of the alignment film usually formed above the light shielding layer via the colored layer is improved. Therefore, the alignment state of the liquid crystal molecules in the vicinity of the end portion of the light shielding layer can be improved, and as a result, the occurrence of light leakage and the decrease in contrast can be suppressed.

Note that the pixels may be called sub-pixels.

The configuration of the color filter substrate of the present invention is not particularly limited as long as such components are formed as essential components, and may or may not include other components. Absent.
A preferred embodiment of the color filter substrate of the present invention will be described in detail below.

The light shielding layer may be thinner at the pixel opening side than at the center. Thereby, the alignment of the liquid crystal molecules in the vicinity of the light shielding layer can be brought close to the alignment of the liquid crystal molecules in the center of the pixel in a mode in which the alignment of the liquid crystal molecules such as the VA mode is controlled by the surface shape of the alignment film. Therefore, in the VA mode or the like, it is possible to suppress light leakage during black display.

One end portion of the light shielding layer may be thinner than the other end portion in a cross section in a direction orthogonal to the longitudinal direction. Thereby, in a mode in which the alignment of liquid crystal molecules such as ECB mode is controlled by rubbing, a region that is shaded by the resin BM of the alignment film during rubbing can be narrowed. That is, the rubbing process can be performed as designed. Therefore, in the ECB mode or the like, it is possible to suppress a decrease in contrast due to a white area in the shadow of the resin BM shining in the rubbing progress direction.

The light shielding layer may have a stepped film thickness or a taper film thickness. Accordingly, the light shielding layer can be formed more easily.

The light shielding layer may contain a resin. That is, the light shielding layer may be a resin BM. As described above, since the resin BM is usually formed thicker than the BM formed of the metal thin film, the effect of the present invention can be more effectively achieved in this embodiment. In addition, the light shielding layer can be formed more easily.

When the light shielding layer contains a resin, the light shielding layer may contain a photosensitive resin or may be composed of a single layer. As a result, the light shielding layer can be more easily formed by a photolithography process using a multi-tone mask such as a gray-tone mask or a half-tone mask without complicating the manufacturing process.

The color filter substrate may not have an overcoat layer. At this time, the alignment film is more easily affected by the film thickness of the light shielding layer. Therefore, according to this embodiment, the effect of the present invention can be achieved more effectively. In addition, the manufacturing process can be simplified.

The present invention is also a liquid crystal display panel including the color filter substrate of the present invention. Thereby, the display quality of the liquid crystal display panel can be improved.

The present invention is also a liquid crystal display device including the liquid crystal display panel of the present invention. Thereby, the display quality of a liquid crystal display device can be improved.

The present invention is a method for manufacturing a color filter substrate of the present invention, wherein the manufacturing method is a method for manufacturing a color filter substrate including a step of forming a light shielding layer using a multi-tone mask. Thereby, a light shielding layer can be produced more easily. Further, since the light transmittance can be easily controlled by using the multi-tone mask, the thickness of the light shielding layer can be controlled more easily.

The multi-tone mask is not particularly limited as long as it is a photomask having a light shielding portion, a light transmitting portion, and a halftone portion having a light transmittance between the light shielding portion and the light transmitting portion. A tone mask and a halftone mask are preferable.

According to the color filter substrate of the present invention, even when the resin BM is formed, it is possible to suppress light leakage or a decrease in contrast during black display.

Embodiments will be described below, and the present invention will be described in more detail with reference to the drawings. However, the present invention is not limited only to these embodiments.

(Embodiment 1)
First, the VA mode liquid crystal display device of Embodiment 1 will be described. The liquid crystal mode of the liquid crystal display device of the present embodiment is not particularly limited as long as it is a mode in which the alignment of liquid crystal molecules is controlled by the surface shape of the alignment film, but the VA mode is preferable. FIG. 1 is a schematic diagram illustrating a configuration in an active area on the color filter substrate side of the liquid crystal display device of Embodiment 1, (a) is a plan view, and (b) is X1- It is sectional drawing in a X2 line. FIG. 2 is a conceptual diagram showing a display state of the liquid crystal display device of Embodiment 1 during black display. In FIG. 2, the brightness of the pixel opening is represented by shades of gray.

