JP2008058579A - Method of manufacturing color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a color filter, which can prevent a trouble of disconnection of a transparent electrode layer on a boundary part between an RGB pixel part and a light shielding film without causing shape defection such as overhang on a pigment dispersion resin layer of the RGB pixel part upon development, in the manufacturing method of a color filter in which a light-shielding film layer of a grid pattern and the RGB pixel part using a colored photosensitive resin are formed and the transparent electrode layer is formed on the light shielding film layer and the RGB pixel part. <P>SOLUTION: In the method of manufacturing the color filter, the exposure, development and baking are performed by using a color filter photomask having a half-tone film layer dividedly formed by the half-tone film on a region in the neighborhood of the outer periphery part of a color filter pixel pattern formed on the color filter photomask, wherein a color filter layer having a forwardly tapered shape is formed by producing a thermal sagging on the outer periphery part of a color filter pixel pattern upon the baking. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a color filter used in a color liquid crystal display device, and a transparent electrode layer is formed on the surface of red (R), green (G), and blue (B) pixels formed on a transparent substrate for a color filter. In particular, the present invention relates to a method for manufacturing a color filter that prevents a disconnection failure of a transparent electrode caused by a side cross-sectional shape of each pixel, and in particular, a reverse tapered shape of each pixel cross-section formed on a transparent substrate for a color filter. That is, the present invention relates to a method of manufacturing a color filter that improves an overhang shape.

  Conventionally, the following manufacturing methods are known as a manufacturing method of a color filter for a color liquid crystal display device (hereinafter referred to as a color filter). First, a light shielding film layer is formed in a lattice pattern having openings on one side of a color filter transparent substrate (hereinafter referred to as a color filter substrate). Next, a red (R) pigment-dispersed photosensitive resin is uniformly applied and prebaked to form a red (R) pigment-dispersed resin layer. Next, pattern exposure is performed on the red (R) pigment-dispersed resin layer using a color filter photomask (hereinafter referred to as a R pixel color filter mask) on which a red (R) pixel pattern is formed, The pattern of R pixels is selectively cured. Next, the red (R) pigment-dispersed resin layer is developed to dissolve and remove the uncured R pixel, that is, the red (R) pigment-dispersed resin layer other than the pattern. Next, post baking is performed to form red (R) pixels.

  Next, a green (G) pigment-dispersed photosensitive resin is uniformly applied and pre-baked to form a green (G) pigment-dispersed resin layer. Next, pattern exposure is performed on the green (G) pigment-dispersed resin layer using a color filter mask for the G pixel, and the pattern of the G pixel is selectively cured. Next, the green (G) pigment-dispersed resin layer is developed to remove the uncured pigment-dispersed resin layer. Next, post-baking is performed to form green (G) pixels.

  Similarly, a blue (B) pigment-dispersed photosensitive resin is uniformly applied and pre-baked to form a blue (B) pigment-dispersed resin layer. Next, pattern exposure is performed on the blue (B) pigment-dispersed resin layer using a color filter mask for the B pixel, and the pattern of the B pixel is selectively cured. Next, the blue (B) pigment-dispersed resin layer is developed to remove the uncured pigment-dispersed resin layer. Next, post-baking is performed to form blue (B) pixels. Thus, red (R), green (G), and blue (B) pixels (hereinafter referred to as RGB pixels) are formed on the color filter substrate.

  Next, a transparent electrode layer having a predetermined pattern shape is formed on the pixel region on the color filter substrate by applying a film of a transparent electrode by a known method, for example, a sputtering method. This completes the color filter.

A method for forming the pixel, for example, the R pixel will be described. In the R pixel, a red (R) pigment-dispersed photosensitive resin (hereinafter referred to as pigment-dispersed resin) layer formed on a color filter substrate is passed through an opening of an R pixel pattern of a predetermined photomask. This is a process in which ultraviolet light is irradiated and only the pigment-dispersed resin at the irradiated site is insolubilized to form an R pixel of the pigment-dispersed resin layer. In the process, it is important that the pigment dispersion resin portion irradiated with ultraviolet light is uniformly insolubilized from the surface layer portion to the bottom layer portion. When the insolubilization becomes non-uniform, there is a problem that the dissolution rate in the developer is different, and the R pixel cannot be formed into a normal shape after the development process in the subsequent process. In the above process, it is necessary to set an optimum irradiation condition for the pigment-dispersed resin to be used. As a device to be applied to the color filter mask, an R pixel pattern opening (mask transparent portion) and pattern portion (mask shielding) are used. A proposal has been made to prevent reverse taper by devising the pattern in the vicinity of the boundary line with the part (see Patent Document 1). Here, the periphery of the pixel pattern opening is used as a boundary light-shielding portion, and a mask having an opening contour line on the outside thereof is used to harden the edge by combining light by diffraction.

