Conductive member

Abstract

To protect wiring embedded in a first groove part and a second groove part having different groove widths.SOLUTION: The conductive member has a substrate in which a linear first groove 8 and a second groove 9 having a width narrower than that of the first groove 8 are formed on the upper surface. A first conductive layer 32 made of a conductive material is embedded in the first trench portion 8, and a first covering layer 35 is laminated on an upper surface of the first conductive layer 32. A second conductive layer 42 made of a conductive material is embedded in the second trench portion 9, and a second covering layer 45 is laminated on an upper surface of the second conductive layer 42. The film thickness of the first covering layer 35 is larger than the film thickness of the second covering layer 45.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to conductive members. [Background technology]

[0002] 2. Description of the Related Art Conventionally, conductive members applicable to touch sensors are disclosed in Patent Document 1 and Patent Document 2, for example.

[0003] For example, Patent Document 1 discloses a conductive substrate having a metal layer formed on the surface of an insulating base material, an organic layer containing a nitrogen-based organic material formed on the metal layer, and a blackening layer formed on the organic layer. Patent Document 1 discloses an example in which the blackening layer is formed by a dry method such as sputtering.

[0004] Furthermore, Patent Document 2 discloses a transparent conductive film that includes a transparent film having grooves on the surface and conductive portions that exist in the grooves of the transparent film. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 022539 [Patent Document 2] Patent Publication No. 2021-163571 Summary of the Invention [Problem to be solved by the invention]

[0006] Here, when a blackened layer is formed by sputtering as in Patent Document 1, if there are multiple patterns on the same substrate, a blackened layer of a constant thickness is formed on each of the wirings. As shown in Figure 3 of Patent Document 2, the same applies when the wiring surface is convex or concave relative to the surface of the transparent film, and a blackened layer of a constant thickness is formed.

[0007] If this happens, when a blackening layer of a certain thickness is formed on a conductive material and then another protective layer or conductive layer is formed on top of that, the film becomes discontinuous at the end of the groove, which may result in loss of functionality.Furthermore, if the cross-sectional shape of the groove is rectangular, it becomes difficult to form a protective layer or conductive layer on the side surface of the groove, further increasing the risk of loss of functionality.

[0008] Furthermore, when considering filling a conductive layer into grooves of different widths, the wider the groove, the lower the filling rate and the greater the recess from the substrate surface. This results in a problem where the conductive layer is insufficient in thickness for a wide groove, and wiring with a wide wiring width and high importance cannot be adequately protected.

[0009] The present disclosure has been made in consideration of these points, and its purpose is to provide a conductive material having a linearly extending, bottomed groove formed therein that can better protect wiring that is wide and of high importance. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, one aspect of the present disclosure includes a substrate having, on its upper surface, a first groove portion that extends linearly and has a bottom, and a second groove portion that extends linearly and has a bottom and has a width narrower than the width of the first groove portion in a planar view; a first conductive wire including a first conductive layer made of a conductive material embedded in the first groove portion and a first coating layer laminated on the upper surface of the first conductive layer; and a second conductive wire including a second conductive layer made of a conductive material embedded in the second groove portion and a second coating layer laminated on the upper surface of the second conductive layer, wherein the film thickness of the first coating layer is greater than the film thickness of the second coating layer. [Effects of the Invention]

[0011] According to the present disclosure, in a conductive material in which a bottomed groove extending linearly is formed, wiring that is wide and important can be better protected. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is an overall perspective view of the touch sensor. [Figure 2]1 is a plan view schematically illustrating a connection state between a conductive member and a flexible wiring board according to an embodiment of the present disclosure. [Figure 3] 1 is a perspective view showing the configuration of a substrate, a transmitting electrode, a receiving electrode, routing wiring, and connection pads, as viewed from the front surface side of a conductive member. [Figure 4] FIG. 2 is a partially enlarged plan view showing a part of the receiving electrode. [Figure 5] FIG. 2 is a partially enlarged plan view showing a part of a first conductive line constituting a lead wiring. [Figure 6] FIG. 2 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] 7 is an enlarged view of the frame line VII in FIG. 6, and corresponds to the cross-sectional view taken along line VII-VII in FIGS. 4 and 5. FIG. [Figure 8] FIG. 8 is a diagram showing a modification of FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0013] 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.

[0014] 1 shows the configuration of a touch sensor 1 to which a conductive member 4 according to an embodiment of the present disclosure is applied. The touch sensor 1 is a sensor-type input device that can be operated by touch. 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 machines, automated teller machines, watches, etc. In this embodiment, an example is shown in which the touch sensor 1 is rectangular in plan view.

[0015] In the following description, the side on which the operation surface 2a of the cover member 2 described later is located is referred to as the "upper side," and the opposite side is referred to as the "lower side," and the positional relationship of each element is defined by this. For example, in the conductive member 4, the surface facing the lower surface of the cover member 2 is referred to as the "upper surface 5a," and the surface located opposite the cover member 2 is referred to as the "lower surface 5b" (see FIG. 6). For convenience of description, the longitudinal direction of the touch sensor 1 is referred to as the first direction X, and the width direction of the touch sensor 1 is referred to as the second direction Y. The vertical direction, the first direction X, and the second direction Y are perpendicular to each other.

