Electrically conductive member

Abstract

In an electrically conductive member (1), the electrical conductivity of a third electrically conductive layer (55) is lower than the electrical conductivity of a first electrically conductive layer (33). The third electrically conductive layer (55) includes a first protruding portion (58a) and a second protruding portion (58b). Each of the first protruding portion (58a) and the second protruding portion (58b) is positioned on an upper surface of the third electrically conductive layer (55) and protrudes upward. Each of the first protruding portion (58a) and the second protruding portion (58b) is closer to a side portion of a second groove portion (8) than a central portion of the upper surface of the third electrically conductive layer (55). The second protruding portion (58b) is positioned on the opposite side to the first protruding portion (58a) with respect to the central portion of the upper surface of the third electrically conductive layer (55).

Description

Conductive material

[0001] The present disclosure relates to conductive members.

[0002] 2. Description of the Related Art Conventionally, a conductive member applicable to a touch sensor, for example, is known from Japanese Patent Application Laid-Open No. 2003-149999.

[0003] Patent Document 1 discloses a conductive member applicable to a touch sensor. The conductive member includes a substrate and a flexible wiring board. The substrate is provided with a plurality of sensor electrodes (a plurality of first electrodes and a plurality of second electrodes) and a plurality of wiring portions (a plurality of first wiring portions and a plurality of second wiring portions). Both the sensor electrodes and the wiring portions are composed of a plurality of conductive wires (a plurality of thin wires). The conductive wires include a conductive layer embedded in a groove formed in the substrate.

[0004] WO2021 / 131319 publication

[0005] In the conductive member of Patent Document 1, the flexible wiring board is configured as a separate body from the substrate. The substrate and the flexible wiring board are fixed to each other with an anisotropic conductive adhesive. This fixed state electrically connects multiple wiring portions provided on the substrate and terminal portions of the flexible wiring board via the anisotropic conductive adhesive. As a result, the multiple sensor electrodes are electrically connected to the drive circuit and detection circuit of the external device via the multiple wiring portions and the flexible wiring board. In other words, in the touch sensor using the conductive member of Patent Document 1, the flexible wiring board ensures stable connection between the multiple sensor electrodes and the drive circuit and detection circuit of the external device.

[0006] In contrast, if multiple wiring sections are connected to an external device without using a flexible wiring board, the conductive wires constituting each wiring section are directly connected to, for example, a connector of the external device, and the lower part of the connector of the external device is generally formed in a hemispherical shape that curves downward.

[0007] As described above, the conductive wire disclosed in Patent Document 1 is composed of a conductive layer embedded in a groove in a substrate. Furthermore, most of the upper surface of the conductive layer (more than half of the upper surface) is flush with the upper surface of the substrate (the surface of the first groove-forming layer) (see, for example, FIG. 11 of Patent Document 1). With this configuration, even when attempting to connect the conductive wire to a connector of an external device, the contact area between the upper surface of the conductive layer embedded in the groove and the lower part of the connector (the aforementioned hemispherical portion) is reduced. Therefore, the conductive member disclosed in Patent Document 1 has a problem in that even when attempting to connect multiple wiring portions to an external device without using a flexible wiring board, it is difficult to ensure stable conduction between the multiple wiring portions and the external device.

[0008] The present disclosure has been made in view of the above points, and its purpose is to ensure stable conduction between conductive lines provided on a substrate and an external device.

[0009] To achieve the above object, a conductive member according to one embodiment of the present disclosure includes a transparent main body portion having a first groove formed on its upper surface, a connection portion integrally formed with the main body portion and having a second groove formed on its upper surface, a first conductive wire disposed in the first groove of the main body portion, and a second conductive wire disposed in the second groove of the connection portion. The first conductive wire includes a first conductive layer including a conductive metal embedded in the first groove of the main body portion, and a first blackened layer stacked above the first conductive layer. The second conductive wire includes a second conductive layer including a conductive metal embedded in the second groove of the connection portion, a second blackened layer stacked above the second conductive layer, and a third conductive layer including a conductive metal stacked above the second blackened layer. The conductivity of the third conductive layer is lower than that of the first conductive layer. The third conductive layer includes a first protrusion located on the upper surface of the third conductive layer and protruding upward, and a second protrusion located on the upper surface of the third conductive layer and protruding upward. The first protrusion is closer to a side of the second groove than to a center of the upper surface of the third conductive layer in a cross-sectional view. The second protrusion is closer to a side of the second groove than to a center of the upper surface of the third conductive layer in a cross-sectional view. The second protrusion is located on the opposite side of the center of the upper surface of the third conductive layer from the first protrusion in a cross-sectional view.

[0010] According to the present disclosure, it is possible to ensure stable conduction between the second conductive wire provided on the substrate and the external device.

[0011] FIG. 1 is an overall perspective view of a touch sensor employing a conductive member. FIG. 2 is a cross-sectional view (schematic diagram) taken along line II-II in FIG. 1. FIG. 3 is a diagram schematically illustrating the configuration of a substrate when the conductive member is viewed from the first surface side. FIG. 4 is a perspective view schematically illustrating the conductive member when viewed from the first surface side. FIG. 5 is a schematic diagram illustrating a transmitting electrode, a first wiring section, and a first ground section when viewed from the second surface side of the substrate. FIG. 6 is a schematic diagram illustrating a receiving electrode, a second wiring section, and a second ground section when viewed from the first surface side of the substrate. FIG. 7 is a partial enlarged view of section VII shown in FIG. 4. FIG. 8 is a diagram schematically illustrating the configuration of a mesh pattern in a sensor electrode. FIG. 9 is a cross-sectional view schematically illustrating the cross-section of a first conductive wire constituting a sensor electrode. FIG. 10 is a partial enlarged view of section X shown in FIG. 9. FIG. 11 is a cross-sectional view schematically illustrating the cross-section of a first conductive wire constituting a wiring section. FIG. 12 is a plan view and a side view showing an enlarged connection portion of the substrate. FIG. 13 is a cross-sectional view schematically illustrating the cross-section of a second conductive wire. Fig. 14 is a partial enlarged view of part XIV shown in Fig. 13. Fig. 15 is a diagram schematically showing a board and a connector of an external device. Fig. 16 is a partial enlarged view schematically showing a state when the lower part of the connector shown in Fig. 15 is brought into contact with the second conductive wire.

