JP2023179898A - Thin wire structure and touch sensor using it - Google Patents

Abstract

To reduce the electrical resistance value of a conductive layer.SOLUTION: In a thin wire structure 20, a bottomed groove portion 10 is provided on at least one outer surface of a substrate 5. The groove portion 10 is provided with a conductive layer 22 made of a conductive material. The conductive layer 22 includes a main body 23 made of a conductive material embedded in the groove portion 10 and a protruding portion 24 that is integrally formed with the main body 23 and made of a conductive material protruding from the main body 23 toward the outside of the groove portion 10. The protruding portion 24 has a width smaller than the width of the groove portion 10 in cross-sectional view.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to a thin wire structure and a touch sensor using the same.

2. Description of the Related Art Touch sensors such as those disclosed in Patent Document 1 have been known for some time. Specifically, Patent Document 1 discloses a touch sensor including a plurality of substrates and a plurality of sensor electrodes provided on each substrate. Each of the plurality of sensor electrodes is constituted by a mesh pattern in which a plurality of conductive thin lines intersect with each other. A bottomed groove portion for forming each thin line is provided on one surface of each substrate. A conductive layer made of a conductive metal such as copper is buried in the groove. The conductive layer is formed so that its upper surface is located near the opening of the groove (see FIG. 8 of Patent Document 1).

JP2020-021184A

By the way, as a general technical knowledge regarding DC resistance, the electrical resistivity of an object is constant, and as the cross-sectional area of the object becomes larger, the electrical resistance value of the object becomes smaller. Based on this common technical knowledge, in the thin wire structure shown in Patent Document 1, the width dimension of the conductive layer (the line width of the thin wire) is narrowed, and the cross-sectional area of the conductive layer is made small (that is, the electrical resistance value is reduced). For this reason, for example, it was necessary to intentionally set the depth of the groove portion to be large.

However, when the depth of the groove is set large, the manufacturing process for forming the groove on the substrate becomes difficult. On the other hand, if the width of the conductive layer is reduced without setting the depth of the groove portion large, the cross-sectional area of the conductive layer will inevitably become smaller. As a result, the electrical resistance value of the conductive layer increases. As described above, in the thin wire structure of Patent Document 1, it is difficult to reduce the cross-sectional area of the conductive layer (reduce the electrical resistance value) while reducing the width of the conductive layer.

The present disclosure has been made in view of the above, and an object thereof is to increase the electrical resistance value of the conductive layer by relatively increasing the cross-sectional area of the conductive layer in a thin wire structure applied to a touch sensor etc. The goal is to make it relatively small.

In order to achieve the above object, an embodiment of the present disclosure is a thin wire structure provided on a substrate, wherein at least one bottomed groove portion is provided on at least one outer surface of the substrate. There is. A conductive layer made of a conductive material is provided in the groove portion. The conductive layer includes a main body made of a conductive material embedded in the groove, a protrusion made of the conductive material that is integrally formed with the main body and protrudes from the main body toward the outside of the groove. including. The protrusion has a width smaller than the width of the groove in a cross-sectional view.

According to the present disclosure, the electrical resistance value of the conductive layer can be reduced.

FIG. 1 is an exploded perspective view showing the entire touch sensor according to the embodiment. FIG. 2 is an exploded perspective view showing the structure of the substrate. FIG. 3 is a partially enlarged plan view showing a part of the sensor electrode in an enlarged manner. FIG. 4 is a vertical cross-sectional view schematically showing the cross-sectional structure of the substrate. FIG. 5 is a partially enlarged view showing the V section shown in FIG. 4. FIG. 6 is a diagram schematically showing the process of forming thin lines in the groove portion. FIG. 7 is a diagram corresponding to FIG. 4 showing a cross-sectional configuration of Modification 1 of the embodiment. FIG. 8 is a diagram corresponding to FIG. 4 showing a cross-sectional configuration of a second modification of the embodiment. FIG. 9 is a diagram corresponding to FIG. 4 showing a cross-sectional configuration of a third modification of the embodiment. FIG. 10 is a vertical cross-sectional view schematically showing a cross-sectional configuration of a substrate in another embodiment.

Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. The following description of the embodiments is merely illustrative in nature and is not intended to limit the present disclosure, its applications, or its uses.

FIG. 1 shows the entire touch sensor 1 according to an embodiment of the present disclosure. The touch sensor 1 is a capacitive sensor type input device applied to a display device (not shown) such as a liquid crystal display, for example. The touch sensor 1 can be used as an input device for, for example, in-vehicle devices such as car navigation systems, display devices for personal computers, mobile phones, personal digital assistants, portable game machines, copy machines, ticket vending machines, automatic teller machines, watches, etc. used.

In the following description, the side on which the operation surface 4 of the cover member 2 (to be described later) is located (the visible side of the touch sensor 1) will be referred to as the "upper side" of the touch sensor 1, and the opposite side will be referred to as the "lower side" of the touch sensor 1. It is assumed that the positional relationship of each element constituting the touch sensor 1 is determined.

(Cover member)
As shown in FIG. 1, the touch sensor 1 includes a cover member 2 having optical transparency. The cover member 2 is made of, for example, a cover glass or a plastic cover lens. The cover member 2 is formed, for example, in a plate shape that is rectangular in plan view.

On the peripheral edge of the lower surface of the cover member 2, a substantially frame-shaped decorative portion 3 is formed in a dark color such as black by screen printing or the like. The internal rectangular area surrounded by the decorative portion 3 serves as a view area through which light can be transmitted. That is, the user can obtain visual information from the display device disposed below the touch sensor 1 via this viewing area. The upper surface of the cover member 2 corresponding to the view area is configured as an operation surface 4 with which a user's fingers or the like comes into contact during a touch operation.

(substrate)
As shown in FIG. 2, the touch sensor 1 includes two substrates 5, 5. The substrates 5, 5 are composed of an upper substrate 6 and a lower substrate 7. Each of the upper substrate 6 and the lower substrate 7 has a substantially rectangular shape in plan view. The upper substrate 6 is arranged on the viewing side of the touch sensor 1. Specifically, the upper substrate 6 is stacked and arranged below the cover member 2. The lower substrate 7 is arranged on the side where a display device (not shown) is located.

As shown in FIG. 4, each substrate 5 has a first layer 8. The material of the first layer 8 may be a light-transmitting material such as acrylic (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin polymer (COP), cycloolefin copolymer (COC), epoxy, etc. Examples include resin materials, silicon materials, and glass materials. The thickness of the first layer 8 is, for example, 20 μm to 100 μm.

Each substrate 5 has a second layer 9. The second layer 9 is a layer for forming a plurality of groove portions 10, which will be described later. The second layer 9 is made of an insulating and transparent resin material. In this embodiment, the second layer 9 is stacked on top of the first layer 8 . The thickness of the second layer 9 is set to, for example, 3 μm to 20 μm in order to ensure flexibility.

As shown in FIGS. 4 and 5, a plurality of bottomed groove portions 10 are provided on the upper surface of the second layer 9 (the upper surface of the substrate 5). The plurality of groove portions 10 are elements for configuring each of a sensor electrode 15, a wiring portion, and a pad 33, which will be described later.

The depth of each groove portion 10 (dimension D shown in FIG. 5) is set to, for example, 0.5 μm to 5.0 μm. The width of each groove portion 10 (dimension W1 shown in FIG. 5) is set to, for example, 0.5 μm to 20.0 μm. Preferably, each groove portion 10 is configured such that the value obtained by dividing the width dimension W1 by the depth dimension D is within the range of 0.8 to 5.0.

Each groove portion 10 has side portions 11 , 11 and a bottom portion 12 . In this embodiment, the side parts 11, 11 are inclined with respect to the thickness direction of the substrate 5 so that the interval between the side parts 11, 11 gradually widens from the bottom 12 of the groove part 10 toward the opening side. There is. The bottom portion 12 is formed in a substantially flat shape. Note that the groove portion 10 of this embodiment has a corner portion formed at a position where the side portion 11 and the bottom portion 12 intersect.