  The pigment-dispersed resin contains a pigment having a particle diameter of 0.01 to 1 μm dispersed in a photosensitive resin. Therefore, in order to photocure the pigment dispersion resin of the RGB pixel part, even if it is irradiated with visible light and ultraviolet rays, there is a problem that the visible light and ultraviolet rays are difficult to reach the bottom layer part by being absorbed by the pigment in the optical path. An RGB pixel portion made of an uncured pigment-dispersed resin remains on the lower bottom portion. That is, the upper bottom portion of the RGB pixel portion is cured and the lower bottom portion is uncured, and the lower bottom portion is easily eroded by the developer from the peripheral portion of the pixel pattern.

  The photosensitive resin is a known one, and is, for example, a multi-component system including a reactive monomer, a reactive oligomer, a sensitizer, a photopolymerization initiator, and the like, and its properties are visible light or ultraviolet light. It is in the property that the solubility changes and becomes insoluble by light irradiation, that is, the solubility change before and after the light irradiation, and the formation of the RGB pixel portion of the photosensitive resin is based on this property. is there. In particular, the photopolymerization initiator has a role of initiating radical polymerization by photoexcitation by irradiation with ultraviolet light and further increasing the rate of radical polymerization reaction. In addition, since the photopolymerization initiator is selected and used as a material that reacts strongly with ultraviolet light in a predetermined wavelength region, the pigment of the RGB pixel portion is excited by photoexcitation by irradiation with ultraviolet light in the predetermined wavelength region. In the upper bottom portion of the dispersed resin layer, the insolubility is increased. Ultraviolet light in the specified wavelength range is absorbed by the photopolymerization initiator in the pigment-dispersed resin layer in the middle of the optical path, increasing the rate of radical polymerization reaction, making it difficult for ultraviolet rays to reach the lower bottom, so radical polymerization at the lower bottom An uncured RGB pixel portion with a low reaction rate is likely to be formed. That is, the vicinity of the upper bottom portion of the pigment-dispersed resin is strongly cured and insoluble, and conversely, the vicinity of the lower bottom portion is an RGB pixel portion that is weakly cured and remains soluble. There is a problem in that the side wall of the uncured RGB pixel portion in the lower bottom portion described above is dissolved in the developing solution at the time of development processing, and excessive dissolution tends to occur in the lower bottom portion. That is, the surface layer portion and the bottom layer portion of the pigment-dispersed resin layer have different insolubility, the surface layer portion is less uncured, the bottom layer portion is more uncured, and there is a difference in insolubility between the surface layer portion and the bottom layer portion. There is an expanding problem. In addition to the R pixel described above, the G pixel and the B pixel have the same problem.

  Next, a conventional color filter mask and color filter pixels using the mask will be described. FIG. 5 is a partially enlarged side sectional view for explaining the structure of a conventional color filter mask and the RGB pixels of a color filter formed using the mask. FIG. 5A is a color filter mask, and FIG. , RGB pixels of the color filter.

  In the conventional color filter mask shown in FIG. 5A, a pattern layer 2 of a shielding film made of a metal thin film or a metal oxide thin film, for example, a two-layer film of Cr / CrO is formed on one side of a transparent mask substrate 1. It is the color filter mask 10 of the formed structure. In the color filter mask, during exposure, the pattern layer 2 of the shielding film layer shields the exposure light, and the transparent substrate 1 layer transmits the exposure light, and only the transparent substrate 1 transmits the exposure light. It has a function of transmitting 100% or shielding all of the exposure light at a portion where the shielding layer 2 exists, that is, having a function of transmitting 0% of the exposure light.

FIG. 5B shows a structure in which the light shielding film layer 13 and the RGB pixels 12 are formed in the openings on the color filter substrate 11. In a conventional color filter mask, the pattern opening is only a transparent substrate, and all (100%) of the exposure light transmitted through the opening is irradiated to the pigment-dispersed resin layer. The difference in insolubility is enlarged. On the other hand, since all of the exposure light transmitted through the shielding portion of the color filter mask 10 is not irradiated to the pigment-dispersed resin layer, the non-pixel is not insoluble. Therefore, in the vicinity of the boundary line of the color filter pixel pattern, which is set outside the contour line of the pixel opening, the upper bottom part of the color filter pixel is insolubilized to the vicinity of the boundary line, and the lower bottom part of the color filter pixel is It remains soluble from the line to the inside. As a result, the upper bottom line width of the pixel is normal, and the lower bottom line width of the pixel becomes an inversely tapered shape. That is, this shape is called an overhang shape.

