WO2013191024A1

WO2013191024A1 - Touch panel, display apparatus provided with touch panel, and method for manufacturing touch panel

Info

Publication number: WO2013191024A1
Application number: PCT/JP2013/065980
Authority: WO
Inventors: 安弘小原
Original assignee: シャープ株式会社
Priority date: 2012-06-18
Filing date: 2013-06-10
Publication date: 2013-12-27
Also published as: JP2015164000A

Abstract

The present invention reduces the number of steps for manufacturing a touch panel. This touch panel is provided with a substrate (12), a light blocking layer (14), first electrodes (16), an insulating layer (18), second electrodes (20C), and metal wiring (22). The light blocking layer is formed on the substrate. A plurality of first electrodes are formed on the substrate by being aligned in the predetermined direction. The insulating layer covers the light blocking layer and the first electrodes. Openings (18A) are formed in the insulating layer, said openings exposing a part of each of the first electrodes. The second electrodes are formed on the insulating layer. Each of the second electrodes electrically connects two first electrodes that are disposed in the predetermined direction with each of the openings therebetween. The metal wiring is formed on the insulating layer. The metal wiring is connected to an external circuit. The metal wiring overlaps the light blocking layer in a planar view of the substrate, and is connected to the first electrodes. The substrate surface on the reverse side of the surface where the light blocking layer is formed is a touch surface.

Description

Touch panel, display device including touch panel, and method for manufacturing touch panel

The present invention relates to a touch panel, a display device including the touch panel, and a method for manufacturing the touch panel.

A touch panel is known as an input device. The touch panel detects a position where a finger or a pen touches.

Japanese Unexamined Patent Application Publication No. 2009-301767 discloses a capacitively coupled touch panel device. This touch panel device includes a touch panel and an LCD panel unit. The touch panel includes a transparent substrate. The transparent substrate is pressed with a finger or the like. A light shielding layer is formed on the outer edge of the lower surface of the transparent substrate. The light shielding layer shields light from the LCD panel unit. On the lower surface of the transparent substrate, an overcoat layer, a transparent conductive layer, and an insulating layer are laminated in this order. The overcoat layer covers the light shielding layer. The transparent conductive layer is formed in a predetermined pattern.

The light shielding layer described in the above publication is, for example, a metal film such as chromium and has conductivity. Therefore, an overcoat layer that covers the light shielding layer is necessary so that the light shielding layer does not adversely affect the detection of the touch position.

In addition, when the light shielding layer is an organic film containing titanium oxide or carbon black, the conductivity is sufficiently lower than that of the light shielding layer made of the metal film. There is a possibility that the layer is broken, the light shielding property is lost, and the generated film is contaminated. Specifically, for example, in the dry etching process when patterning an inorganic insulating film or a metal film, since the lower layer film is etched, it is necessary to consider the above problem. Therefore, even when the light shielding layer is made of an organic film, it is preferable to provide an overcoat layer that covers the light shielding layer.

By the way, in the projected capacitive coupling type touch panel, it is necessary to increase the number of transparent electrodes in order to increase the accuracy of multipoint detection. For example, there is a touch panel in which a plurality of island electrodes are formed in a matrix. In this touch panel, two island-shaped electrodes adjacent in the first direction are electrically connected by a first relay electrode formed in the same layer as the plurality of island-shaped electrodes. Two island-shaped electrodes adjacent in the second direction intersecting the first direction are electrically connected by a second relay electrode formed in a different layer from the plurality of island-shaped electrodes. An insulating layer is formed between the layer in which the plurality of island electrodes are formed and the layer in which the second relay electrode is formed.

Thus, when the electrodes are formed in different layers, an interlayer insulating film is required. Therefore, in the touch panel provided with the light shielding layer, when the electrodes are formed in different layers, the number of manufacturing processes of the touch panel increases.

An object of the present invention is to reduce the number of manufacturing steps in a touch panel provided with a light shielding layer and having electrodes formed in different layers.

The touch panel according to the embodiment of the present invention includes a substrate, a light shielding layer, a first electrode, an insulating layer, a second electrode, and a metal wiring. The light shielding layer is formed on the substrate. A plurality of first electrodes are formed on the substrate and arranged side by side in a predetermined direction. The insulating layer covers the light shielding layer and the plurality of first electrodes. The insulating layer is formed with an opening that partially exposes each of the plurality of first electrodes. The second electrode is formed on the insulating layer. The second electrode conducts the two first electrodes arranged in a predetermined direction through the opening. The metal wiring is formed on the insulating layer. The metal wiring is connected to an external circuit. The metal wiring overlaps the light shielding layer in a plan view of the substrate and is connected to the first electrode. The surface opposite to the surface on which the light shielding layer is formed on the substrate is a touch surface.

The touch panel according to the embodiment of the present invention can reduce the number of manufacturing steps.