The liquid crystal display device of Embodiment 1 includes a liquid crystal display panel 100, a backlight unit disposed on the rear side of the liquid crystal display panel 100, and a cover for housing these.

The liquid crystal display device of this embodiment may be a transmissive type, a transflective type (transmission / reflection type), or a reflection type. In the case of a reflection type, the backlight unit is not necessarily provided.

As a structure of a backlight unit, what is necessary is just to have general structures, such as a light source, a reflecting plate, and optical sheets. The backlight unit may be a direct type or an edge light type (side light type).

The liquid crystal display panel 100 includes a TFT array substrate, which is a pair of opposing substrates, a color filter substrate (CF substrate) 10, and a seal disposed along the contour of the CF substrate 10. A liquid crystal layer sandwiched between the TFT array substrate and the CF substrate 10 is formed by filling a liquid crystal material in a space formed by the substrate 10 and the seal. A pair of polarizing plates are arranged in crossed Nicols on the main surface outside the TFT array substrate and the CF substrate 10.

The TFT array substrate has a thin film transistor (TFT) as a switching element, a pixel electrode, a data wiring, a bus wiring such as a scanning wiring, as a constituent element of the display element of the liquid crystal display panel 100 on the liquid crystal layer side of the transparent substrate as a substrate. A vertical alignment film or the like is provided. Thus, the liquid crystal display panel 100 is an active matrix liquid crystal display panel.

On the other hand, as shown in FIG. 1, the CF substrate 10 is provided with a resin BM12 which is a light shielding layer formed by patterning a photosensitive resin on the liquid crystal layer side of the transparent substrate 11 which is a substrate, in a lattice shape. In the region partitioned by the resin BM12, red, green and blue colored layers (color plates, color filters) 13R, 13G and 13B are formed. As described above, the liquid crystal display panel 100 includes pixels formed of strip-shaped three-color sub-pixels arranged in a matrix. Each subpixel is a region defined by a broken line in FIG. 1A, that is, a region defined by a boundary line passing through the approximate center between adjacent subpixels. Accordingly, each sub-pixel is defined as a region including the resin BM12. The liquid crystal display panel 100 has a pixel arrangement in a stripe arrangement. Furthermore, since the resin BM12 is formed between the colored layers 13R, 13G, and 13B, it is possible to suppress color mixing between adjacent sub-pixels. In particular, the resin BM12 is formed in a staircase shape so that the pixel opening side portion is thinner than the central portion. That is, the resin BM12 has a thick film portion 12a at the center portion and a thin film portion 12b at the pixel opening side portion, and the thick film portion 12a is provided in a lattice shape corresponding to the boundary of each subpixel. The thin film portion 12b is annularly provided in each subpixel along both end portions of the thick film portion 12a.

The transparent substrate 11 is often made of glass, but may be a plastic film or a plastic sheet, for example. Further, if necessary, in order to improve adhesion between the transparent substrate 11 and the resin BM12 and the coloring material (materials of the colored layers 13R, 13G, and 13B), the adhesion is improved on the transparent substrate 11 in advance. A thin film may be formed.

The material of the resin BM12 includes a mixed color black pigment obtained by mixing a resin component and a black pigment and / or a pigment such as red, green, blue, yellow, and purple, and a solvent for dispersing and dissolving these components. It is a black photosensitive resin containing. The material of the resin BM12 may be a negative type or a positive type as long as it is a photosensitive resin such as an acrylic resin used for a general black photosensitive resin. Moreover, as a black pigment component, an organic pigment as a mixed color black pigment obtained by mixing carbon black or a pigment such as red, green, blue, yellow, or purple can be used.

Further, in the resin BM12, the light shielding property is obtained with the black pigment contained in the component, and the light shielding property proportional to the film thickness is obtained. Accordingly, the minimum film thickness of the resin BM12 is defined by the required light shielding characteristics.