[0012] 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.

[0013] 1 shows a touch sensor 100 to which a conductive member 1 (see FIGS. 1 to 6) according to an embodiment of the present disclosure is applied. The touch sensor 100 is configured with a plurality of sensor electrodes provided on the conductive member 1, a plurality of wiring portions, first and second ground portions 23, 24, and a connection terminal portion 40. The plurality of sensor electrodes, the plurality of wiring portions, the first and second ground portions 23, 24, and the connection terminal portion 40 will be described later.

[0014] (Touch Sensor) The touch sensor 100 is a capacitance-type sensor-type input device that is applied to, for example, a display 102 (see FIG. 2 ). The touch sensor 100 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, and the like.

[0015] In the following description, the side on which an operation surface 101b (see FIGS. 1 and 2) of a cover member 101, which will be described later, is located will be referred to as the "upper side" of the touch sensor 100, and the opposite side will be referred to as the "lower side" of the touch sensor 100, and the positional relationship of each element constituting the touch sensor 100 will be defined accordingly. Furthermore, in the embodiment of the present disclosure, for convenience of description, the direction from the left side of the paper to the right side of the paper in FIG. 3 will be defined as the "first direction X," and the direction from the bottom side of the paper to the top side of the paper in FIG. 3 will be defined as the "second direction Y."

[0016] 1 and 2, the touch sensor 100 includes a light-transmitting cover member 101. The cover member 101 is made of, for example, a cover glass or a plastic cover lens. The cover member 101 is formed, for example, in the shape of a rectangular plate in a plan view. The cover member 101 is fixed to a substrate 2, which will be described later.

[0017] A substantially frame-shaped decorative portion 101a is formed on the periphery of the underside of the cover member 101 by screen printing or the like and is dark in color, such as black. The rectangular area inside this decorative portion 101a is a light-transmitting view area. That is, the user can obtain visual information from the display 102 disposed below the touch sensor 100 through this view area. The upper surface of the cover member 101 in the view area is configured as an operation surface 101b that comes into contact with the user's fingers or the like during a touch operation.

[0018] (Conductive Member) The conductive member 1 is attached to the underside of the cover member 101 (see FIG. 2 ). In this embodiment, the conductive member 1 includes a substrate 2, a protective layer 3, a plurality of first conductive wires 10, a plurality of second conductive wires 50, and a reinforcing portion 60.

[0019] 3, the conductive member 1 is provided with a main body region A1 and a connection region A2. The main body region A1 and the connection region A2 are continuous with each other in a plan view. The main body region A1 includes an active area A3 and a non-active area A4.

[0020] A plurality of first conductive wires 10 (see FIGS. 2 and 12) are arranged in the main body region A1. Specifically, in this embodiment, elements (a plurality of sensor electrodes, a plurality of wiring portions, a first ground portion 23, and a second ground portion 24) formed by the plurality of first conductive wires 10 are arranged in the main body region A1 (see FIGS. 4 to 7). Details of the first conductive wires 10 will be described later.

[0021] A plurality of second conductive wires 50 (see FIG. 12) are arranged in the connection region A2. Specifically, in this embodiment, a connection terminal portion 40 constituted by a plurality of second conductive wires 50 is arranged in the connection region A2 (see FIG. 12). Details of the second conductive wires 50 will be described later.

[0022] 2, the substrate 2 has a first surface 2a and a second surface 2b. The first surface 2a faces the lower surface of the cover member 101 with the protective layer 3 sandwiched therebetween. The second surface 2b faces the display 102 with the protective layer 3 (described later) sandwiched therebetween.

[0023] 3, the substrate 2 has a main body portion 4 and a connection portion 5. The main body portion 4 and the connection portion 5 are integrally formed.

[0024] The main body 4 is transparent. In contrast, a non-transparent protective material (such as a PI film) (not shown) is laminated on the connection portion 5 (for example, on the upper surface of the connection portion 5). Therefore, the connection portion 5 is non-transparent. The protective material of the connection portion 5 may be the same as the protective layer of the main body 4. In this case, the protective layer of the connection portion 5 is transparent.

[0025] The main body 4 is formed in a substantially rectangular shape in a plan view. Specifically, the main body 4 in this embodiment is formed in a substantially rectangular shape with long sides extending in the first direction X and short sides extending in the second direction Y.

[0026] The main body portion 4 includes a main body region A1 in a plan view, and the connection portion 5 includes a connection region A2 in a plan view.

[0027] As shown in FIG. 9, the substrate 2 has a base layer 6 and an insulating layer 7 .

[0028] The base layer 6 is made of a transparent resin material, such as polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin polymer (COP), or cycloolefin copolymer (COC).

[0029] The insulating layer 7 is laminated on the upper surface of the base material layer 6. Although not shown, in this embodiment, the insulating layer 7 is also laminated on the lower surface of the base material layer 6.

[0030] The insulating layer 7 is made of a resin material having insulating properties and optical transparency. The thickness of the insulating layer 7 is set to, for example, 2.0 μm or more and 17.0 μm or less in order to ensure flexibility.

[0031] 9 and 11 , the substrate 2 includes a plurality of first groove portions 8. The plurality of first groove portions 8 are arranged in the main body portion 4 of the substrate 2. Specifically, the plurality of first groove portions 8 are arranged in positions of the substrate 2 that correspond to the main body region A1.

[0032] In this embodiment, the plurality of first grooves 8 are provided on both the upper surface and the lower surface of the insulating layer 7. Each of the first grooves 8 provided on the upper surface of the insulating layer 7 is formed with a bottom that is recessed downward from the upper surface of the insulating layer 7. Furthermore, although not shown, each of the first grooves 8 provided in the insulating layer 7 located below the base layer 6 is formed with a bottom that is recessed upward from the lower surface of the insulating layer 7.