FIG. 1 is a plan view showing a touch panel according to a first embodiment of the present invention. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3A is a cross-sectional view for explaining a manufacturing process of the touch panel according to the first embodiment, and is a cross-sectional view showing a state in which a resist is formed on a substrate. FIG. 3B is a cross-sectional view for explaining the manufacturing process of the touch panel according to the first embodiment, and is a cross-sectional view showing a state where the light shielding layer is formed on the substrate. FIG. 3C is a cross-sectional view for explaining a manufacturing process of the touch panel according to the first embodiment, and is a cross-sectional view showing a state in which a transparent conductive film is formed. FIG. 3D is a cross-sectional view for explaining the manufacturing process of the touch panel according to the first embodiment, and is a cross-sectional view showing a state where a plurality of relay electrodes and a light shielding layer are formed on the substrate. FIG. 3E is a cross-sectional view for explaining a manufacturing process of the touch panel according to the first embodiment, and is a cross-sectional view showing a state in which an insulating layer is formed. FIG. 3F is a cross-sectional view for explaining the manufacturing process of the touch panel according to the first embodiment, and is a cross-sectional view showing a state in which a plurality of contact holes are formed in the insulating layer. FIG. 3G is a cross-sectional view for explaining a manufacturing process of the touch panel according to the first embodiment and is a cross-sectional view showing a state in which a metal film is formed. FIG. 3H is a cross-sectional view for explaining a manufacturing process of the touch panel according to the first embodiment and is a cross-sectional view showing a state in which a plurality of wirings are formed. FIG. 3I is a cross-sectional view for explaining a manufacturing process of the touch panel according to the first embodiment and is a cross-sectional view showing a state in which a transparent conductive film is formed. FIG. 3J is a cross-sectional view for explaining a manufacturing process of the touch panel according to the first embodiment, and is a cross-sectional view showing a state where a plurality of transparent electrodes are formed. FIG. 4 is a schematic diagram illustrating a schematic configuration of a display device including the touch panel according to the first embodiment. FIG. 5 is a cross-sectional view showing the relationship between the touch panel and the liquid crystal panel in the display device shown in FIG. FIG. 6 is a cross-sectional view showing a touch panel according to an application example of the first embodiment of the present invention. FIG. 7 is a cross-sectional view showing a touch panel according to a second embodiment of the present invention. FIG. 8A is a cross-sectional view for explaining a manufacturing process of the touch panel according to the second embodiment, and is a cross-sectional view showing a state where a transparent conductive film is formed. FIG. 8B is a cross-sectional view for explaining a manufacturing process of the touch panel according to the second embodiment, and is a cross-sectional view showing a state in which a plurality of transparent electrodes and a light shielding layer are formed on the substrate. FIG. 8C is a cross-sectional view for explaining a manufacturing process of the touch panel according to the second embodiment and is a cross-sectional view showing a state in which an insulating layer is formed. FIG. 8D is a cross-sectional view for explaining the manufacturing process of the touch panel according to the second embodiment and is a cross-sectional view showing a state in which a plurality of contact holes are formed in the insulating layer. FIG. 8E is a cross-sectional view for explaining a manufacturing process of the touch panel according to the second embodiment and shows a state in which a metal film is formed. FIG. 8F is a cross-sectional view for explaining a manufacturing process of the touch panel according to the second embodiment, and is a cross-sectional view showing a state in which a plurality of wirings and relay electrodes are formed.

The touch panel according to the embodiment of the present invention includes a substrate, a light shielding layer, a first electrode, an insulating layer, a second electrode, and a metal wiring. The light shielding layer is formed on the substrate. A plurality of first electrodes are formed on the substrate and arranged side by side in a predetermined direction. The insulating layer covers the light shielding layer and the plurality of first electrodes. The insulating layer is formed with an opening that partially exposes each of the plurality of first electrodes. The second electrode is formed on the insulating layer. The second electrode conducts the two first electrodes arranged in a predetermined direction through the opening. The metal wiring is formed on the insulating layer. The metal wiring is connected to an external circuit. The metal wiring overlaps the light shielding layer in a plan view of the substrate and is connected to the first electrode. The surface of the substrate opposite to the surface on which the light shielding layer is formed is a touch surface (first aspect relating to a touch panel).

In the first aspect, the metal wiring is hidden by the light shielding layer formed on the substrate having the touch surface. For this reason, the touch panel can be made thinner than in the case where the cover member is disposed on the viewer side of the touch panel and the light shielding layer is formed on the cover member.

In the first aspect, the insulating layer functions as an interlayer insulating film disposed between the layer on which the first electrode is formed and the layer on which the second electrode is formed, and the protective insulating film covers the light shielding layer Function as. That is, the interlayer insulating film and the protective insulating film can be formed simultaneously. Therefore, the number of touch panel manufacturing processes can be reduced.

The second aspect further includes a third electrode in the first aspect. The third electrode is formed on the insulating layer, contacts the first electrode through the opening, and contacts the metal wiring.

In the second mode, a configuration in which the first electrode and the metal wiring are connected via the third electrode can be realized.

The third aspect further includes a protective film in the second aspect. The protective film is connected to the third electrode and covers the metal wiring.

In the third mode, for example, when the third electrode is formed, the metal wiring is less likely to be damaged.