Note that the width dimension W1 of the groove portion 10 refers to the distance between the side portions 11, 11 on the opening side of the groove portion 10. Moreover, the width dimension W1 of the groove portion 10 is defined as the distance between the side portions 11, 11 excluding the thickness of the first resin layer 21, which will be described later.

(adhesive layer)
As shown in FIG. 2, an adhesive layer 14 for fixing the cover member 2 and the upper substrate 6 is provided on the upper side of the upper substrate 6. Further, an adhesive layer 14 for fixing the upper substrate 6 and the lower substrate 7 is provided on the lower side of the upper substrate 6. Each adhesive layer 14 has light transmittance. Specifically, each adhesive layer 14 is made of, for example, optical adhesive (OCA: Optical Clear Adhesive). Each adhesive layer 14 has substantially the same size and shape as each of the upper substrate 6 and the lower substrate 7.

(sensor electrode)
As shown in FIGS. 1 and 2, the touch sensor 1 includes a plurality of capacitive sensor electrodes 15. A plurality of sensor electrodes 15 are provided on each substrate 5.

The plurality of sensor electrodes 15 are composed of a plurality of transmitting electrodes 16 and a plurality of receiving electrodes 17. The plurality of transmitting electrodes 16 and the plurality of receiving electrodes 17 are arranged on each substrate 5 at positions corresponding to the viewing area. The touch sensor 1 is capable of detecting a touch operation by a user's finger (detection target) that is in contact with the operation surface 4 through the plurality of transmitting electrodes 16 and the plurality of receiving electrodes 17 located within the viewing area.

Each transmitting electrode 16 is connected to a drive circuit (not shown) via a flexible wiring board 34, which will be described later. Each transmitting electrode 16 is configured to radiate an electric field to its surroundings by this drive circuit. On the other hand, each receiving electrode 17 is connected to a detection circuit (not shown) via a flexible wiring board 34. Each receiving electrode 17 is configured to receive the electric field radiated from each transmitting electrode 16.

Each transmitting electrode 16 and each receiving electrode 17 are arranged so as to intersect with each other (orthogonally in the illustrated example) in plan view. A node is formed in a region where each transmitting electrode 16 and each receiving electrode 17 overlap. This node is configured as a region where capacitance can be generated.

The plurality of transmitting electrodes 16 are provided on the upper surface of the lower substrate 7. Each transmitting electrode 16 extends along the long side direction of the lower substrate 7 . The plurality of transmitting electrodes 16 are arranged side by side in the short side direction of the lower substrate 7 . Note that in FIGS. 1 and 2, only a part of one transmitting electrode 16 is shown to simplify the illustration.

The plurality of receiving electrodes 17 are provided on the upper surface of the upper substrate 6. That is, the plurality of receiving electrodes 17 are arranged on the upper substrate 6 on the viewing side of the touch sensor 1 (the side on which the operation surface 4 of the cover member 2 is located). The plurality of receiving electrodes 17 are insulated from the plurality of transmitting electrodes 16 via the lower substrate 7. Each receiving electrode 17 extends along the short side direction of the upper substrate 6. The plurality of receiving electrodes 17 are arranged at intervals in the long side direction of the upper substrate 6. Note that in FIGS. 1 and 2, only a part of one receiving electrode 17 is shown to simplify the illustration.

Each sensor electrode is configured to include, for example, a mesh pattern 18 formed by regularly arranging a plurality of thin wire structures 20 (described later) (see FIG. 3). The mesh pattern 18 has, for example, a network structure formed by regularly arranging a plurality of cells (for example, rhombus-shaped) constituted by a plurality of thin wire structures 20. Note that each sensor electrode may include a pattern different from the mesh pattern 18.

(Thin wire structure)
As shown in FIG. 4, the touch sensor 1 includes a plurality of thin wire structures 20. As shown in FIG. 5, each thin wire structure 20 of this embodiment is composed of a groove portion 10, a first resin layer 21, and a conductive layer 22. Note that in FIGS. 4 and 5, dot hatching is applied to each of the first resin layer 21 and the conductive layer 22 in order to emphasize the first resin layer 21 and the conductive layer 22.