[0016] -Cover material- As shown in FIG. 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 has, for example, a rectangular plate shape in a plan view. The cover member 2 is fixed to the upper surface 5a of the conductive member 4 by an adhesive layer 21 (described later) (see FIG. 6).

[0017] -Conductive materials- 6, the conductive member 4 includes a substrate 5, a first conductive wire 24, and a second conductive wire 25. In this embodiment, as shown in FIG. 2, the conductive member 4 has a rectangular shape in a plan view and is configured to be attachable to the underside of the cover member 2.

[0018] As shown in FIG. 2, the conductive member 4 has a first region R1 and a second region R2. The first region R1 is a visible region of the touch sensor 1. A user of the touch sensor 1 can obtain visual information from a display panel (not shown) disposed on the back side of the touch sensor 1 through the first region R1. The second region R2 is a non-visible region of the touch sensor 1 that is provided to surround the outer periphery of the first region R1. In other words, the second region R2 is configured such that a user of the touch sensor 1 cannot visually recognize the components of the conductive member 4 located in the second region R2 from the outside by providing a decorative portion 3 (see FIGS. 1 and 6).

[0019] 〔substrate〕 As shown in FIG. 7 , the substrate 5 includes a film substrate 6 and a groove-forming layer 7 laminated on the upper side of the film substrate 6. In this embodiment, the substrate 5 has a rectangular shape in a plan view. The substrate 5 is disposed so that the upper surface 5 a faces the lower surface of the cover member 2 via the adhesive layer 21. The shape of the substrate 5 is not limited to a rectangular shape in a plan view, and may be a shape other than a rectangular shape, such as a circular shape, an elliptical shape, or a polygonal shape in a plan view. Although not shown, the groove-forming layer 7 may be laminated on the lower side of the film substrate 6. In this embodiment, the groove-forming layer 7 is formed on both the upper and lower sides of the film substrate 6, and the first conductive wires 24 are also formed in the groove-forming layer 7 (not shown) on the lower side of the film substrate 6. The groove-forming layer 7 may be formed on only one surface of the film substrate 6. In this case, the surface on which the groove-forming layer 7 is formed corresponds to the upper surface of the present disclosure.

[0020] The film substrate 6 is made of a transparent resin material, such as PET (polyethylene terephthalate), polycarbonate, COP (cycloolefin polymer), or COC (cycloolefin copolymer).

[0021] The groove forming layer 7 is a layer for forming the first groove portion 8 and the second groove portion 9. The groove forming layer 7 is made of a resin material having insulating properties and optical transparency. The groove forming layer 7 has a shape-imparting property for forming grooves. The groove forming layer 7 also serves to firmly bond the first adhesive layers 31, 41 (described later) in the grooves to the film substrate 6. The thickness of the groove forming layer 7 is, for example, 2.0 μm to 17.0 μm. Note that the groove forming layer 7 is not shown in FIG. 6.

[0022] [First groove, second groove] The first groove portions 8 extend linearly to form a predetermined pattern on the upper surface of the groove-formed layer 7, i.e., on the upper surface 5a of the substrate 5. As shown in Figures 6 and 7, the first groove portions 8 are formed, for example, in the second region R2, in a bottomed shape recessed in the thickness direction of the substrate 5 (the direction from the groove-formed layer 7 toward the film base 6). In this embodiment, a plurality of first groove portions 8 are formed, and the groove depth dimensions and groove width dimensions of the first groove portions 8 are the same as each other.

[0023] Here, in the present disclosure, "the same size" refers to the same size at the time of design, and also includes a case where the groove depth dimensions of the plurality of first groove portions 8 and the groove width dimensions of the plurality of first groove portions 8 are slightly different from one another due to manufacturing errors, manufacturing variations, etc. In other words, "the same size" includes those that are substantially the same size. The same applies to the second groove portion 9, and "the same size" also includes those that are substantially the same size.

[0024] An example of the predetermined pattern is a pattern in which a plurality of first groove portions 8 are arranged in a linear or ladder shape. FIG. 5 shows an example of a linear pattern of first groove portions 8. The groove depth D1 of the first groove portions 8 is set to, for example, 0.5 μm or more and 10.0 μm or less. More preferably, the groove depth D1 is set to 0.5 μm or more and 2.0 μm or less.

[0025] Similar to the first groove portions 8, the second groove portions 9 extend linearly to form a predetermined pattern on the upper surface of the groove-formed layer 7, i.e., on the upper surface 5a of the substrate 5. The second groove portions 9 are formed, for example, in the first region R1, in a bottomed shape recessed in the thickness direction of the substrate 5 (the direction from the groove-formed layer 7 toward the film base 6). In this embodiment, a plurality of second groove portions 9 are formed, and the groove depth dimensions and groove width dimensions of the second groove portions 9 are the same as each other.

