JP2008080743A - Touch panel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel device which can prevent a metal layer from being melted or corroded to cause a deterioration in adhesion to a transparent conductive film, when the device has a structure which keeps the metal layer overlying the upper layer of the transparent conductive film. <P>SOLUTION: The transparent conductive film 12 such as an ITO or the like is formed on a substrate 11 such as glass or the like. As the metal layer 14 to be formed on the transparent conductive film 12, a silver-palladium alloy (AgPd) is used. Further, an adhesive layer 13 using an ICO (indium cerium oxide) is provided between the metal layer 14 and the transparent conductive film 12. Additionally, the ICO as a protective layer 15 overlies the metal layer 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a touch panel device, and more particularly to a touch panel device in which a metal layer is formed on a transparent conductive film.

  The touch panel device is a device that detects a contact position or a proximity position when a contact body such as a human finger or pen comes into contact with or approaches the touch panel. As a method for detecting contact, there are a resistance detection method, a capacitance method, an optical method, an ultrasonic method, and the like.

  FIG. 2 is an explanatory diagram for explaining the principle of position detection in the capacitive touch panel device. However, FIG. 2 shows a case where a one-dimensional position is detected in order to simplify the description. In the case of using the electrostatic capacity method, generally, ITO (on a substrate (substrate) 11 such as glass, acrylic plate, polyethylene terephthalate (PET) film, polypropylene (PP) film) having high light transmittance in the visible light region is used. A touch panel 20 on which a transparent conductive film such as Indium Tin Oxide (indium oxide added with tin or tin oxide) 12 is formed is used.

As shown in FIG. 2A, an AC voltage having the same phase is applied to both ends of the touch panel 20 from a current source via a current detection resistor r. When the contact body 51 is not in contact with or in close proximity, no current flows through the touch panel 20. As shown in FIG. 2B, when the contact body 51 that is a conductor contacts or approaches the touch panel 20, a capacitor is formed between the contact body 51 and the touch panel 20, and a weak current flows through the contact body 51. Flows. Therefore, currents I ₁ and I ₂ flow from the current source. When the contact position of the contact body 51 is different, the values of the currents I ₁ and I ₂ are different. Therefore, by detecting the values of the currents I ₁ and I ₂ , it is possible to detect the position where the contact body 51 is in contact with or close to the contact body 51. .

  Actually, the touch panel generally detects a two-dimensional position (hereinafter referred to as a contact position) where the contact body 51 is in contact with or close to the touch body 51. Therefore, an AC voltage is applied from four locations on the touch panel. Applied. FIG. 3 is a plan view showing the configuration of the touch panel 100 described in Patent Document 1. As shown in FIG. In the configuration shown in FIG. 3, a conductor layer 102 is formed outside the touch area 101 in the touch panel 100. Of the conductor layers 102 formed outside the touch region 101, the conductor layers 102 at the four corners of the touch panel 100 are assigned to the electrodes. A voltage is applied to the electrodes. The touch area 101 is an area where the contact position can be detected. Although not explicitly shown in FIG. 3, a transparent conductive film is formed over the entire surface of the touch panel 100 below the conductor layer 102.

  FIG. 4 is a plan view showing the configuration of the touch panel 110 described in Patent Document 2. In the configuration shown in FIG. 4, a conductor layer 112 as a ground pattern is formed outside the touch area 111 on the touch panel 110 in order to prevent interference of AC signals from each power source. Although not clearly shown in FIG. 4, metal electrodes are formed outside the touch region 111.

  Note that the conductor layers 102 and 112 can also act to lower the resistance value R (see FIG. 2) of the touch panel. The lower the resistance value R, the better the detection sensitivity of the contact position.

Japanese Patent Laying-Open No. 2006-23904 (FIG. 2) Japanese Patent Laying-Open No. 2005-84982 (FIG. 8)

  In the touch panel, the transparent conductive film is formed on the substrate by a sputtering method or the like. The conductor layers 102 and 112 are formed by applying a metal paste on the transparent conductive film or fixing the metal to the transparent conductive film with an adhesive. FIG. 5 is a cross-sectional view schematically showing the configuration of a touch panel provided with a protective substrate for protecting the touch panel. The configuration shown in FIG. 5 corresponds to the configuration in a cross section in the region where the conductor layers 102 and 112 are formed in the configuration shown in FIG. 3 or FIG. 4, for example.

