JP6201623B2 - Electrode member, method for manufacturing the same, touch panel using the electrode member, and image display device including the touch panel - Google Patents

Description

  The present invention relates to an electrode member, and more particularly, to an electrode member including a thinned conductor mesh with reduced external light reflection and high line invisibility. The present invention also relates to a method for manufacturing the electrode member, a touch panel using the electrode member, an image display device in which the touch panel is disposed, and the like.

  In recent years, touch panels have become widespread as input devices for various electronic devices. Various types of touch panels such as a resistive film type and a capacitance type have been put into practical use.

A touch panel generally has a transparent conductive film made of an ITO (indium tin oxide) thin film formed on one surface of a transparent substrate made of a glass plate, a polyethylene terephthalate film, or the like as an electrode member for a touch panel. Is used (Patent Document 1).
However, the transparent conductive film made of an ITO thin film is expensive because a rare metal (rare earth element) called indium is used, and the resistance (surface resistivity) is high in order to increase the area of the touch panel. At some point, it is difficult to meet the demands for cost reduction and large screen.

Therefore, an electrode member for a touch panel in which a metal mesh composed of a fine metal wire pattern is formed on a transparent base material instead of the ITO thin film transparent conductive film has been proposed (Patent Document 2). According to the metal mesh, the cost and the resistance can be reduced as compared with the ITO thin film.
However, since the metal mesh exhibits a relatively high reflectance with respect to visible light, the external light is reflected and the mesh pattern is visually recognized, or the reflected light from the conductor mesh is superimposed on the image light and the touch panel. The image contrast of the device is reduced. Therefore, the blackening layer needs to be disposed on the observer side of the metal layer.
In addition, as a metal mesh for electrodes for touch panels, there is a strong demand for further thinning of electrodes in terms of visibility and high transmittance with the recent increase in image quality and the spread of portable small terminals called tablets. Is done.

As an example in which a blackened layer is provided on the surface of a metal mesh, for example, in Patent Document 3, a copper foil having a blackened layer formed on both sides is bonded and laminated on a transparent resin film, and then meshed by photolithography. An electromagnetic wave shielding filter is disclosed. However, the thickness of the copper foil is at least 10 μm or more, and the shape of the main cut surface of the line portion (cut surface perpendicular to the extending direction of the line portion) due to side etching of the copper foil during photoetching is a quadrangular shape Instead, the line width decreases as the distance from the transparent substrate surface increases, resulting in a substantially triangular shape with the transparent substrate side as the base, causing problems such as an increase in the electrical resistance of the line portion or disconnection of the line portion. Therefore, it is difficult to reduce the line width to less than 10 μm.
As a metal mesh having a blackened layer, which enables such thinning, for example, in Patent Document 4, a copper thin film having a thickness of 0.3 μm is formed on a transparent substrate by vapor deposition, A copper oxide thin film having a thickness of 0.05 μm is formed thereon by sputtering, and this is photoetched to obtain a metal mesh having a line width of about 10 μm.
However, even if it is the metal mesh of this patent document 4, in order to make a preferable electrode for touch panels, in order to further reduce external light reflection and increase line invisibility, both sides of the mesh line and the side of the substrate are also provided. A blackening layer is required. However, when a blackened layer is formed by sputtering copper oxide on the side surface of the mesh line, a blackened layer of copper oxide (cupric oxide) is deposited on the mesh opening, which is difficult to remove. Even blacking on both sides is difficult (originally, blackening on the side of the substrate is impossible).

JP 2008-310551 A JP 2011-134311 A Japanese Patent No. 4288235 JP 2008-204974 A

  The present invention has been made under such circumstances, and an object thereof is an electrode member in which a fine conductor mesh is formed on a transparent substrate, and the entire surface of the line portion of the conductor mesh is blackened. It is providing the electrode member processed, its manufacturing method, the touchscreen using the said electrode member, the image display apparatus which has arrange | positioned this touchscreen on the display surface, etc.

  As a result of various studies, the inventor has made a copper layer on the transparent substrate, a first blackening layer containing cupric oxide on the surface of the copper layer on the transparent substrate side, the upper surface and both sides of the copper layer. It has been found that an electrode member for a touch panel that achieves the object of the present invention can be obtained by forming a conductive mesh having a second blackening layer containing tellurium chloride on the surface.

