JPH07315880A - Glass plate coated with transparent conductive film and touch panel using the same - Google Patents

Abstract

PURPOSE:To improve transmittance of visible rays and visibility of the glass base plate by coating the surface with a thin film mainly comprising SiO2, a TiO2 thin film in specified thicknesses and a transparent conductive film mainly consisting of SnO2 in order. CONSTITUTION:A base plate (1) made of float glass having 92% transmission at 550nm wavelength is cleaned and dried, then subjected to the normal-pressure CVD(chemical vapor deposition) process using SiH4 and O2 at 400-600 deg.C to form a thin film 10-40nm thick (2), mainly composed of SiO2 on one surface as an undercoat, then the normal pressure CVD process is conducted using a titanium compound such as a titanium alkoxide, beta-diketone chelate or titanium tetrachloride and an oxidizing agent such as O2 to laminate a thin film 100-120nm thick (3), mainly composed of TiO,z on the undercoat (2), further the normal pressure CVD process is repeated again using a tin compound containing chlorine and oxygen to laminate a transparent conductive film (4) 20-80nm thick, mainly composed of SnO2 so that the transmittance of the laminate thus formed is increased higher than that of the glass plate only.

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, more specifically, a glass plate with a transparent conductive film suitable for obtaining a touch panel having high visible light transmittance and excellent visibility. Relates to a touch panel using.

[Prior art]

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

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

As the performance of mobile terminals has improved, it has become necessary to further improve the performance of glass with a transparent conductive film for touch panels. That is, high visible light transmittance is necessary for improving visibility, and the transmittance at a wavelength of 550 nm is 91%.
The above is desired.

[Problems to be Solved by the Invention]

As described above, tin oxide conventionally used as an inexpensive and high-strength transparent conductive film material for a touch panel cannot satisfy these requirements. In order to improve the transmittance, it is necessary to reduce the film thickness, but the required properties exceed the theoretical limit, and
If the film is made thin, there arises a problem that the resistance value becomes too high.

The present invention has been made in view of the problems of the prior art, and has a high visible light transmittance, specifically,
It is an object to provide 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 relates to a glass plate with a transparent conductive film in which 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 the surface of the glass plate. , The thickness of the thin film mainly composed of SiO2 is 10 to 50n
A glass plate with a transparent conductive film for a touch panel, in which 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 glass plate surface has a thickness of 10 to 50 nm.
A glass plate with a transparent conductive film in which a thin film mainly composed of SiO2, a thin film mainly composed of TiO2 with a thickness of 100 to 120 nm, and a transparent conductive film mainly composed of SnO2 having a thickness of 20 to 80 nm are sequentially coated. A transparent resin plate coated with a transparent conductive film as a second substrate, the first substrate and the second substrate are opposed to each other by the transparent conductive films coated on the respective substrates, and First
The touch panel that is adhered so that a space is formed between the base body and the second base body has a feature that the visibility of the display unit is high.

Further, the glass with the transparent conductive film is made of SiO2.
The thickness of the thin film containing TiO2 as the main component, the thin film containing TiO2 as the main component, and the thickness of the transparent conductive film containing SnO2 as the main component are adjusted within the above range, and the transmittance at a wavelength of 550 nm is 91% or more. 400 ~
It is preferable that the spectral transmittance has one maximum in the 800 nm region and that the maximum is 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 contains only chlorine as a halogen element, but has an electric resistance of 0.5 to 1.5.
KΩ / □ and the above-mentioned SiO2 as a main component thin film and TiO
By laminating 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 the glass base plate used.

The glass with a transparent conductive film of the present invention will be described below 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 containing SiO2 as a main component, (3) is a thin film containing TiO2 as a main component, and (4) is a transparent conductive film containing SnO2 as a main component. .

The substrate glass (1) is not particularly limited as long as it is transparent and is conventionally used for glass with a transparent conductive film, such as float glass.

