JP7645688B2 - Manufacturing method of touch panel and electrode substrate - Google Patents

Description

The present invention relates to a touch panel and a method for manufacturing an electrode substrate used in the touch panel.

Various types of touch panels are known as display devices that can be used for operational input, but some resistive film type transmissive touch panels in particular have static electricity countermeasures in place while maintaining a good appearance (see, for example, Patent Document 1).

Touch panels are also known that are equipped with means for shielding against electromagnetic noise that interferes with the operation of detecting the touch position of a pointer (see, for example, Patent Document 2).

JP 2019-202518 A JP 2010-146192 A

In many conventional touch panels, the edges of the film surface that the user's fingers can approach are covered by the housing, so the conductive materials such as ITO (Indium Tin Oxide) are not exposed and the user cannot directly touch the conductive parts of the touch panel.

However, in recent years, with an emphasis on design, touch panels have been developed in which the outer periphery of the film is decorated with a printed design or other decorative feature, and the edges of the film are not covered by the housing. With such touch panels, there is a risk of sparks or discharges due to static electricity when a user's finger touches or comes close to the edge of the film.

Therefore, the present invention aims to provide a touch panel that has anti-static measures while maintaining design, and a manufacturing method for the electrode substrate used in the touch panel.

One aspect of the present disclosure is a touch panel comprising: a first electrode substrate having a first conductive film formed thereon; a second electrode substrate having a second conductive film formed opposite the first conductive film; a decorative portion disposed between the first conductive film and the second conductive film; and an insulating layer disposed between the decorative portion and the first conductive film, wherein an outer peripheral end face of the first conductive film is located inward in a planar direction from an outer peripheral end face of the first electrode substrate, an outer peripheral end face of the second conductive film is located inward in a planar direction from an outer peripheral end face of the second electrode substrate, an outer peripheral end face of the decorative portion is located inward in a planar direction from an outer peripheral end face of the second electrode substrate, and an outer peripheral portion of the insulating layer is disposed outward in a planar direction from the outer peripheral end faces of the first conductive film, the second conductive film, and the decorative portion .

Another aspect of the present disclosure is a touch panel having a first electrode substrate having a first conductive film formed thereon, a second electrode substrate having a second conductive film formed thereon facing the first conductive film, a decorative portion disposed between the first conductive film and the second conductive film, and an insulating coating covering an end face of the first conductive film , an end face of the second conductive film , and an outer peripheral end face of the decorative portion .

Yet another aspect of the present disclosure is a method for manufacturing an electrode substrate, including the steps of: cutting a sheet on which a conductive film has been formed; selectively removing the conductive film by etching the outer periphery of the cut sheet; forming a decorative portion by depositing a conductive material on the surface of the conductive film; forming a wiring portion by depositing a conductive material on the surface of the decorative portion; and depositing an insulating material on the sheet to form an insulating layer so as to cover at least the surface of the wiring portion and the outer periphery of the sheet from which the conductive film has been selectively removed.

Yet another aspect of the present disclosure is a method for manufacturing an electrode substrate, including the steps of forming a decorative portion by depositing a conductive material on a sheet having a conductive film formed on its surface, depositing a conductive material on the surface of the decorative portion to form a wiring portion, depositing an insulating material on the decorative portion and the wiring portion to form an insulating layer, cutting the sheet, and applying an insulating material to at least the outer peripheral end surfaces of the conductive film and the decorative portion to form an insulating coating.

The present disclosure provides a touch panel that suppresses sparks and discharges caused by static electricity when a user approaches or touches the touch panel, and an electrode substrate that constitutes the touch panel.

FIG. 2 is a top view of the touch panel according to the first embodiment. 2 is a cross-sectional view taken along the line AA' of FIG. FIG. 11 is a cross-sectional view of a touch panel according to a comparative example. 4 is a flowchart showing a part of a manufacturing process of the touch panel according to the first embodiment. FIG. 11 is a cross-sectional view of a touch panel according to a second embodiment. 10 is a flowchart showing a part of a manufacturing process of a touch panel according to a second embodiment. FIG. 11 is a cross-sectional view of a touch panel according to a third embodiment.

Below, the embodiments of the present disclosure will be described with reference to the accompanying drawings. In the following embodiments, the same or similar elements are designated by common reference symbols, and the scale of these drawings has been appropriately changed to facilitate understanding.