  In the example shown in FIG. 5, after the metal layer 14 a is placed on the ITO 12 as a transparent conductive film formed on the substrate 11, the protective substrate 16 is disposed. The protective substrate 16 is fixed to the substrate 11 with an adhesive 13a that hardens when pressed, for example.

  As the metal layer 14a, for example, a laminate of molybdenum (Mo), aluminum neodymium alloy (AlNd), and molybdenum (Mo) can be used. However, in the case where the metal layer 14a made of such a material is used, there is a possibility that the adhesive 13a may be dissolved or corroded by an acidic substance when the adhesive 13a contains an acidic substance. As a result, there is a problem that the adhesion between the metal layer 14a and the ITO 12 decreases, the resistance increases, and the position detection accuracy deteriorates.

  Therefore, the present invention provides a touch panel that can prevent a metal layer from being melted or corroded to deteriorate the adhesion to the transparent conductive film when the metal layer is formed on the transparent conductive film. An object is to provide an apparatus.

  A touch panel device according to the present invention includes a substrate, a touch region that is a region where a proximity position or a contact position of an object formed on the substrate can be detected, and a transparent conductive film formed on the substrate outside the touch region. A touch panel device including a conductive layer having a metal layer disposed thereon, wherein the metal layer is formed of a noble metal or a noble metal alloy, and an adhesive layer formed of a metal oxide is formed between the transparent conductive film and the metal layer. It is characterized by being.

  For example, the metal layer is made of silver palladium alloy, and the adhesive layer is made of indium cerium oxide.

  A protective substrate may be further provided, and the protective substrate may be fixed to the substrate with an adhesive at least at the position of the conductor layer, and a protective layer made of a metal oxide may be disposed on the metal layer.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect which can prevent that a metal layer melt | dissolves or corrodes, adhesiveness with a transparent conductive film falls, and resistance raises.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a part of a touch panel in a touch panel device according to the present invention. The overall configuration of the touch panel is the same as the configuration shown in FIGS. 3 and 4. FIG. 1 shows a cross-sectional configuration in a region where the conductor layers 102 and 112 are formed in the configuration shown in FIGS. 3 and 4, for example. In addition to the touch panel configured as shown in FIGS. 3 and 4, the touch panel device includes a circuit portion for applying a signal to the electrodes of the touch panel and detecting a contact position of an object (such as a human finger). It is a waste.

  In this embodiment, a silver palladium alloy (AgPd) is used as the metal layer 14 formed on the transparent conductive film 12. An adhesive layer 13 using ICO (Indium Cerium Oxide: indium oxide to which cerium or cerium oxide is added) is provided between the metal layer 14 and the transparent conductive film 12. A transparent conductive film 12 such as ITO is formed on a substrate 11 made of glass or the like.

  Here, AgPd is exemplified as the material of the metal layer 14, but other metals can be used as long as the metal is highly resistant to acidic substances, that is, a metal having low corrosiveness and low electrical resistivity. Also good. Since high resistance to acidic substances is required, it is preferable to use a noble metal or a noble metal alloy.

  In addition, the adhesive layer 13 is used to enhance the adhesion between the metal layer 14 and the transparent conductive film 12, but the adhesion between the metal layer 14 and the transparent conductive film 12 can be enhanced, and Other metal oxides may be used as long as they have a low resistivity.

  Further, an ICO as a protective layer 15 is laminated on the metal layer 14. Although not shown in FIG. 1, similarly to the configuration shown in FIG. 5, the protective substrate 16 is fixed to the substrate 11 at least at a position where the adhesive layer 13, the metal layer 14, and the protective layer 15 are formed. . The protective layer 15 serves to protect the metal layer 14 from the adhesive and protect the metal layer 14 from the protective substrate.