[0026] An example of the predetermined pattern is a mesh pattern in which a plurality of second groove portions 9 are arranged in a mesh pattern, as shown in FIG. 4. The groove depth D2 of the second groove portion 9 is, for example, 0.5 μm or more and 10.0 μm or less. More preferably, the groove depth D1 is 0.5 μm or more and 2.0 μm or less. FIG. 7 shows an example in which the groove depth D1 of the first groove portion 8 and the groove depth D2 of the second groove portion 9 described below are the same depth. However, the groove depth D1 of the first groove portion 8 and the groove depth D2 of the second groove portion 9 may be different from each other. Furthermore, when a plurality of first groove portions 8 are provided, the groove depth D1 of the first groove portions 8 may be different from each other. Similarly, when a plurality of second groove portions 9 are provided, the groove depth D2 of the second groove portions 9 may be different from each other.

[0027] The groove width dimension L2 of the second groove portion 9 is narrower than the groove width dimension L1 of the first groove portion 8. The groove width dimension L1 of the first groove portion 8 is, for example, 6 μm or more and 50 μm or less. More preferably, the groove width dimension L1 of the first groove portion 8 is 7.0 μm or more and 12.0 μm or less. The groove width dimension L2 of the second groove portion 9 is, for example, 0.3 μm or more and 10 μm or less. More preferably, the groove width dimension L2 of the second groove portion 9 is 0.5 μm or more and 3.0 μm or less.

[0028] In this embodiment, as shown in Fig. 7, fillets are formed at the corners between the side and bottom surfaces of each of the first groove portion 8 and the second groove portion 9. However, fillets do not have to be formed at the corners. That is, the bottom surfaces of the first groove portion 8 and / or the second groove portion 9 may be flat or curved (not shown). Furthermore, although not shown, the side surfaces of the first groove portion 8 and / or the second groove portion 9 may be inclined so as to gradually widen from the bottom surfaces toward the openings.

[0029] [First conductive wire] The first conductive wire 24 includes a first conductive layer 32 made of a conductive material embedded in the first groove 8, and a first coating layer 35 laminated on the upper surface of the first conductive layer 32. In other words, the first conductive wire 24, like the first groove 8, forms the routing wiring 13 in a predetermined pattern (for example, a linear pattern or a ladder pattern) in the second region R2. The routing wiring 13 is wiring that connects a connection pad 15, which will be described later, to a transmitting electrode 11 or a receiving electrode 12, which will also be described later. Note that, like the first groove 8, the predetermined pattern may be a mesh pattern or any other pattern shape.

[0030] The line width dimension of the first conductive wire 24 (dimension w1 shown in FIG. 7) is the same as the groove width dimension L1 of the first groove portion 8, and is, for example, 6 μm or more and 50 μm or less. More preferably, the line width dimension w1 of the first conductive wire 24 is 7.0 μm or more and 12.0 μm or less. The line width dimension w1 of the first conductive wire 24 is larger than the line width dimension w2 of the second conductive wire 25, which will be described later. The surface roughness Ra of the first conductive wire 24 is set to, for example, 0.01 μm or more and 0.34 μm or less. As a result, the conductivity reliability of the first conductive wire 24 is more easily ensured.

[0031] The first conductive layer 32 is an element that ensures the conductivity of the first conductive line 24. The reflectance of the first conductive layer 32 for visible light wavelengths is 20% or more and 95% or less. The first conductive layer 32 is composed of a first seed layer 33 and a first main layer 34. The first seed layer 33 and the first main layer 34 are both made of a conductive material. A conductive metal such as copper (Cu) or silver (Ag) is suitable as this conductive material. Alternatively, a transparent conductive material having optical transparency, such as a conductive resin material, indium tin oxide, or tin oxide, may be used instead of the conductive metal. The following description will be given of an example in which copper (Cu) is used as the conductive material.

[0032] In order to ensure adhesion of the first conductive layer 32 to the first groove portion 8, a first adhesion layer 31 may be provided between the first groove portion 8 and the first conductive layer 32. The first adhesion layer 31 is a metal layer made of, for example, a metal nitride containing one or more metals selected from the group consisting of Ti, Al, V, W, Ta, Si, Cr, Ag, Mo, Cu, and Zn, a metal oxide, or a metal oxynitride containing both a metal nitride and a metal oxide. The first adhesion layer 31 is formed in the first groove portion 8 using, for example, a vapor deposition or sputtering technique.

[0033] The first seed layer 33 has the function of increasing the adhesion between the first adhesion layer 31 and the first main layer 34. Specifically, the first seed layer 33 functions as a cathode for depositing a plating solution such as copper (Cu) on the first adhesion layer 31, for example, during electroplating to form the first main layer 34. The first seed layer 33 is deposited as a thin film on the first adhesion layer 31 by, for example, vapor deposition or sputtering. Note that if the first main layer 34 is formed by a method other than electroplating, the first seed layer 33 may not be provided.