In a fourth aspect, in the first aspect, among the plurality of first electrodes, the first electrode positioned at one end in a predetermined direction is formed on the light shielding layer. Contact holes are formed in the insulating layer. The contact hole overlaps with the first electrode formed on the light shielding layer in a plan view of the substrate. The metal wiring comes into contact with the first electrode formed on the light shielding layer through the contact hole.

In the fourth aspect, a configuration in which the first electrode and the metal wiring are connected via the contact hole can be realized.

A display device according to an embodiment of the present invention includes a touch panel according to an embodiment of the present invention and a display panel that displays an image. Since the number of manufacturing processes of the touch panel can be reduced, the number of manufacturing processes of the display device can also be reduced.

The method for manufacturing a touch panel according to an embodiment of the present invention includes the following steps (a) to (g). In the step (a), a light shielding layer is formed on the surface opposite to the touch surface in the substrate having the touch surface. In the step (b), a plurality of first electrodes arranged side by side in a predetermined direction are formed on the substrate. In the step (c), an insulating layer that covers the light shielding layer and the plurality of first electrodes is formed. In the step (d), an opening exposing a part of each of the plurality of first electrodes is formed in the insulating layer. In the step (e), a second electrode that conducts the two first electrodes arranged in a predetermined direction through the opening is formed on the insulating layer. In the step (f), a metal wiring that overlaps the light shielding layer in plan view of the substrate and is connected to an external circuit is formed on the insulating layer. In the step (g), a third electrode that is in contact with the first electrode through the opening and is in contact with the metal wiring is formed on the insulating layer (first aspect relating to the touch panel manufacturing method).

In the first aspect, the light shielding layer is formed on the substrate having the touch surface. This light shielding layer hides the metal wiring. For this reason, the touch panel can be made thinner than in the case where the cover member is disposed on the viewer side of the touch panel and the light shielding layer is formed on the cover member.

In the first aspect, the insulating layer realizes the interlayer insulating film disposed between the layer where the first electrode is formed and the layer where the second electrode is formed, and the protective insulating film covering the light shielding layer. Is done. That is, the interlayer insulating film and the protective insulating film can be formed simultaneously. Therefore, the number of touch panel manufacturing processes can be reduced.

2nd aspect WHEREIN: A 3rd electrode is formed in the said process (e) in a 1st aspect. In the second aspect, the configuration in which the first electrode and the metal wiring are connected via the third electrode can be realized with a small number of manufacturing steps.

In a third aspect, in the first or second aspect, in the step (g), a protective film that is connected to the third electrode and covers the metal wiring is formed. In the third aspect, the metal wiring is less likely to be damaged when the third electrode is formed.

A method for manufacturing a touch panel according to an embodiment of the present invention includes the following steps (a) to (i). In the step (a), a light shielding layer is formed on the surface opposite to the touch surface in the substrate having the touch surface. In the step (b), a plurality of first electrodes arranged side by side in a predetermined direction are formed on the substrate. In the step (c), an insulating layer that covers the light shielding layer and the plurality of first electrodes is formed. In the step (d), an opening exposing a part of each of the plurality of first electrodes is formed in the insulating layer. In the step (e), a second electrode that conducts the two first electrodes arranged in a predetermined direction through the opening is formed on the insulating layer. In the step (f), a metal wiring that overlaps the light shielding layer in plan view of the substrate and is connected to an external circuit is formed on the insulating layer. In the step (g), among the plurality of first electrodes, a first electrode located at one end in a predetermined direction is formed on the light shielding layer. In the step (h), a contact hole is formed at a position overlapping the first electrode formed on the light shielding layer in plan view of the substrate. In the step (i), metal wiring is formed at a position overlapping the contact hole in a plan view of the substrate (fourth aspect relating to a touch panel manufacturing method).

In the fourth aspect, the light shielding layer is formed on the substrate having the touch surface. This light shielding layer hides the metal wiring. For this reason, the touch panel can be made thinner than in the case where the cover member is disposed on the viewer side of the touch panel and the light shielding layer is formed on the cover member.

In the fourth aspect, the insulating layer realizes the interlayer insulating film disposed between the layer where the first electrode is formed and the layer where the second electrode is formed, and the protective insulating film covering the light shielding layer Is done. That is, the interlayer insulating film and the protective insulating film can be formed simultaneously. Therefore, the number of touch panel manufacturing processes can be reduced.

5th aspect WHEREIN: A wiring is formed in the said process (e) in a 4th aspect. In the fifth aspect, the number of touch panel manufacturing processes can be further reduced.

Hereinafter, more specific embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated. Note that, in the drawings referred to below, in order to make the explanation easy to understand, the configuration is shown in a simplified or schematic manner, or some components are omitted. Further, the dimensional ratio between the constituent members shown in each drawing does not necessarily indicate an actual dimensional ratio.

[First Embodiment]
A touch panel 10 according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view showing the touch panel 10. 2 is a cross-sectional view taken along the line II-II in FIG.