  Usually, even when the pattern shape of the RGB pixels of the color filter mask is miniaturized, there is a problem that the difference in insolubility is enlarged. The increasing tendency of the difference in insolubility tends to increase as the sensitivity of the pigment-dispersed resin resist increases. As described above, when the difference in insolubility increases, there is a problem that the side cross section of the RGB pixel 12 is formed in a reverse taper, that is, an overhang shape, as a result of development processing.

  FIG. 6 is a partially enlarged cross-sectional view of a conventional color filter, (a) is a side cross-sectional view after the formation of RGB pixels 12, and (b) is a side cross-section on which a transparent electrode layer 14 is further formed. FIG.

  FIG. 6A shows an RGB pixel 12 formed in the opening of the light shielding film layer 13 on the color filter substrate 11, and the side end section of the RGB pixel 12 has an overhanging shape, that is, a reverse tapered sectional shape. Is formed.

  In the RGB pixel 12 that tends to overhang in FIG. 6B, when the transparent electrode layer 14 is formed, it is difficult to form the transparent electrode layer 14 on the side wall of the RGB pixel 12. There is a problem that it becomes a portion 30 with poor disconnection.

  FIG. 7 is a side sectional view for explaining the state of a conventional development process. (A) is before the development process, (b) is after the development process, and (c) is after the post-baking process. Pixels.

7A shows a color filter substrate 11 in a state where the pigment-dispersed resin layer 4 having a thickness of 1.0 to 3.0 μm is irradiated through a conventional color filter mask, and FIG. Is the same state. In the exposure using the proximity exposure apparatus, ultraviolet exposure of 100 to 300 mJ / cm ² is performed, and as a result, the 100% exposure light transmission region 100 in the central portion of the pigment-dispersed resin layer 4 becomes the insoluble portion 4a. The part becomes the semi-insoluble part 4b or the dissolved part 4c.

  FIG. 7B shows the pigment-dispersed resin layer 4 that has been developed with the developer, and the remaining soluble pigment-dispersed resin layer 4 is washed away according to the degree of insolubilization. . The dissolving portion 4c is completely dissolved, and the semi-insoluble portion 4b is greatly different depending on the concentration of the developing solution and the development processing time. As a result, the RGB pixel 12 made of an insoluble pigment dispersion resin is formed.

  FIG. 7C shows the RGB pixel 12 obtained by post-baking the RGB pixel 12 of the insoluble pigment dispersion resin under the condition of 230 ° C./20 minutes. The line width of the lower bottom portion 6 is narrowed, and the line width of the upper bottom portion 9 is finished to a normal line width. At both ends of the upper base portion 9 of the RGB pixel 12, depending on the degree of the overhang shape, a problem of film thickness failure occurs in the film forming process for the transparent electrode in the next process.

As described above, in the pigment-dispersed resin layer, even if visible light and ultraviolet rays are irradiated, it is absorbed by the pigment in the pigment-dispersed resin layer, and the irradiated light does not easily reach the bottom layer portion. The pixel portion is uncured. That is, the vicinity of the upper bottom portion of the pigment-dispersed resin layer is strongly cured and insoluble, and conversely, the vicinity of the lower bottom portion is an RGB pixel portion that is weakly cured and remains soluble. Therefore, at the time of development processing, in the RGB pixel portion, the color filter having the RGB pixel portion 12 having a shape with a wide width in the vicinity of the upper bottom portion and a narrow width in the vicinity of the lower bottom portion, that is, an overhanging side sectional shape. Become. When the transparent electrode layer 14 is formed on the color filter by sputtering or the like, in the overhanging RGB pixel portion, film formation on the side wall portion of the lower bottom portion is hindered, and the transparent electrode layer has a uniform thickness. There is a problem that a portion 30 having a disconnection due to a non-attached film or insufficient film is generated without being formed.

