Fine line structure

Abstract

To reduce the line width of a thin line.SOLUTION: In the thin line structure 18, a bottomed concave groove portion 10 is provided in the sensor substrate 5. The recessed groove part 10 is provided with a pair of thin wires 1919 and composed of a conductive metal material. The pair of fine lines 19,19 are respectively formed at positions including the corner portions 13 of the recessed groove portion 10, and are arranged at an interval in the width direction of the bottom portion 12.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to thin-wire structures. To make It is related to. [Background technology]

[0002] Conventionally, there has been known a touch sensor such as that shown in Patent Document 1. Specifically, the touch sensor of Patent Document 1 has a sensor substrate, and one surface of the sensor substrate is provided with a plurality of bottomed grooves. Each groove is provided with a thin wire (conductor). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6872696 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the single thin wire is made of a conductive metal such as copper embedded across the entire width of the bottom of the groove in a vertical cross-sectional view of the sensor substrate. With this configuration, the line width of the single thin wire is approximately the same as the width of the groove. That is, the line width of the single thin wire is constrained by the width of the groove.

[0005] However, it is generally difficult to minimize the width of the groove due to manufacturing reasons (e.g., constraints on the manufacturing process and / or limitations on the specifications of the manufacturing equipment), and therefore, when it is desired to thin the line to, for example, 1 μm or less, it has been difficult to achieve further thinning due to the manufacturing reasons.

[0006] The present disclosure has been made in view of the above points, and its purpose is to reduce the line width of thin lines in a thin line structure applied to a touch sensor or the like. [Means for solving the problem]

[0007] In order to achieve the above object, one embodiment of the present disclosure comprises: The first corner, the second corner, and the first A thin film disposed on a substrate having a groove portion including a corner portion and a bottom portion located between the corner portion and the second corner portion. The wire structure is a thin wire located in the groove portion and made of a conductive metal material. In a cross-sectional view, the bottom of the recessed groove is closer to the recessed groove than the first corner and the second corner. It rises towards the opening side. [Effects of the Invention]

[0008] According to the present disclosure, the line width of a thin line can be reduced. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an exploded perspective view showing the entire touch sensor according to the embodiment. [Figure 2] FIG. 2 is an exploded perspective view showing the configuration of the sensor substrate. [Figure 3] FIG. 3 is a longitudinal sectional view schematically showing the cross-sectional configuration of the sensor substrate. [Figure 4] FIG. 4 is a partially enlarged view showing a portion IV shown in FIG. [Figure 5] FIG. 5 is a diagram schematically showing a process of forming a thin wire in a groove portion. [Figure 6] FIG. 6 is a view equivalent to FIG. 4 showing a cross-sectional configuration of the first modified example of the embodiment. [Figure 7] FIG. 7 is a view corresponding to FIG. 4, showing a cross-sectional configuration of the second modified example of the embodiment. [Figure 8] FIG. 8 is a longitudinal sectional view schematically showing a cross-sectional configuration of a sensor substrate according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following description of the embodiments is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0011] 1 shows an entire touch sensor 1 according to an embodiment of the present disclosure. The touch sensor 1 is a capacitance-type sensor-type input device that is applied to a display device (not shown) such as a liquid crystal display. The touch sensor 1 is 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, automated teller machines, watches, and the like.

[0012] In the following description, the side on which the operating surface 4 of the cover member 2 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, and the positional relationship of each element that makes up the touch sensor 1 will be defined accordingly.

[0013] (Cover member) 1, the touch sensor 1 includes a light-transmitting cover member 2. The cover member 2 is made of, for example, a cover glass or a plastic cover lens. The cover member 2 is formed in the shape of, for example, a rectangular plate in plan view.

[0014] A roughly frame-shaped decorative portion 3 is formed on the periphery of the underside of the cover member 2 in a dark color such as black by screen printing or the like. The rectangular area inside this decorative portion 3 is a light-transmitting view area. In other words, the user can obtain visual information from a display device arranged below the touch sensor 1 through this view area. The upper surface of the cover member 2 corresponding to the view area is configured as an operation surface 4 that comes into contact with the user's fingers or the like when performing a touch operation.