(First embodiment)
Fig. 1 shows a schematic top view of a touch panel 10 according to a first embodiment, and Fig. 2 is a cross-sectional view taken along line A-A' in Fig. 1. The touch panel 10 includes a first electrode substrate 14 having ITO (Indium Tin Oxide) 12 as a first conductive film, a second electrode substrate 18 having ITO 16 as a second conductive film opposed to the ITO 12, and a case 20 that houses the first electrode substrate 14 and the second electrode substrate 18. In this embodiment, the first electrode substrate 14 is a glass substrate, and the second electrode substrate 18 is a resin film substrate such as PET (Polyethylene terephthalate).

The lower part of the first electrode substrate 14 is fixed to the case 20 by an adhesive layer 22 such as a double-sided adhesive tape. The case 20 is integrally formed by resin injection molding or the like, and in order to enhance the design, the upper end surface 24 of the case 20 is at the same height as the operating surface 26 of the second electrode substrate 18. A display such as an LCD or organic EL panel (not shown) may be provided below the first electrode substrate 14.

The second electrode substrate 18 has a conductive decorative portion 28 and a wiring portion 31. For example, the decorative portion 28 is formed by printing a conductive material such as conductive carbon in a frame shape on the surface of the second conductive film 16, and the wiring portion 31 is formed by printing a conductive material such as silver on the surface of the decorative portion 28. The second electrode substrate 18 further has an insulating layer 30 formed by printing an insulating material such as insulating ink. The insulating layer 30 is provided so as to cover the surfaces of the decorative portion 28 and the wiring portion 31 as well as the outer peripheral end faces of the second conductive film 16 and the decorative portion 28.

The first electrode substrate 14 has a wiring portion 33 and an insulating layer 32. For example, the wiring portion 33 is formed by printing a conductive material such as silver on the surface of the first conductive film 12, and the insulating layer 32 is formed by printing an insulating material such as insulating ink. The insulating layer 32 is provided so as to cover the outer peripheral end face of the first conductive film 12 together with the surfaces of the first conductive film 12 and the wiring portion 33. The insulating layer 30 and the insulating layer 32 are adhered to each other by an adhesive layer 34 such as a double-sided adhesive tape.

Figure 3 shows a schematic cross-sectional side view of touch panel 100 according to a comparative example. Note that among the components of touch panel 100, those that may be functionally equivalent to the components of touch panel 10 are denoted by the reference numerals of the components of touch panel 10 plus 100, and detailed descriptions are omitted.

The touch panel 100 has a case 120 similar to that of the first embodiment, but the outer dimensions of the second conductive film 116, the decorative portion 128, and the insulating layer 130 match those of the second electrode substrate 118. The outer dimensions of the first conductive film 112 also match those of the first electrode substrate 114. As a result, the outer peripheral end faces of the conductive parts, the second conductive film 116, the decorative portion 128, and the first conductive film 112, are exposed, and when the user's finger 136 comes into contact with or approaches the end faces of the conductive parts, there is a possibility that sparks or discharges due to static electricity may occur.

Therefore, in the first embodiment, the outer peripheral end surface 38 of the second conductive film 16 is located inside the outer peripheral end surface 40 of the second electrode substrate 18 in the surface direction. For example, the second conductive film 16 corresponds to the second conductive film 116 of the touch panel 100 according to the comparative example, with the outer peripheral portion removed by etching or the like. The decorative portion 28 is formed on the surface of the second conductive film 16 by printing or the like, and the outer peripheral end surface 42 of the decorative portion 28 is also located inside the outer peripheral end surface 40 of the second electrode substrate 18 in the surface direction. And, outside the outer peripheral end surfaces of the second conductive film 16 and the decorative portion 28 in the surface direction, there is an outer peripheral portion 44 of the insulating layer 30 formed by printing or the like. Therefore, the second conductive film 16 and the decorative portion 28, which are conductive portions, are not exposed to the outside, and no sparks or discharges due to static electricity occur even if the user's finger touches or approaches them.