The thin film (2) containing SiO2 as a main component is provided as an undercoat, and sodium or the like contained in the substrate diffuses into the transparent conductive film (4) containing SnO2 as a main component so that its electrical characteristics are improved. It is intended to prevent the influence on. Such a film containing SiO2 as a main component does not affect the transmittance after lamination due to the thickness thereof, so that the film may have a thickness sufficient to exhibit the function as an undercoat, and a thickness of 10 to 50 nm is preferable. Preferably 20 to
30 nm is preferable. From the point of view of productivity, SiH4 (silane) and O2
It is preferable to apply an atmospheric pressure CVD method in which (oxygen) is reacted at 400 to 600 ° C. Alternatively, a compound containing P (phosphorus) or B (boron) may be mixed in the raw material to form a film containing SiO 2 containing these elements as a main component.

The thin film (3) containing TiO2 as a main component is provided to increase the transmittance of the glass plate with the transparent conductive film. From the viewpoint of productivity, the atmospheric pressure CVD method in which a titanium compound and an oxidizing agent such as oxygen are reacted at 400 to 600 ° C. is preferable as a means for forming a thin film containing TiO 2 as a main component. Titanium compounds include titanium tetraisopropoxide (Ti [OCH (CH3) 2] 4) and titanium tetra-n-butoxide (Ti
(OCH2CH2CH2CH3) 4) and other alkoxides, di-i-propoxy bis (acetylacetonato) titanium (Ti [OCH (CH
3) 2] 2 [OC (CH3) CHCOCH3] 2) and other β-diketone chelates and titanium tetrachloride (TiCl4) can be used. The thickness of the thin film composed mainly of TiO2 thus obtained is 100-120 nm.
It is preferable that it is, and it is preferable that it is 105 to 115 nm.
When the film thickness is thinner than 100 nm, the peak of the transmittance shifts to the short wavelength side and the transmittance at the wavelength of 550 nm becomes less than 91%. When the film thickness is thicker than 120 nm, the peak of the transmittance shifts to the long wavelength side, the transmittance in the short wavelength region decreases, the transmitted color becomes yellowish, and the designability is deteriorated, which is not preferable.

The thin film (4) containing SnO2 as a main component is provided to impart conductivity to the glass with a transparent conductive film. Sn
As a means for forming a transparent conductive film containing O2 as a main component, an atmospheric pressure CVD method in which a tin compound containing chlorine and oxygen are reacted at 400 to 600 ° C. is preferable from the viewpoint of productivity and electric characteristics of the film. . As the tin compound containing chlorine, monobutyltin trichloride (C4H9SnCl3), tin tetrachloride (SnCl4) and the like are used. Alternatively, a tin raw material may be mixed with a vapor of HF, a compound containing fluorine such as CF3Br, or a vapor containing a compound containing antimony pentachloride, and a trace amount of fluorine or antimony may be added to the film. The transparent conductive film containing SnO2 as the 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 thinner than 20 nm, the linearity of the resistance value exceeds 5%. When the film thickness is thicker than 80 nm, the transmittance peak shifts to the long wavelength side, and the transmittance in the short wavelength region decreases, so the transmitted color of the glass with a transparent conductive film becomes yellowish and the design is good. Damaged and not preferable.

[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 the surface of the glass plate in a predetermined thickness range. The visible light transmittance is high. Therefore, the 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 and a thickness of 1.1 mm and a transmittance of 92% at a wavelength of 550 nm was washed and dried to obtain a substrate. This substrate was heated to 450 ° C., and a gas in which SiH4 (silane), N2 (nitrogen) and O2 (oxygen) were adjusted was supplied to the surface of the substrate to form a SiO2 thin film having a thickness of 30 nm. After that, the substrate is heated to 500 ° C., vapor of Ti [OCH (CH3) 2] 4, and gas adjusted with N2 and O2 are supplied to the surface of the SiO2 film to form TiO with a thickness of 110 nm.
Two thin films were formed. Next, while keeping the substrate at 500 ℃, C4H9
A chlorine-containing SnO2 film having a thickness of 60 nm was formed on the surface of the TiO2 film by supplying adjusted gases of SnCl3 vapor, N2, O2 and water vapor. The glass with a transparent conductive film having a laminated structure thus obtained was gradually cooled and used as a sample. The results of measuring the visible light transmittance of this sample with a spectrophotometer are shown in FIG. It has a peak at a wavelength of 520 nm and a transmittance of 93 at a wavelength of 550 nm.
%Met. The linearity of the resistance value was 2% when the sheet resistance was measured at 10 points where a straight line passing through the center of the sample and parallel to the long side was divided into 11 equal parts.