[0034] The first main layer 34 is formed by, for example, vapor deposition, sputtering, electroless plating, or electroplating. In this embodiment, the first main layer 34 is laminated on the first seed layer 33 by electroplating. After the electroplating, the first seed layer 33 and the first main layer 34 are integrally formed, and the interface between the first seed layer 33 and the first main layer 34 cannot be distinguished.

[0035] The first covering layer 35 is laminated on the upper surface of the first conductive layer 32 (first main body layer 34). The reflectance of the first covering layer 35 for visible light wavelengths is lower than the reflectance of the first conductive layer 32 for visible light wavelengths. For example, the reflectance of the first covering layer 35 for visible light wavelengths is 20% or more and 65% or less. More preferably, it is 3% or more and 25% or less.

[0036] The film thickness dimension of the first coating layer 35 (reference symbol d1 in FIG. 7) is larger than the film thickness dimension of the second coating layer 45 (reference symbol d2 in FIG. 7), which will be described later. Specifically, the film thickness dimension of the first coating layer 35 (reference symbol d1 in FIG. 7) is, for example, 0.01 μm or more (10 nm or more) and 5 μm or less. For example, when the line width dimension w1 of the first conductive wire 24 is set to 8 μm, the film thickness dimension d1 (average film thickness) of the first coating layer 35 is 0.6 μm (600 nm). Preferably, the lower limit of the film thickness dimension d1 is 0.02 μm (20 nm). More preferably, the lower limit of the film thickness dimension d1 is 0.05 μm (50 nm). Preferably, the upper limit of the film thickness dimension d1 is 3 μm. More preferably, the upper limit of the film thickness dimension d1 is 1 μm.

[0037] The first coating layer 35 may contain a metal that is more base than the first conductive layer 32. Examples of indicators for determining whether a metal is more base include ionization tendency or standard potential. For example, if the metal atoms of the first conductive layer 32 (first main layer 34) are copper (Cu), the base metal atoms (i.e., the constituent atoms of the first coating layer 35) deposited on the copper (Cu) may be one or more elements selected from the group consisting of Al, Zn, Fe, Ni, Sn, and Pb. The metal atoms (i.e., the constituent atoms of the first coating layer 35) deposited on the copper (Cu) are not limited to metals more base than the first conductive layer 32, but may also be noble metals. For example, the constituent atoms of the first coating layer 35 may contain one or more elements selected from the group consisting of Pd, Hg, Ag, Ir, Pt, and Au, in addition to or instead of the above-mentioned base metals. The first coating layer 35 is formed by, for example, vapor deposition, sputtering, electrolytic plating, or electroless plating. In this embodiment, a form is illustrated in which the first coating layer 35 is laminated on the first conductive layer 32 by electroless plating. The composition of the electroless plating solution used in the electroless plating is not particularly limited.

[0038] In this embodiment, an example in which nickel (Ni) is used as the constituent atoms of the first coating layer 35 is shown.

[0039] [Second conductive wire] The second conductive wire 25 includes a second conductive layer 42 made of a conductive material embedded in the second groove 9 and a second coating layer 45 laminated on the upper surface of the second conductive layer 42. In other words, the second conductive wire 25 constitutes the receiving electrode 12 of the touch sensor 1 in a predetermined pattern (e.g., a mesh pattern) in the first region R1. Although not shown, the transmitting electrode 11 may be formed by forming second grooves 9 in a predetermined pattern (e.g., a mesh pattern) on the lower surface 5b of the substrate 5 and embedding the second conductive wires 25 in the second grooves 9. When the predetermined pattern is a mesh pattern, for example, the second conductive wires 25 are arranged at predetermined intervals and so as to intersect with each other. That is, the second conductive wires 25 extend obliquely with respect to both the first direction X and the second direction Y at predetermined intervals, forming a mesh structure in which diamond-shaped cells are regularly arranged. The predetermined pattern is not limited to a mesh pattern and may be, for example, a ladder pattern or other pattern shape.

[0040] The line width dimension (dimension w2 shown in FIG. 7 ) of the second conductive wire 25 is the same as the groove width dimension L2 of the second groove portion 9, and is, for example, 0.3 μm to 10 μm. More preferably, the line width dimension w2 of the second conductive wire 25 is 0.5 μm to 3.0 μm. The surface roughness Rb of the second conductive wire 25 is, for example, 0.01 μm to 0.34 μm. This reduces reflection (specular reflection) of external light, such as sunlight or illumination light, on the surface of the second conductive wire 25. As a result, when a user views the device from the operation surface 2a side, the second conductive wires 25 constituting the transmitting electrode 11 and the receiving electrode 12 are difficult to see, preventing so-called "line visibility." Furthermore, setting the surface roughness Rb of the second conductive wire 25 within the above-described range facilitates ensuring the reliability of conduction of the second conductive wire 25.