[Overall configuration of touch panel]
The touch panel 10 is a projected capacitive touch panel. The touch panel 10 includes a substrate 12, a light shielding layer 14, a relay electrode 16, an insulating layer 18, a transparent electrode 20, a lead wiring 22, and a protective layer 24.

The substrate 12 is not particularly limited as long as it is a transparent insulating substrate. For example, the substrate 12 may be an alkali-free glass substrate or an acrylic resin substrate.

The light shielding layer 14 is formed in contact with the surface of the substrate 12. In the present embodiment, the light shielding layer 14 is formed in a frame shape in plan view of the substrate 12. In this embodiment, the outer edge of the light shielding layer 14 coincides with the outer edge of the substrate 12, but this is not necessary. The light shielding layer 14 is not particularly limited as long as it has light shielding properties. The light shielding layer 14 may be, for example, an organic film containing carbon black or a titanium compound, or may be an inorganic film such as chromium.

A plurality of relay electrodes 16 are formed in contact with the surface of the substrate 12. In this embodiment, the some relay electrode 16 is arrange | positioned along with the 1st direction (up-down direction of FIG. 1) and the 2nd direction (left-right direction of FIG. 1). The relay electrode 16 is not particularly limited as long as it is a transparent conductive film. The relay electrode 16 may be, for example, indium tin oxide (ITO) or indium zinc oxide (IZO). In the present embodiment, the relay electrode 16 corresponds to the first electrode.

The insulating layer 18 is formed on the substrate 12 and covers the light shielding layer 14 and the plurality of relay electrodes 16. The insulating layer 18 is not particularly limited as long as it has insulating properties. The insulating layer 18 is, for example, an acrylic resin film, a siloxane film, a polyimide film, or a silicon inorganic film.

In the insulating layer 18, a plurality of contact holes 18A are formed. Each contact hole 18 A overlaps the relay electrode 16 in a plan view of the substrate 12. In the present embodiment, two contact holes 18A overlap one relay electrode 16. That is, in the present embodiment, the plurality of contact holes 18A correspond to openings that partially expose each of the plurality of relay electrodes 16.

A plurality of transparent electrodes 20 are formed in contact with the insulating layer 18. The transparent electrode 20 is not particularly limited as long as it is a transparent conductive film. The transparent electrode 20 may be, for example, indium tin oxide (ITO) or indium zinc oxide (IZO).

The plurality of transparent electrodes 20 include a first transparent electrode 20A, a second transparent electrode 20B, and a third transparent electrode 20C.

The first transparent electrodes 20A and the second transparent electrodes 20B are alternately arranged in the first direction. A plurality of electrode rows (first electrode rows) including the first transparent electrode 20A and the second transparent electrode 20B are arranged in the second direction. In the first electrode row, the first transparent electrode 20A and the second transparent electrode 20B are integrally formed.

In a plan view of the substrate 12, the third transparent electrodes 20C and the relay electrodes 16 are alternately arranged in the second direction. A plurality of electrode rows (second electrode rows) each including the third transparent electrode 20C and the relay electrode 16 are arranged in the first direction. In the second electrode row, the relay electrode 16 is connected to two third transparent electrodes 20C adjacent in the second direction via the contact hole 18A. That is, among the plurality of third transparent electrodes 20C constituting the second electrode row, the third transparent electrodes 20C other than the third transparent electrodes 20C located at both ends conduct two adjacent relay electrodes 16 in the second direction. To do. In short, in the present embodiment, among the plurality of third transparent electrodes 20C constituting the second electrode row, the third transparent electrodes 20C other than the third transparent electrodes 20C located at both ends correspond to the second electrodes.

A plurality of lead wires 22 are formed on the insulating layer 18. The lead wiring 22 overlaps the light shielding layer 14 in plan view of the substrate 12. The lead wiring 22 is made of metal. The metal includes, for example, at least one of aluminum, molybdenum, titanium, tantalum, copper, silver, and gold.

The plurality of lead wires 22 include a first lead wire 22A and a second lead wire 22B.

The first lead wire 22A is connected to the first transparent electrode 20A located at one end in the first direction among the plurality of first transparent electrodes 20A constituting the first electrode row. In the present embodiment, among the plurality of first transparent electrodes 20A constituting the first electrode row, the first transparent electrode 20A located at one end in the first direction covers one end of the first lead-out wiring 22A. The lead wiring 22A is connected to the first transparent electrode 20A. A terminal portion connected to an external circuit is formed at the other end of the first lead wiring 22A.

Here, the first lead-out wiring 22A is covered with a protective film 23A extending from the first transparent electrode 20A covering one end thereof. That is, the protective film 23A is made of the same material as the first transparent electrode 20A.

The second lead-out wiring 22B is connected to the third transparent electrode 20C located at one end in the second direction among the plurality of third transparent electrodes 20C constituting the second electrode row. In the present embodiment, among the plurality of third transparent electrodes 20C constituting the second electrode row, the third transparent electrode 20C located at one end in the second direction covers one end of the second lead-out wiring 22B, whereby the second The lead wiring 22B is connected to the third transparent electrode 20C. A terminal portion connected to an external circuit is formed at the other end of the second lead wiring 22B. In the present embodiment, the second lead wire 22B corresponds to a metal wire, and the third transparent electrode 20C connected to one end of the second lead wire 22B corresponds to a third electrode.