Example 2 A sample was prepared in the same manner as in Example 1 except that the TiO2 film had a thickness of 120 nm and the chlorine-containing SnO2 film had a thickness of 40 nm. When the visible light transmittance of the sample was measured by a spectrophotometer, the wavelength of 54
It had a peak at 0 nm and had a transmittance of 92% at a wavelength of 550 nm. Further, the linearity of the resistance value of the sample was 3% by the same measuring method as in Example 1.

Example 3 A sample was prepared in the same manner as in Example 1 except that the TiO2 film had a thickness of 100 nm and the chlorine-containing SnO2 film had a thickness of 80 nm. When the visible light transmittance of the sample was measured by a spectrophotometer, the wavelength of 50
It had a peak at 0 nm and a transmittance of 91% at a wavelength of 550 nm. Further, the linearity of the resistance value of the sample was 3% by the same measuring method as in Example 1. $ 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 this glass and the ITO transparent conductive film (8) patterned in a stripe shape were covered. With the PET film (7), the transparent conductive film is directed inward and the stripe direction is perpendicular to the inside.
Further, the glass plate and the PET film were attached using a spacer (6) so that the distance between them 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 not shown) was obtained. As shown in FIG. 3 (b), this touch panel changes the resistance between the electrodes when it is pressed with a finger. For example, when used in combination with a liquid crystal display cell, it is a display element with good visibility that can be controlled by the pressing force of the finger. was gotten. Comparative Example 1 A sample was prepared in the same manner as in Example 1 except that the TiO2 film had a thickness of 130 nm and the chlorine-containing SnO2 had a thickness of 60 nm. When the visible light transmittance of the sample was measured by a spectrophotometer, the wavelength was 560n.
It had a peak at m and had a transmittance of 90% at a wavelength of 550 nm.
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 TiO2 film had a thickness of 90 nm and the chlorine-containing SnO2 film had a thickness of 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 had a transmittance of 88% at a wavelength of 550 nm.
The linearity of the resistance of the sample was 1%.

Comparative Example 3 Float glass having a size of 300 × 300 mm and a thickness of 1.1 mm was washed and dried to obtain a substrate. This substrate was heated to 450 ° C., and a gas adjusted to have SiH4, N2, and O2 was supplied to the surface of the substrate to form a SiO2 thin film having a thickness of 30 nm. After that, the substrate is heated to 500 ℃
Heated to C4H9SnCl3 vapor, N2, O2, HF vapor and vapor adjusted gas to supply the SiO2 film surface with thickness.
A SnO2 thin film containing 25 nm of fluorine was formed. The glass with a transparent conductive film thus obtained was gradually cooled and used as a sample. The results of measuring the visible light transmittance of the sample with a spectrophotometer are shown in FIG. 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 a high visible light transmittance and an excellent visibility.

[Brief description of drawings]

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

FIG. 2 is a diagram showing visible light transmission characteristics according to an embodiment of the present invention.

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

[Explanation of symbols]

(1): Transparent substrate (2): Thin film containing SiO2 as a main component (3): Thin film containing TiO2 as a main component (4): Transparent conductive film containing SnO2 as a main component (5): (2), ( Transparent electrode in which 3) and (4) are sequentially laminated (6): Spacer (7): PET film (8): Transparent conductive film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B32B 17/06 27/06 8413-4F G02F 1/133 530 G06F 3/033 350 A 0832-5E

Claims (3)

[Claims] 1. A thin film containing SiO2 as a main component on the surface of a glass plate,
A thin film containing TiO2 as a main component, a glass plate with a transparent conductive film obtained by sequentially coating a transparent conductive film containing SnO2 as a main component,
A glass plate with a transparent conductive film for a touch panel, wherein the thickness of the thin film containing SiO2 as a main component is 10 to 50 nm, 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. . 2. The transmittance at a wavelength of 550 nm is higher than the transmittance of the glass plate used alone, and the spectral transmittance has one maximum in the wavelength range of 400 to 800 nm, and the maximum is 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 is used as a first substrate, and a transparent resin plate coated with a transparent conductive film is used as a second substrate. The first substrate and the second substrate are bonded 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. Touch panel.