[0041] The second conductive layer 42 is an element that ensures the conductivity of the second conductive line 25. The second conductive layer 42 is embedded in the second groove portion 9. The reflectance of the second conductive layer 42 for visible light wavelengths is 20% or more and 95% or less. The second conductive layer 42 is composed of a second seed layer 43 and a second main layer 44. The main configuration of the second conductive layer 42 is similar to that of the first seed layer 33 and the first main layer 34 described above. For example, the second seed layer 43 and the second main layer 44 are both made of a conductive material. The second seed layer 43 and the second main layer 44 can be formed in the same manner, for example, using the same conductive material as the first seed layer 33 and the first main layer 34. In the following explanation, an example in which copper (Cu) is used as the conductive material will be shown.

[0042] In addition, in order to ensure adhesion of the second conductive layer 42 to the second groove portion 9, a second adhesion layer 41 may be provided between the second groove portion 9 and the second conductive layer 42. The second adhesion layer 41 has the function of making the second conductive lines 25 less visible when a user looks from the operation surface 2a of the touch sensor 1. The second adhesion layer 41 is, for example, a metal layer made of the same compound as the first adhesion layer 31. The second adhesion layer 41 is formed in the second groove portion 9 by, for example, vapor deposition or sputtering.

[0043] The second covering layer 45 is laminated on the upper surface of the second conductive layer 42 (second main body layer 44). The second covering layer 45 has the function of making the second conductive wires 25 less visible when a user of the touch sensor 1 views the operation surface 2a. The reflectance of the second covering layer 45 for visible light wavelengths is lower than the reflectance of the second conductive layer 42 for visible light wavelengths. For example, the reflectance of the second covering layer 45 for visible light wavelengths is 20% or more and 65% or less. More preferably, it is 3% or more and 25% or less.

[0044] The film thickness dimension (reference symbol d2 shown in FIG. 7) of the second coating layer 45 is, for example, 0.01 μm or more and 0.5 μm or less (10 nm or more and 500 nm or less). For example, when the line width dimension w2 of the second conductive wire 25 is set to 2 μm, the film thickness dimension d2 (average film thickness) of the second coating layer 45 is 0.12 μm (120 nm). Preferably, the lower limit of the film thickness dimension d2 is 0.02 μm (20 nm). More preferably, the lower limit of the film thickness dimension d2 is 0.025 μm (25 nm). Preferably, the upper limit of the film thickness dimension d2 is 0.2 μm (200 nm). More preferably, the upper limit of the film thickness dimension d2 is 0.1 μm (100 nm). Even more preferably, the upper limit of the film thickness dimension d2 is 0.05 μm (50 nm).

[0045] The second coating layer 45 may contain a metal that is more base than the second conductive layer 42. For example, when the metal atoms of the second conductive layer 42 (second main layer 44) are copper (Cu), the metal atoms (i.e., the constituent atoms of the second coating layer 45) deposited on the copper (Cu) may be the same elements as those in the first coating layer. The method for forming the second coating layer 45 and an example in which nickel (Ni) is used as the second coating layer 45 are the same as those in the first coating layer 35 described above.

[0046] [Protective layer] As shown in FIG. 6 , the conductive member 4 may include a protective layer 21 on the upper surface 5a of the substrate 5 to protect the first conductive wires 24 and the second conductive wires 25. Similarly, when the first conductive wires 24 and the second conductive wires 25 are formed on the lower surface 5b of the substrate 5, the conductive member 4 may include a protective layer 22 to protect the first conductive wires 24 and the second conductive wires 25. The protective layer 21 is formed on the upper surface 5a so as to cover the first region R1 and the second region R2. Similarly, when the protective layer 22 is provided on the lower surface 5b, the protective layer 21 is formed so as to cover the first region R1 and the second region R2. In the following description, when there is no need to distinguish between the protective layer 21 and the protective layer 22, they may be referred to collectively as "protective layer 20."

[0047] The protective layer 20 is made of, for example, an optically transparent optical clear adhesive (OCA). The thickness of the protective layer 20 is, for example, 25 μm or more and 250 μm or less. The protective layer 21 is provided between the cover member 2 and the substrate 5, and the cover member 2 and the substrate 5 are bonded to each other by the protective layer 21. The protective layer 22 is provided between the substrate 5 and the protective film 23. The protective film 23 is a film material for protecting the transmitting electrodes 11 and the routing wiring 13 located mainly on the back surface 5b side. Examples of this film material include resin materials such as PET (polyethylene terephthalate), polycarbonate, COP (cycloolefin polymer), COC (cycloolefin copolymer), and PE. The provision of the protective layer 21 improves the smoothness of the surface of the conductive member 4. This improves adhesion between the protective layer and / or conductive layer when another protective layer and / or conductive layer is formed on the upper surface of the protective layer 21. The same effect can be achieved with the protective layer 22.