(first resin layer)
As shown in FIG. 5, the first resin layer 21 is a layer that serves as a base for forming the conductive layer 22 in the groove portion 10. As shown in FIG. The first resin layer 21 is made of a resin solvent containing an electroless plating catalyst. The electroless plating catalyst includes, for example, palladium (Pd). Note that the electroless plating catalyst may contain platinum (Pt) or chromium (Cr) instead of palladium (Pd).

The first resin layer 21 is arranged on the bottom part 12 and side parts 11, 11 of the groove part 10, and on the outer surface of the substrate 5 located around the groove part 10 (in this embodiment, the outer surface of the second layer 9). has been done. The first resin layer 21 is formed by a solid component containing palladium (Pd) remaining on the sides 11, 11 and bottom 12 of the groove portion 10 and the outer surface of the substrate 5 after the solvent component has evaporated due to drying. Equivalent to. The thickness of the first resin layer 21 (dimension T shown in FIG. 5) is, for example, 10 nm to 100 nm.

(conductive layer)
As shown in FIG. 5, the conductive layer 22 is an element for ensuring the conductivity of the thin wire structure 20. In this embodiment, the conductive layer 22 is a plating layer formed by electroless plating, for example. Specifically, the conductive layer 22 is laminated on the first resin layer 21 formed on the side parts 11, 11 and the bottom part 12 of the groove part 10 by electroless plating.

The conductive layer 22 is made of a conductive material. Examples of the conductive material include conductive metals such as copper (Cu), gold (Au), silver (Ag), aluminum (Al), and nickel (Ni), or alloys thereof.

Conductive layer 22 includes a main body portion 23 and a protrusion portion 24 . The main body portion 23 is made of a conductive material embedded in the groove portion 10. The protrusion 24 is made of a conductive material that protrudes from the main body 23 toward the outside of the groove 10 . The protruding portion 24 is formed integrally with the main body portion 23. The protrusion 24 of this embodiment is formed so that the cross-sectional shape of the protrusion 24 is approximately rectangular.

In this embodiment, the virtual interface A between the main body 23 and the protrusion 24 shown in FIG. ). Thereby, the height dimension (dimension H1 shown in FIG. 5) of the main body part 23 becomes the value obtained by subtracting the thickness dimension T of the first resin layer 21 from the depth dimension D of the groove part 10. Further, the height dimension of the protrusion 24 (dimension H2 shown in FIG. 5) corresponds to the distance from the interface A to the apex of the protrusion 24.

As a characteristic feature of the embodiment of the present disclosure, the protrusion 24 has a width smaller than or equal to the width of the groove 10 in cross-sectional view. In this embodiment, the width dimension of the protruding portion 24 (dimension W2 shown in FIG. 5) is approximately the same as the width dimension W1 of the groove portion 10. That is, the width dimension W2 of the protruding portion 24 is set to, for example, 0.5 μm to 20.0 μm, similarly to the width dimension W1 of the groove portion 10. Note that the width dimension W2 of the protruding portion 24 is determined as a dimension at a position showing a maximum value in the width direction of the groove portion 10.

Here, the height dimension (dimension H2 shown in FIG. 5) of the protrusion 24 is set to, for example, 1.0 μm. That is, the height of the conductive layer 22 (dimension H3 shown in FIG. 5) is set to, for example, 1.5 μm to 6.0 μm.

(Wiring section)
As shown in FIGS. 1 and 2, the touch sensor 1 includes a plurality of wiring sections. The plurality of wiring sections are constituted by a plurality of transmitting electrodes 16 and a plurality of receiving electrodes 17. The plurality of transmitting electrodes 16 and the plurality of receiving electrodes 17 are electrically connected to an external circuit (the above-mentioned drive circuit and detection circuit) not shown.