That is, the present invention
(1) An electrode member for a touch panel including a transparent base material and a conductor mesh provided on the transparent base material, wherein the conductor mesh is a copper layer and a surface of the copper layer on the transparent base material side A first blackening layer containing cupric oxide, and a second blackening layer containing tellurium chloride on the upper surface and both side surfaces of the copper layer,
(2) The electrode member for a touch panel according to (1), wherein the conductor mesh has a line width of less than 10 μm,
(3) A first blackening film made of cupric oxide, a copper film, and a resist film are sequentially provided on a transparent substrate, and the resist film is patterned and developed to be patterned into a mesh, and then patterned. Using the resist pattern layer as a mask, the copper film in the resist opening is etched to form a copper layer, and then the first black film in the resist opening is dissolved and removed with hydrochloric acid to remove the resist pattern layer. Furthermore, the electrode member for a touch panel according to the above (1) or (2) is manufactured by blackening the upper surface and both side surfaces of the copper layer meshed with the tellurium blackening solution to form a second blackened layer. Method,
(4) The touch panel including the electrode member according to (1) or (2) above or (2),
(5) An image display device in which the touch panel according to (4) is arranged on a display surface,
Is to provide.

  According to the present invention, an electrode member in which a fine wire conductor mesh is formed on a transparent substrate, the entire surface of the line portion of the conductor mesh being blackened, a method for manufacturing the same, and the electrode member It is possible to provide a touch panel using the image display device and an image display device in which the touch panel is arranged on a display surface. Since the electrode member of the present invention is blackened on the entire surface of the line portion of the conductor mesh, the effect of reducing external light reflection, high line invisibility, and no interference with light from the display side is obtained. Played. In addition, when used on a touch panel, the electrode member may be on the conductor mesh side or on the transparent substrate side, but the entire surface of the electrode member of the present invention is blackened. Therefore, there is an advantage that the same effect can be obtained in any case.

It is a schematic sectional drawing which shows the structure of the electrode member of this invention. It is a figure for demonstrating the manufacturing method of the electrode member of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are conceptual diagrams, and the scale relations, aspect ratios, and the like of components may be exaggerated as appropriate for convenience of explanation.
In the following, for a film or layer, a pattern formed in a specific shape such as a mesh is referred to as a “layer”, and a form formed over the entire surface before being patterned is referred to as a “film”. It is called.

[Electrode member]
FIG. 1 is a schematic cross-sectional view showing the configuration of the electrode member of the present invention.
The electrode member 100 is a transparent base material 10 and the electrode 30 which is a conductor mesh provided thereon is a first blackening containing a copper layer 21 and cupric oxide on the surface of the copper layer on the transparent base material side. A second blackening layer 23 containing tellurium chloride is formed on the upper surface and both side surfaces of the layer 22 and the copper layer.

The transparent substrate 10 is not particularly limited as long as it is a transparent substrate, polyester resin such as polyethylene terephthalate and polyethylene naphthalate, acrylic resin such as polymethyl methacrylate, polyolefin resin such as polypropylene, triacetyl cellulose (cellulose triacetate). ), A resin sheet made of a cellulose resin, a polycarbonate resin, or the like, or a glass such as soda glass, potassium glass, or quartz glass, or a plate made of an inorganic material such as crystalline quartz or fluorite.
The thickness of these transparent substrates is selected from a range of about 20 to 3000 μm according to the application, required performance, price, and the like.

The electrode 30 includes a copper layer 21 which is a highly conductive metal layer, a first blackening layer 22 containing cupric oxide (CuO) on the surface of the copper layer on the transparent substrate side, an upper surface and both sides of the copper layer. A second blackening layer 23 containing tellurium chloride is formed on the surface.
The thickness of the copper layer is preferably 0.1 to 5 μm, and more preferably 0.5 to 2.5 μm.
By making the copper layer thin, the problems due to side etching at the time of etching processing are reduced, and it becomes easy to make a thin line. Particularly, a thin line of a copper layer having a line width of 10 μm or less, especially 7 μm or less. Processing can be performed with good shape reproducibility.
The thickness of the first blackened layer and the second blackened layer is preferably 0.01 to 0.4 μm.

