JPH0740082B2 - Color filter manufacturing method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a color filter used in a color television, a color camera, a color display device, a color image pickup device, and the like.

2. Description of the Related Art In general, color filters used in color televisions, color cameras, etc., have pixels of three colors such as red, green, and blue arranged in a stripe shape or a matrix shape at a predetermined pitch. In order to improve the pixel efficiency, a black thin stripe or grid (orthogonal grid) is used between the three color pixels.

As a conventional method of manufacturing a color filter, as shown in FIG. 7A, a photocurable resin 21 is applied onto a glass substrate 20 and a dried sample is exposed by using a mask 22 in which a pattern to be transferred is drawn, A desired pattern portion (pixel) is photocured to obtain a cured resin portion, which is then colored with a dye, or a material in which a dye or a pigment is added in advance to the photocurable resin is used. The patterning film formation for each color of black, red, green, blue, etc. is repeated a plurality of times to form a color filter as shown in FIG. 7b.

However, according to the conventional method, the size of the pixel portion of each color is several μm to several hundreds μm, and the pixel pitch is as fine as ten and several μm to several hundreds μm, and therefore, during the exposure process, It is necessary to perform alignment within several μm or 1 μm in an extreme case, and due to an alignment error, a non-colored portion called white blank is generated as shown by 23 in FIG. However, the transparent electrode film formed thereon is broken due to the overlapped projections 24 and loses the flatness, or when the liquid crystal device is used, the opposing electrodes are short-circuited to cause a display defect.

The present invention has been made in view of the above points, and an object thereof is to provide a method of manufacturing a color filter that can stably obtain a defect-free pattern.

Means for Solving the Problems The manufacturing method of the present invention is, in order to solve the above problems, applying a photocurable photoresist in which a black material is dispersed on a transparent substrate, drying, and using a photomask. A first step of forming a pattern-formed black sample by exposing to ultraviolet light, developing, and curing; a pigment material of one color exhibiting red, blue or green containing at least one or more pigments on the surface of the sample Is applied, dried, and then exposed to ultraviolet light from the non-coated surface of the sample through a photomask having an exposure light transmitting portion that is enlarged from a predetermined transfer pattern, causing a phenomenon, curing, and one color A second step of forming a pattern of, and the second step is sequentially repeated in the order of increasing the product of the absorption coefficient with respect to the spectral transmission spectrum and the film thickness to form pixels of a plurality of colors. To do.

Action The present invention can improve the pattern accuracy by utilizing the light shielding property in the photo-curable colored photoresist photosensitive wavelength region of the pixel portion formed of the photo-curable colored photoresist already formed in the exposure step, and By designating an exposure area by using a mask having an opening pattern having a light transmission area wider than the pixel pattern, light leakage and pixel overlap are eliminated, and a good color filter can be stably manufactured.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings. 1 to 4 are process explanatory views showing the manufacturing method of the present invention.

In FIG. 1a, a black photocurable photoresist 2 in which carbon or a black pigment is dispersed is applied and dried on a substrate 1 made of a transparent material such as glass. Next, this is irradiated with an ultraviolet ray emitted from a high-pressure mercury lamp through the mask 3 on which a desired pattern is drawn and collimated by an optical system (not shown) at a uniform exposure power to form the mask 3 pattern. Bake on the photoresist. Then, in another step, which is a developing step, the resist in the non-irradiated portion is etched and peeled off, and then the resist in the light-irradiated portion remaining in the curing step is thermally cured, as shown in FIG. 1b. A sample 5 having a black portion 4 which is a stripe-shaped or orthogonal grid-shaped first pixel is formed on the base material 1.

Then, as shown in FIG.
The photoresist 6 in which the coloring material (for example, a red pigment) is dispersed is applied in an overlapping manner, and the transparent substrate 2 is irradiated with ultraviolet rays from the non-coated surface as in FIG. In this case, the exposure is performed through the mask 7 on which the patterns of the light transmitting portion 7a and the light shielding portion 7b are printed so that unnecessary portions are not exposed. The width W ₁ of the transparent portion 7a of the mask 7 is made larger than the width W _{2 of the} pixel portion 6a where the pixel pattern after exposure is desired to be formed. After that, similarly,
After the curing step, a sample 9 having pixels 8 is prepared as shown in FIG. 2b.

Further, also for the third pixel (for example, green), as shown in FIGS. 3a and 3b, a photoresist in which a color material such as a green pigment is dispersed is applied on the sample 9 so as to be coated, Material 2
From the non-coated surface, an ultraviolet ray is applied through the mask 10 for exposure as in the case of FIG. The width of the light-transmitting portion of the mask 10 is made larger than the width of the third pixel as in the case of FIG. A sample 13 having pixels 12 formed is prepared.

Similarly, for the final fourth pixel (for example, blue color), a photoresist 14 in which a blue pigment is dispersed is applied on the sample 13, and ultraviolet rays are irradiated through the mask 15 in the same manner as described above to develop,
After the curing process, a color filter 17 having a fourth pixel 16 is prepared as shown in FIG. 4b. If it is desired to cover all the pixel non-formation portions of the substrate 1 with the fourth photoresist 14, it is not necessary to use the mask 15.

The material of the photocurable photoresist is, for example, a pigment-filled resist made by Fuji Hunt Electronics Technology Co., Ltd., that is, a blue resist (product name Color Mosaic R, abbreviation CR), a green resist (product name Color Mosaic) made of an acryloid photosensitive resin. G, abbreviation CG), red resist (trade name color mosaic R, abbreviation CR), and black resist (trade name color mosaic K, abbreviation CK) were used. As the developer, a 1 wt% sodium carbonate aqueous solution was used.

