JP2011048237A - Method of manufacturing color filter and color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a color filter by which a dummy laminate photospacer is arranged at an optional position outside of the display screen area using a small-sized mask exposure system and the color filter manufactured by the same. <P>SOLUTION: In the method of manufacturing the color filter provided with a laminate photospacer including a color pixel of at least ≥3 layers and a color pattern of at least one or more layers on a glass substrate, the color pixel and the laminate spacer are formed using a small-sized mask continuous exposure system. When the laminate photospacer is formed, a shading pattern formed by using an inkjet method or a printing method is arranged on a part having no use for the laminate photospacer on a resist for forming the laminate photospacer to be masked and after that, the whole surface of the substrate is exposed and next, the shading pattern and the unexposed resist for forming the laminate photospacer on the part of the shading pattern part are removed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a color filter manufacturing method using a small mask exposure method for a large substrate, and a color filter manufactured thereby.

  The color filter used in the color liquid crystal display device is an indispensable member for the color liquid crystal display device, and improves the image quality of the liquid crystal display device, and each pixel has red (R), green (G), and blue (B). It has the role of giving the primary color. The manufacturing process of this color filter generally includes a colored photosensitive resin or a transparent photosensitive resin in which a coloring agent such as a pigment or a dye is dispersed and mixed in a photosensitive resin, and a spin coating method or a spinless coating method on a glass substrate. After applying to a uniform thickness and drying and removing excess solvent, an ultra-high pressure mercury lamp is used for proximity exposure (proximity exposure) through a photomask of the desired shape for this resist film by photolithography. Then, irradiate with active energy rays, cure (negative type) or increase alkali solubility (positive type), remove the part that dissolves with alkaline solution, etc., and develop and post bake as many times as necessary Is done.

  Conventionally, the exposure apparatus that exposes the photosensitive resin region has an illumination optical system capable of irradiating light on the entire surface of a rectangular glass substrate, and a mask pattern is exposed between the glass substrate and exposure. It has been known to perform a batch exposure by arranging a mask for shielding the formed area. The proximity exposure system generally uses an ultra-high pressure mercury lamp as a light source, and converts illumination light with uniform illuminance unevenness by a fly-eye lens into parallel light by a collimator lens. The mask and the substrate are arranged with a gap of several tens to several hundreds of μm. Parallel light is irradiated from above the mask to transfer the mask pattern onto the substrate. As described above, in the proximity exposure method, it is not necessary to use a projection optical system, and the apparatus configuration is very simple. Therefore, the apparatus price is low, and the same substrate area as the mask can be exposed in one shot. Therefore, if a mask corresponding to the dimensions of the substrate is used, there is an advantage that the tact is short.

However, the color filter substrate and TFT (Thin
With the increase in size of the film transistor substrate, the glass substrate has recently become larger year by year as called the 6th generation (1500 mm × 1800 mm), 8th generation (2160 mm × 2400 mm), or 10th generation (2850 mm × 3050 mm), The photomask for pixel formation is also forced to increase in size. In the above-described batch exposure apparatus, not only the illumination optical system and the mask become large and cost increases, but also energy efficiency is low and it is difficult to cope with the material technology. It has become. Among them, reducing the cost of the photomask has been an issue in order to reduce the manufacturing cost of the color filter.

  Thus, as a method for reducing the manufacturing cost of a photomask, for example, in Patent Document 1, a laser is used as a light source, and a two-dimensional image is formed by performing relative scanning while modulating light based on image data. A maskless exposure method is disclosed. In this method, since a pixel can be formed without using an expensive photomask, significant cost reduction can be expected. However, in the maskless exposure method, it is difficult to develop a photosensitive resin composition suitable for a spatial modulation element and a laser used for exposure. For example, in the method described in Patent Document 1, an oxygen barrier film is provided, In reality, there are many problems in applying to color filters on large substrates where cost reduction is severe, such as the need to improve sensitivity.