Here, the second lead wiring 22B is covered with a protective film 23B extending from the third transparent electrode 20C covering one end thereof. That is, the protective film 23B is made of the same material as the third transparent electrode 20C.

The protective layer 24 is formed on the insulating layer 18 and covers the plurality of transparent electrodes 20 and the

protective films

23A and 23B. The protective layer 24 is not particularly limited as long as it has insulating properties. The protective layer 24 is, for example, an acrylic resin film, a siloxane film, a polyimide film, or a silicon inorganic film.

[Method for manufacturing touch panel]
A method for manufacturing the touch panel 10 will be described with reference to FIGS. 3A to 3J. In addition, the manufacturing method of the touch panel 10 is not limited to the manufacturing method demonstrated below.

The manufacturing method of the touch panel 10 includes a step of forming the light shielding layer 14, a step of forming the plurality of relay electrodes 16, a step of forming the insulating layer 18, a step of forming the plurality of lead wires 22, and a plurality of contacts. The method includes the step of forming the hole 18A, the step of forming the plurality of transparent electrodes 20, and the step of forming the protective layer 24.

[Step of forming light shielding layer]
First, as shown in FIG. 3A, a resist 26 is applied to the entire surface of the substrate 12. The resist 26 contains a black component such as carbon black, for example.

Subsequently, the resist 26 is patterned. Specifically, for example, the exposure is performed with the negative resist 26 covered with a mask. Thereafter, an unexposed area of the resist 26 is removed with a developer. Thereby, as shown in FIG. 3B, the light shielding layer 14 is formed in contact with the surface of the substrate 12.

[Step of forming a plurality of relay electrodes]
After the light shielding layer 14 is formed, a plurality of relay electrodes 16 are formed. Specifically, first, as shown in FIG. 3C, a transparent conductive film 28 that covers the surface of the substrate 12 and the light shielding layer 14 is formed. The transparent conductive film 28 is formed by sputtering, for example.

Subsequently, the transparent conductive film 28 is patterned by photolithography. Specifically, first, a resist having a predetermined pattern is formed on the transparent conductive film 28. Subsequently, a region of the transparent conductive film 28 that is not covered with the resist is removed by wet etching. Thereafter, the resist is removed with a stripping solution. Thereby, as shown in FIG. 3D, the plurality of relay electrodes 16 and the light shielding layer 14 are formed in contact with the surface of the substrate 12. The etchant used for wet etching is, for example, ferric chloride or an oxalic acid-based acidic etchant.

[Step of forming insulating layer]
When the plurality of relay electrodes 16 are formed, as shown in FIG. 3E, an insulating layer 18 that covers the surface of the substrate 12, the plurality of relay electrodes 16, and the light shielding layer 14 is formed. When the insulating layer 18 is made of a silicon oxide film, the insulating layer 18 is formed by, for example, CVD (Chemical Vapor Deposition).

[Step of forming a plurality of contact holes]
After the insulating layer 18 is formed, a plurality of contact holes 18A are formed in the insulating layer 18 as shown in FIG. 3F. The plurality of contact holes 18A are formed by photolithography. Specifically, first, a resist having a predetermined pattern is formed on the insulating layer 18. Subsequently, the region of the insulating layer 18 that is not covered with the resist is removed by etching. Thereafter, the resist is removed with a stripping solution.

When the insulating layer 18 is a silicon oxide film, dry etching is used. Here, the light shielding layer 14 is covered with an insulating layer 18. Further, the contact hole 18A is not formed in the region of the insulating layer 18 that is in contact with the light shielding layer 14. Therefore, even if dry etching is used, the light shielding layer 14 is not damaged.

In addition, since the insulating layer 18 covers the light shielding layer 14, the light shielding layer 14 is protected by the insulating layer 18 in the subsequent manufacturing process.

[Process for forming a plurality of lead wires]
When a plurality of contact holes 18A are formed, a plurality of lead lines 22 are formed. Specifically, first, as shown in FIG. 3G, a metal film 30 covering the entire surface of the insulating layer 18 is formed. The metal film 30 is formed by sputtering, for example.

Subsequently, the metal film 30 is patterned by photolithography. Specifically, first, a resist having a predetermined pattern is formed on the metal film 30. Subsequently, a region of the metal film 30 that is not covered with the resist is removed by etching. Thereafter, the resist is removed with a stripping solution. Thereby, as shown in FIG. 3H, a plurality of lead wires 22 are formed in contact with the surface of the insulating layer 18.

The etching of the metal film 30 may be dry etching or wet etching. Here, the light shielding layer 14 is covered with an insulating layer 18. Therefore, as long as the insulating layer 18 can withstand the dry etching, the light shielding layer 14 is not damaged by the dry etching.