The plurality of first wiring sections 31 and the plurality of second wiring sections 32 are arranged outside the viewing area. Specifically, the plurality of first wiring parts 31 and the plurality of second wiring parts 32 are arranged at positions overlapping with the decoration part 3 in a plan view viewed from the operation surface 4 side. That is, the plurality of first wiring sections 31 and the plurality of second wiring sections 32 are made invisible from the operation surface 4 side by the decoration section 3 .

As shown in FIG. 2, the plurality of first wiring parts 31 are formed on the upper surface of the lower substrate 7. One end of each first wiring section 31 is electrically connected to an end of each transmitting electrode 16 . The plurality of first wiring portions 31 are arranged such that the other end portions of each are converged at a predetermined position on the lower substrate 7 (the side located on the left side of the paper in FIG. 2).

The plurality of second wiring sections 32 are formed on the upper surface of the upper substrate 6. One end of each second wiring section 32 is electrically connected to an end of each receiving electrode 17 . The plurality of second wiring portions 32 are arranged such that the other end portions of each are converged at a predetermined position on the upper substrate 6 (the side located on the left side of the paper in FIG. 2).

Although not shown, each of the first and second wiring sections 31 and 32 is composed of at least one thin wire structure 20.

(pad)
As shown in FIGS. 1 and 2, the other end of each first wiring section 31 is provided with a pad 33 for electrical connection to a flexible wiring board 34, which will be described later. Further, a pad 33 is also provided at the other end of each second wiring section 32.

(Flexible wiring board)
As shown in FIG. 1, the touch sensor 1 includes a flexible wiring board 34. The flexible wiring board 34 has flexibility and is configured so that its electrical characteristics do not change even in a deformed state. The flexible wiring board 34 is made of a flexible insulating film such as polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or the like. The flexible wiring board 34 is fixed to the substrate 5 using, for example, an anisotropic conductive adhesive (not shown).

(Formation process of thin wire structure)
Next, a process for forming the thin wire structure 20 will be described with reference to FIG. The process of forming the thin wire structure 20 includes first to fifth steps.

In the first step, a plurality of grooves 10 are formed in the second layer 9 of the substrate 5 using, for example, an imprint method. At this time, it is preferable to form the plurality of groove portions 10 so that the taper angle θ shown in FIG. 5 is in the range of 90° to 135°. Note that the taper angle θ is defined as the angle formed between the bottom portion 12 and the side portions 11 of the groove portion 10.

In the second step, a first resin layer 21 is formed on the outer surface of the substrate 5 and on the plurality of grooves 10 . Specifically, in the second layer 9 of the substrate 5 in which the plurality of grooves 10 are formed, a plating primer is coated on the outer surface of the substrate 5 and the plurality of grooves 10 using a bar coater or printing. The plating primer is made of, for example, a resin solvent containing an electroless plating catalyst (Pd).

In the coating described above, by drying the liquid plating primer for a predetermined period of time, the solvent component in the plating primer evaporates. As this volatilization progresses, the solid component containing palladium (Pd) solidifies. As a result, the first resin layer 21 is formed on the outer surface of the substrate 5 and on the plurality of grooves 10.

In the third step, a second resin layer 25 having a function as a transfer type resist is formed around each groove part 10 (in FIG. 6, between groove parts 10, 10) using a resin material different from that of the substrate 5. It is formed on the outer surface of the substrate 5 located at. Specifically, the second resin layer 25 is laminated and arranged on the first resin layer 21 located on the outer surface of the substrate 5 so that the second resin layer 25 is the same height as the dimension H2 shown in FIG. do. As the material for the second resin layer 25, a material applicable as a permanent resist material (for example, an acrylic or polyester resin material) is used. Note that by adjusting the height of the second resin layer 25 in the third step, it is possible to appropriately change the height dimension H2 of the protrusion 24 in the fourth step.