[0048] (transmitting and receiving electrodes) In this embodiment, the touch sensor 1 is of a capacitance type and includes a transmitting electrode 11 and a receiving electrode 12. The transmitting electrode 11 and the receiving electrode 12 are arranged in the first region R1. As described above, the transmitting electrode 11 and the receiving electrode 12 are formed of the second conductive wire 25. The touch sensor 1 detects a touch operation by a user's finger F (i.e., a detection object grounded to ground (GND)) that touches the operation surface 2a, based on a change in capacitance.

[0049] As shown in Figures 3 and 6, the transmitting electrodes 11 are provided on the lower surface 5b and extend in a strip shape along the first direction X in a plan view. The transmitting electrodes 11 are also arranged at intervals in the second direction Y. The transmitting electrodes 11 are connected to a drive circuit (not shown) via a flexible wiring board 16 (see Figure 1). The transmitting electrodes 11 radiate an electric field to the surroundings via this drive circuit. The receiving electrodes 12 are provided on the upper surface 5a and extend in a strip shape along the second direction Y in a plan view. The receiving electrodes 12 are also arranged at intervals in the first direction X. The transmitting electrode and receiving electrode are insulated from each other by the substrate 5 interposed between them. The receiving electrode 12 is connected to a detection circuit (not shown) via the flexible wiring board 16 and receives the electric field radiated from the transmitting electrode 11.

[0050] [Routing wiring] The touch sensor 1 includes the lead wiring 13. The lead wiring 13 is disposed on each of the upper surface 5a and the lower surface 5b, and is composed of the first conductive wire 24. As described above, the lead wiring 13 is disposed in the second region R2 so as to overlap with the decorative portion 3 in a plan view.

[0051] The routing wiring 13 electrically connects the transmitting electrode 11 and the receiving electrode 12 to an external circuit (not shown). Specifically, the routing wiring 13 connects the transmitting electrode 11 or the receiving electrode 12 to the connection pad 15. The connection pad 15 is electrically connected to the front-side connection portion 18 and the back-side connection portion 19 of the flexible wiring board 16. The connection pad 15 is formed by, for example, a second conductive wire 25.

[0052] (flexible wiring board) 1 and 2, touch sensor 1 includes flexible wiring board 16. Flexible wiring board 16 has main body portion 17, front side connection portion 18, and back side connection portion 19.

[0053] The main body 17 is flexible and configured so that its electrical characteristics do not change even when deformed. The main body 17 is made of a flexible insulating film such as polyimide (PI), polyethylene terephthalate (PET), or polyethylene naphthalate (PEN).

[0054] 2, the front-side connection portion 18 and the back-side connection portion 19 are formed integrally with the main body portion 17. Furthermore, the front-side connection portion 18 and the back-side connection portion 19 branch out in two directions from one end of the main body portion 17. The front-side connection portion 18 is, for example, fixed to the peripheral edge of the upper surface 5a of the substrate 5, and the back-side connection portion 19 is fixed to the peripheral edge of the lower surface 5b of the substrate 5. The front-side connection portion 18 and the back-side connection portion 19 are electrically connected to the connection pads 15 on the upper surface 5a and the lower surface 5b of the substrate 5, respectively.

[0055] (Film thickness of first coating layer and second coating layer) As described above, this embodiment employs electroless Ni plating (reduction plating). In the electroless Ni plating according to this embodiment, the first coating layer and the second coating layer are formed by plating using an electroless Ni plating bath containing nickel sulfate as a water-soluble nickel salt. Furthermore, sodium hypophosphite, for example, is used as a reducing agent. More specifically, nickel (Ni) is precipitated using palladium (Pd) as a catalyst, and subsequently nickel (Ni) is precipitated using nickel (Ni) as a catalyst.

[0056] Here, the number of Ni ions per unit volume in the electroless plating solution is constant. Therefore, the amount of catalyst attached varies depending on the line width of the first conductive layer 32 (dimension w1 shown in FIG. 7 ) and the line width of the second conductive layer 42 (dimension w2 shown in FIG. 7 ). In this example, a larger number of Pd / Ni catalysts are attached to the first conductive wire 24, which has a relatively larger wiring width. This increases the anode reaction, resulting in a larger number of emitted electrons and a larger amount of Ni deposited. In other words, the larger the wiring width, the thicker the film thickness of the base metal (Ni). This results in a thicker first coating layer 35 being formed on the top surface of the first conductive wire 24, which has a relatively larger wiring width, thereby improving its ability to shield from the external environment. As a result, the protection performance of the first conductive wire 24, which has a relatively larger wiring width (e.g., the wiring 13), can be improved.

[0057] [Other embodiments] 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.

[0058] For example, in addition to or instead of the protective layer 20 of the above embodiment, a metal layer 50 may be provided on the upper surface 5a of the substrate 5 so as to cover the upper surfaces of the first covering layer 35 and the second covering layer 45. This can increase and improve the smoothness of the surface of the conductive member 4, similar to the case where the protective layer 20 is provided. Note that the protective layer 20 and the metal layer 50 are not essential, and the protective layer 20 and the metal layer 50 do not have to be provided. In this case, for example, it is preferable to omit the protective layer 20 (protective layer 21 and / or protective layer 22) from the configuration of FIG. 6.