[Step of forming a plurality of transparent electrodes]
If the several extraction wiring 22 is formed, the some transparent electrode 20 will be formed. Specifically, first, as shown in FIG. 3I, a transparent conductive film 32 that covers the insulating layer 18 and the plurality of lead-out wirings 22 is formed. The transparent conductive film 32 is also formed in the contact hole 18A and is in contact with the relay electrode 16.

Subsequently, the transparent conductive film 32 is patterned by photolithography. Specifically, first, a resist having a predetermined pattern is formed on the transparent conductive film 32. Subsequently, a region of the transparent conductive film 32 that is not covered with the resist is removed by wet etching. Thereafter, the resist is removed with a stripping solution. Thereby, as shown in FIG. 3J, a plurality of transparent electrodes 20 are formed in contact with the surface of the insulating layer 18. The protective film 23A covers the first lead wiring 22A, and the protective film 23B covers the second lead wiring 22B. The etchant used for wet etching is, for example, ferric chloride or an oxalic acid-based acidic etchant. Moreover, about the lead-out

wirings

22A and 22B, the damage at the time of patterning the transparent conductive film 32 can be avoided by covering the

protective films

22A and 23B.

[Step of forming protective layer]
When the plurality of transparent electrodes 20 are formed, the protective layer 24 is formed. When the protective layer 24 is made of an acrylic resin, the protective layer 24 is applied by, for example, spin coating, and is patterned to cover a predetermined region by photolithography. Thereby, the touch panel 10 shown in FIG. 2 is manufactured.

In the touch panel 10 described above, an interlayer insulating film disposed between the layer in which the plurality of relay electrodes 16 are formed and the layer in which the plurality of transparent electrodes 20 are formed, and the protective insulating film that covers the light shielding layer 14 are provided. This is realized by the insulating layer 18. That is, the interlayer insulating film and the protective insulating film can be formed simultaneously. Therefore, the number of manufacturing processes of the touch panel 10 can be reduced.

Further, in the touch panel 10, the number of layers to be stacked is reduced. Therefore, it is possible to suppress a decrease in the transmittance of the touch panel 10 in the touch position detection area (specifically, the area inside the light shielding layer 14).

[Display device with touch panel]
The touch panel 10 can be used for a display device. A display device including the touch panel 10 will be described with reference to FIGS. 4 and 5. FIG. 4 is a schematic diagram showing a schematic configuration of the display device 40 according to the embodiment of the present invention. FIG. 5 is a cross-sectional view showing a main part of the display device 40.

The display device 40 includes a touch panel 10, a liquid crystal panel 42 as a display panel, and a backlight 44. In the display device 40, an image displayed on the liquid crystal panel 42 is visually recognized by an observer through an input area of the touch panel 10 (specifically, an area inside the light shielding layer 14). When the observer's fingers touch the input area of the touch panel 10, processing corresponding to the contact position is executed on the liquid crystal panel 42.

The liquid crystal panel 42 includes an active matrix substrate, a counter substrate, and a liquid crystal layer sealed between these substrates. A region where a plurality of pixels are formed in a matrix is a display region of the liquid crystal panel 42. In the liquid crystal panel 42, the operation mode of the liquid crystal is not particularly limited. The operation mode of the liquid crystal may be a TN mode, for example.

The backlight 44 is disposed on the back side of the liquid crystal panel 42. The illumination method of the backlight 44 is not particularly limited. For example, the backlight 44 may be a direct type or an edge light type. The light source of the backlight 44 is not particularly limited. The light source of the backlight 44 may be, for example, a cold cathode tube or a light emitting diode.

The touch panel 10 is disposed on the surface side (observer side) of the liquid crystal panel 42. As shown in FIG. 5, in the touch panel 10, the protective layer 24 is bonded to the base substrate 46 included in the counter substrate of the liquid crystal panel 42. At this time, the substrate 12 positioned on the viewer side functions as a cover member. In the substrate 12, a surface 12 A opposite to the surface on which the light shielding layer 14 is formed functions as a touch surface that is touched by an observer's fingers when operating the touch panel 10.

In such a display device 40, since the substrate 12 functions as a cover member, the display device can be thinned.

[Application example of touch panel]
An application example of the touch panel according to the first embodiment of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view of the touch panel 50 according to the application example.

In the touch panel 50, the contact hole 18A is not formed in the insulating layer 18. Instead, the opening 18 B is formed in the insulating layer 18. Thereby, the insulating layer 18 is divided into a first insulating layer 52A and a plurality of second insulating layers 52B. The first insulating layer 52A covers the entire light shielding layer 14. The second insulating layer 52B partially covers the relay electrode 16. In the example shown in FIG. 6, both end portions in the second direction of the relay electrode 16 are in contact with the third transparent electrode 20C.

[Second Embodiment]
A touch panel 60 according to a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view of the touch panel 60 according to the second embodiment of the present invention.

[Overall configuration of touch panel]
In the touch panel 60, the plurality of transparent electrodes 20 are formed in contact with the surface of the substrate 12 as compared with the touch panel 10. A plurality of relay electrodes 16 are formed in contact with the surface of the insulating layer 18.