In order to form the pattern of the resin BM12 on the transparent substrate 11, for example, a thin film having a thickness of about 1 to 3 μm is formed by spin coating or the like, followed by exposure, development, washing, and post-baking. it can. The resin BM12 is, for example, a lattice-shaped pattern having openings of about 60 μm × 100 μm and delimited by the resin BM12 having a width of about 20 μm. By filling the openings with a coloring material, a strip-shaped colored layer is formed. 13R, 13G, and 13B are formed. At this time, the colored layers 13R, 13G, and 13B are formed so that the end portions of the colored layers 13R, 13G, and 13B overlap the resin BM12.

The CF substrate 10 is completed by forming the transparent electrode (not shown) and the vertical alignment film 14 in this order on the resin BM12 and the colored layers 13R, 13G, and 13B formed as described above. In addition, it does not specifically limit as a material of a transparent electrode, For example, an indium tin oxide film (ITO film | membrane) is mentioned. The material of the vertical alignment film 14 is not particularly limited as long as the liquid crystal molecules are aligned substantially perpendicular to the alignment film surface, and examples thereof include thermosetting polyimide resins.

In the present embodiment, the color combination of the colored layers is not particularly limited to red, green, and blue. For example, cyan, yellow, and magenta may be used, and the color of the colored layer may be four or more colors. There may be. Further, the arrangement of the colored layers is not particularly limited to the stripe arrangement, and may be, for example, a delta arrangement, a mosaic arrangement, or the like.

According to the present embodiment, the resin BM12 is formed so that the pixel opening side is thinner than the central portion. Therefore, the inclination of the vertical alignment film 14 due to the thickness of the resin BM12 can be reduced, and the flatness of the vertical alignment film 14 in the pixel opening, particularly in the vicinity of the end of the resin BM12, can be improved. Thereby, the alignment of the liquid crystal molecules 15 in the vicinity of the resin BM 12 can be brought close to the alignment of the liquid crystal molecules 15 in the center of the pixel. That is, during black display, the liquid crystal molecules 15 near the resin BM 12 can be aligned in a direction perpendicular to the main surface of the transparent substrate 11, and as shown in FIG. The occurrence of light leakage can be suppressed.

8A to 8C are schematic cross-sectional views showing the vicinity of the resin BM of the liquid crystal display device according to the first embodiment. From the viewpoint of sufficiently suppressing the occurrence of light leakage while ensuring the necessary light shielding characteristics, the film thickness T1b of the thin film portion 12b of the resin BM12 is as thin as possible within a range that can ensure the necessary light shielding characteristics. preferable. Further, the width W1b of the thin film portion 12b is preferably as large as possible within a range in which a necessary aperture ratio can be secured. On the other hand, the film thickness T1a of the thick film portion 12a of the resin BM12 may be set as appropriate according to the necessary light shielding characteristics. Further, the width W1a of the thick film portion 12a of the resin BM12 may be appropriately set according to the width W1b of the thin film portion 12b. As described above, the angle θ1 formed by the line (surface) connecting the end boundary on the pixel opening side of the thin film portion 12b and the boundary between the thin film portion 12b and the thick film portion 12a with the main surface of the transparent substrate 11 is as shown in FIG. As shown to (a), it is preferable that it is as small as possible. Thereby, generation | occurrence | production of light leakage can fully be suppressed, ensuring a required light-shielding characteristic. On the other hand, if the width W1b of the thin film portion 12b is too short as shown in FIG. 8B, or if the film thickness T1b of the thin film portion 12b is too large as shown in FIG. In some cases, the inclination of the liquid crystal molecules 15 becomes large, and the occurrence of light leakage cannot be sufficiently suppressed.

The CF substrate 10 is provided with a transparent overcoat layer (protective layer) that protects the resin BM12 and the colored layers 13R, 13G, and 13B in a layer between the colored layers 13R, 13G, and 13B and the transparent electrode. Also good. However, when the overcoat layer does not sufficiently exhibit the flattening action, that is, when the unevenness of the resin BM12 is not flattened even when the overcoat layer is provided, or when the overcoat layer is not provided, this embodiment is particularly preferred. CF substrate 10 can be suitably used. That is, according to the CF substrate 10, even if an overcoat layer that does not sufficiently perform the planarization function is provided or an overcoat layer is not provided, the flatness of the vertical alignment film 14 is improved and black display is achieved. Occurrence of light leakage at the time can be suppressed. In addition, it does not specifically limit as a material of an overcoat layer, Transparent resins, such as a thermosetting type using an acrylic resin etc., and an ultraviolet curable type, are mentioned.