Similarly, the outer peripheral end surface 46 of the first conductive film 12 is located inside the outer peripheral end surface 48 of the first electrode substrate 14 in the surface direction, and for example, the first conductive film 12 corresponds to the first conductive film 112 of the touch panel 100 according to the comparative example, with the outer peripheral portion removed by etching or the like. And, outside the outer peripheral end surface 46 of the first conductive film 12 in the surface direction, there is an outer peripheral portion 50 of the insulating layer 32 formed by printing or the like. Therefore, the first conductive film 12, which is a conductive portion, is not exposed to the outside, and no sparks or discharge due to static electricity occurs even if the user's finger touches or approaches it. Therefore, according to the first embodiment, a touch panel that does not generate static electricity is provided.

In the first embodiment, since the second electrode substrate 18 is transparent, when the touch panel 10 is viewed from above, in addition to the decorative portion 28, the outer periphery 44 of the insulating layer 30 that is located outside the decorative portion 28 is visible. Therefore, in order not to impair the design of the touch panel 10, it is preferable that the decorative portion 28 and the outer periphery 44 of the insulating layer 30 are the same color.

Here, whether the decorative portion 28 and the insulating layer 30 (outer periphery 44) are "the same color" can be determined, for example, by the index value ΔE that represents the color difference defined by the International Commission on Illumination (CIE), and it is preferable that ΔE be 0.6 or less for the decorative portion 28 and the insulating layer 30. This is because if ΔE is 0.6 or less, the color difference between the two is almost invisible to the naked eye.

FIG. 4 is a flow chart showing a part of the manufacturing process of the touch panel 10 of the first embodiment, and shows the manufacturing process of the film side of the touch panel 10, that is, the assembly including the second electrode substrate 18, the second conductive film 16, the decorative portion 28, the wiring portion 31, and the insulating layer 30. First, a rolled sheet such as PET on which ITO is formed as the second conductive film 16 is cut to a predetermined size based on the size of the touch panel 10 (step S11). Next, an etching process is performed on the outer periphery of the cut sheet to remove the ITO (step S12). Next, a conductive material such as conductive carbon is formed on the surface of the ITO to form the decorative portion 28 (step S13). Next, a conductive material such as silver is formed on the surface of the decorative portion 28 to form the wiring portion 31 (step S14). Finally, an insulating material such as insulating ink is formed on the sheet to form the insulating layer 30 (step S15). In this way, a film-side assembly is obtained in which the second conductive film 16, the decorative portion 28, the wiring portion 31, and the insulating layer 30 are formed on the sheet serving as the second electrode substrate 18. Here, the deposition of each conductive material in steps S13 and S14, and the deposition of the insulating material in step S15 can be performed by, for example, printing.

The manufacturing process for the glass side of the touch panel 10, i.e., the assembly including the first electrode substrate 14, the first conductive film 12, the wiring portion 33, and the insulating layer 32, may be the same as that shown in FIG. 4, except that a glass substrate is prepared instead of a rolled sheet, and the decorative portion 28 is not formed (step S13).

Second Example
5 is a schematic cross-sectional side view of a touch panel 10a according to Example 2. Among the components of the touch panel 10a, those that may be functionally equivalent to the components of the touch panel 10 are denoted by the same reference numerals as those of the touch panel 10, and detailed descriptions thereof will be omitted.

The second conductive film 16a, the decorative portion 28a, and the insulating layer 30a have approximately the same external dimensions as the second electrode substrate 18, and the outer periphery of the second conductive film 16a and the decorative portion 28a is not removed by etching or the like as in the first embodiment. The touch panel 10a has an insulating coating 52a that covers the outer peripheral end faces from the second electrode substrate 18 to the insulating layer 32, i.e., the outer peripheral end faces of the second electrode substrate 18, the second conductive film 16a, the decorative portion 28a, the insulating layer 30a, the adhesive layer 34, and the insulating layer 32.

Similarly, the first conductive film 12a has approximately the same outer dimensions as the first electrode substrate 14, i.e., the outer periphery of the first conductive film 12a is not removed by etching or the like as in the first embodiment. The touch panel 10a has an insulating coating 54a that covers each outer periphery end surface of the first electrode substrate 14 and the first conductive film 12a.