[0033] The depth of each first groove 8 is smaller than the thickness of the insulating layer 7. The depth of each first groove 8 is set to, for example, not less than 0.5 μm and not more than 10.0 μm.

[0034] The groove width of the first groove portion 8 is equal to or greater than 0.3 μm and smaller than 30.0 μm. In this embodiment, the plurality of first groove portions 8 are formed so that the groove widths thereof are different from one another. Specifically, the groove width dimension of the first groove portion 8 illustrated in FIG. 9 is smaller than the width dimension of the first groove portion 8 illustrated in FIG. 11.

[0035] In the first groove portion 8 illustrated in Fig. 9, the groove width preferably has a lower limit of 0.5 µm or more, and an upper limit of 3.0 µm or less.

[0036] In the first groove portion 8 illustrated in Fig. 11, the preferred lower limit of the groove width is 8.0 µm or more. On the other hand, in the first groove portion 8 illustrated in Fig. 11, the preferred upper limit of the groove width is 12.0 µm or less.

[0037] (Second Groove Portion) The substrate 2 includes a plurality of second groove portions 9 (see FIG. 13 ). The plurality of second groove portions 9 are arranged in the connection portion 5 of the substrate 2. Specifically, the plurality of second groove portions 9 are arranged in positions of the substrate 2 corresponding to the connection region A2 (see FIGS. 12 and 13 ).

[0038] 13 , in this embodiment, a plurality of second grooves 9 are provided on the upper surface of the insulating layer 7 in the connection portion 5. The second grooves 9 are formed in a bottomed shape that is recessed from the upper surface of the insulating layer 7 downward toward the substrate 2.

[0039] The depth of the second groove 9 is smaller than the thickness of the insulating layer 7. The depth of the second groove 9 is set to, for example, not less than 0.5 μm and not more than 10.0 μm.

[0040] The groove width of the second groove portion 9 (dimension W2 shown in FIG. 13) is larger than the groove width of the first groove portion 8 (dimension W1 shown in FIGS. 9 and 11). Specifically, the groove width (dimension W2) of the second groove portion 9 is set to be larger than 0.3 μm and equal to or smaller than 30 μm.

[0041] 13, the preferred lower limit of the dimension W2 is 8.0 μm or more, and the preferred upper limit of the dimension W2 is 12.0 μm or less.

[0042] In this embodiment, the plurality of second groove portions 9 are formed so that the groove widths thereof are the same as each other (see FIGS. 12 and 13). Although not shown, the plurality of second groove portions 9 may have different groove widths.

[0043] (Protective Layer) As shown in Fig. 2, the conductive member 1 of this embodiment includes protective layers 3, 3. The protective layers 3 have the function of protecting the multiple first conductive wires 10 provided on the substrate 2. The protective layers 3 are made of, for example, an optically transparent optical clear adhesive (OCA). The thickness of the protective layers 3 is, for example, 25 µm or more and 250 µm or less.

[0044] The upper protective layer 3 is laminated on the first surface 2a of the substrate 2. The lower protective layer 3 is laminated on the second surface 2b. That is, the protective layers 3, 3 are disposed on the front and back sides of the touch sensor 100, respectively.

[0045] The protective layer 3 is located above the main body portion 4 (see FIG. 2). That is, the protective layer 3 located above the main body portion 4 is disposed at a position including the main body region A1 (see FIG. 3) of the substrate 2. Note that in this embodiment, the protective layer 3 is not stacked above the connection portion 5.

[0046] The protective layer 3 located on the first surface 2 a side is laminated between the cover member 101 and the substrate 2. The protective layer 3 located on the first surface 2 a side causes the cover member 101 and the substrate 2 to be adhered to each other.

[0047] The protective layer 3 located on the second surface 2b side is laminated between the substrate 2 and the display 102. The protective layer 3 located on the second surface 2b side causes the substrate 2 and the display 102 to be adhered to each other.

[0048] (Sensor Electrodes) The multiple sensor electrodes are composed of multiple transmitting electrodes 11 and multiple receiving electrodes 12 (see FIG. 4). The multiple transmitting electrodes 11 and multiple receiving electrodes 12 are arranged in positions on the substrate 2 corresponding to the active area A3 (see FIG. 3). The touch sensor 100 is capable of detecting a touch operation by a user's finger (detection target) that touches the operation surface 101b through the multiple transmitting electrodes 11 and multiple receiving electrodes 12 located in the active area A3.

[0049] Each transmitting electrode 11 is electrically connected to a drive circuit of an external device (not shown) via a connection terminal 40 (described later). Each transmitting electrode 11 is configured to radiate an electric field to the surroundings via this drive circuit. Meanwhile, each receiving electrode 12 is electrically connected to a detection circuit of an external device (not shown) via a connection terminal 40 (described later). Each receiving electrode 12 is configured to receive the electric field radiated from each transmitting electrode 11.

[0050] 4 and 7 , the transmitting electrodes 11 and the receiving electrodes 12 are arranged to intersect (orthogonally intersect) each other in a plan view. A node is formed in the area where each transmitting electrode 11 and each receiving electrode 12 overlap. This node is configured as an area where capacitance can be generated. The capacitance value of the node is determined by the number of intersections between the multiple first conductive lines 10 that make up each transmitting electrode 11 and the multiple first conductive lines 10 that make up each receiving electrode 12.

[0051] As shown in Fig. 5, a plurality of transmitting electrodes 11 are provided on the second surface 2b of the substrate 2. Each transmitting electrode 11 extends along the long side direction (first direction X) of the substrate 2. The plurality of transmitting electrodes 11 are arranged at intervals from one another in the short side direction (second direction Y) of the substrate 2. The interval between the transmitting electrodes 11, 11 (see Fig. 7) is set to, for example, 1 µm or more and 20 µm or less.