The electrode 30 of the present invention is a mesh (mesh pattern or lattice pattern) pattern, the conductor mesh preferably has a line width of less than 10 μm, more preferably 2 to 7 μm, and the mesh pattern has an aperture ratio of 95 to 95 μm. It is preferably about 99%. Such a thin line has a high aperture ratio, and thus has high visibility and high transmittance, and is suitable as a metal mesh for a touch panel electrode.
In addition, when the electrode member of this invention and its manufacturing method are applied when it has a conductor mesh with a line | wire width of less than 10 micrometers, the effect is fully show | played. However, the electrode member having the configuration of the present invention may be applied to the case where the line width of the conductor mesh is 10 μm or more, and the present invention includes a form having a line width of 10 μm or more.
The electrode member for a touch panel of the present invention has the conductor mesh 20 as an essential component on at least one of the front and back surfaces of the transparent substrate 10. However, the electrode member of the present invention usually has other parts in addition to this. Other parts include an extraction electrode, a terminal, an FPC, a surface protection plate, and the like. These other components may be appropriately selected and adopted from those known in the field of touch panels as necessary. Illustration and further explanation are omitted.

[Method for producing electrode member]
FIG. 2 illustrates a method for producing an electrode member of the present invention.

  First, as shown to Fig.2 (a), the transparent base material 10 is prepared.

  Next, as shown in FIG. 2B, a first blackening film 11 made of cupric oxide (which will later become a constituent material of the first blackening layer) is formed on the entire surface of the transparent substrate 10. . As a method for forming the first blackening film 11, sputtering or vapor deposition of cupric oxide is employed.

  Subsequently, as shown in FIG. 2C, a copper film 12 (which will be a constituent material of the copper layer 21 later) is formed on the entire surface of the first blackening film 11. As the copper film 12, the copper film 12 having a desired thickness is formed on the first blackening film 11. As a method for forming the copper film 12, various methods such as sputtering, vapor deposition, electroplating, and electroless plating can be employed. However, when the thickness is about 3 μm or less, the copper film 12 is manufactured in a relatively short time and at a low cost. Vapor deposition is preferred because it can be used.

Thereafter, the first blackening film 11 and the copper film 12 on the transparent substrate 10 are patterned in a desired pattern by patterning using a photolithography technique.
Specifically, first, a photosensitive resist film 13 is provided on the copper film 12 (FIG. 2D), and the resist film 13 is patterned and developed by patterning into a mesh pattern or a lattice pattern (FIG. 2). (E)). The photosensitive resist can be selected from, for example, bichromate casein-based, cinnamic ester-based, acrylic ester-based, and rubber-based resists. For the exposure, for example, ultraviolet irradiation emitted from a mercury lamp can be adopted. Next, the copper film 12 in the resist opening is etched using the patterned resist pattern layer 14 as a mask. For example, the etching is preferably performed at 35 to 45 ° C. using a 40 ° Baume ferric chloride aqueous solution.
Thereby, the copper layer 21 is formed in a desired pattern from the copper film 12 on the transparent base material 10 and the first blackening film 11 (FIG. 2F).

  Next, the first blackened film 11 made of cupric oxide remaining in the mesh opening is dissolved and removed with hydrochloric acid having a concentration of about 0.5 to 5% (FIG. 2 (g)).

  Thereafter, the resist pattern layer 14 on the copper layer 21 is peeled off to obtain a laminate in which the first blackened layer 22 and the copper layer 21 are formed on the transparent substrate 10 in a mesh shape (FIG. 2 (h)). .

  Three surfaces of the obtained electrode member (side surfaces and both side surfaces opposite to the transparent base material 10 of the copper wire portion constituting the conductor mesh 20; see FIGS. 1 and 2 (j)) are unblackened. A second blackening layer 23 is formed on the upper surface and both side surfaces of the copper mesh layer 21 by contacting with a blackening treatment solution that is a hydrochloric acid solution in which tellurium is dissolved (FIG. 2 (i)).