The known literature is described below.
JP-A-7-318715

  An object of the present invention is to produce a color filter using a pigment-dispersed resin, particularly when proximity exposure is performed on a light-irradiated portion-curable pigment-dispersed resin layer, and shape defects such as overhangs are present. A transparent electrode layer having a uniform film thickness is formed on the light shielding film of the RGB pixel portion and the lattice pattern without being generated, and the transparent electrode layer is deposited on the boundary between the RGB pixel portion and the lattice pattern of the light shielding film. Provided are a color filter mask and a color filter manufacturing method using the same, which can prevent disconnection failure due to shortage or the like.

  According to the first aspect of the present invention, a light shielding film layer having a lattice pattern and a color filter layer using a colored photosensitive resin are formed on a transparent substrate for a color filter, and the light shielding film layer and the color filter layer are formed on the light shielding film layer and the color filter layer. In a color filter manufacturing method for forming a transparent electrode layer, a color filter photomask having a halftone film layer partitioned and formed by a halftone film in the vicinity of the pattern outer periphery of the color filter formed on the color filter photomask A color filter manufacturing method is characterized in that a forward-tapered color filter layer is formed by exposing, developing, and baking using a film, and causing thermal sagging at the pattern outer periphery of the color filter during the baking.

  In the invention according to claim 2 of the present invention, the halftone film layer is formed in a region extending outward from a boundary region for partitioning the color filter pattern, and the expansion width is equal to or less than the resolution of the photosensitive resin to be used. The method for producing a color filter according to claim 1, wherein:

  According to the manufacturing method of the present invention, the RGB pixel portion that has passed through the transparent layer of the mask substrate and the RGB that has passed through the halftone film layer by the exposure method using the color filter mask having the halftone film layer of the present invention. Since the irradiation amount is different at the outer peripheral portion of the pixel portion, that is, the outer peripheral portion of the RGB pixel portion has a smaller exposure amount than the RGB pixel portion, in the development process of the next process, the RGB pixel portion and its outer peripheral portion are: A difference in solubility of the pigment-dispersed resin layer is caused, and heat sagging occurs at the outer peripheral portion during post-baking, resulting in the formation of an RGB pixel portion having a forward tapered cross-sectional shape, and a uniform film thickness on the RGB pixel and the light shielding film. Thus, a transparent electrode layer is formed, and a color filter free from defective disconnection of the transparent electrode layer can be produced on the pattern boundary between the RGB pixel portion and the light shielding film. The transparent electrode exhibits a stable resistance value.

  The mask for color filters of the present invention will be described below based on an embodiment.

FIG. 1 is a partially enlarged side sectional view for explaining a color filter mask of the present invention and a color filter formed using the color filter mask. FIG. 1 (a) is a color filter mask, and FIG. 3 is an enlarged view of a pixel of the color filter 20. FIG.

  A mask 10 for a color filter according to the present invention shown in FIG. 1A has a shielding film pattern layer 2 made of a metal thin film or a metal oxide thin film, for example, a two-layer film of Cr / CrO, on one surface of a transparent mask substrate 1. , And a half-tone film pattern having an extremely narrow width formed on the peripheral portion of the pattern layer, the transparent substrate portion 1 through which the exposure light is totally transmitted, and a half portion in which the specified wavelength region is mainly semi-transmitted. This is a color filter mask 10 having a configuration in which a tone film layer 3 and a shielding film pattern layer 2 that shields the entire wavelength region are formed.

  The mask substrate 1 is made of quartz glass (hereinafter referred to as QZ).

  The pattern layer 2 of the shielding film made of the metal thin film or the metal oxide thin film is for shielding exposure light, using a metal such as Cr (metal chromium), the first layer being Cr, and the two layers thereon. The eyes are formed of a two-layer film of CrO (metal oxide chromium). Usually, a mask blank is one in which a Cr / CrO two-layer shielding film is formed on the entire surface of one side of a mask substrate, or a photoresist layer is formed on the shielding film. As a method for forming the shielding film, a vacuum deposition method for forming a metal thin film layer in an atmosphere in which a minute amount of gas is mixed in a vacuum is used.

  The halftone film layer 3 will be described. The halftone film layer 3 is formed by partitioning with a film layer having a transmittance between the transmission part and the shielding part.