[0052] 6 , the plurality of receiving electrodes 12 are provided on the first surface 2a of the substrate 2. That is, the plurality of receiving electrodes 12 are arranged on the substrate 2 on the viewing side of the touch sensor 100 (the side on which the operation surface 101b of the cover member 101 is located). The plurality of receiving electrodes 12 are insulated from the plurality of transmitting electrodes 11 via the substrate 2. Each receiving electrode 12 extends along the short side direction of the substrate 2 (second direction Y). The plurality of receiving electrodes 12 are arranged at intervals from one another in the long side direction of the substrate 2 (first direction X).

[0053] As shown in FIG. 7 , the pitch EP between the receiving electrodes 12, 12 in the first direction X is, for example, 3 mm or more and 7 mm or less. The electrode width EW2 of the receiving electrodes 12 is smaller than the pitch EP between the receiving electrodes 12, 12. Specifically, the electrode width EW2 of the receiving electrodes 12 is, for example, 0.5 mm or more. The electrode width EW2 of the receiving electrodes 12 is also smaller than the electrode width EW1 of the transmitting electrodes 11. Note that in FIG. 6 , only the receiving electrodes 12 are hatched with dots to make it easier to see the overlapping state between the transmitting electrodes 11 and the receiving electrodes 12. Also, for convenience of illustration, the first and second ground portions 23, 24 and the first and second ground portions 23, 24 are not shown in FIG.

[0054] As shown in Fig. 8 , each of the transmitting electrodes 11 and each of the receiving electrodes 12 includes a mesh pattern 13. The mesh pattern 13 is formed so that a plurality of cells 14, each of which is made up of a plurality of first conductive wires 10, are arranged side by side. The mesh pattern 13 constituting each of the transmitting electrodes 11 and the mesh pattern 13 constituting each of the receiving electrodes 12 overlap each other in the thickness direction of the substrate 2. The line width of the first conductive wires 10 constituting each of the transmitting electrodes 11 and the receiving electrodes 12 is the same as the groove width (dimension W1) of the first groove portion 8 illustrated in Fig. 9 .

[0055] (Wiring Portion) The wiring portions are elements for electrically connecting the transmitting electrodes 11 and the receiving electrodes 12 to external circuits (the driving circuit and the detection circuit described above) not shown.

[0056] Each wiring portion is composed of at least one first conductive line 10 (see FIG. 7). The first conductive line 10 constituting the wiring portion extends along the extension direction of the wiring portion. The line width of the first conductive line 10 constituting the wiring portion is the same as the groove width (dimension W1) of the first groove portion 8 illustrated in FIG. 11.

[0057] As shown in FIGS. 4 to 7, the plurality of wiring portions are configured by a plurality of first wiring portions 21 and a plurality of second wiring portions 22.

[0058] The first wiring portions 21 and the second wiring portions 22 are arranged in the inactive area A4 (see FIG. 3 ). Specifically, the first wiring portions 21 and the second wiring portions 22 are arranged at positions overlapping the decorative portion 101a (see FIGS. 1 and 2 ) in a plan view seen from the operation surface 101b side. That is, the decorative portion 101a prevents the first wiring portions 21 and the second wiring portions 22 from being seen from the operation surface 101b side.

[0059] 5, the plurality of first wiring portions 21 are arranged on the second surface 2b of the substrate 2. One end of each first wiring portion 21 is electrically connected to an end of each transmitting electrode 11. The plurality of first wiring portions 21 are arranged such that the other end of each first wiring portion 21 converges at approximately the center of the lower side of the substrate 2 (near the boundary between the main body region A1 and the connection region A2).

[0060] 6 , the multiple second wiring portions 22 are arranged on the first surface 2 a of the substrate 2. One end of each second wiring portion 22 is electrically connected to an end of each receiving electrode 12. The multiple second wiring portions 22 are arranged such that the other end of each second wiring portion 22 converges at approximately the center of the bottom side of the substrate 2 (near the boundary between the main body region A1 and the connection region A2).

[0061] (First and Second Ground Sections) The first and second ground sections 23, 24 shown in FIGS. 5 and 6 are set to ground potential. The first and second ground sections 23, 24 are electrically insulated from the multiple sensor electrodes and multiple wiring sections. The first and second ground sections 23, 24 are disposed in the inactive area A3 (see FIG. 3). Specifically, the first and second ground sections 23, 24 surround the outer periphery of the active area A3. Although not shown, each of the first and second ground sections 23, 24 is formed of a conductive wire similar to the first conductive wire 10.

[0062] 5, the first ground portion 23 is disposed on the second surface 2b of the substrate 2. The first ground portion 23 is disposed on the lower surface of the substrate 2 at a position close to the peripheral edge.

[0063] 6 , the second ground portion 24 is disposed on the first surface 2 a of the substrate 2. The second ground portion 24 is disposed near the peripheral edge of the upper surface of the substrate 2. Both ends of the first ground portion 23 are located near the approximate center of the lower side of the substrate 2.

[0064] 9 and 11 , the first conductive wire 10 is disposed in the first groove portion 8 of the main body portion 4. The first conductive wire 10 is composed of a first adhesion layer 31, a first seed layer 32, a first conductive layer 33, and a first blackening layer 34. The first adhesion layer 31, the first seed layer 32, the first conductive layer 33, and the first blackening layer 34 are stacked in this order from the bottom side of the first groove portion 8 toward the opening side of the first groove portion 8.

[0065] In the first conductive wire 10 of this embodiment, in a cross-sectional view, the surface portion corresponding to the first blackening layer 34 is curved from the side of the first groove portion 8 toward the center in the groove width direction, recessing from a position corresponding to the outer surface of the insulating layer 7 (the surface in contact with the protective layer 3) toward the bottom of the first groove portion 8. Although not shown, the first blackening layer 34 may be flush with the outer surface of the insulating layer 7.

[0066] The first adhesion layer 31 is an element for ensuring the adhesion of the first seed layer 32 to the first groove portion 8. The first adhesion layer 31 has the function of making the first conductive wire 10 less visible when viewed by a user from the operation surface 101b side.

[0067] The first adhesion layer 31 is a metal layer composed of, for example, a metal nitride or metal oxide containing at least one metal selected from the group consisting of Ti, Ni, Al, V, W, Ta, Si, Cr, Ag, Mo, Cu, and Zn. The first adhesion layer 31 may be a single layer or a laminate of multiple layers with different compositions. The first adhesion layer 31 is laminated in the form of a thin film on the first groove portion 8 by, for example, vapor deposition or sputtering.