[0059] For example, as shown in FIG. 8 , a first recess 37 may be formed on the upper surface of the first conductive layer 32, and a second recess 47 may be formed on the upper surface of the second conductive layer 42. For example, the depth of the first recess 37 may be greater than the depth of the second recess 47. A first coating layer 35 may be laminated on the upper surface of the first conductive layer 32. Similarly, a second coating layer 45 may be provided on the upper surface of the second conductive layer 42. In this case, the thickness d1 of the first coating layer 35 is greater than the thickness d2 of the second coating layer 45. The configuration shown in FIG. 8 increases the contact area between the first coating layer 35 and the second coating layer 45 and the protective layer 20. This improves the corrosion protection performance of the first conductive wire 24 and the second conductive wire 25. Furthermore, the first coating layer 35 complements the depression of the first recess 37, thereby reducing unevenness on the substrate. Similarly, the second coating layer 45 complements the depression of the second recess 47, thereby reducing unevenness on the upper surface 5 a of the substrate 5. This reduces the risk of functional loss due to discontinuity in the protective layer 20 and the metal layer 50 when the protective layer 20 and the metal layer 50 are formed on the upper surface of the substrate 5.

[0060] For example, in the above embodiment, the touch sensor 1 to which the conductive member 4 according to the embodiment of the present disclosure is applied is illustrated, but the present disclosure is not limited thereto. For example, the conductive member 4 according to the embodiment of the present disclosure can be widely applied to technical fields other than the touch sensor 1 (for example, various technical fields such as liquid crystal display devices, organic electroluminescence display devices (OLEDs), micro LED display devices, solar cell devices, heater devices, antenna devices, and electromagnetic wave shielding sheets).

[0061] In the conductive member 4 according to the above embodiment, the first conductive wires 24 and the second conductive wires 25 are formed on both surfaces (upper surface 5a and lower surface 5b) of the substrate 5, but this is not limiting. For example, the first conductive wires 24 and the second conductive wires 25 may be formed only on the upper surface 5a of the substrate 5. Furthermore, in the conductive member 4 according to the above embodiment, a single substrate 5 is used, but a laminated substrate (not shown) in which two base materials are bonded together may also be used.

[0062] In the conductive member 4 according to the above embodiment, the groove-forming layer 7 is provided on the film substrate 6, but the conductive member 4 is not limited to this. For example, the conductive member 4 may be configured without the groove-forming layer 7, that is, configured with only the film substrate 6. In such a configuration, for example, the first groove portion 8 and the second groove portion 9 are formed directly on the surface of the film substrate 6.

[0063] In the above embodiment, when a plurality of first groove portions 8 are provided, the groove width dimension L1 of the first groove portions 8 is the same. However, this is not limited to this. For example, the groove width dimension L1 of the first groove portions 8 may be different from one another within the numerical range described in the above embodiment. With such a configuration, the line widths of the first conductive lines 24 differ depending on the first groove portion 8. Furthermore, a conductive member 4 having a configuration in which the line widths of the first conductive lines 24 differ from one another may be applied to technical fields other than the touch sensor 1 described above. Similarly, in the above embodiment, the groove width dimension L2 of the second groove portions 9 is the same. However, this is not limited to this. For example, the groove width dimension L2 of the second groove portions 9 may be different from one another within the numerical range described in the above embodiment. With such a configuration, the line widths of the second conductive lines 25 differ depending on the second groove portion 9. Furthermore, a conductive member 4 having a configuration in which the line widths of the second conductive lines 25 differ from one another may be applied to technical fields other than the touch sensor 1 described above.

[0064] In the conductive member 4 according to the above embodiment, the first adhesive layer 31 is formed in the first groove portion 8, and the second adhesive layer 41 is formed in the second groove portion 9, but the present invention is not limited to this. That is, the first conductive layer 32 may be formed directly on the first groove portion 8, and the second conductive layer 42 may be formed directly on the second groove portion 9, without providing the first adhesive layer 31 and the second adhesive layer 41.

[0065] <Summary> A conductive member 4 according to one embodiment of the present disclosure includes a substrate 5, a first conductive wire 24, and a second conductive wire 25. The substrate 5 has, on its upper surface, a first groove 8 that extends linearly and has a bottom, and a second groove 9 that also extends linearly and has a bottom and a width narrower than that of the first groove 8 in a plan view. The first conductive wire 24 includes a first conductive layer 32 made of a conductive material embedded in the first groove 8, and a first coating layer 35 laminated on the upper surface of the first conductive layer 32. The second conductive wire 25 includes a second conductive layer 42 made of a conductive material embedded in the second groove 9, and a second coating layer 45 laminated on the upper surface of the second conductive layer 42. The thickness of the first coating layer 35 is greater than the thickness of the second coating layer 45.