In the CF substrate 10, the resin BM 12 may also be formed in a region (element region) corresponding to a switching element such as a TFT provided on the TFT array substrate. Thereby, generation | occurrence | production of optical leak current can be suppressed. In order to suppress the light leakage current of the TFT, a certain degree of OD value is required. Therefore, it is preferable that the resin BM12 in the element region has a corresponding thickness. Thus, it is preferable that the resin BM12 in the element region has a film thickness comparable to that of the thick film portion 12a, which can more effectively suppress the occurrence of light leakage current.

Further, the CF substrate 10 may be formed with a resin BM12 in the outer peripheral area of the active area where image display is performed, so-called frame area. Thereby, generation | occurrence | production of the light leak in a frame area can be suppressed. Note that if the OD value of the resin BM12 in the frame area is small, the frame area becomes bright and the display quality is adversely affected. Therefore, the resin BM12 in the frame area is preferably formed to be thick to some extent. As described above, the resin BM12 in the frame area preferably has the same film thickness as that of the thick film portion 12a. Thus, the occurrence of light leakage in the frame area can be more effectively suppressed.

When the thickness of the resin BM12 is changed stepwise, the number of steps of the resin BM12 is not particularly limited as long as it is two or more as shown in FIG. 1, and may be three or more. From the viewpoint of forming the resin BM12 more easily while sufficiently exhibiting the above effect, it is preferable that the number of steps of the resin BM12 is small.

FIG. 3 is a schematic cross-sectional view showing a modification of the color filter substrate of Embodiment 1. As shown in FIG. 3, the resin BM 12 may have a film thickness that changes in a tapered shape. That is, the resin BM11 may have a thick film portion 12a and a tapered portion 12c. This also has the same effect as when the film thickness of the resin BM12 is changed stepwise.

When the film thickness of the resin BM12 is changed to a taper shape, the film thickness T1c at the end of the taper portion 12c on the pixel opening side is a necessary light shielding characteristic from the same viewpoint as the case where the resin BM12 is changed to a staircase shape. Is preferably as thin as possible within a range in which On the other hand, the film thickness T1a of the thick film portion 12a may be set as appropriate in accordance with the required light shielding characteristics.

Further, even when the film thickness of the resin BM12 is changed to a taper shape, the width W1c of the taper portion 12c can be within a range in which a necessary opening ratio can be secured from the same viewpoint as when the resin BM12 is changed to a step shape. It is preferable that it is as large as possible. On the other hand, the width W1a of the thick film portion 12a may be appropriately set according to the width W1c of the tapered portion 12c.

Below, the manufacturing method of the liquid crystal display device of this embodiment is demonstrated in detail. Note that the TFT array substrate of the present embodiment can be manufactured by a general method, and the description thereof is omitted.

First, as a material of the resin BM12 on the transparent substrate 11, for example, a black negative resist material is applied by a spin coating method, a slit coating method, various printing methods, or the like, prebaked using a hot plate, and black A negative resist layer is formed.

Next, a gray tone mask is disposed above the transparent substrate 11 with a gap between the mask and the substrate, and then the pattern of the resin BM 12 is exposed through the gray tone mask for the photocuring of the black negative resist. The black negative resist layer is exposed in an amount. The gray-tone mask includes a translucent part that transmits light almost completely and a light-shielding part that almost completely blocks light, and a mosaic pattern (for example, a line and space of 4 μm in both vertical and horizontal directions). (Mosaic pattern) is formed, and a halftone portion that transmits light to a predetermined intermediate level is provided. Therefore, according to the gray tone mask, a completely exposed portion, an intermediate exposed portion, and an unexposed portion can be formed on the resist layer by one exposure. Further, the intermediate exposure portion exposed through the halftone portion of the resist layer has a small exposure amount and is dissolved to some extent in the developer. Therefore, the thin film portion 12b of the resin BM12 can be formed in the intermediate exposure portion of the resist layer.

