JPH05188366A - Light shielding film and liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide the light shielding film which enables the formation of fine patterns by using a photosensitive resist dispersed with fine particles which are changed in color tones by a thermal effect and the liquid crystal display element. CONSTITUTION:The photosensitive resist 2 previously dispersed with fine particles 1 of manganese carbonate is applied on a glass substrate 3 and' is subjected to exposing and development processing, by thereby the fine matrix- shaped light shielding film 5 is formed. Then, the light shielding film of the color filters to be used for the liquid crystal display element, etc., is easily formed and a large contribution is made to the rationalization of process and the reduction of production costs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-shielding film used for light-based electronic parts such as semiconductor devices, liquid crystal display elements, line sensors, etc., and performs fine patterning by a particularly simple process. Suitable light-shielding film and liquid crystal display device.

[0002]

2. Description of the Related Art The active matrix liquid crystal display is expected to expand its market as a large display for small televisions and office automation equipment. The color filter that is indispensable for this display is made by a dyeing method or a pigment dispersion method as shown in Flat Panel Display '91 (Nikkei BP, P.129, 1991).
In either method, color misregistration and white spots (blank areas) occur due to pattern alignment errors that occur when forming the red, green, and blue filters, so matrix-shaped light shielding is performed around each filter. Forming a part is essential.

This light-shielding portion (hereinafter abbreviated as a black matrix) is generally exposed to light after a resist is applied to a chromium (Cr) film formed on a glass substrate by a sputtering method.
It is formed into a matrix through the steps of development and etching. Since this method requires the steps of forming a Cr film in a vacuum and performing wet etching, the cost thereof is large in the cost of the glass substrate material including the color filter.
Furthermore, as the size of substrates increases, there are many factors that cause a significant increase in the unit price of the substrates and the development of processing equipment for large substrates. Therefore, as in the case of producing a color filter as a black matrix replacing the Cr film, a resist in which pigment, for example, submicron carbon fine particles are mixed in advance is exposed and developed to form a matrix light-shielding portion. A method of forming is under consideration. However, the car
Since the fine particles of Bonn originally do not transmit light, it is difficult to expose the resist, and fine patterning is impossible. At present, the cost is 3,000 yen for a 300 mm square substrate with a Cr film, 6,000 yen for a 400 mm square substrate, and the cost increases 3 to 5 times when a matrix pattern is formed. Considering the above-mentioned applications, cost reduction is indispensable, but the prior art cannot meet the demand.

[0004]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems of the prior art, and enables fine patterning without using complicated steps such as vacuum film formation and wet etching. An object of the present invention is to provide a light-shielding film and a method of manufacturing the light-shielding film.

[0005]

To achieve the above object, fine particles of a color-changing material are mixed into a resist in advance, and then the resist is exposed and developed to form a matrix pattern. The color change material is sufficiently transparent to the wavelength of light at the time of exposure, and the substance whose light transmittance changes by heat treatment after forming a fine pattern, that is, its color tone with respect to the wavelength of the visible light region A substance that changes to opaque may be used.

[0006]

[Function] By exposing and developing a photosensitive resist in which fine particles made of a substance whose light transmittance changes from transparent to opaque by heat treatment are preliminarily mixed, a trouble such as film formation using vacuum and wet etching of the film is required. It is possible to easily form the black matrix without using such a step. Furthermore, since the substance is transparent before the heat treatment, it is possible to form a fine pattern as fine as when using an ordinary photosensitive resist containing no fine particles.

[0007]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a process flow of forming a light shielding film of the present invention. First, the surface of fine particles 1 of manganese carbonate (MnCO ₃ ) (particle diameter: about 0.1 to 0.2 μm) is covered with an organic polymer, or the fine particles 1 are encapsulated to obtain a polyimide or acrylic photosensitive material. Are uniformly mixed in the photosensitive resist 2. Next, the photosensitive resist 2 containing the fine particles 1 is uniformly applied to the glass substrate 3 in a thickness of about 1 to 3 μm by using a well-known spin coat method or spray coat method. . After that, through the steps of ordinary exposure and development, a predetermined matrix pattern is formed.
Get 4 At this time, the manganese carbonate fine particles 1 mixed in the photosensitive resist 2 have a slight white tinge, but have a sufficient light transmittance with respect to the resist photosensitive wavelength.
A fine pattern 4 can be formed with a resolution of 0 micron or less. After that, the above resist pattern 4
Is heat-treated for about 1 hour in an atmosphere of 150 to 300 degrees using a heat treatment furnace or a heating furnace. By this heat treatment, manganese carbonate (MnCO ₃ ) changes into manganese oxide, for example, manganese (III) compound (Mn ₂ O ₃ ) or manganese (IV) oxide (MnO ₂ ), and its color easily changes from white to black. Change. As a result, the fine matrix pattern 4 is colored from white to black,
The black matrix 5 will be formed.

FIG. 2 shows a color filter 6 of a liquid crystal display element formed by using the above black matrix 5. The fine black matrix 5 shown in FIG. 1 is formed on the glass substrate 3. Then the particle size, about 0.1
In the case of making a pigment of ~ 0.2 micron, for example, a blue filter 7, phthalocyanine blue E or cobalt blue is mixed in the photosensitive resist 2, and the photosensitive resist 2 is placed on the glass substrate 3 including the black matrix 5. To a uniform thickness of about 1 to 3 microns. After that, the blue color filter 7 having a predetermined area is formed through the steps of ordinary exposure and development. The above steps are repeated three times to previously add phthalocyanine green or the like to form the green color filter 8 and pigments such as quinacridone magenta or dianthraquinonyl red to form the red color filter 9. It is dispersed in the photosensitive resist 2 and individually formed through the same exposure and phenomenon steps as described above.

The spectral characteristics of the resist 2 containing the pigment used for forming the color filter show good characteristics for a resist film thickness of 1 to 3 μm, and as a result, a resolution of 10 μm or less can be easily obtained. it can.

[0011]

As described above, the light-shielding portion around the color filter and the black matrix are formed by exposing the photosensitive resist in which the fine particles of the metal compound whose color tone is changed by the thermal action are dispersed in advance and processing the phenomenon. Therefore, it is possible to easily obtain a light-shielding film having good spectral characteristics by an extremely simple process as compared with the methods using vacuum film formation and wet etching which are generally used at present.
Further, since the vacuum process is not used, not only the color filter forming process can be rationalized, the labor cost can be reduced, the processing speed can be improved and the productivity can be improved, but also the panel size can be easily coped with. Furthermore, since a matrix-like pattern can be created by performing exposure-phenomenon treatment before changing the color tone of the fine particles in the resist from white to black, it is much more remarkable than when the carbon fine particles having poor light transmittance are dispersed. A fine pattern can be formed.

[Brief description of drawings]

FIG. 1 is a light-shielding film according to the present invention and a process flow diagram thereof.

FIG. 2 is a structural diagram of a color filter including a light shielding film in an example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fine particles 2 ... Photosensitive resist 3 ... Glass substrate 4 ... Matrix pattern 5 ... Black matrix 6 ... Color filter 7 ... Blue filter 8 ... Green filter 9 ... Red filter

Claims (3)

[Claims] 1. A light-shielding film, characterized in that patterning is performed using a resist containing a color-changing material, and then the resist pattern is colored. 2. The light-shielding film according to claim 1, wherein a color-changing material whose color tone is changed by thermal action is used. 3. A liquid crystal display device comprising the light-shielding film according to claim 1.