JP2651940B2 - Substrate with transparent conductive film - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate with a transparent conductive film, and more particularly to a transparent conductive film used for various displays and having a light-shielding film applied to improve contrast. The present invention relates to a substrate with a film.

[Prior Art] Conventionally, as this type of substrate with a transparent conductive film, there is one shown in FIG. 5 (plan view). This substrate 1 with a transparent conductive film
Is used for a simple matrix type of a liquid crystal display, in which electrodes 3 made of a plurality of strip-shaped transparent conductive films are attached in parallel on one main surface of a glass substrate 2, and between the electrodes 3. A light-shielding film pattern 4 of an insulating organic resin made of an acrylic resin containing carbon particles was applied by screen printing or the like.

[Problem to be Solved by the Invention] However, since the light-shielding film pattern 4 for improving the contrast in the conventional substrate 1 with a transparent conductive film is made of an organic resin, the light-shielding ratio is reduced when an electric field is applied for a long time to start. There was a problem that it decreased. That is, there is a problem that the temporal change of the light blocking ratio occurs and the contrast is reduced. In addition, a light-shielding film pattern made of an organic resin is considered to improve the light-shielding rate by increasing the amount of carbon particles in the organic resin.However, when the amount of carbon particles is increased, conductivity is generated. Become. Therefore, in order for the light-shielding film pattern made of organic resin to maintain sufficient insulation, the light-shielding rate is up to 96%.
(Visible light range), which is not suitable for a high-contrast display with high contrast recently required.

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and is characterized in that a light-shielding film pattern made of a metal-containing inorganic substance is formed on one main surface of a substrate. Then, an insulating film is stacked on the light-shielding film pattern and on the exposed portion of the one main surface by a sputtering method, and a transparent conductive film-coated substrate characterized by further stacking a transparent conductive film on the insulating film. is there.

Embodiment An embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 is a cross-sectional view taken along the line XX of FIG. 2 of the present example, FIG. 2 is a plan view of the present example, and FIG. 3 is a light shielding film pattern formed on a substrate. FIG. 4 is a cross-sectional view showing a manufacturing process of the present example.

First, the substrate 10 with a transparent conductive film of the present example is used for a simple matrix type of a liquid crystal display, and two substrates of the substrate 10 with a transparent conductive film are arranged to face each other so as to incorporate a known liquid crystal. You. In this arrangement direction, one of the substrates 10 with a transparent conductive film is as shown in the plan view of FIG. 2, and the other substrate 10 with a transparent conductive film is rotated by 90 ° It is the direction you are doing.

As shown in FIGS. 1 and 2, the substrate 10 with a transparent conductive film of the present example has a light-shielding film pattern 12 made of a metal-containing inorganic substance laminated on one main surface of a light-transmitting substrate 11. The insulating film 13 and the transparent conductive film 14 are sequentially laminated on the light-shielding film pattern 12 and the exposed surface 11a (exposed portion) of the light-transmitting substrate 11.

Further, the substrate 10 with a transparent conductive film will be described in detail below with reference to FIGS. 3 and 4.

First, on a main surface of a light-transmitting substrate 11 made of aluminoborosilicate glass having a thickness of 1.1 mm and a side of 190 mm (for example, trade name NA-45 manufactured by HOYA Corporation), a sputtering method or a vacuum evaporation method is used. Shielding film made of chromium film (film thickness:
About 1200Å). Next, a positive resist film (for example, NPR-3300 (trade name, manufactured by Nagase Sangyo Co., Ltd., having a film thickness of about 1.0 μm) is formed on the light-shielding film by a spin coating method.
And pre-baking (100 ° C. for 30 minutes).

Next, the above-described positive resist film is exposed to light by a contact exposure method using a photomask having a desired pattern, and is developed with a dedicated developer. The light-shielding film is etched with a mixed solution of cerium ammonium and perchloric acid to form a light-shielding film pattern 12 (the light-shielding rate is 99.8% in the visible light region (380 nm to 780 nm) (FIGS. 3 and 4). See FIG. As shown in FIG. 3, the light-shielding film pattern 12 has an exposed surface 11a where the light-shielding film is etched and the surface of the light-transmitting substrate 11 is exposed, and the exposed surface 11a has one side. the length L ₁ forms the approximately 50μm square of, and the distance L ₂ between the exposed surface 11a adjacent is 20 [mu] m.