In Patent Document 2 and Patent Document 3, exposure light passing through a small mask pattern is scanned on an exposed substrate transported in a fixed direction, and a plurality of exposure regions sequentially pass under the photomask. A technique of an exposure method (hereinafter referred to as a small mask exposure method) in which a stripe pattern or a dot pattern is printed by switching irradiation and blocking of exposure light with a shutter in synchronization with this is disclosed.

  In this small mask exposure system, a conventional substrate to be exposed coated with colored photosensitive resin or transparent photosensitive resin is used, a blinking light source such as a YAG laser, and a shutter provided above the mask during scanning exposure. The exposure area and the non-exposure area are divided by opening and closing the (blind shutter) in synchronization with the conveyance of the substrate to be exposed. With this small mask exposure method, the size of the mask can be greatly reduced compared to the conventional exposure method, but basically the same pattern is repeated because the pattern drawn on the mask is repeatedly printed. Will form.

  In general, photo spacers (PS: Photo Spacer) arranged in a color filter are arranged outside a display screen region, for example, on a black matrix (referred to as BM) frame or on an inter-panel glass. These have a role of preventing the photo spacer around the panel from being crushed in the panel bonding process. These photo spacers that hold the bonding gap on the outside of the panel and stabilize the cell gap on the outer periphery of the panel are called dummy PSs. The arrangement pattern of the dummy PS is often not arranged at an equal pitch as in the display pixel area. For example, the dummy PS on the glass on the outer periphery of the frame is arranged so as not to interfere with alignment marks required in the panel manufacturing process. Has been. However, as described above, in the small mask exposure method, since it is a precondition that the pattern is arranged at a repetitive pitch, the area in which the dummy PS can be formed is limited, which causes a problem in the panel manufacturing process. There are concerns.

JP 2007-11231 A JP 2007-281317 A JP 2007-121344 A

  The present invention was made to solve the above-described problems, and a method for manufacturing a color filter in which a dummy laminated photo spacer can be arranged at an arbitrary position outside the display screen area using a small mask exposure method, and An object is to provide a color filter manufactured thereby.

  The invention according to claim 1 of the present invention is the method for producing a color filter in which a laminated photo spacer including a colored pixel of at least three layers and a colored pattern of at least one layer is provided on a glass substrate. A method of manufacturing a color filter, wherein the laminated spacer is formed using a small mask exposure method.

  In the invention according to claim 2 of the present invention, when the laminated photo spacer is formed, it is formed by using an ink jet method or a printing method on a portion where the laminated photo spacer on the laminated photo spacer forming resist is unnecessary. 2. The light shielding pattern is disposed and masked, and then the entire surface of the substrate is exposed, and then the unexposed layered photo spacer forming resist on the light shielding pattern and the light shielding pattern portion is removed. This is a method for manufacturing a color filter.

  Next, in the invention according to claim 3 of the present invention, the laminated photo spacer manufactured by the method for manufacturing a color filter according to claim 1 or 2 is arranged in the panel display unit pixel region of the glass substrate and panel display. The color filter is formed outside the partial pixel region.

  According to a fourth aspect of the present invention, there is provided the color filter according to the third aspect, wherein a plurality of types of the laminated photo spacers are arranged at arbitrary positions.

  In the conventional small mask exposure method, the design restriction that the pattern arrangement area could not be finely divided and patterned was large, but the pattern was formed at an arbitrary position by the small mask exposure method by the color filter manufacturing method of the present invention. It becomes possible to do. Therefore, in the color filter of the present invention, the dummy laminated photo spacer can be disposed at an arbitrary position outside the display screen region, and a stable cell gap can be obtained in the panel bonding process. That is, according to the present invention, it is possible to manufacture a color filter with a laminated photo spacer with low cost and high design flexibility.