[0015] (sensor board) As shown in FIG. 2, the touch sensor 1 includes two sensor substrates 5, 5 (substrates). The two sensor substrates 5, 5 are composed of an upper substrate 6 and a lower substrate 7. The upper substrate 6 and the lower substrate 7 each have a substantially rectangular shape in a plan view. The upper substrate 6 is disposed on the visible side of the touch sensor 1. Specifically, the upper substrate 6 is disposed and stacked below the cover member 2. The lower substrate 7 is disposed on the side where a display device (not shown) is located.

[0016] As shown in Fig. 3, each sensor substrate 5 has a first layer 8. The material of the first layer 8 may be, for example, acrylic (PMMA), polyethylene terephthalate (PET), polycarbonate, or the like. Examples of the material include a resin material having optical transparency such as polycarbonate (PC), cycloolefin polymer (COP), cycloolefin copolymer (COC), epoxy, a silicon material, or a glass material. The thickness of the first layer 8 is, for example, 20 μm to 100 μm.

[0017] Each sensor substrate 5 has a second layer 9. The second layer 9 is a layer for forming a plurality of recessed grooves 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 to ensure flexibility.

[0018] 3 and 4, a plurality of bottomed grooves 10 are provided on the upper surface of the second layer 9 (the upper surface of the sensor substrate 5). The plurality of grooves 10 are elements for constituting the sensor electrode 15, the first and second wiring portions 23 and 24, and the pads 25, which will be described later. The depth of each groove 10 is set to, for example, 1.0 μm to 2.0 μm. The width of each groove 10 is set to, for example, 2.0 μm to 20.0 μm.

[0019] Each groove 10 has side portions 11, 11, a bottom portion 12, and corner portions 13, 13. The side portions 11, 11 may be inclined so as to gradually widen from the bottom portion 12 of the groove 10 toward the opening. The bottom portion 12 is formed in a substantially flat shape. Each corner portion 13 may have a fillet formed therein.

[0020] (Adhesive layer) As shown in FIG. 2, an adhesive layer 14 is provided between the cover member 2 and the upper substrate 6. An adhesive layer 14 is also provided between the upper substrate 6 and the lower substrate 7. Each adhesive layer 14 is optically transparent. Specifically, each adhesive layer 14 is made of, for example, an optical clear adhesive (OCA). Each adhesive layer 14 has approximately the same size and shape as the upper substrate 6 and the lower substrate 7, respectively.

[0021] (sensor electrode) 1 and 2, the touch sensor 1 includes a plurality of capacitance-type sensor electrodes 15. The plurality of sensor electrodes 15 are provided on each sensor substrate 5.

[0022] The plurality of sensor electrodes 15 is 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 at positions on each sensor substrate 5 corresponding to the above-mentioned view area. The touch sensor 1 is capable of detecting a touch operation by a user's finger (detection target) that touches the operation surface 4 through the plurality of transmitting electrodes 16 and the plurality of receiving electrodes 17 located within the view area.

[0023] Each transmitting electrode 16 is connected to a drive circuit (not shown) via a flexible wiring board 26 (described later). Each transmitting electrode 16 is configured to radiate an electric field to the surroundings via this drive circuit. Meanwhile, each receiving electrode 17 is connected to a detection circuit (not shown) via a flexible wiring board 26 (described later). Each receiving electrode 17 is configured to receive the electric field radiated from each transmitting electrode 16.

[0024] The transmitting electrodes 16 and the receiving electrodes 17 are arranged to intersect with each other (orthogonal in the illustrated example) in a plan view. A node is formed in the area where each transmitting electrode 16 and each receiving electrode 17 overlap. This node is configured as an area where capacitance can be generated.

[0025] A 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 of the lower substrate 7. The plurality of transmitting electrodes 16 are arranged side by side along the short side of the lower substrate 7. Note that, for the sake of simplicity, only a portion of one transmitting electrode 16 is shown in FIGS. 1 and 2.