The light transmittance of the halftone portion is appropriately set according to the desired film thickness of the thin film portion 12b by adjusting the density and size of the pattern below the resolution. Further, when the thickness of the resin BM12 is changed stepwise, a gray tone mask in which a pattern having a resolution or less is formed at a constant density may be used. When the thickness of the resin BM12 is changed to a taper shape. In this case, a gray-tone mask on which a pattern of resolution or less whose density changes gradually may be used.

Next, after developing with a predetermined developer and rinsing with pure water to remove the developer, baking in an oven and curing, as shown in FIG. Resin BM12 is formed.

The resin BM12 formed in this way has an opening serving as a pixel opening, and the colored layers 13R, 13G, and 13B are formed in this portion by, for example, a pigment dispersion method. More specifically, the colored layers 13R, 13G, and 13B are formed by applying a photosensitive resist material in which a red, green, or blue pigment is dispersed, and then repeating exposure and development three times. The colored layers 13R, 13G, and 13B may be formed using a non-photosensitive material or may be formed by a dyeing method.

Next, a transparent electrode made of an ITO film is formed on the substrate by a sputtering method, and further, a vertical alignment film 14 containing a polyimide resin is formed by an offset printing method, thereby forming the CF substrate 10.

Thereafter, the TFT array substrate TFT substrate in which TFTs and the like are formed for each sub-pixel and the CF substrate 10 in which the gap material for maintaining the cell gap is formed on the substrate surface are opposed to each other. Place and seal around the panel to form empty cells. Then, a liquid crystal material containing nematic liquid crystal having a negative dielectric constant is injected into the empty cell, and the injection port is sealed. Further, the liquid crystal display panel of the present embodiment is manufactured by attaching a polarizing plate to the outer main surface of the TFT array substrate and the CF substrate 10. Furthermore, the liquid crystal display device of this embodiment can be completed by performing a module assembly process by a general method.

As described above, according to the manufacturing method of the present embodiment, the exposure amount for the portion of the resin BM12 on the pixel opening side is selected by exposing the material of the resin BM12 using the gray tone mask having a halftone portion. Therefore, the film thickness can be reduced during development, and the configuration of the resin BM12 can be easily realized. In addition, a resin BM having a single layer and having different thicknesses can be easily formed by a single photolithography process. Furthermore, the liquid crystal display device of this embodiment can be realized without adding a special process such as providing a light shielding layer on the TFT array substrate side.

In addition, as a pattern below the resolution formed in a gray tone mask, the pattern of a mosaic pattern other than a lattice pattern may be repeated. Moreover, the pattern below the resolution may be a pattern in which opening patterns having the same shape are arranged in a matrix, and may be an opening pattern such as a circle or a polygon.

Further, the material of the resin BM12 may be exposed through a halftone mask provided with a semi-transparent (semi-transparent) halftone part in addition to the light-transmitting part and the light-shielding part.

(Embodiment 2)
Next, an ECB mode liquid crystal display device according to the second embodiment will be described. The liquid crystal mode of the liquid crystal display device of the present embodiment is not particularly limited as long as the alignment of liquid crystal molecules is controlled by rubbing, and is a TN (Twisted Nematic) mode or an IPS (In-Plane Switching) mode. Etc. Further, the description of the same contents in the first embodiment and the present embodiment is omitted. 4A and 4B are schematic views showing a configuration in an active area on the color filter substrate side of the liquid crystal display device of Embodiment 2, wherein FIG. 4A is a plan view and FIG. 4B is a view of Y1- in FIG. It is sectional drawing in the Y2 line.

The liquid crystal display panel 200 of the present embodiment has a CF substrate 20, and the CF substrate 20 is arranged on the liquid crystal layer side of the transparent substrate 11 as shown in FIG. Resin BM22, which is a light shielding layer formed by patterning a photosensitive resin, is provided in a lattice shape, and red, green, and blue colored layers 13R, 13G, and 13B are formed in regions partitioned by resin BM22. Has been. Further, a transparent electrode (not shown) and an alignment film 24 are provided in this order from the transparent substrate 11 side on the resin BM22 and the colored layers 13R, 13G, and 13B. Each sub-pixel is a region defined by a broken line in FIG. 4A as in the first embodiment, and is defined as a region including the resin BM22.