[0068] The first seed layer 32 has a function of bonding the first conductive layer 33 to the first adhesive layer 31. Specifically, the first seed layer 32 functions as a cathode for depositing the constituent material (conductive metal) of the first conductive layer 33 on the first adhesive layer 31 during the electroplating process described below. The first seed layer 32 is deposited in the form of a thin film on the first adhesive layer 31 by, for example, vapor deposition or sputtering.

[0069] The first conductive layer 33 includes a conductive metal such as copper (Cu) embedded in the first groove 8 of the main body 4. The first conductive layer 33 is formed, for example, by electroplating. When electroplating is performed, the first seed layer 32 and the first conductive layer 33 are formed integrally. This makes it impossible to distinguish the interface between the first seed layer 32 and the first conductive layer 33. Note that the conductive metal is not limited to copper, and may be silver, gold, or a copper alloy.

[0070] The first blackening layer 34 has a function of making the first conductive wire 10 less visible when a user looks from the operation surface 101b side. The first blackening layer 34 is laminated above the first conductive layer 33. Specifically, the first blackening layer 34 is formed by substituting, with palladium (blackening treatment), copper crystal grains located at the boundaries between copper crystal grains located on the upper surface of the first conductive layer 33. The thickness of the first blackening layer 34 is, for example, not less than 0.007 μm and not more than 0.04 μm.

[0071] (Connection Terminal Portion) The connection terminal portion 40 is an element for electrically connecting a plurality of sensor electrodes located in the main body region A1 to a drive circuit and a detection circuit of an external device (not shown).

[0072] 12 , the connection terminal portion 40 is composed of a plurality of second conductive wires 50. The connection terminal portion 40 is disposed in the connection portion 5 of the substrate 2. Specifically, the connection terminal portion 40 is disposed in the connection region A2.

[0073] 12 , the second conductive wires 50 extend in the connection region A2 from the boundary between the main body region A1 and the connection region A2 toward the side opposite the boundary (the end of the connection portion 5 located below the paper surface of FIG. 12 ). The second conductive wires 50 are arranged at intervals in the first direction X in the connection region A2.

[0074] The end of each second conductive wire 50 located at the boundary between the main body region A1 and the connection region A2 is continuous with the end of the first conductive wire 10 corresponding to each wiring portion. In other words, each second conductive wire 50 is electrically connected to each wiring portion.

[0075] As shown in FIG. 13 , the line width of the second conductive wire 50 (corresponding to the dimension W4 shown in FIG. 13 ) corresponds to the distance, in a cross-sectional view, from a first protruding portion 58 a (protruding portion 58) described below, located on the left side of the paper in FIG. 13 , to a second protruding portion 58 b (protruding portion 58) located on the right side of the paper in FIG. 13 .

[0076] The line width (dimension W4) of the second conductive wire 50 is larger than the line width (dimension W1 shown in FIGS. 9 and 11 ) of the first conductive wire 10. The line width (dimension W4) of the second conductive wire 50 is also larger than the groove width (dimension W2) of the second groove portion 9.

[0077] The line width (dimension W4) of the second conductive wire 50 is set to be 8.0 μm or more and 43 μm or less. Specifically, the preferable lower limit of the dimension W4 is 10.0 μm or more. On the other hand, the preferable upper limit of the dimension W4 is 18 μm or less.

[0078] 13 and 14 , the second conductive wire 50 is disposed in the second groove portion 9 of the connection portion 5. The second conductive wire 50 is composed of a second adhesion layer 51, a second seed layer 52, a second conductive layer 53, a second blackening layer 54, and a third conductive layer 55. The second adhesion layer 51, the second seed layer 52, the second conductive layer 53, the second blackening layer 54, and the third conductive layer 55 are stacked in this order from the bottom side of the second groove portion 9 toward the opening side of the second groove portion 9.

[0079] In the second conductive wire 50, when viewed in cross section, the surface portion corresponding to the third conductive layer 55 is curved and recessed from the protrusion 58 toward the bottom side of the second groove portion 9 as it moves from the protrusion 58 described below toward the reference position Rp described below.

[0080] The second conductive layer 53 includes a conductive metal (such as copper (Cu)) embedded in the second groove portion 9 of the connection portion 5. The second adhesion layer 51, the second seed layer 52, and the second conductive layer 53 each have the same configuration as the first adhesion layer 31, the first seed layer 32, and the first conductive layer 33, respectively. Therefore, a description of the second adhesion layer 51, the second seed layer 52, and the second conductive layer 53 will be omitted.

[0081] Unlike the first blackening layer 34, the second blackening layer 54 has the function of enhancing the bonding strength between the second conductive layer 53 and the third conductive layer 55 (specifically, the base layer 56 described below). The second blackening layer 54 is laminated above the second conductive layer 53. Specifically, the second blackening layer 54 is formed by substituting palladium for copper crystal grains located at the boundaries between copper crystal grains located on the upper surface of the second conductive layer 53 (blackening treatment). The thickness of the second blackening layer 54 is, for example, 0.001 μm or more and 0.5 μm or less.

[0082] The third conductive layer 55 is disposed on the second blackening layer 54. The third conductive layer 55 includes a conductive metal. The conductivity of the third conductive layer 55 is lower than the conductivity of the first conductive layer 33.

[0083] As shown in FIGS. 13 and 14 , the third conductive layer 55 includes a base layer portion 56 and an outer layer portion 57 .

[0084] The base layer 56 mainly functions to enhance the corrosion resistance of the second conductive wire 50. The base layer 56 is laminated above the second blackening layer 54. The base layer 56 is made of, for example, nickel (Ni).

[0085] The thickness of the base layer 56 is greater than the thickness of the second blackening layer 54. The thickness of the base layer 56 is, for example, not less than 0.1 μm and not more than 6 μm.