[0026] 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 visible 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 of the upper substrate 6. The plurality of receiving electrodes 17 are arranged side by side at intervals along the long side of the upper substrate 6. Note that, for simplicity of illustration, only a portion of one receiving electrode 17 is shown in FIGS. 1 and 2.

[0027] Although not shown, each of the transmitting electrode 16 and the receiving electrode 17 is configured to include, for example, a mesh pattern formed by regularly arranging a plurality of fine wires 19, which will be described later. This mesh pattern has, for example, a mesh structure formed by regularly arranging a plurality of cells (e.g., diamond shapes) formed by the plurality of fine wires 19. Note that each of the transmitting electrode 16 and the receiving electrode 17 may include a pattern different from the mesh pattern described above.

[0028] (Thin wire structure) As shown in Fig. 3, the touch sensor 1 has a plurality of fine line structures 18. As shown in Fig. 4, in each of the plurality of fine line structures 18, a pair of fine lines 19, 19 and a protective layer 22 are provided in one groove portion 10. Each fine line 19 is arranged at a position including a corner portion 13 of the groove portion 10. The fine lines 19, 19 are arranged at intervals from each other in the width direction of the bottom portion 12 of the groove portion 10. The line width of each fine line 19 is preferably set to 0.5 µm to 1.0 µm.

[0029] Each thin wire 19 is composed of a catalyst layer 20 and a plating layer 21 .

[0030] The catalyst layer 20 is a layer that serves as a base for forming a plating layer 21 in the recessed groove portion 10. The catalyst layer 20 is made of a solvent containing an electroless plating catalyst. The electroless plating catalyst contains, for example, palladium (Pd).

[0031] The catalyst layers 20, 20 are provided in one groove portion 10. The catalyst layers 20, 20 are arranged at intervals from each other in the width direction of the groove portion 10. Each catalyst layer 20 is arranged on a side portion 11 and a corner portion 13 of the groove portion 10. Each catalyst layer 20 corresponds to a solid component containing palladium (Pd) remaining on the side portion 11 and the corner portion 13 after the solvent component has evaporated due to drying.

[0032] The plating layer 21 is an element for ensuring the conductivity of the thin wire 19. The plating layer 21 is made of a conductive material. Suitable conductive materials include, for example, conductive metals such as copper (Cu) or nickel (Ni).

[0033] The plating layers 21, 21 are provided in one groove portion 10. The plating layers 21, 21 are stacked on the catalyst layer 20 by, for example, electroless plating. The plating layers 21, 21 are arranged at intervals from each other in the width direction of the groove portion 10. Each plating layer 21 is arranged at a position that includes a corner portion 13 of the groove portion 10. The plating layers 21, 21 are configured to be electrically non-conductive to each other by a protective layer 22 embedded in the groove portion 10.

[0034] The protective layer 22 is a layer for protecting the plating layers 21, 21 from the outside. The protective layer 22 is made of a material that has high adhesion to the second layer 9 and is insulating. Specifically, the protective layer 22 is made of an adhesive whose main component is a resin material such as an epoxy, acrylic, or urethane type. It is preferable that the protective layer 22 be approximately flush with the upper surface of the second layer 9.

[0035] (Wiring section) 1 and 2, the touch sensor 1 includes a plurality of wiring portions. The plurality of wiring portions is 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 electrically connected to external circuits (the driving circuit and the detection circuit described above) not shown.

[0036] The plurality of first wiring portions 23 and the plurality of second wiring portions 24 are arranged outside the view area. Specifically, the plurality of first wiring portions 23 and the plurality of second wiring portions 24 are arranged at positions overlapping with the decorative portion 3 in a plan view seen from the operation surface 4 side. In other words, the plurality of first wiring portions 23 and the plurality of second wiring portions 24 are made invisible from the operation surface 4 side by the decorative portion 3.

[0037] 2, the plurality of first wiring portions 23 are formed on the upper surface of the lower substrate 7. One end of each of the first wiring portions 23 is electrically connected to an end of each of the transmitting electrodes 16. The plurality of first wiring portions 23 are arranged such that the other end of each of them converges at a predetermined position on the lower substrate 7 (the side located on the left side of the paper surface in FIG. 2).