Schematic explanatory drawing which looked at the small mask exposure system in perspective. Plane explanatory drawing of the dummy lamination PS arrangement area in the conventional color filter design. The partial top explanatory view of the BM substrate of dummy lamination PS manufacture concerning one embodiment of the present invention. Explanatory drawing of the partial plane of the resist application of dummy lamination PS manufacture concerning one embodiment of the present invention. Explanatory drawing of the partial plane of masking of dummy lamination PS manufacture concerning one embodiment of the present invention. Explanatory drawing of the partial plane of exposure of dummy lamination PS manufacture concerning one embodiment of the present invention. Plane explanatory drawing of arrangement of a photomask concerning one embodiment of the present invention. Explanatory drawing of the partial plane of development of dummy lamination PS manufacture concerning one embodiment of the present invention. FIG. 6 is a partial plan explanatory view of a completed dummy laminated PS arrangement area according to an embodiment of the present invention.

  A color filter according to the method for producing a color filter of the present invention will be described below based on an embodiment.

  In the conventional small mask exposure method, since there is a great design restriction that the pattern placement area cannot be finely divided and patterning is performed, as shown in FIG. 2, a dummy stack between pixel display areas 1 facing a glass substrate is used. The dummy laminated PS3 of the PS placement unit 2 is placed at a constant pitch.

The method for producing a color filter of the present invention is such that a photosensitive resin layer made of a colored photosensitive resin composition is applied on at least a BM substrate 4 on which a black matrix (BM) pattern is previously formed on a glass substrate. A masking process in which a light shielding material is applied to a portion where the dummy PS is not desired to be shielded, an exposure process in which the entire surface of the photosensitive resin layer on the substrate is subjected to pattern exposure by a small mask exposure method, and a photosensitive process. The developing step comprises removing the unexposed (uncured) portion of the photosensitive resin layer and developing the exposed photosensitive resin layer, and the firing step thermally curing the developed photosensitive resin layer. By repeating a plurality of times, a laminated photo spacer including at least three layers of colored pixels and at least one layer of colored patterns is formed. The filter segment can be selected from the group consisting of red, green, blue, yellow, orange and cyan. When this is used for a liquid crystal, a transparent conductive layer such as ITO is formed by sputtering as necessary, further a photo spacer and a dummy PS are formed, and an alignment film layer is sequentially laminated to form a color filter substrate. To do. For example, a liquid crystal display device is configured through a liquid crystal layer so as to face a counter substrate on which electrodes such as thin film transistors are formed.

  First, on a glass substrate, using a general photolithography method, a black matrix (BM) pattern, a band-shaped light-shielding region (BM frame) 5 around the display unit pixel region, and a peripheral dummy pattern using a black pigment dispersion resist An alignment mark is formed, and the BM substrate 4 is produced as shown in FIG.

  A known transparent substrate material such as a glass substrate, a quartz substrate, or a plastic substrate can be used for the transparent substrate of the color filter. Among them, the glass substrate is excellent in transparency, strength, heat resistance, and weather resistance.

  Next, as shown in FIG. 4, a red resist 6 is applied to the BM substrate 4 on which the BM has been formed and dried. In the coating process of the photosensitive resin coloring composition, the coating is uniformly performed using a known coating apparatus such as a slit die coater or a spin coater. Then, in order to remove a solvent component, a vacuum drying process and a prebaking process are performed as needed.

  Next, as shown in FIG. 5, a portion where the dummy laminate PS is not desired to be formed is masked with a light shielding pattern 7 to shield the light. As the light shielding material, a water-soluble resin such as PVA (polyvinyl alcohol) resin mixed with a light shielding material such as carbon black is used. An aqueous material is desirable because it does not damage the resist applied to the base.

  As a masking method for the light shielding pattern 7, masking is performed by selectively applying a light shielding material only to a desired portion by an ink jet method or a printing method. Note that the inkjet device used here does not need a micron-level high-precision device used for producing colored pixels of a color filter, and a sub-millimeter level device is sufficient. Further, since the discharge pitch in the scan orthogonal direction does not need to be variable, the apparatus cost can be kept relatively low.

  Next, using the small mask continuous exposure apparatus as shown in FIG. 1, the entire surface of the substrate is exposed as shown in FIG. In this whole surface exposure substrate 8, since the light does not reach the red resist 6 layer under the light shielding pattern 7, only the red resist in the dummy laminated PS arrangement portion 2 and the pixel display region 1 is exposed.

