JP2000171792A - Manufacture of reflection substrate for reflective liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a base film for a reflection plate with an excellent projecting and recessing shape on a surface of a hardened matter by applying a resin material which hardens by light, heat or both of them on a substrate and controlling the internal stress. SOLUTION: A resin material 2, prepared by mixing photo- and thermosetting acrylic resin and carbon of 50% based on the resin component, is spin coated on a glass substrate 1 and is exposed from the arrowed direction with a light filter 3 and developed (a). After the development, although surface hardening with light occurs, the inside is not hardened and the surface remains flat (b). After sintering, on the surface of the carbon mixed resin material 2, a shrinking shape resulting from the internal stress due to hardening of the previously unhardened inside appears and projecting and recessing parts are formed on the surface corresponding to the bigger internal energy. As a consequence of deposition of aluminum on the substrate 1, a diffusion substrate with an excellent projecting and recessing shape M is formed on the surface of the hardened matter 2a (c).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a reflective substrate of a reflective liquid crystal display device suitable for forming a reflective base film.

[0002]

2. Description of the Related Art In recent years, the spread of personal computers has been remarkable, and in particular, the demand for a reflective liquid crystal display having a reduced weight by eliminating a backlight tends to increase. In the case of the reflection type, it is important to efficiently capture and scatter light into the panel. Usually, 1) a method of giving reflection characteristics by a combination of a mirror reflection film and a scattering film, 2) a method of making a substrate a rough surface by polishing or the like, and treating it with hydrofluoric acid to form a reflection plate, 3) patterning There is known a method of forming a metal thin film such as aluminum or an aluminum alloy on an organic film having characteristics by sputtering or vapor deposition.

[0003]

However, in the method 1), the reflection from the mirror surface must be controlled by a scattering film, which causes blurring of an image and difficulty in effective use of light. There is. In addition, the method 2) has a problem that reproducibility is low due to subtle changes in the surface state of the substrate.

At present, the method 3) for forming a reflection plate is becoming effective. Furthermore, this reflector is provided with an electrode through a contact hole or the like to increase the aperture ratio, and improvement in parallax and brightness is considered by forming a color filter on a conventional counter substrate on the reflector. . However, the formation of the reflector base film before the formation of the metal thin film is difficult to reproduce, and an effective manufacturing method has not yet been obtained.

[0005]

Accordingly, the present invention relates to the formation of a base film, using a resin material which is cured by light, heat, or both on a substrate and controlling the internal stress thereof to form a surface of the cured product. The technical means is to form a good uneven shape on the surface.

The above means is to form an uneven shape on the surface of a cured product by controlling internal stress by heat.

The above means may control the internal stress by light to form an uneven shape on the surface of the cured product.

Further, the above means is to form an uneven shape on the surface of the cured product by controlling the internal stress generated in the order of light, heat or heat-light, light-heat.

According to the above-mentioned means, it is also possible to form an uneven shape on the surface of the cured product by selectively controlling the internal stress.

Further, the present invention is characterized in that an uneven shape is formed on the surface of a reflective film by utilizing light diffraction on a substrate.

In this means, it is preferable to use diffraction of light generated by performing exposure from the back surface of the substrate.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a method for changing the film forming manufacturing conditions of a conventional material for a part or all of the amount of a solvent in a material for a base film or curing conditions such as light and heat. Alternatively, the material is filled with an additive for adjusting the internal stress, so that a desired surface state is obtained during the film formation state. At this time, the additive may be organic or inorganic as long as it can adjust the internal stress of the material. Examples of the additives include silica, carbon, organic resin, mica, talc and the like, and these are appropriately selected.

A material that is cured by light or heat is applied to the reflection substrate in advance, and exposure is performed through a mask having a certain slit. At this time, the method of application is not limited as long as a constant film thickness can be obtained on the substrate. The shape and material of the mask are not limited as long as the mask is provided with slits or obstacles for obtaining light diffraction. When exposure is performed in this mode, light is diffracted by slits or obstacles, and diffraction marks appear on the surface of the cured product.

The diffraction marks can be controlled by the number and shape of the slits. Therefore, a desired surface shape can be obtained. in this case,
The master for black matrix has many slits,
Light diffraction occurs over the entire surface. These diffraction marks appear on the surface when the coloring material is cured. In this case, since the diffraction direction usually has a certain direction, only one of a vertical streak and a horizontal streak usually appears on the surface of the cured product (Fresnel or Fraunhofer diffraction or the like).
However, by diffusing light in advance with respect to the traveling direction and phase of the light, the diffraction of the light after passing through the slit is not constant, and a surface shape in which vertical and horizontal streaks are mixed can be obtained.