  A shielding film 2 is provided on one side of the mask substrate 1, a halftone film 3 is provided on the outer periphery of the shielding film, and the outside of the halftone film is a transparent portion of the mask substrate. The shielding film is mainly a pattern part. Between the region formed by the shielding film and the transparent portion region, a region having a constant width and formed by the halftone film is provided. If the width of the halftone film region is set to be smaller than the resolution width of the photosensitive resin used for forming the color filter on the color filter substrate, the original pattern shape and its dimensions are less affected. In the formation of the area defined by the halftone film, the data of the halftone film can be easily obtained by expanding the original pattern data in the direction of the outer periphery and expanding it by a predetermined width, that is, the data resizing method. Can be created. The predetermined width is a method of expanding by the minimum unit of data, for example, a method of setting three times the minimum unit and four times the minimum unit. In this method, for example, when the resolution limit of the current resist is around 12 μm and the minimum unit (address size) is 1 μm, the data is resized in the positive direction by 12 times the width of 12 μm, Only the data area is extracted, and the extracted data is used as halftone film data. In some cases, a halftone film having a width larger than the resolution limit may be formed, and it is necessary to optimize accordingly.

The material of the halftone film will be described. The halftone film material is for obtaining an effect due to a difference in transmittance between the light transmission part and the transmitted light in the halftone film part. For this reason, the halftone film is preferably a metal or metal silicide oxide film or a nitrided oxide film, and the proportion of metal in the film is suitably about 3% to 10%. As the metal, SiO ₂ (silicon oxide), ITO (oxide indium), or the like is used. A sputtering method is effective as the film forming method. As a sputtering target, silicon, indium tin alloy, or the like is used, and an argon film and a mixed gas of oxygen, oxygen, and nitrogen are used as a sputtering gas, whereby an oxide film, a nitride film, and a nitrided oxide film can be obtained. . The film thickness is suitably about 1000 to 3000 mm.

Next, a method for manufacturing a color filter mask will be described. A pattern resist in which a pattern figure is drawn by an electron beam drawing apparatus is formed by a known manufacturing method, for example, using drawing information including pattern data prepared in advance and a mask blank. After the pattern resist is developed, the exposed shielding film surface is etched using the pattern resist as a mask. After the resist stripping process, the shielding film pattern layer 2 is partitioned and further formed from the shielding film pattern to the transparent substrate. Further, after forming a halftone film by sputtering and applying a resist on the halftone film, a pattern resist in which a halftone pattern figure is drawn by an electron beam drawing apparatus is formed. After developing the pattern resist, the exposed halftone film surface is etched using the pattern resist as a mask, and after the resist stripping process, the halftone film layer 3 is partitioned and the color having the halftone of the present invention The filter mask is completed.

  In FIG. 1A, shielding films 2 that shield exposure light are formed on both sides. The shielding film 2 is an area that completely shields exposure light, and the surface of the pigment-dispersed resin layer 4 corresponding to the area on the color filter in FIG. The pigment-dispersed resin layer can maintain a 0% insoluble (that is, 100% -dissolved) pigment-dispersed resin layer. The transparent glass portion 1 of the mask substrate 1 is an area that completely transmits exposure light, and sufficient exposure light hits the surface of the pigment-dispersed resin layer 4 corresponding to the area on the color filter, The pigment-dispersed resin layer is transformed into a 100% insoluble pigment-dispersed resin layer. On the other hand, the halftone film layer 3 is an area that transmits about half of the exposure light, and about half of the exposure light hits the surface of the pigment-dispersed resin layer 4 corresponding to the area on the color filter. For example, the pigment-dispersed resin layer is transformed into an insoluble pigment-dispersed resin layer of about 50%. In the halftone film layer 3 region, that is, at the boundary between the shielding film layer 2 and the transparent glass part 1, the insolubility of the resist is particularly nonuniform, and the surface of the pigment-dispersed resin layer 4 in the vicinity of the boundary At the interface from the substrate surface to the substrate surface, the solubility varies stepwise, and the insolubility is lower toward the substrate surface side. In general, the half-tone film layer 3 side is an approximately 50% insoluble pigment dispersion resin layer, and the transparent glass portion 1 side is an insoluble pigment dispersion resin layer of 100%. In the exposure light irradiation, the RGB pixel pattern formed on the color filter substrate 11 after development and baking by using the color filter mask of the present invention has normal line widths at the upper and lower bases. FIG. 5 shows a forward tapered cross section in which the lower bottom line width is wider than the upper bottom line width. In the exposure of the present invention, the halftone film layers 3 are formed at the side edges on both sides of the RGB pixel pattern, respectively, and the effect of the halftone film, that is, the thermal sagging phenomenon at the time of baking after exposure and development is added. This is the result.