Next, the operation of this embodiment will be described. First, each pixel of red, blue, and green is newly patterned by utilizing the light shielding property with respect to the exposure wavelength of the pixel already formed by exposure, development, and curing. When the photoresist film to be formed is exposed, it is self-aligned and patterned according to the pixel pattern.

FIG. 5 is a diagram for explaining this action, in which the transmittance of the transparent substrate 1 with respect to the exposure wavelength is T, the film thickness of the existing pixel 18 is d ₁ , and the absorption coefficient K ₁ with respect to the photosensitive wavelength is set. If the exposure energy is I and the film thickness of the photoresist film 19 is d ₂ and the absorption coefficient is K ₂ , the intensity I ₁ of the ultraviolet rays passing through the existing pixel 19 is expressed by the following equation (1). The intensity I ₂ of the transmitted ultraviolet rays of the photoresist film 19 is expressed by the equation (2).

I ₁ = IT × exp (−K ₁ d ₁ ) (1) I ₂ = IT × exp (−K ₂ d ₂ ) (2) Without photo-curing the photoresist on the existing pixel, In order to cure the photoresist, the condition of I ₂ > I ₁ , that is, the condition of the expression (3) is required.

K ₁ d ₁ > K ₂ d ₂ (3) FIG. 6 shows the spectral transmittances of the black, red, green, and blue photoresists used in this example (all film thicknesses are 2 μm). Photosensitive wavelength range of resist (wavelength 315 to 400n
m) is the g-line (436 nm) and h-line (405 n) of ultraviolet light emitted from an ultra-high pressure mercury lamp that is generally used as an exposure light source.
m), i-line (365 nm), in order to cure the prescribed film thickness without curing the photoresist on the existing pixel, the coating and exposure order must be made so that the condition of formula (3) is satisfied. Should be decided.

In particular, by using the black photoresist in the first step, the transmittance of the formed black portion in the photosensitive wavelength region is low as shown in FIG. 6, so that this portion is sufficient for use as a mask. It can provide a light-shielding property.

As described above, it has been shown that the existing pixels can be used as a mask instead of the mask. However, since only two kinds of pixels can be formed only by the above operation, when three or more kinds of pixels are formed, it is already shown in FIGS. As shown in, cover only the areas you do not want to expose with a mask, and expose only the areas you need. At this time, depending on the thickness of the transparent base material, the base material thickness is 0.
When it is set to 5 to 2 m, in order to prevent light leakage due to diffraction by the mask edge, if the width of the opening shown in Fig. 2 is made slightly wider than the width of the portion to be exposed, it will be diffracted about 1 to 10 μm. The influence of light wraparound is small, and the edge of the exposed portion is patterned by existing pixels. Here, the mask 15 of FIG. 4a may be omitted when the remaining photoresist is covered with the last photoresist.

EFFECTS OF THE INVENTION The present invention utilizes the light shielding property of an existing pixel for exposure light,
In addition, since a mask wider than the pixel pattern covers unnecessary portions, it is possible to stably obtain pixels of three colors or more without light leakage and pixel overlap, and the second step is to obtain an absorption coefficient for the spectral transmission spectrum. The coating, drying, and curing are sequentially repeated in order of increasing product of the film thickness and the film thickness, that is, the filters are sequentially formed from dark colors, so that a good color filter can be manufactured.

In particular, by using the black photoresist in the first step, it is possible to provide an industrially superior method of manufacturing a color filter.

[Brief description of drawings]

1 to 4 are process explanatory diagrams showing an embodiment of the method for producing a color filter of the present invention, FIGS. 5 and 6 are explanatory diagrams showing the action of the present invention, and spectral transmittance curve diagrams, FIG. FIG. 7 is a process explanatory view of a conventional color filter manufacturing method. 1 ... substrate, 2, 6, 10, 14 ... coated photoresist,
3, 7, 11, 15 ... Mask, 4, 8, 12, 16 ... Pixel,
17 ... Color filter.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kei Inami, 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Tokhiko Shimizu, 1006, Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 56) References JP-A 63-129322 (JP, A) JP-A 2-804 (JP, A) JP-A 63-66502 (JP, A) JP-A 63-159810 (JP, A) JP JP-A-62-267702 (JP, A) JP-A-61-77004 (JP, A) JP-A-57-190912 (JP, A) JP-A-62-42104 (JP, A) JP-A-54-17627 (JP , A) JP 63-172202 (JP, A) JP 63-66502 (JP, A)

Claims (1)

[Claims] 1. A pattern is formed by applying a photocurable photoresist in which a black material is dispersed on a transparent base material, drying it, exposing it to ultraviolet light using a photomask, developing and curing it. The first step of preparing a black sample, a photo-curable photoresist in which a pigment material of one color exhibiting red, blue or green containing at least one kind of pigment is dispersed is applied to the surface of the sample, dried, and predetermined. The second step of forming a one-color pattern by subjecting the non-coated surface of the sample to ultraviolet exposure, development and curing through a photomask having an exposure light beam transmission portion enlarged from the transfer pattern of FIG. However, the method for producing a color filter is characterized in that pixels of a plurality of colors are formed by sequentially repeating the order of increasing the product of the absorption coefficient and the film thickness for the spectral transmission spectrum.