[0086] The width of the base layer 56 (dimension W3 shown in FIG. 13) corresponds to the distance from the end of the base layer 56 located on the left side of the paper in FIG. 13 to the end of the base layer 56 located on the right side of the paper in FIG. 13. The width (dimension W3) of the base layer 56 is greater than the width (dimension W2) of the second groove portion 9. The width (dimension W3) of the base layer 56 is, for example, greater than 8 μm and equal to or less than 42 μm.

[0087] The outer layer 57 is laminated on the base layer 56. The conductivity of the outer layer 57 is lower than the conductivity of the second conductive layer 53. The outer layer 57 includes a conductive metal such as gold (Au).

[0088] The thickness of the outer layer 57 is smaller than the thickness of the base layer 56. The thickness of the outer layer 57 is, for example, not less than 0.02 μm and not more than 0.6 μm.

[0089] The width of the outer layer portion 57 (dimension W4 shown in FIG. 13 ) corresponds to the distance from the end of the outer layer portion 57 located on the left side of the paper in FIG. 13 to the end of the outer layer portion 57 located on the right side of the paper in FIG. 13 . The width of the outer layer portion 57 (dimension W4) is equal to or greater than the width of the base layer portion 56 (dimension W3). The width of the outer layer portion 57 (dimension W4) is, for example, greater than 8 μm and equal to or less than 43 μm.

[0090] 13 , the third conductive layer 55 includes protruding portions 58, 58. In a cross-sectional view, each protruding portion 58 is located closer to the side of the second groove portion 9 than a reference position Rp provided on the third conductive layer 55.

[0091] In this embodiment, the protrusions 58, 58 correspond to the first protrusion 58a and the second protrusion 58b shown in Fig. 13. The first protrusion 58a and the second protrusion 58b are line-symmetric with each other about the center line (reference symbol CL shown in Fig. 13) of the third conductive layer 55. Note that the first protrusion 58a and the second protrusion 58b do not have to be line-symmetric with each other about the center line CL.

[0092] The first protrusion 58 a is located on the upper surface of the third conductive layer 55 and protrudes upward. In a cross-sectional view, the first protrusion 58 a is closer to a side of the second groove 9 (for example, a side located on the left side of the paper in FIG. 3 ) than to a central portion (reference position Rp) of the upper surface of the third conductive layer 55.

[0093] The second protrusion 58b is located on the upper surface of the third conductive layer 55 and protrudes upward. In a cross-sectional view, the second protrusion 58b is closer to a side of the second groove 9 (for example, a side located on the right side of the paper in FIG. 3 ) than to a central portion (reference position Rp) of the upper surface of the third conductive layer 55. In other words, in a cross-sectional view, the second protrusion 58b is located on the opposite side of the first protrusion 58a with respect to the reference position Rp (the central portion of the upper surface of the third conductive layer 55).

[0094] Here, the reference position Rp is located on the outer surface of the third conductive layer 55 and is located at the center of the second groove portion 9 on the outer surface in the width direction (see FIG. 13 ). The reference position Rp illustrated in FIG. 13 is set to be approximately the same position as the first surface 2 a of the substrate 2 in the thickness direction of the substrate 2. Note that the reference position Rp may be set at a position different from the position shown in FIG. 13 .

[0095] In this embodiment, for convenience of explanation, an imaginary plane that is at the same position as the reference position Rp in the thickness direction of the substrate 2 is defined as an imaginary plane Vs (see FIGS. 13 and 14).

[0096] As a characteristic configuration of an embodiment of the present disclosure, the protrusion 58 is configured such that, in a cross-sectional view, a portion of the third conductive layer 55 protrudes from the reference position Rp toward the side opposite to the side on which the bottom of the second groove portion 9 is located, as the portion moves from the reference position Rp toward the side of the second groove portion 9.

[0097] The protruding portion 58 protrudes upward (toward the side opposite to the side where the bottom of the second groove portion 9 is located) from the first surface 2 a of the insulating layer 7. A part of the outer layer portion 57 constituting the protruding portion 58 is in contact with the first surface 2 a of the insulating layer 7 located near the side of the second groove portion 9.

[0098] In this embodiment, the width of the protruding portion 58 is set to the dimension W5 illustrated in Fig. 14. Specifically, the dimension W5 corresponds to the distance on the imaginary plane Vs from the end of the outer layer portion 57 located on the left side of the paper in Fig. 14 to the point of contact between the imaginary plane Vs and the base layer portion 56 located on the right side of the paper in Fig. 14. The protruding portion 58 includes both the base layer portion 56 and the outer layer portion 57 within the range determined by the dimension W5.

[0099] (Reinforcing portion) The reinforcing portion 60 is an element for increasing the rigidity of the portion corresponding to the connection area A2 of the substrate 2 (i.e., the connection portion 5 of the substrate 2). As shown in Fig. 12, the reinforcing portion 60 is located below the connection portion 5. The reinforcing portion 60 is disposed on the second surface 2b of the substrate 2 at a position corresponding to the connection area A2. The reinforcing portion 60 is fixed to the lower surface of the connection portion 5 with, for example, an adhesive (not shown).

[0100] The reinforcing portion 60 is made of a rigid material. Specifically, suitable materials for the reinforcing portion 60 include, for example, PET (polyethylene terephthalate), PI (polyimide), GE (glass epoxy), and SUS (stainless steel).

[0101] The reinforcing portion 60 has a substantially plate-like shape. The thickness of the reinforcing portion 60 is, for example, 50 μm to 400 μm. The outer shape of the reinforcing portion 60 in a plan view is substantially the same as the outer shape of the connecting portion 5 in a plan view.

[0102] As described above, the protruding portion 58 is configured such that, in a cross-sectional view, a portion of the third conductive layer 55 protrudes from the reference position Rp toward the side of the second groove 9, and from the reference position Rp toward the side opposite to the side where the bottom of the second groove 9 is located. With this configuration, when the second conductive wire 50 (i.e., the connection terminal portion 40) located in the connection region A2 is connected to a connector of an external device, the third conductive layer 55 including the protruding portion 58 is more likely to come into contact with the connector of the external device.