In the fourth step, a conductive layer 22 is formed. Specifically, after forming the first resin layer 21 and the second resin layer 25, electroless plating treatment is performed. By performing the electroless plating process, plating growth progresses using palladium (Pd) contained in the first resin layer 21 formed in each groove portion 10 as a catalyst, and plating metal (for example, Cu) is deposited. As a result, the main body portion 23 of the conductive layer 22 is formed in each groove portion 10 . Further, as the plating growth progresses, the plating metal is precipitated beyond the outer surface of the substrate 5 to a height that is substantially flush with the upper surface of the second resin layer 25 located on both sides of each groove portion 10. Become. As a result, protrusions 24 of the conductive layer 22 are formed.

In the fifth step, the second resin layer 25 is removed after the conductive layer 22 is formed. This completes the process of forming the thin wire structure 20.

[Operations and effects of embodiment]
As described above, the conductive layer 22 includes a main body 23 embedded in the groove 10 and a protrusion 24 that is integrally formed with the main body 23 and protrudes from the main body 23 toward the outside of the groove 10. ,including. That is, the conductive layer 22 is configured such that its height dimension (dimension H3 shown in FIG. 5) is larger than the depth dimension of the groove portion 10 (dimension D shown in FIG. 5).

By the way, as a general technical knowledge regarding DC resistance, the electrical resistivity of an object is constant, and as the cross-sectional area of the object becomes larger, the electrical resistance value of the object becomes smaller. Based on this common knowledge, in the thin wire structure 20 according to the embodiment of the present disclosure, the main body portion 23 is The cross-sectional area of the conductive layer 22 becomes relatively large due to the combination of the cross-sectional area of the protrusion 24 and the cross-sectional area of the protrusion 24 . As a result, the electrical resistance value of the conductive layer 22 becomes smaller than the electrical resistance value of the conventional conductive layer described above.

The protrusion 24 has a width smaller than the width of the groove 10 in cross-sectional view. That is, the width dimension of the protruding portion 24 (dimension W2 shown in FIG. 5) is suppressed to be equal to or smaller than the width dimension of the groove portion 10 (dimension W1 shown in FIG. 5). As a result, in the thin wire structure 20, the width of the conductive layer 22 (that is, the line width of one thin wire) can be narrowed while the depth of the groove 10 is not intentionally set large. It becomes possible to relatively increase the cross-sectional area of.

Therefore, in the thin wire structure 20 according to the embodiment of the present disclosure, the electrical resistance value of the conductive layer 22 can be reduced.

Furthermore, the protruding portion 24 of this embodiment has the same width dimension (dimension W2) as the width dimension (dimension W1) of the groove portion 10. According to this configuration, the cross-sectional area of the conductive layer 22 can be further increased while reducing the width dimension (line width of the thin line) of the conductive layer 22. Therefore, the electrical resistance value of the conductive layer 22 can be further reduced.

Furthermore, a first resin layer 21 made of a resin solvent containing an electroless plating catalyst is laminated on at least the bottom 12 and side 11 of the groove 10 . This first resin layer 21 can stabilize the laminated state of the conductive layer 22 (particularly the main body part 23) embedded in the groove part 10.

[Modification 1 of embodiment]
In the embodiment described above, the second resin layer 25 is removed after the conductive layer 22 is formed in the fifth step of forming the thin wire, but the present invention is not limited to this embodiment. For example, as in Modification 1 shown in FIG. 7, the fifth step may be omitted and the second resin layer 25 may be left.

As shown in FIG. 7, the second resin layer 25 is arranged on the outer surface of the substrate 5 located around the groove portion 10 in a laminated manner with respect to the first resin layer 21 located on the outer surface. The second resin layer 25 is made of a resin material different from the material of the substrate 5, as described in the above embodiment. The second resin layer 25 is configured to cover the exposed portion (side surface portion) of the protrusion 24 in the conductive layer 22 . With this configuration, the exposed portion of the protrusion 24 is reduced, and the protrusion 24 can be appropriately protected.

[Modification 2 of embodiment]
In the above embodiment, the cross-sectional shape of the protruding portion 24 is approximately rectangular, but the present invention is not limited to this shape. For example, as in Modification 2 shown in FIG. 8, the cross-sectional shape of the protrusion 24 may be approximately semicircular. Even in such a modification, as in the above embodiment, the width dimension of the conductive layer 22 (line width of the thin line) is narrowed while the depth dimension of the groove portion 10 does not have to be intentionally set large. Also, it is possible to relatively increase the cross-sectional area of the conductive layer 22.

