JPH0619622A - Transparent touch panel switch - Google Patents

Abstract

PURPOSE:To provide a transparent touch panel switch which is mounted on a CRT, a liquid crystal display panel, etc., to input the coordinates on a screen with the finger touch, etc., while transparently viewing the screen and suppresses the resistance changing rate of the indium tin oxicide (ITO) film of a transparent electrode lower and free from malfunctions after an environment resistant test. CONSTITUTION:The outer circumferential part formed between an upper substrate 1 and a lower substrate 2 is sealed by an adhesive 3, and the inactive gas is enclosed. Thus the adsorption of O2 is prevented for an ITO film of a transparent electrode 5. Then the resistance changing rate is decreased and the reliability is improved for a transparent touch panel switch.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a transparent touch panel switch which is mounted on a cathode ray tube (CRT), a liquid crystal display (LCD) or the like and which is touched with a finger or the like while seeing through a display screen to input the coordinates of the screen. The present invention relates to a contact-type transparent touch panel switch in which transparent electrodes facing each other are contacted and input.

[0002]

2. Description of the Related Art A conventional transparent touch panel switch will be described with reference to FIG. As shown in the figure, the upper substrate 1 and the lower substrate 2 having the transparent electrodes 5 on the surfaces facing each other are fixed by the adhesive 3 containing glass beads. The transparent electrode 5
Is a thin film formed by sputtering indium synoxide (hereinafter referred to as ITO). The upper substrate 1 is a polyethylene terephthalate film (hereinafter PE
T), and the lower substrate 2 is made of a glass substrate (the upper substrate 1 may also be made of a glass substrate in some cases). The upper substrate 1 and the lower substrate 2 are separated by a dot spacer 4 so as not to come into contact with each other when no pressure is applied to the upper substrate 1.

[0003]

However, in the structure of the above-mentioned conventional transparent touch panel switch, since the air 8 is sealed between the upper substrate 1 and the lower substrate 2 by the adhesive 3, it is possible to use it for a long time. However, the ITO film 5 is oxidized by O ₂ and humidity in the sealed air, resulting in a very high resistance value. Especially when a high temperature and high humidity test (60 ° C., 95% RH) is performed, as shown in FIG.
After 2000 hours, the resistance value became about double the initial value, and the panel switch sometimes malfunctioned.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a transparent touch panel switch having excellent environment resistance characteristics and a small change in resistance value.

[0005]

In order to solve the above-mentioned problems, the present invention is configured such that an outer peripheral portion between an upper substrate and a lower substrate is completely adhered and sealed with an adhesive, and an inert gas is sealed inside. It was done.

[0006]

Therefore, according to the present invention, since the inert gas is sealed between the upper substrate and the lower substrate, the amount of oxygen adsorbed by the ITO film, which is the transparent electrode, becomes extremely small, and the transparent touch panel switch is Even if used for a long time, I
This has the effect that the change in the resistance value of the TO film can be suppressed small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of one embodiment of the transparent touch panel switch of the present invention will be described with reference to FIG.

In the description, the same parts as in the prior art will be designated by the same reference numerals. As shown in the figure, the upper substrate 1 and the lower substrate 2 having the transparent electrodes 5 on the surfaces facing each other are fixed by the adhesive 3 containing glass beads. Using PET for the upper substrate 1 and a glass substrate for the lower substrate 2, a transparent electrode 5 was formed into a thin film of ITO on each of the substrates 1 and 2 by sputtering, and then formed into a predetermined shape by etching. On each of the etched substrates 1 and 2, a lead wiring (not shown) was formed by Ag paste from the end of the transparent electrode 5 of ITO to the end of the substrate.

After the dot spacers 4 were printed on the lower substrate 2 and cured, the adhesive 3 was printed on the entire periphery of the substrate to a thickness of 60 μm by printing. Upper substrate 1
A Ag electrode 6 for connection was printed and formed by Ag paste for electrical connection between the electrodes of the upper and lower substrates 1 and 2.

The above-mentioned upper and lower substrates 1 and 2 are made to face each other as shown in FIG. 1 and are aligned and bonded together. The bonding atmosphere was N ₂ gas atmosphere, and they were bonded together therein. In the bonded upper and lower substrates, the adhesive 3 and the connecting Ag electrode 6 on the outer peripheral portion were thermally cured while the upper substrate 1 was pressed using a flat jig.

The sheet resistance of the ITO film of the transparent touch panel switch thus prepared was measured and found to be 350Ω / □ as an initial value. When this transparent touch panel switch was subjected to a high temperature and high humidity test (60 ° C., 95% RH), it was 410 Ω / □ at 2000 Hr. The resistance change rate (ΔR / R) was 17%, and as shown in FIG. 3, the resistance change rate was extremely small as compared with the conventional example. The same effect was shown in the heat resistance test (85 ° C).

Ar gas was used in addition to N ₂ gas, but the resistance change rate in the environment resistance test was small as with N ₂ gas.

[0013]

As is apparent from the above embodiment, the present invention is configured such that the outer peripheral portion between the upper substrate and the lower substrate is completely adhered and sealed with an adhesive, and an inert gas is sealed inside. So
The amount of O ₂ adsorbed by the transparent electrode ITO film is extremely small, and even if the transparent touch panel switch is used for a long time,
In addition to providing a highly reliable transparent touch panel switch by reducing the resistance change rate of the TO film, in particular, an analog type touch panel switch (voltage is applied to both ends of the transparent electrode to detect partial pressure from any position of the transparent electrode). Type)
In this case, the change in linearity indicating the relationship between the operating position and the output voltage can be reduced, which contributes to downsizing of the transparent touch panel switch.

[Brief description of drawings]

FIG. 1 is a side sectional view of a transparent touch panel switch that is an embodiment of the present invention.

FIG. 2 is a side sectional view of a conventional transparent touch panel switch.

FIG. 3 is a comparison diagram of resistance change rates in a high temperature and high humidity test (60 ° C., 95% RH) of a transparent touch panel switch of a conventional example and an example of the present invention.

[Explanation of symbols]

1 Upper Substrate 2 Lower Substrate 3 Adhesive 4 Dot Spacer 5 Transparent Electrode (ITO) 6 Connection Ag Electrode 7 Inert Gas (N ₂ )

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahide Fukui 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. A transparent touch panel switch having transparent electrodes on opposite surfaces of an upper substrate and a lower substrate, wherein an outer peripheral portion between the upper substrate and the lower substrate is adhesively sealed with an adhesive, and the insides of the upper substrate and the lower substrate are sealed. A transparent touch panel switch in which an inert gas is filled in.