[0103] 15 and 16 , the lower portion Cb of the connector C in the external device (i.e., the portion that comes into contact with the second conductive wires 50) is generally formed in a hemispherical shape (e.g., a hemispherical surface with a dimension SR of 0.5 mm) that curves downward in the plane of the paper in FIG. 15 . The lower portion Cb of the connector C is capable of coming into contact with a plurality of second conductive wires 50. Note that the insulating layer 7 and the second conductive wires 50 are not shown in the substrate 5 shown in FIG. 15 .

[0104] In contrast, in the second conductive wire 50, the third conductive layer 55 includes a first protrusion 58a and a second protrusion 58b (see FIGS. 13 and 16 ). The portion between the first protrusion 58a located on the left side of the paper in FIGS. 13 and 16 and the second protrusion 58b located on the right side of the paper in those figures (i.e., most of the upper surface of the third conductive layer 55) is curved downward in a concave shape. This increases the contact area between the upper surface of the third conductive layer 55 and the lower part Cb of the connector C, as shown in FIG. 16 . As a result, the connection stability between the second conductive wire 50 and the connector C is improved.

[0105] Thus, with the conductive member 1 according to the embodiment of the present disclosure, stable conduction between the external device and the plurality of second conductive wires 50 located in the connection area A2 of the connection portion 5 can be easily achieved without using a flexible wiring board as in the prior art (for example, the above-mentioned Patent Document 1). Therefore, with the conductive member 1, stable conduction between the second conductive wires 50 provided on the substrate 2 and the external device, etc. can be ensured.

[0106] Furthermore, the groove width of the second groove 9 is larger than the groove width of the first groove 8. That is, the line width of the second conductive wire 50 is larger than the line width of the first conductive wire 10. With this configuration, when the connection terminal 40 is connected to a connector of an external device, the third conductive layer 55 including the protrusion 58 is more likely to come into contact with the connector of the external device. As a result, it is possible to ensure stable conduction between the second conductive wire 50 and the external device.

[0107] Furthermore, the groove width of the second conductive wire 50 is larger than the groove width of the second groove portion 9. This makes it easier for the third conductive layer 55, including the protrusion 58, to come into contact with the connector of the external device when the connection terminal portion 40 is connected to the connector of the external device. As a result, it is possible to ensure stable conduction between the second conductive wire 50 and the external device.

[0108] The width of the base layer portion 56 is also greater than the width of the second groove portion 9. Furthermore, the width of the outer layer portion 57 is also greater than the width of the base layer portion 56. That is, the outer layer portion 57 of the third conductive layer 55 (the portion made of a conductive metal having a lower conductivity than the conductive metal constituting the second conductive layer 53) is relatively large. This further improves the stability of conduction between the second conductive wire 50 and the external device when the connection terminal portion 40 is connected to a connector of the external device.

[0109] Furthermore, the protective layer 3 covers the first blackened layer 34 of the first conductive wire 10. The protective layer 3 can adequately protect the first conductive wire 10 located in the main body region A1 of the substrate 2.

[0110] The conductive member 1 also includes a reinforcing portion 60 disposed on the second surface 2b of the substrate 2 at a position corresponding to the connection area A2. The reinforcing portion 60 is made of a rigid material. The reinforcing portion 60 improves the rigidity of the portion of the connection portion 5 corresponding to the connection area A2 of the substrate 2. As a result, it becomes easier to connect the connection portion 5 to a connector of an external device. This ensures stable conduction between the external device and the multiple second conductive wires 50 located in the connection area A2.

[0111] [Other Embodiments] In the above embodiment, a configuration using one substrate 2 is shown, but this is not limiting. That is, a configuration using two substrates (not shown) may also be used. Although not shown, it is sufficient to use two substrates in which one insulating layer 7 is laminated on one surface of the base layer 6.

[0112] In the above embodiment, the substrate 2 has the base layer 6 and the insulating layer 7, but is not limited to this. For example, the substrate 2 may have only the base layer 6. In such a configuration, a plurality of first grooves 8 and a plurality of second grooves 9 are formed in the base layer 6.

[0113] In the above embodiment, the direction from the left side to the right side on the paper surface of Fig. 3 is defined as the first direction X, and the direction from the bottom side to the top on the paper surface of Fig. 3 is defined as the second direction Y, but this is not limited to this. That is, the direction from the bottom side to the top on the paper surface of Fig. 3 may be defined as the first direction X, and the direction from the left side to the right side on the paper surface of Fig. 3 may be defined as the second direction Y.

[0114] In the above embodiment, a configuration has been described in which the plurality of transmitting electrodes 11, the plurality of first wiring portions 21, and the first ground portion 23 are provided on the second surface 2b of the substrate 2, while the plurality of receiving electrodes 12, the plurality of second wiring portions 22, the second ground portion 24, and the connection terminal portion 40 are provided on the first surface 2a of the substrate 2. However, this configuration is not limited to this. For example, although not shown, the plurality of transmitting electrodes 11, the plurality of first wiring portions 21, and the first ground portion 23 may be provided on the first surface 2a of the substrate 2, while the plurality of receiving electrodes 12, the plurality of second wiring portions 22, the second ground portion 24, and the connection terminal portion 40 may be provided on the second surface 2b of the substrate 2.

[0115] Although not shown in the above embodiment, a dummy pattern (not shown) may be provided on at least one of the transmitting electrode 11 and the receiving electrode 12 .

[0116] Although not shown in the above embodiment, a dummy electrode (not shown) may be provided between the transmitting electrodes 11, 11. Similarly, a dummy electrode may be provided between the receiving electrodes 12, 12.

[0117] In the above embodiment, the groove width of the second groove portion 9 is larger than the groove width of the first groove portion 8, but this is not limiting. For example, the groove width of the second groove portion 9 may be the same as the groove width of the first groove portion 8. Even in this embodiment, as long as the third conductive layer 55 includes the protrusions 58, 58 (first protrusion 58a and second protrusion 58b), stable conduction can be obtained between the external device and the plurality of second conductive wires 50 (connection terminal portions 40) located in the connection region A2.