[0038] The plurality of second wiring portions 24 are formed on the upper surface of the upper substrate 6. One end of each second wiring portion 24 is electrically connected to an end of each receiving electrode 17. The plurality of second wiring portions 24 are arranged so that the other end of each second wiring portion 24 converges at a predetermined position on the upper substrate 6 (the side located on the left side of the paper surface in FIG. 2).

[0039] Although not shown, each of the first and second wiring portions 23 and 24 is made up of at least one thin wire 19 embedded in each recessed groove portion 10 located on each sensor substrate 5.

[0040] (pad) 1 and 2, a pad 25 is provided at the other end of each first wiring portion 23 for electrical connection to a flexible wiring board 26, which will be described later. In addition, a pad 25 is also provided at the other end of each second wiring portion 24.

[0041] (flexible wiring board) As shown in Fig. 1, the touch sensor 1 includes a flexible wiring board 26. The flexible wiring board 26 is configured to be flexible and to maintain its electrical characteristics even when deformed. The flexible wiring board 26 is made of a flexible insulating film such as polyimide (PI), polyethylene terephthalate (PET), or polyethylene naphthalate (PEN). The flexible wiring board 26 is fixed to the sensor substrates 5, 5 by, for example, an anisotropic conductive adhesive (not shown).

[0042] (Process for forming thin line structure) Next, the process of forming the thin line structure 18 will be described with reference to FIG.

[0043] As shown in Fig. 5, catalyst layers 20, 20 are formed in one groove portion 10. Specifically, in the second layer 9 of the sensor substrate 5 in which a plurality of groove portions 10 are formed, a plating primer P is coated onto each groove portion 10 using a bar coater or printing. The plating primer P is made of a solvent containing, for example, an electroless plating catalyst (Pd).

[0044] After the above coating, a process is performed using, for example, a squeegee S to keep the plating primer P accumulated in each of the grooves 10, so that no plating primer P remains on the upper surface of the second layer 9. In this process, instead of using the squeegee S, a rag or the like may be used to wipe off the plating primer P remaining on the upper surface of the second layer 9.

[0045] In the coating, the liquid plating primer P accumulated in each groove 10 is recessed toward the bottom 12 at the approximate center in the width direction of the groove 10 due to surface tension. By further drying for a predetermined time, the solvent component in the plating primer P volatilizes. As this volatilization progresses, the solid component containing palladium (Pd) is absorbed into the side 12 located on both sides of the groove 10. The catalyst particles are concentrated and solidified at the corners 13 and 11 and at the corners 13. As a result, catalyst layers 20 are formed in the grooves 10.

[0046] Next, plating layers 21, 21 are formed in the recessed groove portion 10. Specifically, after the catalyst layers 20, 20 are formed, electroless plating is performed. By performing the electroless plating, plating growth progresses using palladium (Pd) contained in each catalyst layer 20 as a catalyst, and a plating metal (for example Cu) is deposited at positions corresponding to the side portions 11, 11 and the corner portions 13, 13. As a result, plating layers 21, 21 are formed in the groove portions 10. The thickness of each plating layer 21 depends on the width and depth of each groove portion 10 and the content of palladium (Pd) in the plating primer P. Varies depending on quantity.

[0047] Next, the protective layer 22 is formed in the groove portion 10. Specifically, after the plating layers 21, 21 are formed, a thermosetting or ultraviolet-curing adhesive whose main component is a resin material such as an epoxy, acrylic, or urethane resin is filled into the groove portion 10. The adhesive is then solidified by irradiating it with a predetermined amount of heat or ultraviolet light. This forms the protective layer 22 in the groove portion 10.

[0048] In the process of forming the protective layer 22, it is preferable that the adhesive filled in the grooves 10 be approximately flush with the upper surface of the second layer 9, but the adhesive may be in a state of overflowing from the grooves 10. Alternatively, the upper surface of the adhesive filled in the grooves 10 may be lower than the upper surface of the second layer 9.

