JP2874556B2 - Glass plate with transparent conductive film and touch panel using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a transparent conductive glass plate and a touch panel using the same, and more particularly, to a glass plate with a transparent conductive film suitable for obtaining a touch panel having high visible light transmittance and excellent visibility. And a touch panel using the same.

[Prior art]

In recent years, with the miniaturization of various information processing devices,
Portable terminals called personal digital information devices are attracting attention. In such a mobile terminal, the importance of a touch panel for signal input used integrally with a liquid crystal display is increasing, and various developments have been made. The touch panel is used to input a signal to a drive circuit with a finger or a pen point while watching the display screen. In this case, one electrode is formed on the substrate on the back surface side of the display element, and a transparent conductive film formed on the surface of a transparent substrate such as glass facing the electrode is the other electrode.

[0003] Such a transparent conductive film is required to have as high a visible light transmittance as possible and to have a linearity of resistance. Here, the linearity of the resistance indicates the degree of the proportional relationship between the resistance value and the distance between two points when an arbitrary point is selected with respect to a certain starting point. Normally, the linearity of the resistance value is evaluated by measuring the sheet resistance of the coating along a straight line and evaluating the percentage by dividing the standard deviation by the average value. As the transparent conductive film material, a thin film containing indium oxide or tin oxide as a main component can be used.

As the performance of mobile terminals has improved, the performance of glass with a transparent conductive film for touch panels has also been required to be further improved. That is, high visible light transmittance is necessary for improving visibility, and the transmittance at a wavelength of 550 nm is 91%.
It is hoped that this is the case.

[Problems to be solved by the invention]

As described above, tin oxide which has been conventionally used as an inexpensive and high-strength transparent conductive film material for touch panels cannot satisfy these requirements. In order to improve the transmittance, it is necessary to reduce the thickness of the film, but the required characteristics are beyond the theoretical limit, and,
If the thickness of the film is reduced, there arises a problem that the resistance value becomes too high.

The present invention has been made in view of the above-mentioned problems of the prior art, and has a high visible light transmittance, specifically,
An object of the present invention is to provide a glass with a transparent conductive film for a touch panel exceeding 91% and a touch panel using the same.

[Means for Solving the Problems]

The present invention is a glass plate with a transparent conductive film in which a thin film mainly composed of SiO2, a thin film mainly composed of TiO2, and a transparent conductive film mainly composed of SnO2 are sequentially coated on the surface of the glass plate. The thickness of the thin film mainly composed of SiO2 is 10 to 50 n
m, a glass plate with a transparent conductive film for a touch panel, wherein the thickness of the thin film containing TiO2 as a main component is 100 to 120 nm, and the thickness of the transparent conductive film is 20 to 80 nm.

The thickness of the glass plate is 10 to 50 nm.
A glass plate with a transparent conductive film, which is sequentially coated with a thin film mainly composed of SiO2, a thin film mainly composed of 100 to 120 nm and TiO2, and a transparent conductive film mainly composed of SnO2 having a thickness of 20 to 80 nm, A first substrate, a transparent resin plate coated with a transparent conductive film as a second substrate, and the first substrate and the second substrate are opposed to each other by a transparent conductive film coated on each substrate; and First
The touch panel bonded so that a space is formed between the base and the second base has a feature that the visibility of the display unit is high.

Further, the glass with the transparent conductive film is made of SiO2
By adjusting the thickness of the thin film containing TiO2 as the main component, the thin film containing TiO2 as the main component, and the transparent conductive film containing SnO2 as the main component in the above range, the transmittance at the wavelength of 550 nm is 91% or more. 400 ~
It is preferable to have a spectral transmittance having one maximum in the 800 nm region and to have the maximum on the shorter wavelength side than 550 nm in order to obtain a touch panel with excellent visibility.

In the glass with a transparent conductive film of the present invention, the transparent conductive film containing SnO2 as a main component containing only chlorine as a halogen element has an electric resistance of 0.5 to 1.5.
KΩ / □ and the above-mentioned thin film mainly composed of SiO2 and TiO
By laminating with a thin film containing 2 as a main component, the transmittance of the obtained glass with a transparent conductive film can be made higher than the transmittance of a glass base plate using the glass.

Hereinafter, the glass with a transparent conductive film of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing a laminated structure of a glass plate with a transparent conductive film of the present invention. In FIG. 1, (1) is a substrate glass, (2) is a thin film mainly composed of SiO2, (3) is a thin film mainly composed of TiO2, and (4) is a transparent conductive film mainly composed of SnO2. .

As the substrate glass (1), those conventionally used for glass with a transparent conductive film, such as float glass, are used and are not particularly limited as long as they are transparent.