[0118] In the above embodiment, the line width of the second conductive wire 50 is larger than the line width of the first conductive wire 10, but this is not limiting. For example, the line width of the second conductive wire 50 may be the same as the line width of the first conductive wire 10. Even in this embodiment, as long as the third conductive layer 55 of the second conductive wire includes the protrusions 58, 58 (first protrusion 58a and second protrusion 58b), stable conduction can be obtained between the multiple second conductive wires 50 (connection terminal portions 40) located in the connection region A2 and the external device.

[0119] In the above embodiment, the groove width of the second conductive wire 50 is larger than the groove width of the second groove portion 9, but this is not limiting. For example, the line width of the second conductive wire 50 may be the same as the groove width of the second groove portion 9. Even in this embodiment, the protrusions 58, 58 (first protrusion 58a and second protrusion 58b) can ensure stable conduction between the external device and the multiple second conductive wires 50 (connection terminal portions 40) located in the connection region A2.

[0120] In the above embodiment, the width of the base layer 56 is greater than the width of the second groove 9, and the width of the outer layer 57 is greater than the width of the base layer 56. However, this is not limiting. For example, the width of both the base layer 56 and the outer layer 57 may be the same as the groove width (dimension W2) of the second groove 9. Even in this embodiment, as long as the third conductive layer 55 includes the protrusions 58, 58 (first protrusion 58a and second protrusion 58b), stable conduction between the plurality of second conductive wires 50 (connection terminal 40) and the external device can be achieved when the connection terminal 40 is connected to a connector of the external device.

[0121] In the above embodiment, the touch sensor 100 to which the conductive member 1 is applied has been exemplified, but the present invention is not limited thereto. For example, the conductive member 1 can be widely applied to devices and components relating to technical fields other than the touch sensor 100 (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).

[0122] In the above embodiment, the conductive member 1 includes the protective layer 3, but the present invention is not limited to this. That is, the conductive member 1 does not need to include the protective layer 3. For example, when the protective layer 3 does not need to be provided in a device other than the touch sensor 100, the conductive member 1 without the protective layer 3 may be applied to the device.

[0123] In the above embodiment, the conductive member 1 includes the reinforcing portion 60, but this is not limiting. That is, the conductive member 1 does not need to include the reinforcing portion 60. For example, regardless of the rigidity of the portion (connection portion 5) corresponding to the connection area A2 of the substrate 2, if the connection portion 5 can be connected to an external device using an electronic member such as solder, the reinforcing portion 60 does not need to be provided.

[0124] In the above embodiment, the protruding portion 58 includes both the base layer portion 56 and the outer layer portion 57 (see FIG. 14 ), but this is not limiting. For example, the protruding portion 58 does not have to include the base layer portion 56. That is, the protruding portion 58 only needs to include at least the outer layer portion 57. Even with this configuration, the above-described effect (the effect of ensuring stable conduction between the multiple second conductive wires 50 provided on the substrate 2 and external devices, etc.) can be achieved.

[0125] The present disclosure is industrially applicable, for example, as a conductive member applied to a touch sensor.

[0126] 1: Conductive member 2: Substrate 2a: First surface 2b: Second surface 3: Protective layer 4: Main body portion 5: Connection portion 6: Base material layer 7: Insulating layer 8: First groove portion 9: Second groove portion 10: First conductive wire 11: Transmitting electrode 12: Receiving electrode 21: First wiring portion 22: Second wiring portion 31: First adhesion layer 32: First seed layer 33: First conductive layer 34: First blackening layer 40: Connection terminal portion 50: Second conductive wire 51: Second adhesion layer 52: Second seed layer 53: Second conductive layer 54: Second blackening layer 55: Third conductive layer 56: Base layer portion 57: Outer layer portion 58: Protrusion portion 58a: First protrusion portion 58b: Second protrusion portion 100: Touch sensor 101: Cover member 102: Display X: First direction Y: Second direction A1: Main body region A2: Connection area A3: Active area A4: Inactive area Rp: Reference position Vs: Virtual surface

Claims

a first conductive wire disposed in the first groove of the main body part; and a second conductive wire disposed in the second groove of the connection part, wherein the first conductive wire has: a first conductive layer including a conductive metal embedded in the first groove of the main body part; and a first blackened layer laminated above the first conductive layer; the second conductive wire has: a second conductive layer including a conductive metal embedded in the second groove of the connection part; a second blackened layer laminated above the second conductive layer; and a third conductive layer including a conductive metal laminated above the second blackened layer, wherein the conductivity of the third conductive layer is lower than that of the first conductive layer; and the third conductive layer has: a first protrusion located on an upper surface of the third conductive layer and protruding upward; and a second protrusion located on an upper surface of the third conductive layer and protruding upward. A conductive member, wherein, in a cross-sectional view, the first protrusion is closer to a side of the second groove portion than to a central portion of the top surface of the third conductive layer, the second protrusion is closer to a side of the second groove portion than to a central portion of the top surface of the third conductive layer, and the second protrusion is located on the opposite side of the central portion of the top surface of the third conductive layer from the first protrusion.

2. The conductive member according to claim 1, wherein the groove width of the second groove portion is greater than the groove width of the first groove portion.

3. A conductive member according to claim 1 or 2, wherein the line width of the second conductive wire is greater than the line width of the first conductive wire.

4. A conductive member according to claim 1 or 2, wherein the line width of the second conductive wire is greater than the groove width of the second groove portion.

5. A conductive member as described in claim 1, wherein the third conductive layer includes a base layer portion laminated above the second blackening layer and an outer layer portion laminated above the base layer portion, the electrical conductivity of the outer layer portion being lower than the electrical conductivity of the second conductive layer, the width of the base layer portion being greater than the groove width of the second groove portion, and the width of the outer layer portion being greater than the width of the base layer portion.

6. The conductive member according to claim 1, further comprising a protective layer laminated on the upper side of the main body portion, the protective layer covering the first blackening layer of the first conductive wire.

7. The conductive member according to claim 1, further comprising a reinforcing portion located below said connection portion, said reinforcing portion being made of a material having rigidity.

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