[Modification 3 of embodiment]
In the embodiment described above, a corner portion is formed at a position where the side portion 11 and the bottom portion 12 intersect in the groove portion 10, but the present invention is not limited to this form. For example, as in Modification 3 shown in FIG. 9, the corner portion may not be formed at the position where the side portion 11 and the bottom portion 12 intersect. That is, in the third modification, the bottom portion 12 of the groove portion 10 is formed in a curved shape when viewed in cross section. Specifically, the groove portion 10 is configured such that the entire bottom portion 12 has a substantially semicircular shape when viewed in cross section.

According to this modification, for example, when external light enters toward the groove part 10 from the outer surface side of the substrate 5 located on the opposite side of the groove part 10 shown in FIG. In addition, when the external light hits the substantially semicircular bottom part 12 (specifically, the main body part 23 of the conductive layer 22 located on the bottom part 12 side), the external light is diffusely reflected. This diffused reflection makes it easier for the external light to diffuse in various directions. As a result, a person viewing from the outer surface of the substrate 5 located on the opposite side of the groove 10 (for example, a user of the touch sensor 1) can visually recognize the conductive layer 22 provided in the groove 10 shown in FIG. It becomes difficult to do. That is, so-called "line visibility" of the thin line structure 20 is prevented. Therefore, in this modification, the appearance of the touch sensor 1 can be improved.

By the way, in the embodiment described above, the plurality of sensor electrodes 15, the plurality of wiring parts, and the plurality of pads 33 are provided on the upper surface side of the substrate 5 (on the operation surface 4 side), but the plurality of sensor electrodes 15, The plurality of wiring parts and the plurality of pads 33 may be provided on the lower surface side of the substrate 5 (that is, the surface of the substrate 5 located on the opposite side to the operation surface 4). In such a configuration, each groove portion 10 is formed on the lower surface side of the substrate 5. As a result, when external light enters from the upper surface side of the board 5 (the surface of the board 5 on the side where the operation surface 4 is located), the external light hits the substantially semicircular bottom 12 and is diffusely reflected. spread in various directions. As a result, as described above, so-called "line visibility" of the thin line structure 20 is prevented, and the appearance of the touch sensor 1 is improved.

In addition, although FIG. 10 shows the form in which the whole bottom part 12 was formed in the substantially circular shape, it is not restricted to this shape. For example, although not shown, the corner portion may be formed on either the right side or the left side of the bottom portion 12 in FIG. 10 . That is, if at least a portion of the bottom portion 12 is formed in a curved shape, as described above, so-called "line visibility" of the thin line structure 20 can be prevented, and the appearance of the touch sensor 1 can be improved.

[Other embodiments]
Although the touch sensor 1 of the above embodiment and each modification example has a substantially rectangular view area, the present invention is not limited to this embodiment. That is, the view area may have a polygonal shape such as a substantially circular shape or a pentagonal shape when viewed from above, for example.

In the embodiment and each modification described above, the second layer 9 is located above the first layer 8, but the present invention is not limited to this embodiment. For example, the second layer 9 may be located below the first layer 8.

In the embodiment and each modification described above, a configuration using two substrates 5, 5 (upper substrate 6 and lower substrate 7) is shown, but the present invention is not limited to this configuration. That is, a configuration using only one substrate 5 may be used. In this embodiment, one substrate 5 (not shown) in which two second layers 9, 9 are formed both above and below the first layer 8 may be used. In this case, for example, the plurality of transmitting electrodes 16 and the plurality of first wiring parts 31 are provided on the second layer 9 located below the first layer 8, while the plurality of receiving electrodes 17 and the plurality of second wiring parts 32 may be provided on the second layer 9 located above the first layer 8.