  In the exposure method of the present invention, an exposure unit that irradiates parallel light parallel to the optical axis, a stage unit on which a color filter substrate is mounted, and a color filter mask are mounted in parallel in the vicinity of the color filter substrate. This is a method using a proximity exposure apparatus including a mask mounting portion. For example, in the case of a mercury lamp, the light source mainly has an ultraviolet wavelength range of 312 nm which is an emission line wavelength and a wavelength band near 365 nm.

  FIG. 2 is a side cross-sectional view of a partially enlarged color filter of the present invention, (a) is a side cross-sectional view in a state where up to RGB pixels 12 are formed, and (b) is further a transparent electrode layer 14. It is a sectional side view in the state where was formed.

  FIG. 2A is a side cross-sectional view of a structure in which RGB pixels 12 are formed in the openings of the light shielding film layer 13 on the color filter substrate 11. The end side cross section of the RGB pixel 12 is formed in a gentle mountain shape, that is, a forward tapered cross section.

  FIG. 2B is a side sectional view in which a transparent electrode layer 14 is further formed. A transparent electrode layer 14 having a predetermined thickness is formed on the entire surface of the light shielding film layer 13 and the RGB pixels 12. The transparent electrode 14 is formed with a uniform film thickness, and in particular, the RGB pixels 12 are also formed with a normal film thickness on the gentle chevron-shaped end side wall surface. Not done.

FIG. 4 is a side sectional view for explaining the state of the development processing of the present invention, (a) is before development processing, (b) is after development processing, and (c) is post-baking processing. It is a later pixel.

  FIG. 4A shows the color filter substrate 11 in a state where the pigment-dispersed resin layer 4 having a thickness of 1.0 to 3.0 μm is irradiated through the color filter mask having the halftone film layer of the present invention. This is the same state as in FIG. In the exposure using the proximity exposure apparatus, ultraviolet exposure of 100 to 300 mJ / cm 2 is performed, and as a result, the pigment-dispersed resin layer 4 has a 100% exposure light transmission region 100 in the center as an insoluble portion 4a. The 50% exposure light transmission region 50 at both ends becomes the semi-insoluble portion 4b, and the outer 0% exposure light transmission region 200 becomes the dissolution portion 4c.

  FIG. 4B shows the pigment-dispersed resin layer 4 that has been developed with the developer, and is formed by washing away the remaining soluble pigment-dispersed resin layer 4 according to the degree of insolubilization. . All the dissolving portions 4c are dissolved, and the semi-insoluble portion 4b is melted in an intermediate taper, so that the developing speed is fast, and in particular, it is dissolved in a reverse taper shape on the side of the substrate surface. As a result, the RGB pixel 12 made of an insoluble pigment dispersion resin is formed. The side walls on both sides of the RGB pixel 12 are 50% exposure light transmission areas, that is, exposure areas by a halftone film layer, and are formed in a reverse tapered side shape although the film thickness is thin as a whole.

  FIG. 4C shows the RGB pixel 12 obtained by post-baking the RGB pixel 12 of the insoluble pigment dispersion resin under the condition of 230 ° C./20 minutes. The line width of the lower bottom portion 6 is widened, and the line width of the upper bottom portion 9 is finished to a normal line width. This is because the resin is softened by heat during the post-baking process, and the semi-insoluble portion 4b becomes a gentle chevron-shaped forward tapered side wall due to thermal deformation. At both ends of the RGB pixel 12, the reverse taper shape has been eliminated between the upper surface of the light shielding film layer 13 that is in contact with the lower bottom portion 6, so that the film thickness is normal and uniform in the subsequent transparent electrode film forming process. It becomes.

  Next, the manufacturing method of the color filter of this invention is demonstrated.

  3a to 3f are side sectional views for explaining the method for producing a color filter of the present invention.

  In the method for producing a color filter of the present invention, a step of forming a light-curable pigment-dispersed resin layer in many cases after forming a light-shielding film (black matrix) layer on one side of a color filter substrate; A step of irradiating the pigment-dispersed resin layer with exposure light from a mercury lamp through a color filter mask; a step of developing and baking the pigment-dispersed resin layer; and repeatedly executing the steps, R pixel, G pixel, After forming the B pixel, a transparent electrode layer having a predetermined shape is formed.

  FIG. 3A shows a transparent substrate preparation process, in which a color filter substrate 11 for LCD is formed in a lot, and the transparent substrate is placed in a charging case. The color filter substrate 11 is formed to have a predetermined size, and a plate thickness of 1.1 mm to 0.35 mm is prepared with 0.7 mm as the center, and the process is performed for each input case. The color filter substrate is a transparent substrate on which a light shielding film is formed in advance or is not processed. In this step, processing such as surface cleaning is mainly performed.