However, as shown in FIG. 4B, the resin BM22 is stepped so that one end is thinner than the other end in the cross section in the direction orthogonal to the longitudinal direction of the resin BM22. Is formed. That is, the resin BM22 has a thick film portion 22a on one end side and a thin film portion 22b on the other end side, and the thick film portion 22a has a lattice shape corresponding to the boundary of each sub-pixel. The thin film portion 22b is provided in a substantially L shape in each subpixel along the end of the thick film portion 22a. As described above, the resin BM22 has an end side closer to the front side of the direction in an arbitrary direction than an end side closer to the rear side of the direction.

According to the present embodiment, the resin BM22 is formed so that one end is thinner than the other end. In addition, the alignment film 24 is inclined more gently on the thin film portion 22b side of the resin BM22 than on the thick film portion 22a side of the resin BM22. Therefore, by rubbing from the thick film portion 22a side to the thin film portion 22b side (in the direction of the white arrow in FIG. 4), a region (FIG. The white areas in a) and the white areas of the alignment film 24 in FIG. 4B can be narrowed. That is, the region to be rubbed as designed (the region painted with diagonal lines in FIG. 4A and the region painted with diagonal lines of the alignment film 24 in FIG. 4B) can be widened. . Therefore, it is possible to suppress a decrease in contrast due to the white area in the shadow of the resin BM22 shining in the rubbing direction. Thus, in the CF substrate 20, the portion on the opposite side to the rubbing origin of the resin BM 22 is thinner than the portion in the rubbing origin.

FIG. 9 is a schematic cross-sectional view showing the vicinity of the resin BM of the liquid crystal display device of Embodiment 2 in the rubbing process. From the viewpoint of sufficiently suppressing the decrease in contrast while ensuring the necessary light shielding characteristics, it is preferable that the film thickness T2b of the thin film portion 22b of the resin BM22 is as thin as possible within a range that can ensure the necessary light shielding characteristics. . In addition, the width W2b of the thin film portion 22b is preferably as large as possible within a range in which a necessary aperture ratio can be secured. On the other hand, the film thickness T2a of the thick film portion 22a of the resin BM22 may be set as appropriate according to the necessary light shielding characteristics. Further, the width W2a of the thick film portion 22a of the resin BM22 may be appropriately set according to the width W2b of the thin film portion 22b. As described above, the angle θ2 formed by the line (surface) connecting the end boundary on the pixel opening side of the thin film portion 22b and the boundary between the thin film portion 22b and the thick film portion 22a with the main surface of the transparent substrate 11 is as shown in FIG. It is preferable that it is as small as possible. As a result, the width W of the shadowed area of the resin BM 22 can be shortened without the rubbing roll 30 coming into contact with the rubbing roll 30, thereby sufficiently suppressing the decrease in contrast while ensuring the necessary light shielding characteristics. Can do.

FIG. 5 is a schematic cross-sectional view showing a modification of the color filter substrate of the second embodiment. As shown in FIG. 5, the film thickness of the resin BM22 may change in a tapered shape. That is, the resin BM21 may have a thick film portion 22a and a tapered portion 22c. This also has the same effect as when the film thickness of the resin BM22 is changed stepwise.

When the film thickness of the resin BM22 is changed to a taper shape, the film thickness T2c at the end on the pixel opening side of the taper portion 22c is a necessary light shielding characteristic from the same viewpoint as the case where the resin BM22 is changed to a staircase shape. Is preferably as thin as possible within a range in which On the other hand, the film thickness T2a of the thick film portion 22a may be set as appropriate in accordance with necessary light shielding characteristics.

Further, when the film thickness of the resin BM22 is changed to a taper shape, the width W2c of the taper portion 22c can be within a range in which a necessary opening ratio can be secured from the same viewpoint as the case where the resin BM22 is changed to a step shape. It is preferable that it is as large as possible. On the other hand, the width W2a of the thick film portion 22a may be set as appropriate in accordance with the width W2c of the tapered portion 22c.