  For example, as shown in FIG. 7, the exposure photomask used for the entire substrate exposure is equivalent to a photomask (b) 6 plate having an exposure pattern (A) and smaller than a glass substrate which is a substrate to be exposed. A total of 12 plates are arranged by arranging six photomasks in the rear in a similar manner so that they are arranged in a row at a pitch and the gap between the photomasks is complemented. By exposing the substrate to be exposed in the vertical direction (c), exposure light through the photomask is irradiated onto the substrate to be exposed.

  In the exposure pattern (a) of the photomask (b), slits of dot-like dots or dot-like holes are formed, and the exposure light through the slits is irradiated onto the substrate to be exposed. Alternatively, a dot-like pixel pattern is formed. As for the alignment of the exposure position, scan exposure is performed by sequentially adjusting the exposure position while monitoring the positional relationship by reading the pattern arranged on the photomask and the BM pattern of the substrate to be exposed with a CCD camera. It is a mechanism to do.

  After the above exposure process, as shown in FIG. 8, the light shielding pattern 7 and the red resist 6 are simultaneously dissolved and removed by alkali development or the like and removed. Further, it is also possible to remove only the light-shielding pattern 7 in advance by performing a washing process or the like before alkali development. Thereafter, baking is performed to complete patterning of the red pixel layer. In the development, an unexposed portion of the photosensitive resin layer is removed by a conventionally known development method. In removing the unexposed portion, an aqueous solution such as sodium carbonate or sodium hydroxide is used as an alkali developer, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Moreover, an antifoamer and surfactant can also be added to a developing solution. As a development processing method, a shower development method, a spray development method, a dip (immersion) development method, a paddle (liquid accumulation) development method, or the like can be applied. In addition, a step of performing heat treatment after development and performing heat curing is provided. As a heating method, a convection oven, a hot plate, a halogen heater, heating by an IR oven, or the like can be used.

  The other color layers such as the green pixel layer and the blue pixel layer are patterned in the same manner as the red pixel layer. Thereafter, if necessary, a transparent electrode film (ITO) is formed by sputtering.

  Next, a photo spacer and a dummy laminate PS are formed. As shown in FIG. 9, since the same pattern as the display pixel portion is conventionally formed continuously, an extra pattern is formed. According to the present invention, a dummy stack having a height equivalent to the current design is formed. PS3 can be formed only in necessary portions.

  Thus, in the small mask exposure method, the design restriction that the pattern placement area cannot be finely divided and patterned is large. However, according to the present invention, a pattern can be formed at any position by the small mask exposure method. Thus, the dummy laminate PS can be formed only in a necessary portion.

a ... exposure pattern b ... photomask c ... substrate transport direction 1 ... pixel display part 2 ... dummy laminated PS placement part 3 ... dummy laminated PS
4 ... BM substrate 5 ... BM frame 6 ... Red resist
7 ... Light-shielding pattern 8 ... Fully exposed substrate

Claims (4)

  In a manufacturing method of a color filter in which a laminated photo spacer including a colored pixel of at least three layers and a colored pattern of at least one layer is provided on a glass substrate, the colored pixels and the laminated spacer are used in a small mask exposure method. A method for producing a color filter, characterized by comprising:   When forming the laminated photo spacer, a masking pattern formed by using an ink jet method or a printing method is arranged and masked on a portion where the laminated photo spacer on the laminated photo spacer forming resist is unnecessary, and then the substrate is formed. 2. The method for manufacturing a color filter according to claim 1, wherein the light-shielding pattern and the unexposed resist for forming a laminated photospacer on the light-shielding pattern portion are removed.   The laminated photo spacer produced by the method for producing a color filter according to claim 1 or 2 is formed in a panel display unit pixel region and outside a panel display unit pixel region of the glass substrate. Color filter.   The color filter according to claim 3, wherein a plurality of types of the laminated photo spacers are arranged at arbitrary positions.