  FIG. 3B shows a process for forming a light shielding film layer, which is a light shielding film layer, for example, a metal having a thickness of 1000 mm or a composite film of a metal and a metal oxide film, or a light shielding film having a thickness of 1 to 3 μm made of black polymer resin. Layer 13 is formed. In this step, the former light shielding film layer 13 made of metal is formed through a photo process method, for example, resist coating, pattern transfer through a mask, resist development, etching of the exposed surface, and resist stripping. The black polymer resin light-shielding film layer 13 is formed through a photo process method, for example, resist coating, pattern transfer through a mask, and resist development.

  FIG. 3C shows a red (R) pixel formation process, in which an R pixel is formed. In this step, a process of forming the pigment dispersion resin layer 4 by a photo process method, for example, a resist coating method, a preheating treatment (prebaking treatment) to the pigment dispersion resin layer, and the color filter mask of the present invention are used. The R pixel 32 is formed by a pattern exposure process for pattern transfer, a development process for the pigment-dispersed resin layer, and a post-heating process (post-bake process) for the R pixel of the pigment-dispersed resin layer.

  FIG. 3D shows a green (G) pixel formation process, in which the G pixel 42 is formed. This process is similar to the formation of the R pixel.

  FIG. 3E shows a blue (B) pixel formation process, in which the B pixel 52 is formed. This process is similar to the formation of the R pixel. As described above, the light shielding film layer 13 is formed on the color filter substrate 11, and the RGB pixel (12) is formed in the opening.

  FIG. 3F shows a transparent electrode forming step, and vacuum deposition is performed through a metal mask in which openings are defined only in portions corresponding to the display region portion of the light shielding film layer 13 and the RGB pixels 12 and the extraction terminal portion. By the method, a conductive transparent electrode, specifically, a metal oxide, for example, usually a transparent electrode 14 made of ITO, is sectioned to complete the color filter of the present invention.

  Next, the present invention will be described below according to specific examples.

  First, on a transparent substrate for a color filter having a thickness of 0.7 mm, a light shielding film having a thickness of 0.1 μm is formed by a known method, for example, by vapor deposition of metal chromium, and then a metal chromium lattice pattern is formed by a photo process method. A light shielding film layer 13 was formed.

  Subsequently, the mask for color filters of this invention was created. The mask substrate was formed of QZ and the light shielding film was formed of a single layer film of Cr. The thickness of the single layer film of Cr is 1000 mm. The halftone film layer 3 is made of ITO metal oxide, has a thickness of 2500 mm, and a width of 12 μm.

The pigment-dispersed resin layer is formed by applying the pigment-dispersed resin resist uniformly to the entire surface of the color filter substrate 11 with the light-shielding film layer 13 having a lattice pattern by spin coating. Then, the resist was pre-baked by heating at 70 ° C. for 20 minutes. As the pigment-dispersed resin resist, CR-2000 (product number, manufactured by Fuji Hunt) was used. Under the exposure light irradiation treatment conditions, ultraviolet exposure was performed using the color filter mask of Example 1 under an exposure amount of 180 mJ / cm ² . Next, after developing using a dedicated developer, the resist was subjected to post-baking for 20 minutes at a temperature of 230 ° C. to form R pixels 32. The cross-sectional shape of the R pixel 32 is in a normal state and has a forward taper inclination angle.

Next, the G pixel 42 was formed. The pigment-dispersed resin resist was uniformly applied to the entire surface of the color filter substrate 11 with a thickness of 1.7 μm by spin coating, and then pre-baked by heating the resist at a temperature of 70 ° C. for 20 minutes. . CG-2000 (product number, manufactured by Fuji Hunt Co., Ltd.) was used as the pigment dispersion resin resist. Under the exposure light irradiation treatment conditions, ultraviolet exposure was performed using the color filter mask of Example 1 under an exposure amount of 180 mJ / cm ² . Next, after developing using a dedicated developer, the resist was subjected to post-baking for 20 minutes at a temperature of 230 ° C. to form the G pixel 42. The cross-sectional shape of the G pixel 42 is in a normal state and has a forward taper inclination angle.