The thin film (2) containing SiO2 as a main component is provided as an undercoat, and sodium and the like contained in the substrate diffuse into the transparent conductive film (4) containing SnO2 as a main component, and its electrical characteristics are changed. It is intended to prevent the influence on. Such a film containing SiO2 as a main component, since the transmittance after lamination is not affected by its thickness, it is sufficient that the film has a thickness sufficient to exhibit the function as an undercoat, and a thickness of 10 to 50 nm is preferable. Preferred, more preferably 20-
It is preferably 30 nm. As a method of forming a film containing SiO2 as a main component, SiH4 (silane) and O2
It is preferable to apply a normal pressure CVD method in which (oxygen) is reacted at 400 to 600 ° C. Further, a compound of P (phosphorus) or B (boron) may be mixed in the raw material to form a film mainly composed of SiO2 containing these elements.

The thin film (3) containing TiO2 as a main component is provided to increase the transmittance of a glass plate with a transparent conductive film. As a means for forming a thin film containing TiO2 as a main component, a normal pressure CVD method in which a titanium compound and an oxidizing agent such as oxygen are reacted at 400 to 600 [deg.] C. is preferable in terms of productivity. Examples of titanium compounds include titanium tetraisopropoxide (Ti [OCH (CH3) 2] 4) and titanium tetra-n-butoxide (Ti
Alkoxides such as (OCH2CH2CH2CH3) 4) and di-i-propoxybis (acetylacetonato) titanium (Ti [OCH (CH
3) β-diketone chelates such as 2] 2 [OC (CH3) CHCOCH3] 2) and titanium tetrachloride (TiCl4) can be used. The thickness of the thin film mainly composed of TiO2 thus obtained is 100 to 120 nm.
Preferably, the thickness is 105 to 115 nm.
If the film thickness is smaller than 100 nm, the peak of the transmittance shifts to the shorter wavelength side, and the transmittance at a wavelength of 550 nm becomes smaller than 91%. If the film thickness is greater than 120 nm, the peak of the transmittance shifts to the long wavelength side, and the transmittance in the short wavelength region decreases, so that the transmitted color becomes yellowish and the design is impaired, which is not preferable.

The thin film (4) containing SnO2 as a main component is provided to impart conductivity to the glass with the transparent conductive film. Sn
As a means for forming a transparent conductive film containing O2 as a main component, a normal pressure CVD method in which a tin compound containing chlorine and oxygen are reacted at 400 to 600 ° C. in terms of productivity and electric characteristics of the film is preferable. . As the tin compound containing chlorine, monobutyltin trichloride (C4H9SnCl3), tin tetrachloride (SnCl4), or the like is used. Further, a vapor of HF or a compound containing fluorine such as CF3Br or a vapor of a compound containing antimony pentachloride may be mixed in the tin raw material, and a small amount of fluorine or antimony may be added to the film. The transparent conductive film containing SnO2 as a main component thus obtained is selected to have a thickness of 20 to 80 nm, more preferably 40 to 80 nm. When the film thickness is smaller than 20 nm, the linearity of the resistance value exceeds 5%. When the film thickness is greater than 80 nm, the transmittance peak shifts to the long wavelength side, and the transmittance in the short wavelength region decreases. It is not preferable because it is spoiled.

[Action]

In the glass plate with a transparent conductive film of the present invention, a thin film containing SiO2 as a main component, a thin film containing TiO2 as a main component, and a transparent conductive film containing SnO2 as a main component are sequentially coated on a glass plate surface in a predetermined thickness range. And visible light transmittance is high. Therefore, a touch panel using this glass plate has excellent visibility of the display unit.

【Example】

Example 1 A float glass having a size of 300 × 300 mm, a thickness of 1.1 mm and a transmittance of 92% at a wavelength of 550 nm and a wavelength of 550 nm was washed and dried to obtain a substrate. The substrate was heated to 450 ° C., and a controlled gas of SiH4 (silane), N2 (nitrogen) and O2 (oxygen) was supplied to the substrate surface to form a 30 nm thick SiO2 thin film. Thereafter, the substrate is heated to 500 ° C., and a vapor of Ti [OCH (CH3) 2] 4 and a regulated gas of N2 and O2 are supplied to the surface of the SiO2 film to form a TiO having a thickness of 110 nm.
Two thin films were formed. Next, with the substrate kept at 500 ° C, C4H9
A controlled gas of SnCl3 vapor, N2, O2 and water vapor was supplied to form a 60 nm thick chlorine-containing SnO2 film on the TiO2 film surface. The glass with a transparent conductive film having a laminated structure thus obtained was gradually cooled to obtain a sample. FIG. 2 shows the result of measuring the visible light transmittance of this sample using a spectrophotometer. Peak at 520 nm and transmittance at 550 nm is 93
%Met. The sheet resistance was measured at 10 points obtained by dividing a straight line parallel to the long side through the center of the sample into 11 equal parts, and the linearity was evaluated. As a result, the linearity of the resistance was 2%.

Example 2 A sample was prepared in the same manner as in Example 1 except that the thickness of the TiO2 film was 120 nm and the thickness of the chlorine-containing SnO2 film was 40 nm. The visible light transmittance of the sample was measured with a spectrophotometer.
It had a peak at 0 nm and the transmittance at a wavelength of 550 nm was 92%. The linearity of the resistance value of the sample was 3% by the same measurement method as in Example 1.