  In addition, the thicknesses of the adhesive layer 13, the metal layer 14, and the protective layer 15 are 50 to 100 mm, 1500 to 2000 mm, and 50 to 100 mm, respectively, as an example.

  When realizing the structure shown in FIG. 1, first, for example, the transparent conductive film 12 is formed on the substrate 11 by sputtering or the like. Next, a material for the adhesive layer 13 is formed in a predetermined region on the transparent conductive film 12, and a material for the metal layer 14 is formed thereon. Further, a material for the protective layer 15 is formed thereon. Thereafter, the material of the adhesive layer 13, the material of the metal layer 14, and the material of the protective layer 15 are etched at a time to form a desired shape (see the shapes of the conductor layers 102 and 112 in FIGS. 3 and 4). .

  In this embodiment, a metal having low corrosiveness and low electrical resistivity is used as the metal layer 14. Therefore, even when an adhesive containing an acidic substance is used when the metal layer 14 or the like is fixed to the transparent conductive film 12, the possibility that the metal layer 14 is melted or corroded is reduced. In addition, since the adhesive layer 12 is provided between the metal layer 14 and the transparent conductive film 12 so as to improve the adhesion between the metal layer 14 and the transparent conductive film 12 and has a low electrical resistivity, the metal layer 14 is provided. However, the role of lowering the electrical resistivity of the entire touch panel is not impaired, and the metal layer 14 and the transparent conductive film 12 are more firmly fixed.

  In this embodiment, the metal layer 14 is assumed to correspond to the conductor layer 102 shown in FIG. 3 or the conductor layer 112 shown in FIG. However, for example, the present invention can also be applied to the case where the metal layer 14 is used only for the purpose of reducing the electrical resistivity of the entire touch panel.

  In this embodiment, it is assumed that the transparent conductive film 12 is formed over the entire surface of the touch panel. However, even when the transparent conductive film 12 is formed only on a part of the touch panel, the touch region The present invention can be applied to a structure in which the metal layer 14 needs to be formed on the transparent conductive film 12 on the outside. For example, in the touch panel, when the plurality of transparent conductive films 12 are linearly formed or ITO as a large number of detection electrodes is discretely formed, the transparent conductive film 12 is only formed on a part of the touch panel. In some cases, a film is formed.

  Furthermore, when a display device such as a liquid crystal display device is installed below the touch panel device, the upper substrate of the display device can also be used as the touch panel substrate 11. Further, as the protective layer 15 on the metal layer, an ICO that can be easily etched and patterned is illustrated, but other metal oxides such as silicon oxide and aluminum oxide may be used.

  The present invention is suitably applied to a touch panel device having a structure in which a metal layer is formed on an upper layer of a transparent conductive film.

Sectional drawing which shows a part of touchscreen in the touchscreen apparatus by this invention. Explanatory drawing for demonstrating the principle of position detection in the touchscreen apparatus by an electrostatic capacitance system. The top view which shows the structure of the conventional touch panel. The top view which shows the structure of the other conventional touch panel. Sectional drawing which shows typically the structure of the touchscreen which arrange | positioned the protective substrate for protecting a touchscreen.

Explanation of symbols

11 Substrate 12 Transparent conductive film 13 Adhesive layer 14 Metal layer 15 Protective layer 16 Protective substrate

Claims (3)

A substrate, a touch region that is an area where the proximity position or contact position of an object formed on the substrate can be detected, and a metal layer formed on the transparent conductive film on the substrate formed outside the touch region. In the touch panel device provided with the disposed conductor layer,
The metal layer is formed of a noble metal or a noble metal alloy,
An adhesive layer made of a metal oxide is formed between the transparent conductive film and the metal layer. The metal layer is formed of silver palladium alloy,
The touch panel device according to claim 1, wherein the adhesive layer is formed of indium cerium oxide. A protective substrate,
The protective substrate is fixed to the substrate with an adhesive at least at the position of the conductor layer,
The touch panel device according to claim 1, wherein a protective layer made of a metal oxide is disposed on the metal layer.

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