The blackening treatment solution used here is a hydrochloric acid solution in which tellurium is dissolved, and it is preferable to use tellurium oxide as the source of tellurium. Tellurium oxide is used as tellurium source in the present invention can be represented by TeO _2.
In this blackening treatment solution (100% by weight), tellurium is an amount in the range of 0.01 to 0.45% by weight, preferably 0.05 to 0.40% by weight, in terms of oxide. It is contained in. Since the blackening treatment liquid used in the present invention has a tellurium concentration lower than that of the conventional tellurium-based blackening treatment liquid, the deposition rate of the blackening layer is reduced, the thickness is black, and the adhesion between the metal and blackening layers is high. A chemical layer can be deposited.
When the tellurium content of the blackening treatment liquid exceeds 0.45% by weight, the deposition rate of the blackened layer is too high, the blackened layer deposited on the metal surface is cracked, and the blackened layer-to-metal Adhesion may be insufficient. If the amount is less than 0.01% by weight, the adhesion between the blackened layer and the metal is sufficient, but the deposition rate of the blackened layer is small and the processing efficiency may be inferior.
An aqueous hydrochloric acid solution that dissolves tellurium oxide is usually formed by blending water with 35% hydrochloric acid (hereinafter also simply referred to as hydrochloric acid). The concentration of HCl (hydrogen chloride) in the aqueous hydrochloric acid solution is in the range of 0.05 to 8% by weight, preferably 0.1 to 2% by weight, and more preferably 0.3 to 1% by weight. By using an aqueous hydrochloric acid solution having such a concentration, the tellurium oxide can be completely dissolved.

The tellurium blackening treatment is a kind of substitution plating, and the surface of the copper is substituted with a black compound, but the surface of the transparent substrate 10 such as a PET film which is a nonmetal in the opening is a metal atom that undergoes substitution reaction with tellurium. Because there is no, it will not be black. According to the analysis result, the composition of the second blackening layer 23 includes tellurium chloride. In addition to this, it may further contain copper chloride.
Thus, the electrode member 100 of the present invention in which the entire mesh line is blackened is obtained.

[Application of electrode members]
(Touch panel)
The electrode member of the present invention can be preferably used as a touch panel sensor (position detection electrode), and the touch panel including the touch panel sensor is a portable small terminal, electronic paper, computer display, electronic blackboard, small game machine, cash automatic It can be preferably used as a touch panel to be mounted on a display surface of a payment machine, a display surface of a ticket vending machine or the like. Such a display device may be a liquid crystal display device (LCD), a plasma display device (PDP), an electroluminescence (EL) display device, a cathode ray tube (CRT) display device, an electrophoretic display device, or the like. Good.

(Other)
In addition, since the electrode member of the present invention is conductive and invisible to the mesh, it is preferably used as an electromagnetic shielding material to be attached to the front surface of a display of an image display device such as a PDP, a window of a building or a vehicle as an application other than a touch panel sensor. be able to.
Furthermore, the electrode member of the present invention can be preferably used as a transparent antenna element. Since the transparent antenna element has both functions of transparency and transmission / reception, it can be used for various transparent antennas.
The transparent antenna can be preferably used by being attached to a site where transparency is required. In particular, it can be attached to the front of the display of mobile communication devices such as mobile phones and used for receiving terrestrial and satellite broadcasts. It can be attached to the window glass of automobiles, buses, trucks, railway vehicles, new transportation systems, etc. Transparent antenna for building windows that can be used for receiving radio waves such as radio waves, television, radio, vehicle radio, etc., and installed on window glass in houses, various buildings, and partitions to receive terrestrial waves and satellite broadcasts Can be used as etc.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by this example.

[Example 1]
As the transparent base material 10, a continuous belt-shaped, uncolored and transparent biaxially stretched polyethylene terephthalate film (thickness: 100 μm) is prepared (see FIG. 2A). A layer of cupric oxide having a thickness of 0.05 μm was formed at .5 Pa, target: copper, introduced gas fraction: oxygen 100%) to form a first blackened film 11 (FIG. 2B). Next, copper vapor deposition was performed by a resistance heating vacuum vapor deposition method (vacuum degree: 3 × 10 ⁻³ Pa) to form a copper film 12 having a thickness of 3 μm on the first blackened film 11 (FIG. 2C). )).
Next, the first blackened film 11 / copper film 12 portion is processed into a mesh shape by a corrosion process using a photolithography method, and the mesh-shaped first blackened layer 22 is formed on the transparent substrate 10. And the mesh lamination sheet in which the mesh-like copper layer 21 was formed was created. Here, “A / B” represents a stacked body in which the A layer and the B layer are stacked in this order.