In the touch panel 100, the conductive parts such as the second conductive film are exposed to the outside, so there is a risk of static electricity causing sparks or discharges when the finger 136 touches or approaches the panel. However, in the touch panel 10a, the outer peripheral end 38a of the second conductive film 16a, which is a conductive part, and the outer peripheral end 42a of the decorative part 28a are covered with an insulating coating 52a, and the outer peripheral end 46a of the first conductive film 12a is covered with an insulating coating 54a, so that no static electricity causing sparks or discharges occur even when the user's finger touches or approaches the panel. Thus, according to the second embodiment, a touch panel that does not generate static electricity is provided.

Figure 6 is a flow chart showing a part of the manufacturing process of the touch panel of the second embodiment, and shows the manufacturing process of the film side of the touch panel 10a, i.e., the assembly including the second electrode substrate 18, the second conductive film 16a, the decorative portion 28a, the wiring portion 31, and the insulating layer 30a. First, a rolled sheet such as PET with ITO formed on the entire surface as the second conductive film 16a is prepared, and a conductive material such as conductive carbon is deposited on the surface of the ITO to form the decorative portion 28a (step S21). Next, a conductive material such as silver is deposited on the surface of the decorative portion 28a to form the wiring portion 31 (step S22). Next, an insulating material such as insulating ink is deposited on the sheet to form the insulating layer 30a (step S23). Next, the sheet is cut to a predetermined size based on the size of the touch panel 10, etc. (step S24). Finally, a liquid insulating material such as varnish is applied to the outer peripheral end surfaces of the second electrode substrate 18, the second conductive film 16a, the decorative portion 28a, and the insulating layer 30, usually including at least the outer peripheral end surfaces of the second conductive film 16a and the decorative portion 28a, to form an insulating coating 52a (step S25). Here, the deposition of the conductive materials in steps S21 and S22 and the deposition of the insulating material in step S23 can be performed by, for example, printing.

The manufacturing process of the glass side of the touch panel 10a, i.e., the assembly including the first electrode substrate 14, the first conductive film 12a, the wiring portion 33, and the insulating layer 32, may be the same as that shown in FIG. 6, except that a glass substrate is prepared instead of a rolled sheet, and the decorative portion 28a is not formed (step S21). The formation of the insulating coating 52a (step S25) and the formation of the insulating coating 54a may be performed simultaneously by applying an insulating material after the film side assembly and the glass side assembly are bonded to each other with the adhesive layer 34. In this case, as shown in FIG. 5, the insulating coating 52a is applied from the second electrode substrate 18 to the insulating layer 32, and the insulating coating 54a is applied from the first electrode substrate 14 to the first conductive film 12a.

In the second embodiment, in the manufacturing process of the film side assembly including the second electrode substrate 18, the decorative portion 28a and the insulating layer 30a are printed on a rolled sheet, i.e., printed before the sheet is cut to a predetermined size. Such printing on the rolled sheet can be efficiently performed using an automated machine. On the other hand, in the first embodiment, the process of removing the ITO by etching is performed after the rolled sheet is cut, so the printing of the decorative portion and the insulating layer is performed after the sheet is cut, and such printing is usually performed manually. Therefore, in the second embodiment, the labor hours and costs related to printing can be reduced by using an automated machine compared to the first embodiment in which the decorative portion and the insulating layer are printed manually.

(Third Example)
7 is a schematic side cross-sectional view of a touch panel 10a according to the third embodiment. The touch panel 10b according to the third embodiment has the features of both the first and second embodiments. The outer peripheral end surface of the second conductive film 16b of the touch panel 10b is located inside the outer peripheral end surface of the second electrode substrate 18 in the same manner as in the first embodiment, and the outer peripheral portion 44b of the insulating layer 30b is located outside the outer peripheral end surface of the second conductive film 16b in the surface direction. In this embodiment, the outer peripheral end surface of the first conductive film 12 is also located inside the outer peripheral end surface of the first electrode substrate 14 in the surface direction, and the outer peripheral portion 45b of the insulating layer 32 is located outside the outer peripheral end surface of the first conductive film 12 in the surface direction. The outer peripheral end surface of the outer peripheral portion 45b of the insulating layer 32, together with the outer peripheral portion 44b of the insulating layer 30b and the outer peripheral end surfaces of the adhesive layer 34, coincides with the outer peripheral end surface 40 of the second electrode substrate 18. Here, if the distance d between the outer peripheral end face 38b of the second conductive film 16b and the outer peripheral end face 40 of the second electrode substrate 18, i.e., the width of the outer peripheral portion 44b of the insulating layer 30b, becomes relatively short in relation to the size required for the decorative portion 28b, etc., the static electricity suppression effect may not be sufficiently obtained.