In the above embodiment and each modification example, the substrate 5 has the first layer 8 and the second layer 9, but the present invention is not limited to this embodiment. For example, as shown in FIG. 10, the substrate 5 may have only the first layer 8. In this embodiment, the groove portion 10 and the thin wire structure 20 may be formed on at least one of the upper surface and the lower surface of the first layer 8.

In the above embodiment and each modification, each transmitting electrode 16 extends along the longitudinal direction of the substrate 5 shown in FIG. 2, while each receiving electrode 17 extends along the lateral direction of the substrate 5. However, it is not limited to this form. That is, each transmitting electrode 16 may extend along the lateral direction of the substrate 5, while each receiving electrode 17 may extend along the longitudinal direction.

In the embodiment and each modification described above, the touch sensor 1 is shown in which the cover member 2 and the flexible wiring board 34 are attached to the substrate 5, but the present invention is not limited to this embodiment. That is, the concept of the touch sensor 1 according to the present disclosure includes a state before the cover member 2, the flexible wiring board 34, and the like are attached to the substrate 5. Furthermore, the concept of the touch sensor 1 of the present disclosure includes a plurality of sensor electrodes as described above in a long base material (for example, a long hoop-shaped member not shown) in a state before the substrate 5 is formed. A configuration in which 15 is formed on the base material is also included.

In the embodiment and each modification described above, the first resin layer 21 is provided on both the outer surface of the substrate 5 and the groove portion 10, but the present invention is not limited to this embodiment. That is, the first resin layer 21 only needs to be provided at least in the groove portion 10 . In this case, in the second step related to the step of forming the thin wire structure 20, after coating, for example, a squeegee (not shown) may be used to prevent the plating primer from remaining on the upper surface of the second layer 9. . Note that the plating primer remaining on the upper surface of the second layer 9 may be wiped off using a waste cloth or the like instead of a squeegee.

In the embodiment and each modification described above, the touch sensor 1 to which the thin wire structure 20 of the present disclosure is applied is illustrated, but the present invention is not limited thereto. For example, the thin wire structure 20 of the present disclosure may be used in technical fields other than touch sensors (for example, liquid crystal display devices, organic electroluminescent display devices (OLED), micro LED display devices, solar cell devices, heater devices, antenna devices, electromagnetic wave shielding sheets). It can be widely applied to various technical fields such as

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various changes can be made within the scope of the present disclosure.

The present disclosure can be industrially used as a thin wire structure and a touch sensor using the same.

1: Touch sensor 2: Cover member 4: Operation surface 5: Substrate 6: Upper substrate 7: Lower substrate 8: First layer 9: Second layer 10: Concave groove portion 11: Side portion 12: Bottom portion 14: Adhesive layer 15 : Sensor electrode 16: Transmitting electrode 17: Receiving electrode 18: Mesh pattern 20: Thin wire structure 21: First resin layer 22: Conductive layer 23: Main body part 24: Projecting part 25: Second resin layer

Claims (6)

A thin wire structure provided on a substrate,
At least one bottomed groove portion is provided on the outer surface of at least one of the substrates,
A conductive layer made of a conductive material is provided in the groove,
The conductive layer is
a main body made of the conductive material embedded in the groove;
a protrusion formed integrally with the main body and made of the conductive material and protruding from the main body toward the outside of the groove,
The protruding portion has a thin line structure having a width smaller than or equal to the width of the groove portion in a cross-sectional view. The thin wire structure according to claim 1,
The protrusion has a thin line structure having the same width as the groove. The thin wire structure according to claim 1 or 2,
A thin wire structure, wherein at least the groove portion is provided with a first resin layer made of a resin solvent containing an electroless plating catalyst. The thin wire structure according to any one of claims 1 to 3,
A thin wire structure, wherein a second resin layer made of a resin material different from the material of the substrate is provided on the outer surface of the substrate located around the groove portion. A touch sensor comprising the thin wire structure according to any one of claims 1 to 4. The touch sensor according to claim 5,
In the touch sensor, the bottom of the groove is configured such that at least a portion of the bottom is curved in cross-sectional view.