The insulating layer 18 has a plurality of contact holes 18C. The contact hole 18C overlaps the relay electrode 16 in plan view of the substrate 12. The relay electrode 16 contacts the third transparent electrode 20C through the contact hole 18C. That is, in the present embodiment, the third transparent electrode 20C corresponds to the first electrode, and the relay electrode 16 corresponds to the second electrode.

Among the plurality of third transparent electrodes 20C arranged in the second direction, the third transparent electrodes 20C located at both ends partially cover the light shielding layer 14, respectively. A plurality of contact holes 18D are formed in the insulating layer 18. The contact hole 18D overlaps the third transparent electrode 20C that partially covers the light shielding layer 14 in a plan view of the substrate 12. The lead-out wiring 22 is in contact with the third transparent electrode 20 C that partially covers the light shielding layer 14 through a contact hole 18 D formed in the insulating layer 18. That is, the contact hole 18 D is formed at a position overlapping the extraction wiring 22 in plan view of the substrate 12.

[Method for manufacturing touch panel]
A method for manufacturing the touch panel 60 will be described below. The manufacturing method of the touch panel 60 includes a step of forming the light shielding layer 14, a step of forming the plurality of transparent electrodes 20, a step of forming the insulating layer 18, a step of forming the plurality of

contact holes

18C and 18D, and a plurality of steps. The step of forming the lead wiring 22 and the relay electrode 16 and the step of forming the protective layer 24 are provided. In addition, since the process of forming the light shielding layer 14 is the same as 1st Embodiment, the description is abbreviate | omitted (refer FIG. 3A and FIG. 3B).

[Step of forming a plurality of transparent electrodes]
As shown in FIG. 3B, when the light shielding layer 14 is formed, a plurality of transparent electrodes 20 are formed. Specifically, first, as shown in FIG. 8A, a transparent conductive film 28 that covers the surface of the substrate 12 and the light shielding layer 14 is formed. The transparent conductive film 28 is formed by sputtering, for example.

Subsequently, the transparent conductive film 28 is patterned by photolithography. Specifically, first, a resist having a predetermined pattern is formed on the transparent conductive film 28. Subsequently, a region of the transparent conductive film 28 that is not covered with the resist is removed by wet etching. Thereafter, the resist is removed with a stripping solution. Thereby, as shown in FIG. 8B, the plurality of transparent electrodes 20 and the light shielding layer 14 are formed in contact with the surface of the substrate 12. The etchant used for wet etching is, for example, ferric chloride or an oxalic acid-based acidic etchant.

[Step of forming insulating layer]
When the plurality of transparent electrodes 20 are formed, as shown in FIG. 8C, an insulating layer 18 that covers the surface of the substrate 12, the plurality of transparent electrodes 20, and the light shielding layer 14 is formed. When the insulating layer 18 is made of a silicon oxide film, the insulating layer 18 is formed by, for example, CVD (Chemical Vapor Deposition).

[Step of forming a plurality of contact holes]
After the insulating layer 18 is formed, a plurality of

contact holes

18C and 18D are formed in the insulating layer 18 as shown in FIG. 8D. The plurality of

contact holes

18C and 18D are formed by photolithography. Specifically, first, a resist having a predetermined pattern is formed on the insulating layer 18. Subsequently, the region of the insulating layer 18 that is not covered with the resist is removed by etching. Thereafter, the resist is removed with a stripping solution.

When the insulating layer 18 is a silicon oxide film, dry etching is used. Here, the light shielding layer 14 is covered with an insulating layer 18. Further,

contact holes

18C and 18D are not formed in the region of the insulating layer 18 that is in contact with the light shielding layer 14. Therefore, even if dry etching is used, the light shielding layer 14 is not damaged.

[Process for forming a plurality of lead wires and relay electrodes]
When the plurality of

contact holes

18C and 18D are formed, the plurality of lead wires 22 and the relay electrode 16 are formed. Specifically, first, as shown in FIG. 8E, a metal film 30 covering the entire surface of the insulating layer 18 is formed. The metal film 30 is formed by sputtering, for example. The metal film 30 is also formed in the

contact holes

18C and 18D and is in contact with the third transparent electrode 20C.

Subsequently, the metal film 30 is patterned by photolithography. Specifically, first, a resist having a predetermined pattern is formed on the metal film 30. Subsequently, a region of the metal film 30 that is not covered with the resist is removed by etching. Thereafter, the resist is removed with a stripping solution. Thereby, as shown in FIG. 8F, a plurality of lead wires 22 and relay electrodes 16 are formed.

[Step of forming protective layer]
When the plurality of lead wires 22 and the relay electrode 16 are formed, the protective layer 24 is formed. When the protective layer 24 is made of an acrylic resin, the protective layer 24 is applied by, for example, spin coating, and is patterned to cover a predetermined region by photolithography. Thereby, the touch panel 80 shown in FIG. 7 is manufactured.