Therefore, the touch panel 10b has an insulating coating 52b and an insulating coating 54b that cover the outer peripheral end surfaces of the outer peripheral portion 44b of the insulating layer 30b and the outer peripheral portion 45b of the insulating layer 32. In this way, sparks and discharges caused by static electricity can be more reliably prevented.

The manufacturing process of the second electrode substrate 18b in the third embodiment corresponds to steps S11 to S15 shown in FIG. 4, followed by step S25 shown in FIG. 6. Note that in this embodiment as well, the formation of the insulating coating 52b and the formation of the insulating coating 54b can be performed simultaneously by applying an insulating material after the film-side assembly and the glass-side assembly are bonded to each other with the adhesive layer 34.

In the third embodiment, from the viewpoint of the design of the touch panel 10b, it is preferable that the decorative portion 28b and the outer periphery 44b of the insulating layer 30b are the same color, as in the first embodiment.

Although the above-mentioned embodiments have been described with respect to resistive touch panels, the present disclosure is not limited thereto. For example, the touch panel according to the present disclosure may be of a capacitive type or an electrostatic coupling type, and if it is of a resistive type, it may be of a 4-wire, 5-wire, 7-wire, or 8-wire type, etc. Furthermore, the silver wiring may be replaced with copper wiring, conductive polymer wiring, or conductive carbon wiring, and ITO may be replaced with a conductive polymer, etc.

10: touch panel; 12, 12a: first conductive film; 14: first electrode substrate;
16, 16a, 16b Second conductive film, 18 Second electrode substrate, 20 Case,
22, 34 Adhesive layer; 28, 28a, 28b Decorative portion;
30, 30a, 30b, 32 insulating layer, 31, 33 wiring portion, 136 finger,
38, 38a, 38b, 40, 42, 24a, 40, 42b, 46, 46a end surface,
44, 44a, 44b, 45b, 50 Outer periphery,
52a, 54a, 52b, 54b Insulation coating

Claims (5)

A first electrode substrate on which a first conductive film is formed;
a second electrode substrate on which a second conductive film is formed so as to face the first conductive film;
a decorative portion disposed between the first conductive film and the second conductive film;
an insulating layer disposed between the decorative portion and the first conductive film,
A touch panel, wherein an outer peripheral end face of the first conductive film is located inward in a planar direction from an outer peripheral end face of the first electrode substrate, an outer peripheral end face of the second conductive film is located inward in a planar direction from an outer peripheral end face of the second electrode substrate, an outer peripheral end face of the decorative portion is located inward in a planar direction from an outer peripheral end face of the second electrode substrate, and an outer peripheral portion of the insulating layer is arranged outward in a planar direction from the outer peripheral end faces of the first conductive film, the second conductive film, and the decorative portion. The touch panel of claim 1 , further comprising an insulating coating covering an outer peripheral end face of the insulating layer. A first electrode substrate on which a first conductive film is formed;
a second electrode substrate on which a second conductive film is formed so as to face the first conductive film;
a decorative portion disposed between the first conductive film and the second conductive film;
A touch panel having an insulating coating covering an end face of the first conductive film , an end face of the second conductive film , and an outer peripheral end face of the decorative portion . A step of cutting the sheet on which the conductive film is formed;
a step of selectively removing the conductive film by etching the outer periphery of the cut sheet;
forming a decorative portion by depositing a conductive material on a surface of the conductive film;
forming a wiring portion by depositing a conductive material on a surface of the decorative portion;
forming an insulating layer on the sheet so as to cover at least the surface of the wiring portion and the outer periphery of the sheet from which the conductive film has been selectively removed;
A method for manufacturing an electrode substrate, comprising: forming a decorative portion by depositing a conductive material on a sheet having a conductive film formed on its surface;
forming a wiring portion by depositing a conductive material on a surface of the decorative portion;
forming an insulating layer by depositing an insulating material on the decorative portion and the wiring portion;
cutting the sheet;
applying an insulating material to at least the outer peripheral end surfaces of the conductive film and the decorative portion to form an insulating coating;
A method for manufacturing an electrode substrate, comprising:

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