Example 3 A sample was prepared in the same manner as in Example 1 except that the thickness of the TiO2 film was 100 nm and the thickness of the chlorine-containing SnO2 film was 80 nm. When the visible light transmittance of the sample was measured with a spectrophotometer, the wavelength was 50
It had a peak at 0 nm and the transmittance at a wavelength of 550 nm was 91%. The linearity of the resistance value of the sample was 3% by the same measurement method as in Example 1. ４ Example 4 The transparent conductive film (5) of the glass plate with a transparent conductive film prepared in Example 1 was patterned in a stripe shape, and the glass and the ITO transparent conductive film (8) patterned in a stripe shape were coated. The PET film (7) is placed so that the transparent conductive film is on the inside and the direction of the stripe is orthogonal.
In addition, they were attached using a spacer (6) so that the distance between the glass plate and the PET film was about 100 μm. Lead wires were attached so that a constant voltage could be applied between the transparent conductive films, and a touch panel having a cross-sectional structure as shown in FIG. 3A (lead wires are not shown) was obtained. As shown in FIG. 3 (b), this touch panel changes the resistance between the electrodes when pressed with a finger. For example, when the touch panel is used in a state of being superposed on a liquid crystal display cell, the display element can be controlled by the pressing force of the finger and has good visibility. was gotten. Comparative Example 1 A sample was prepared in the same manner as in Example 1 except that the thickness of the TiO2 film was 130 nm and the thickness of the chlorine-containing SnO2 was 60 nm. When the visible light transmittance of the sample was measured with a spectrophotometer, the wavelength was 560n
It had a peak at m and the transmittance at a wavelength of 550 nm was 90%.
The linearity of the resistance value of this sample was 2%.

Comparative Example 2 A sample was prepared in the same manner as in Example 1, except that the thickness of the TiO2 film was 90 nm and the thickness of the chlorine-containing SnO2 film was 80 nm. When the visible light transmittance of the sample was measured with a spectrophotometer, the wavelength was 490n.
It had a peak at m and the transmittance at a wavelength of 550 nm was 88%.
The linearity of the resistance of the sample was 1%.

Comparative Example 3 A float glass having a size of 300 × 300 mm and a thickness of 1.1 mm was washed and dried to obtain a substrate. The substrate was heated to 450 ° C., and a controlled gas of SiH4, N2, and O2 was supplied to the substrate surface to form a 30-nm-thick SiO2 thin film. After that, the substrate is heated to 500 ℃
And supply a regulated gas of C4H9SnCl3 vapor, N2, O2, HF vapor and water vapor to increase the thickness on the SiO2 film surface.
A SnO2 thin film containing fluorine of 25 nm was formed. The glass with the transparent conductive film thus obtained was gradually cooled to obtain a sample. FIG. 2 shows the result of measuring the visible light transmittance of the sample with a spectrophotometer. The transmittance at a wavelength of 550 nm was 90%. The linearity of the resistance value of the sample was 4%. Comparative Example 4

【The invention's effect】

According to the present invention, it is possible to obtain a glass with a transparent conductive film for a touch panel, which has high visible light transmittance and excellent visibility.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a glass with a transparent conductive film of the present invention.

FIG. 2 is a view showing a visible transmission characteristic of one embodiment of the present invention.

FIG. 3 is a sectional view of the touch panel of the present invention.

[Explanation of symbols]

(1): Transparent substrate (2): Thin film mainly composed of SiO2 (3): Thin film mainly composed of TiO2 (4): Transparent conductive film mainly composed of SnO2 (5): (2), (2) 3) Transparent electrode in which (4) is sequentially laminated (6): Spacer (7): PET film (8): Transparent conductive film

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 17/06 B32B 17/06 27/06 27/06 G02F 1/133 530 G02F 1/133 530 G06F 3/033 350 G06F 3 / 033 350A

Claims (3)

(57) [Claims] 1. A thin film containing SiO2 as a main component on a surface of a glass plate.
A thin film containing TiO2 as a main component, a glass plate with a transparent conductive film sequentially coated with a transparent conductive film containing SnO2 as a main component,
A glass plate with a transparent conductive film for a touch panel having a thickness of the thin film containing SiO2 as a main component of 10 to 50 nm, a thickness of the thin film containing TiO2 as a main component of 100 to 120 nm, and a thickness of the transparent conductive film of 20 to 80 nm. . 2. The transmittance at a wavelength of 550 nm is higher than the transmittance of a glass plate used alone, has a spectral transmittance having one maximum in a wavelength range of 400 to 800 nm, and has a maximum shorter than 550 nm. The glass plate with a transparent conductive film for a touch panel according to claim 1, wherein the glass plate is on the wavelength side. 3. A glass plate with a transparent conductive film according to claim 1 as a first base, a transparent resin plate coated with a transparent conductive film as a second base, The first substrate and the second substrate are adhered so that the transparent conductive films coated on the respective substrates face each other and a space is formed between the first substrate and the second substrate. Become a touch panel.