[0066] According to the above embodiment, for conductive wires of different widths, the first conductive wire 24 with a wider wiring width has a thicker coating layer formed thereon than the second conductive wire 25 with a narrower wiring width. The thicker the coating layer formed, the better the blocking performance from the external environment. In other words, by adopting the configuration of the above embodiment, the first conductive wire 24 with a wider wiring width and higher importance can be better protected from the external environment.

[0067] In the above embodiment, the reflectance of first coating layer 35 for visible light wavelengths may be lower than the reflectance of first conductive layer 32 for visible light wavelengths. Similarly, the reflectance of second coating layer 45 for visible light wavelengths may be lower than the reflectance of second conductive layer 42 for visible light wavelengths. This makes first conductive wires 24 and second conductive wires 25 less visible when viewed from the top surface side.

[0068] In the above embodiment, the first coating layer 35 may contain a metal that is more base than the first conductive layer 32. Similarly, the second coating layer 45 may contain a metal that is more base than the second conductive layer 42. This can improve the barrier performance against corrosion when attacked by acid or the like. In other words, the protective performance of the first conductive layer 32 of the first conductive wire 24 and the second conductive layer 42 of the second conductive wire 25 can be further improved.

[0069] In the above embodiment, a first recess 37 may be formed on the upper surface of the first conductive layer 32, and a second recess 47 may be formed on the upper surface of the second conductive layer 42. In this case, the depth of the first recess 37 may be greater than the depth of the second recess 47. With this configuration, the area of ​​the upper surfaces of the first conductive layer 32 and the second conductive layer 42 increases, thereby increasing the contact area between the first coating layer 35 and the second coating layer 45 and the laminated material thereon (e.g., the protective layer 20 or the metal layer 50). This improves the corrosion protection performance of the first conductive wire 24 and the second conductive wire 25.

[0070] In the above embodiment, the upper surface 5a of the substrate 5 may further include a protective layer 20 that covers the upper surfaces of the first coating layer 35 and the second coating layer 45. Similarly, in the above embodiment, the upper surface 5a of the substrate 5 may further include a metal layer 50 that covers the upper surfaces of the first coating layer 35 and the second coating layer 45. By providing the protective layer 20 and / or the metal layer 50, the smoothness of the upper surface of the conductive member 4 is increased, and when another protective layer and / or conductive layer is further formed on the upper surface of the protective layer 20 and / or the metal layer 50, adhesion with the protective layer and / or conductive layer can be improved.

[0071] In the above embodiment, the thickness d1 of the first coating layer 35 may be 0.01 μm or more and 5 μm or less, and the thickness d2 of the second coating layer 45 may be 0.001 μm or more and 1 μm or less. Setting the thickness dimensions d1 and d2 within this range can improve the visibility of the first region R1 and stabilize the electrical connection state of the first conductive wire 24 in the second region R2. [Industrial Applicability]

[0072] The present disclosure is industrially applicable to a conductive member that can be applied to a touch sensor or the like. [Explanation of symbols]

[0073] 4 Conductive materials 5. Substrate 8 First groove 9 Second groove 20 protective layer 24 First conductive wire 25 Second conductive wire 32 First conductive layer 35 First coating layer 37 First recess 42 Second conductive layer 45 Second coating layer 47 Second recess 50 metal layer

Claims

1. a substrate having, on its upper surface, formed thereon, a first groove portion that extends linearly and has a bottom, and a second groove portion that also extends linearly and has a bottom and has a width narrower than that of the first groove portion in a plan view; a first conductive wire including a first conductive layer made of a conductive material embedded in the first groove portion and a first coating layer laminated on an upper surface of the first conductive layer; a second conductive wire including a second conductive layer made of a conductive material and embedded in the second groove, and a second coating layer laminated on an upper surface of the second conductive layer; A conductive member, wherein the thickness of the first coating layer is greater than the thickness of the second coating layer.

2. The conductive member according to claim 1 , the reflectance of the first coating layer at visible light wavelengths is lower than the reflectance of the first conductive layer at visible light wavelengths; A conductive member, wherein the reflectance of the second coating layer for visible light wavelengths is lower than the reflectance of the second conductive layer for visible light wavelengths.

3. The conductive member according to claim 1 , the first coating layer contains a metal that is less noble than the first conductive layer; The conductive member, wherein the second coating layer contains a metal that is more base than the second conductive layer.

4. The conductive member according to claim 1 , a first recess formed in an upper surface of the first conductive layer; a second recess is formed in an upper surface of the second conductive layer; The conductive member, wherein the depth of the first recess is greater than the depth of the second recess.

5. The conductive member according to claim 1 , The conductive member further comprises a protective layer on the upper surface of the substrate, the protective layer covering the upper surfaces of the first coating layer and the second coating layer.

6. The conductive member according to claim 1 , The conductive member further comprises a metal layer on the upper surface of the substrate, the metal layer covering the upper surfaces of the first coating layer and the second coating layer.

7. The conductive member according to claim 1 , The thickness of the first coating layer is 0.01 μm or more and 5 μm or less, The conductive member has a film thickness of the second coating layer of 0.01 μm or more and 0.5 μm or less.

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