In such a touch panel 60, the light shielding layer 14 and the interlayer insulating film disposed between the layer in which the plurality of transparent electrodes 20 are formed and the layer in which the plurality of lead wires 22 and the relay electrodes 16 are formed are covered. The protective insulating film is realized by the insulating layer 18. That is, the interlayer insulating film and the protective insulating film can be formed simultaneously. Therefore, the number of touch panel manufacturing processes can be reduced.

Particularly in this embodiment, the wiring 22 and the relay electrode 16 are formed simultaneously. Therefore, the number of touch panel manufacturing processes can be further reduced.

In the present embodiment, the width of the relay electrode 16 (the dimension in the direction perpendicular to the paper surface of FIG. 9) is desirably 6 μm or less. Thereby, even if it is the relay electrode 16 which consists of metals, it becomes difficult to see.

As mentioned above, although embodiment of this invention has been explained in full detail, these are illustrations to the last and this invention is not limited at all by the above-mentioned embodiment.

For example, the display panel may be a plasma display panel (PDP), an organic EL (electroluminescence) panel, an inorganic EL panel, or the like.

Further, a protective film for protecting the light shielding layer may be provided in order to prevent the light shielding layer from being damaged when forming the first electrode.

Further, the light shielding layer does not need to have a frame shape in plan view of the substrate. For example, in the first embodiment, the light shielding layer 14 may be formed only in a region where the lead wiring 22 is formed.

Claims

A substrate,
A light shielding layer formed on the substrate;
A plurality of first electrodes formed on the substrate and arranged side by side in a predetermined direction;
An insulating layer that covers the light shielding layer and the plurality of first electrodes, and in which an opening that exposes a part of each of the plurality of first electrodes is formed;
A second electrode formed on the insulating layer and conducting the two first electrodes arranged in the predetermined direction through the opening;
A metal wiring formed on the insulating layer and connected to an external circuit;
The metal wiring overlaps the light shielding layer in a plan view of the substrate and is connected to the first electrode,
The touch panel, wherein the surface of the substrate opposite to the surface on which the light shielding layer is formed is a touch surface.
The touch panel according to claim 1,
A touch panel, further comprising a third electrode formed on the insulating layer and in contact with the first electrode through the opening and in contact with the metal wiring.
The touch panel according to claim 2,
The touch panel further comprising a protective film connected to the third electrode and covering the metal wiring.
The touch panel according to claim 1,
Of the plurality of first electrodes, the first electrode located at one end in a predetermined direction is formed on the light shielding layer,
The insulating layer is formed with a contact hole overlapping the first electrode formed on the light shielding layer in a plan view of the substrate,
The said metal wiring is a touch panel which contacts the said 1st electrode formed on the said light shielding layer through the said contact hole.
The touch panel according to any one of claims 1 to 4,
A display device comprising a display panel for displaying an image.
Forming a light shielding layer on a surface opposite to the touch surface in a substrate having a touch surface;
Forming a plurality of first electrodes arranged side by side in a predetermined direction on the substrate;
Forming an insulating layer covering the light shielding layer and the plurality of first electrodes;
Forming an opening in the insulating layer to partially expose each of the plurality of first electrodes;
Forming a second electrode on the insulating layer that conducts the two first electrodes arranged in the predetermined direction through the opening; and
Forming a metal wiring on the insulating layer that overlaps the light shielding layer in a plan view of the substrate and is connected to an external circuit;
A method of manufacturing a touch panel, comprising: a step of contacting the first electrode through the opening and forming a third electrode in contact with the metal wiring on the insulating layer.
It is a manufacturing method of the touch panel according to claim 6,
A method of manufacturing a touch panel, wherein the third electrode is formed in the step of forming the second electrode.
It is a manufacturing method of the touch panel according to claim 6 or 7,
A method of manufacturing a touch panel, wherein in the step of forming the third electrode, a protective film that is connected to the third electrode and covers the metal wiring is formed.
Forming a light shielding layer on a surface opposite to the touch surface in the substrate having the touch surface;
Forming a plurality of first electrodes arranged side by side in a predetermined direction on the substrate;
Forming an insulating layer covering the light shielding layer and the plurality of first electrodes;
Forming an opening in the insulating layer to partially expose each of the plurality of first electrodes;
Forming a second electrode on the insulating layer that conducts the two first electrodes arranged in the predetermined direction through the opening; and
Forming a metal wiring on the insulating layer that overlaps the light shielding layer in a plan view of the substrate and is connected to an external circuit;
In the step of forming the plurality of first electrodes,
Of the plurality of first electrodes, a first electrode located at one end in a predetermined direction is formed on the light shielding layer,
In the step of forming the opening,
Forming a contact hole at a position overlapping the first electrode formed on the light shielding layer in a plan view of the substrate;
In the step of forming the metal wiring,
A method for manufacturing a touch panel, wherein the metal wiring is formed at a position overlapping the contact hole in plan view of the substrate.
It is a manufacturing method of the touch panel according to claim 9,
A method of manufacturing a touch panel, wherein the metal wiring is formed in the step of forming the second electrode.