Next, the B pixel 52 was formed. The pigment-dispersed resin resist was uniformly applied to the entire surface of the color filter substrate 11 with a thickness of 1.3 μm by spin coating, and then pre-baked by heating the resist at a temperature of 70 ° C. for 20 minutes. . CB-2000 (product number, manufactured by Fuji Hunt Co., Ltd.) was used as the pigment dispersion resin resist. Under the exposure light irradiation treatment conditions, ultraviolet exposure was performed using the color filter mask of Example 1 under an exposure amount of 180 mJ / cm ² . Next, after developing using a dedicated developer, the resist was subjected to post-baking for 20 minutes at a temperature of 230 ° C. to form B pixels 52. The cross-sectional shape of the B pixel 52 was in a normal state, and the inclination angle was a forward taper. As described above, the light shielding film layer 13 with the lattice and the RGB pixels 12 were partitioned on the color filter substrate 11.

  Next, after pre-treating the surface of the color filter substrate 11 with RGB pixels, the color filter substrate is introduced into the apparatus line from the supply unit of the vacuum vapor deposition apparatus, and a metal mask having a predetermined shape Then, after forming the transparent electrode layer 14, the color filter substrate with the transparent electrode discharged from the discharge portion was completed.

  In the color filter of the present invention obtained by the above method, the cross-sectional shape of the RGB pixel is mountain-shaped, the transparent electrode layer formed on the entire surface of the image display portion is formed with a uniform film thickness, and there is no disconnection near the RGB pixel. An electrode layer was formed. Ten color filters of Example 1 were extracted at random, and the cross-sectional shape of the RGB pixels of the ten color filters and the presence or absence of the defective portion 30 of the transparent electrode were inspected. As a result, the upper base line width was measured to be 13.8 to 14.6 μm and the average of 14.3 μm, and the lower base line width was measured to be 14.6 to 15.3 μm and the average of 15.0 μm. The angle of the forward taper shape was measured in the range of 60 degrees to 70 degrees. Further, the disconnection failure portion 30 is zero, and no other quality problems were found.

FIG. 2 is a partially enlarged side cross-sectional view illustrating a color filter mask of the present invention and a color filter formed using the color filter mask, where (a) is a color filter mask and (b) is a color filter 20. It is an enlarged view of a pixel. It is a side cross section of the partial expansion of the color filter of this invention, (a) is a side cross section of RGB pixel 12, (b) is a side cross section in which the transparent electrode layer 14 was formed. (A)-(f) is a sectional side view explaining the manufacturing method of the color filter of this invention. It is a sectional side view explaining the state of the development processing of this invention, (a) is before development processing, (b) is after development processing, (c) is a pixel after post-baking processing. is there. FIG. 2 is a partially enlarged side sectional view for explaining the structure of a conventional color filter mask and a color filter formed using the mask, wherein (a) is a color filter mask and (b) is an enlargement of RGB pixels of the color filter. FIG. FIG. 2 is a side sectional view of a conventional color filter partially enlarged, (a) is a side sectional view of an RGB pixel 12, and (b) is a side sectional view in which a transparent electrode layer 14 is formed. It is a side sectional view explaining the state of conventional development processing, (a) is before development processing, (b) is after development processing, and (c) is a pixel after post-baking processing. .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mask substrate 2 ... Shielding film layer 3 ... Halftone film layer 4 ... Pigment dispersion resin layer 6 ... Bottom bottom part (line width)
9 ... Upper bottom (line width)
DESCRIPTION OF SYMBOLS 10 ... Color filter mask 11 ... Color filter substrate 12 ... RGB pixel 4a ... Undissolved part 4b ... Semi-dissolved part 4c ... Dissolved part 13 ... Light-shielding film layer 14 ... Transparent electrode 20 ... Color filter 30 ... Broken-off part 32 ... R pixel 42 ... G pixel 52 ... B pixel 50 ... 50% exposure light transmission area 100 ... 100% exposure light transmission area 200 ... 0% exposure light transmission area

Claims (2)

  A method for producing a color filter, wherein a light shielding film layer having a lattice pattern and a color filter layer using a colored photosensitive resin are formed on a transparent substrate for a color filter, and a transparent electrode layer is formed on the light shielding film layer and the color filter layer In this case, exposure, development, and baking are performed using a color filter photomask having a halftone film layer partitioned and formed by a halftone film in a region near the outer periphery of the color filter pattern formed on the color filter photomask. A method for producing a color filter, characterized by forming a forward-tapered color filter layer by causing thermal sag at the outer periphery of the pattern of the color filter during baking.   2. The halftone film layer is formed in a region extending outward from a boundary region for partitioning a color filter pattern, and the expansion width is equal to or less than the resolution of the photosensitive resin used. Manufacturing method of color filter.

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