Specifically, using a production line for a color TV shadow mask, the laminate of transparent substrate 1 / first black film 11 / copper film 12 is supplied as a continuous belt-like sheet unwound from winding. Then, this strip-shaped sheet (laminated body) was subjected to masking to etching.
First, a photosensitive resist film 13 made of casein-based photosensitive negative resist was applied to the entire surface of the copper film 12 of the laminate by a dipping method (FIG. 2D). The film was conveyed intermittently to the next station and irradiated with ultraviolet rays from a mercury lamp using a negative pattern plate (photomask), and the negative pattern was closely exposed on the resist film 13 (not shown).
The negative pattern plate is formed by forming a negative (negative) light shielding pattern of a predetermined electrode pattern on the surface of a transparent glass plate. The electrode pattern has a square opening, a line width of 5 μm, a line interval (period) of 500 μm, a subordinate angle formed by two sets of lines orthogonal to the sides on both sides of the belt-like sheet, that is, a bias angle of 41 degrees and A rectangular region (consisting of the first blackened layer 22 / copper layer 21) of 49 degrees and having an outer contour width of 4 mm and a length of 300 mm (the inside of the rectangular region is partitioned into the mesh shape) It includes 50 detection electrode patterns arranged in parallel at an interval of 4 mm. Further, an extraction circuit pattern is connected to one end of each rectangular area.

After the exposure, the resist film 13 was developed with water, hardened, and baked at 100 ° C. to obtain the negative pattern resist pattern layer 14 (FIG. 2E). Further, it is transported to the next station, and is corroded by spraying using a ferric chloride solution of 50 ° C. and 42 ° Baume as a corrosive solution, and copper at the opening of the resist pattern layer 14 (resist layer absent portion). The film 12 was removed. The first blackening film 11 remained in the opening (FIG. 2F).
Next, at the next station, 1% hydrochloric acid is used for spraying to corrode and the first blackening film 11 at the opening of the resist pattern layer 13 (resist layer absent portion) is also removed to open the opening. Formed (FIG. 2G).
Next, while transporting the station, it is washed with water, the resist pattern layer 14 is peeled off, washed, and dried at 60 ° C. to form a first blackened layer formed in a mesh shape remaining in the electrode pattern. The laminated body which formed the laminated body of 22 / copper layer 21 on the transparent base material 10 was obtained (FIG.2 (h)).

Next, an aqueous solution of 0.25% by weight of tellurium dioxide (0.2% by weight of tellurium concentration), 0.45% by weight of hydrochloric acid, and 20% by weight of sulfuric acid is used as the metal blackening treatment solution, and the laminate is used as the treatment solution. (FIG. 2 (h)) is immersed for 30 seconds at a treatment temperature of 25 ° C., and a second blackening layer 23 containing tellurium chloride (TeCl ₂ ) is formed on the exposed portion of copper to form a mesh. As a result, an electrode 30 made of the conductive mesh 20 made of the first blackened layer 22, the copper layer 21, and the second blackened layer 23 was obtained (FIG. 2 (i)).
Thereafter, through a water washing and drying process, the transparent substrate 10 / electrode 30 (consisting of the conductive mesh 20 composed of the first blackened layer 22, the copper layer 21, and the second blackened layer 23) is laminated. An electrode member 100 for a touch panel was obtained (FIG. 2 (j)).

DESCRIPTION OF SYMBOLS 10 Transparent base material 11 1st blackening film 12 Copper film 13 Resist film 14 Resist pattern layer 20 Conductor mesh 21 Copper layer 22 1st blackening layer 23 2nd blackening layer 30 Electrode 100 Electrode member

Claims (4)

A transparent substrate, an electrode member having a conductive mesh provided on the transparent substrate, the electrically conductor mesh, and the copper layer, the oxide in contact with the surface of the transparent substrate side of the copper layer first blackened layer made of cupric, is obtained by forming the second blackened layer containing tellurium chloride in contact with the upper surface and both side surfaces of the copper layer, the electrode line width of the conductor collector mesh is less than 10μm Element. A first blackened film made of cupric oxide, a copper film, and a resist film are sequentially provided on a transparent substrate, and the resist film is patterned and developed to be patterned into a mesh, and then the patterned resist pattern Using the layer as a mask, the copper film in the resist opening is etched to form a copper layer, and then the first black film in the resist opening is dissolved and removed with hydrochloric acid, and the resist pattern layer is removed. The method of manufacturing the electrode member according to claim 1, wherein the upper surface and both side surfaces of the copper layer formed into a mesh shape with a tellurium blackening solution are blackened to form a second blackened layer. A touch panel comprising the electrode member according to claim 1 . The image display apparatus which has arrange | positioned the touchscreen of Claim 3 on the display surface.