[0049] [Effects of the embodiment] As described above, in the thin wire structure 18, a pair of thin wires 19, 19 made of a conductive metal material is provided in the groove portion 10 of the sensor substrate 5. The thin wires 19, 19 are formed at positions including the corners 13, 13 of the groove portion 10 and are spaced apart from each other in the width direction of the bottom 12. That is, the thin wire structure 18 is configured so that two thin wires 19, 19 are located in one groove portion 10. With this configuration, the line width of each thin wire 19 formed at a position including the corner 13 of the groove portion 10 can be made smaller than the width dimension of the groove portion 10. For example, the line width of each thin wire 19 can be reduced to a dimension equal to or smaller than half the width dimension of the groove portion 10. That is, the line width of each thin wire 19 is not restricted by the width dimension of the groove portion 10. As a result, even if it is difficult to minimize the width dimension of the groove portion 10 due to manufacturing reasons (e.g., constraints on the manufacturing process and / or limitations in the specifications of the manufacturing equipment), it is possible to achieve thinning of each thin wire 19 to, for example, 1 μm or less. In this way, in the thin wire structure 18 of the present disclosure, the line width of each thin wire 19 can be made small.

[0050] Furthermore, since the above-described thinning can be realized, in the touch sensor 1 using the plurality of thin line structures 18, it is possible to increase the arrangement density of the plurality of thin lines 19 on the sensor substrate 5. This makes it possible to, for example, make the mesh pattern constituting each sensor electrode 15 denser. Furthermore, it is also possible to make the sensor substrate 5 smaller.

[0051] Furthermore, a protective layer 22 for protecting the thin wires 19 is embedded in the groove 10. This protective layer 22 can appropriately protect the thin wires 19 provided in the groove 10 from the outside. In particular, even when the sensor substrate 5 is subjected to an external force such as bending, the protective layer 22 can maintain a tight contact state between the groove 10 and each thin wire 19. This can prevent the thin wires 19 from peeling off from the groove 10. Furthermore, because the protective layer 22 is embedded in the groove 10, there is no need to provide a separate protective layer (not shown) different from the protective layer 22 on the upper surface of the sensor substrate 5 (the upper surface of the second layer 9). This eliminates the need to provide an additional thickness of the sensor substrate 5.

[0052] [Modification of the embodiment] In the above embodiment, the bottom 12 of the groove 10 is formed to be substantially flat in the longitudinal cross section of the sensor electrode 15, but this is not limiting. For example, as shown in Figures 6 and 7, the groove 10 may be formed so that the approximate center of the bottom 12 rises upward (toward the opening of the groove 10) relative to the positions of the corners 13, 13 in the longitudinal cross section of the sensor substrate 5.

[0053] In the groove portion 10 of the first modification shown in Fig. 6, the bottom 12 is formed in an inclined shape that slopes upward from corners 13 located on both the left and right sides of the paper surface of Fig. 6 toward the widthwise center of the bottom 12. In the first modification, the widthwise center of the bottom 12 is formed in an angular shape.

[0054] In the groove portion 10 of the second modification shown in Fig. 7, the widthwise center portion of the bottom portion 12 protrudes upward from positions near the corner portions 13 located on both the left and right sides of the paper surface of Fig. 6. In the second modification, the widthwise center portion of the bottom portion 12 is formed in a gently curved shape.

[0055] In the above-described modified examples 1 and 2, it is easy to form each thin wire 19 at a position including each corner 13 of the recessed groove portion 10. Also, it is easy to arrange the thin wires 19, 19 at intervals from each other in the width direction of the bottom portion 12. As a result, it is easy to maintain the insulation between the thin wires 19, 19.

[0056] [Other embodiments] Although the touch sensor 1 of the above embodiment has a substantially rectangular view area, the present invention is not limited to this. The view area may have a substantially circular or polygonal shape such as a pentagonal shape in plan view.

[0057] In the above embodiment and each modified example, the second layer 9 is located above the first layer 8, but this is not limiting. For example, the second layer 9 may be located below the first layer 8.