As mentioned above, although this invention was demonstrated more concretely by Embodiment 1 and 2, you may combine each embodiment suitably in the range which does not deviate from the summary of this invention.

FIG. 2 is a schematic diagram illustrating a configuration in an active area on the color filter substrate side of the liquid crystal display device of Embodiment 1, (a) is a plan view, and (b) is a cross section taken along line X1-X2 in (a). FIG. It is a conceptual diagram which shows the display state of the liquid crystal display device of Embodiment 1 at the time of black display. FIG. 6 is a schematic cross-sectional view showing a modification of the color filter substrate of Embodiment 1. FIG. 5 is a schematic diagram illustrating a configuration in an active area on the color filter substrate side of the liquid crystal display device of Embodiment 2, wherein (a) is a plan view and (b) is a cross section taken along line Y1-Y2 in (a). FIG. FIG. 6 is a schematic cross-sectional view showing a modification of the color filter substrate of Embodiment 2. It is a schematic diagram which shows the structure and display state in the active area by the side of the color filter board | substrate of the conventional VA mode liquid crystal display device at the time of black display, (a) is a top view, (b) is (a). It is sectional drawing in the P1-P2 line in the inside. It is a schematic diagram which shows the structure in the active area by the side of the color filter substrate of the liquid crystal display device of the conventional ECB mode, (a) is a top view, (b) is in Q1-Q2 line | wire in (a). It is sectional drawing. (A)-(c) is a cross-sectional schematic diagram which shows resin BM vicinity of the liquid crystal display device of Embodiment 1. FIG. It is a cross-sectional schematic diagram which shows resin BM vicinity of the liquid crystal display device of Embodiment 2 in a rubbing process.

Explanation of symbols

10, 20: Color filter substrate (CF substrate)
11, 111: Transparent substrate (substrate)
12, 22, 112, 122: Resin BM
12a, 22a: Resin BM thick film part 12b, 22b: Resin BM thin film part 12c, 22c: Resin BM taper part 13R, 113R: Red colored layer 13G, 113G: Green colored layer 13B, 113B: Blue Colored layers 14, 114: vertical alignment films 15, 115: liquid crystal molecules 24, 224: alignment film 30: rubbing roll 100, 200: liquid crystal display panel T1a, T2a: film thickness T1b, T2b of thick film portion of resin BM : Film thickness T1c of the thin film portion of the resin BM, T2c: Film thickness W1a of the end portion on the pixel opening side of the taper portion of the resin BM, W2a: Width W1b of the thick film portion of the resin BM, W2b: Thin film portion of the resin BM Width W1c, W2c: Width of taper portion of resin BM W: Width of areas shadowed by resin BM θ1, θ2: Angle

Claims (12)

A color filter substrate comprising a substrate, a plurality of colored layers arranged corresponding to pixels on one main surface side of the substrate, and a light shielding layer provided in a boundary region of the plurality of colored layers,
The color filter substrate, wherein the light shielding layer has partially different film thicknesses within one pixel. The color filter substrate according to claim 1, wherein the light shielding layer is thinner at a pixel opening side than at a central portion. 2. The color filter substrate according to claim 1, wherein one end portion of the light shielding layer is thinner than the other end portion in a cross section in a direction orthogonal to the longitudinal direction. The color filter substrate according to claim 1, wherein the thickness of the light shielding layer changes stepwise. The color filter substrate according to claim 1, wherein the thickness of the light shielding layer changes in a tapered shape. The color filter substrate according to claim 1, wherein the light shielding layer includes a resin. The color filter substrate according to claim 6, wherein the light shielding layer includes a photosensitive resin. The color filter substrate according to claim 6, wherein the light shielding layer includes a single layer. The color filter substrate according to claim 6, wherein the color filter substrate does not have an overcoat layer. A liquid crystal display panel comprising the color filter substrate according to claim 1. A liquid crystal display device comprising the liquid crystal display panel according to claim 10. A method for producing a color filter substrate according to claim 1,
The manufacturing method includes a step of forming a light shielding layer using a multi-tone mask.

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