Next, as shown in FIG. 3B, an insulating film 13 (thickness: about 3000 Å) made of SiO ₂ is laminated on the light-shielding film pattern 12 and the exposed surface 11a by a sputtering method. Note that the sputtering method is a reactive sputtering method, the target is SiO ₂ , and sputtering is performed in a mixed atmosphere of argon and oxygen. This insulating film 13
As shown in the figure, it has irregularities (steps).

Next, as shown in FIG. 3C, a transparent conductive film 14 (thickness: about 1700 °) made of indium and tin oxide (ITO) is laminated on the insulating film 13 by a sputtering method. A substrate 10 with a transparent conductive film is produced. Note that the sputtering method is a reactive sputtering method. In addition, the surface of the transparent conductive film 14 also becomes uneven, substantially following the uneven shape of the insulating film 13. That is, as shown in FIG. 2, the surface 14a of the transparent conductive film 14 corresponding to the exposed surface 11a of the light-shielding film pattern 12 is concave, and the other surface 14b is convex.

Further, the transparent conductive film 14 of the substrate 10 with a transparent conductive film of the present example is etched to form a square pattern corresponding to the exposed surface 11a shown in FIG. A method of removing the portion and leaving the concave portion will be described below.

First, a positive resist film similar to the above-described resist is applied to a thickness of about 1 μm on the above-described transparent conductive film 14 by spin coating, and is prebaked at 100 ° C. for 30 minutes. Next, the light-shielding film pattern shown in FIG. 3 and FIG.
Exposure is performed using the photomask used when forming 12, and the one whose pattern is inverted, and developed with a dedicated developer.

Next, the transparent conductive film 14 is etched with a predetermined transparent conductive film etchant (for example, a mixed solution of ferric chloride and hydrochloric acid), and as shown in FIG. The transparent conductive film pattern 14c leaving the concave portion is produced.

The present invention is not limited to the above embodiment, but may be the following.

First, in the above-described embodiment, the light-shielding film pattern made of a metal-containing inorganic substance was made of a chromium film. However, other metal films, for example, Ta, W, Mo, etc. And metal oxides such as tantalum oxide and molybdenum oxide, and metal silicides such as tantalum silicide, tungsten silicide and molybdenum silicide. Further, the light-shielding film pattern is not limited to one layer, but may be formed of a plurality of layers such as two layers. The light-shielding ratio of the light-shielding film pattern is preferably 99.8% or more in the visible light region (wavelength 380 nm to 780 nm).

In the above embodiment, the insulating film is made of SiO ₂ , but may be another transparent metal oxide insulating film. The method for forming the insulating film is not limited to the reactive sputtering method, but may be another sputtering method such as a magnetron sputtering method or a high-frequency sputtering method.

Further, as the transparent conductive film, other than ITO, SnO ₂ doped with antimony or the like may be used.

Further, the substrate is not limited to glass, but may be ceramic, metal, or the like, and may be appropriately determined according to the application.

[Effects of the Invention] As described above, according to the present invention, since the light-shielding film pattern is made of a metal-containing inorganic substance, a temporal change in the light-shielding rate can be prevented and the light-shielding rate is improved, so that a high-quality display with high contrast can be obtained. There is also an effect that can be used.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a sectional view taken along line XX of FIG. 2, FIG. 2 is a plan view, and FIG.
FIG. 4 is a plan view of a light-shielding film pattern adhered on a substrate, and FIG. 4 is a cross-sectional view showing a manufacturing process. FIG. 5 is a plan view showing a conventional substrate with a transparent conductive film. 10 ... substrate with transparent conductive film, 11 ... substrate, 12 ... light-shielding film pattern, 13 ... insulating film, 14 ... transparent conductive film

Claims (1)

(57) [Claims] A light-shielding film pattern made of a metal-containing inorganic substance is applied on one main surface of a substrate, and an insulating film is formed on the light-shielding film pattern and on an exposed portion of the one main surface by a sputtering method. A substrate with a transparent conductive film, wherein the substrate is laminated, and a transparent conductive film is further laminated on the insulating film.