[0058] In the above-described embodiments and modifications, two sensor substrates 5, 5 (upper substrate 6 and lower substrate 7) are used, but this is not limiting. That is, a configuration using only one sensor substrate 5 may be used. In such a configuration, a single sensor substrate 5 having second layers 9, 9 formed on both the upper and lower sides of the first layer 8 may be used (not shown). For example, a touch sensor 1 according to another embodiment may be configured such that a plurality of transmitting electrodes 16 and a plurality of first wiring portions 23 are provided on the second layer 9 located below the first layer 8, while a plurality of receiving electrodes 17 and a plurality of second wiring portions 24 are provided on the second layer 9 located above the first layer 8.

[0059] In the above embodiment and each modified example, the sensor substrate 5 has the first layer 8 and the second layer 9, but is not limited to this. For example, as shown in FIG. 8 , the sensor substrate 5 may have only the first layer 8. In such a configuration, the groove portion 10 and the fine line structure 18 may be formed on at least one of the upper and lower surfaces of the first layer 8. Even in such a configuration, the same effects as those of the above embodiment can be achieved.

[0060] In the above embodiment, the transmitting electrodes 16 extend along the longitudinal direction of the sensor substrate 5 shown in Fig. 2, while the receiving electrodes 17 extend along the lateral direction of the sensor substrate 5. However, the present invention is not limited to this. That is, the transmitting electrodes 16 may extend along the lateral direction of the sensor substrate 5, while the receiving electrodes 17 may extend along the longitudinal direction.

[0061] In the above embodiment, the touch sensor 1 is shown in a state in which the cover member 2 and the flexible wiring board 26 are attached to the sensor substrate 5, but this is not limiting. 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 26, etc. are attached to the sensor substrate 5. Furthermore, the concept of the touch sensor 1 according to the present disclosure also includes a configuration in which the above-described multiple sensor electrodes 15 are formed on a long base material (for example, a long hoop-shaped member not shown) in a state before the sensor substrate 5 is formed.

[0062] In the above embodiment and each modified example, the touch sensor 1 to which the thin line structure 18 of the present disclosure is applied has been illustrated, but the present disclosure is not limited thereto. For example, the thin line structure 18 of the present disclosure can be widely applied to technical fields other than touch sensors (e.g., other technical fields such as liquid crystal display devices and antenna devices).

[0063] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure. [Industrial Applicability]

[0064] The present disclosure relates to thin-wire structures. Construction and The present invention is therefore industrially applicable. [Explanation of symbols]

[0065] 1: Touch sensor 2: Cover material 5: Sensor board 6: Upper board 7: Lower board 8: 1st layer 9:Second layer 10: Concave groove part 11: Side 12: Bottom 13: Corner 15: Sensor electrode 16: Transmitting electrode 17: Receiving electrode 18: Thin wire structure 19: Thin line 20: Catalyst layer 21: Plating layer 22:Protective layer

Claims

1. A thin line structure provided on a substrate, At least one bottomed recessed groove is provided on at least one surface of the substrate, a pair of thin wires made of a conductive metal material are provided in the recessed groove; the pair of thin wires are formed at positions including corners of the groove portion, and are spaced apart from each other in the width direction of the bottom portion; The groove portion has a thin-line structure in which the approximate center of the bottom portion is formed so as to rise toward the opening side of the groove portion relative to the position of the corner portion in a vertical cross-sectional view of the substrate.

2. 2. The thin line structure according to claim 1, A thin wire structure in which a protective layer for protecting the pair of thin wires is embedded in the recessed groove.

3. A thin wire structure disposed on a substrate having a groove portion including a first corner portion, a second corner portion, and a bottom portion located between the first corner portion and the second corner portion, a first thin wire located at the first corner portion and made of a conductive metal material; a second thin wire located at the second corner portion and made of a conductive metal material; the first thin wire and the second thin wire are arranged at an interval from each other, In a cross-sectional view, the bottom of the groove portion has a thin-line structure that rises higher toward the opening side of the groove portion than the first corner portion and the second corner portion.

4. A touch sensor comprising the thin line structure according to any one of claims 1 to 3.

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