(Example 1) Referring to FIG. 1, Example 1 of the present invention will be described. Normally, 50% of carbon is added to a photothermally transparent curable acrylic resin used as a color filter protective film and its resin component. The resin material 2 mixed with the addition of 2% was spin-coated on the glass substrate 1 and exposed to light in the direction of the arrow using the optical filter 3 for development (see FIG. 1A). The film thickness was adjusted to 1.5 μm at the time of coating. After development, surface curing by light occurs, but the inside is uncured and the surface state is flat (see (b) in FIG. 1). After the firing, the surface of the carbon-mixed resin material 2 At the same time, the uncured interior was cured and a contracted shape due to internal stress was developed, and irregularities were formed on the surface due to the large internal energy.
As a result of performing aluminum deposition on the substrate 1,
A diffusion substrate having a good uneven shape M was formed on the surface of the cured product 2a (see FIG. 1C). At this time, the surface step was about 0.5 μm.

Next, film formation was performed in the same manner as described above, and only the film thickness was reduced to 2 μm. At this time, the surface step became 1.4 μm and the surface shape changed. Aluminum was vapor-deposited on this substrate to obtain a good diffusion plate in the same manner as described above.

Exposure, development and baking were carried out in the same manner as described above, except that a pigment different from carbon was mixed with the same transparent resin as described above. When the surface state was observed after firing, a shape different from that of the resin mixed with carbon was developed. Aluminum was vapor-deposited on this substrate to obtain a good diffusion plate in the same manner as in (1). As a result, it has been found that in this production method, the surface shape and the level difference can be adjusted by appropriately selecting the film thickness and the additive.

(Embodiment 2) Referring to FIG. 2, an embodiment 2 for selectively controlling internal stress will be described.
1 is spin-coated with the same resin material 12 as in Example 1,
Using the optical filter 13 and the original plate 14 obtained by inverting the black matrix original plate, exposure and baking were performed in the direction of the arrow (see FIG. 2A). At this time, the film thickness, exposure amount, and baking time were exactly the same as in Example 1. Observation of the surface after baking revealed that the projections T occurred in the portions that were exposed to light and did not occur in the unexposed portions (see (b) of FIG. 2).
By this manufacturing method, a surface shape having irregularities in each pixel partitioned by the black matrix was obtained. As a result of depositing aluminum on the substrate, a favorable diffusion plate was obtained.

[0019]

The present invention is the embodiment as described above,
It has the following specific effects.

By controlling the internal stress of the resin, the surface shape and surface roughness can be arbitrarily and easily changed, and a good base for a reflective substrate can be obtained.

The manufacturing method can be a combination of heat, light, light and heat, and the like. Since the internal stress of each material can be controlled by an additive, the types of materials that can be selected are abundant, and a wide variety of base materials for a reflective substrate can be manufactured.

By utilizing the diffraction of light, the surface shape and surface roughness can be arbitrarily and easily changed, and a good base for a reflective substrate can be obtained.

When diffracting light, many surface shapes and roughness can be obtained by changing the intensity of light, the number and shape of obstacles (slits and the like) for diffraction, and the distance to the substrate. Therefore, it is possible to produce a variety of base materials for a reflective substrate.

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory diagrams of Embodiment 1, wherein FIG.
(B) shows the state during light curing, and (c) shows the state after firing.

FIGS. 2A and 2B are explanatory diagrams of Embodiment 2, wherein FIG.
(B) shows the state at the time of completion.

[Explanation of symbols]

 1,11 substrate 2,12 resin material 2a cured product 3,13 optical filter 14 original M

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akinari Tsuji 1-12-32 Shizuka, Otawara-shi Inose Residence A-202 F-term (reference) 2H042 BA03 BA15 BA20 2H091 FA14Z FA19Z FA31Z FB02 FB08 FB12 FB13 FC02 FC10

Claims (7)

[Claims] 1. A method of manufacturing a reflective substrate for a reflective liquid crystal display device, wherein a resin material that is cured by light, heat, or both is used on a substrate, and the internal stress is controlled to form an uneven shape on the surface of the cured product. Law. 2. The method according to claim 1, wherein the internal stress is controlled by heat to form an uneven shape on the surface of the cured product. 3. The method according to claim 1, wherein the unevenness is formed on the surface of the cured product by controlling the internal stress by light. 4. The reflection substrate of a reflection type liquid crystal display device according to claim 1, wherein the unevenness is formed on the surface of the cured product by controlling the internal stress generated in the order of light, heat or heat-light, light-heat. Manufacturing method. 5. The method according to claim 1, wherein the unevenness is formed on the surface of the cured product by selectively controlling the internal stress. 6. A method for manufacturing a reflective substrate of a reflective liquid crystal display device, wherein an uneven shape is formed on the surface of a cured product by utilizing light diffraction on the substrate. 7. The method of manufacturing a reflective substrate for a reflective liquid crystal display device according to claim 6, wherein an uneven shape is formed on the surface of the cured product using diffraction of light generated by performing exposure from the back surface of the substrate.