conductive film

Abstract

Ensures visibility as a conductive film. [Solution] The conductive film 1 comprises an insulator 2 having a groove 5 that opens upward, and wiring 10 having a conductor 12 embedded in the groove 5. The upper surface 12a of the conductor 12 has a first surface 15 and a second surface 16 that slopes downward from the first surface 15 toward the side surface of the groove 5.

Description

Technical Field

[0001] The present disclosure relates to a conductive film.

Background Art

[0002] Conventionally, regarding a conductive film applicable to a touch sensor or the like, for example, the technique disclosed in Patent Document 1 is known.

[0003] Specifically, Patent Document 1 discloses a substrate applicable as a touch panel. The substrate includes an insulating imprint layer. The imprint layer is provided with a conductive layer formation groove portion that opens upward. A conductive layer made of a conductive metal material is embedded in the conductive layer formation groove portion. The conductive layer is configured as a touch electrode or a wiring.

Prior Art Document

Patent Document

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The upper surface of the conductive layer embedded in the conductive layer forming groove is formed in a planar shape (see Figures 2 and 12 of Patent Document 1). The entire upper surface of the conductive layer is flush with the upper surface (outermost surface) of the imprint layer (see paragraph 0018 of Patent Document 1). In this configuration, when viewed from the upper surface side of the imprint layer, light incident from outside the substrate (touch panel) toward the upper surface of the imprint layer is specularly reflected across the entire upper surface of the conductive layer. As a result, the conductive layer provided on the imprint layer becomes conspicuous due to the specularly reflected light (reflected light) across the entire upper surface of the conductive layer. Thus, the configuration of Patent Document 1 has the problem of causing the touch electrodes or wiring lines to be visible (hereinafter simply referred to as "wiring line visibility"), which impairs the visibility of the substrate.

[0006] This disclosure has been made in view of the above points, and its purpose is to ensure the visibility of the conductive film by suppressing the visibility of the wiring. [Means for solving the problem]

[0007] To achieve the above objective, one embodiment of the present disclosure is a conductive film comprising an insulator having a groove that opens upward, and wiring having a conductor embedded in the groove. The upper surface of the conductor has a first surface and a second surface that slopes downward from the first surface toward the side surface of the groove. [Effects of the Invention]

[0008] According to this disclosure, visibility as a conductive film can be ensured. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic front view showing a configuration in which the conductive film according to the present disclosure is provided on the entire surface of the windshield of an automobile, and a plan view showing a partially enlarged view of the structure of the conductive film. [Figure 2] Figure 2 is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] Figure 3 is a magnified view of part III shown in Figure 2. [Figure 4] Figure 4 is a magnified view of section IV shown in Figure 2. [Figure 5] Figure 5 is a partially enlarged view of the left cross-sectional structure of the conductive film according to Modification 1, which is equivalent to Figure 3. [Figure 6] Figure 6 is a partially enlarged view of the right-side cross-sectional structure of the conductive film according to Modification 2, which is equivalent to Figure 4. [Figure 7] Figure 7 is a diagram equivalent to Figure 2, showing the cross-sectional configuration of the conductive film according to Modification 3. [Figure 8] Figure 8 is a diagram equivalent to Figure 2, showing the cross-sectional configuration of the conductive film according to Modification 4. [Figure 9] Figure 9 is a diagram equivalent to Figure 2, showing the cross-sectional configuration of the conductive film according to Modification 5. [Modes for carrying out the invention]

[0010] [Problems with conventional technology] As mentioned above, the substrate disclosed in Patent Document 1 had the problem that the wiring lines were visible, impairing the visibility of the substrate.

[0011] One possible measure to suppress such visible wires is to simply make the wiring width thinner. However, if the process of thinning the wiring width (e.g., etching) is performed excessively, the uniformity of the wiring width as a whole may be compromised. Furthermore, if the wiring width is made excessively thin, the electrical resistance of the wiring may exceed the standard value of electrical resistance assumed in the design.

[0012] Furthermore, in the conductive layer forming groove disclosed in Patent Document 1, the side surface of the conductive layer forming groove is tapered, widening in the groove width direction from the bottom (bottom surface) to the top (opening) side of the groove. In such a tapered conductive layer forming groove, the conductive layer is embedded without gaps in the bottom and side surfaces of the conductive layer forming groove (see, for example, Figure 12 of Patent Document 1). The entire upper surface of the conductive layer is flush with the upper surface (outermost surface) of the imprint layer. With this configuration, when the upper surface of the conductive layer is viewed from above the substrate (touch panel), the line width of the wiring appears to be the same as the groove width of the conductive layer forming groove. In other words, the line width of the wiring appears larger. As a result, the visibility of the wiring becomes even more prominent, impairing the visibility of the substrate.

[0013] The inventors of this disclosure, taking into consideration the problems caused by the prior art described above (Patent Document 1), have taken specific measures to suppress optical reflection on the wiring surface in the conductive film 1 according to the embodiment of this disclosure shown below.

[0014] [Embodiments of this Disclosure] Embodiments of the present disclosure will be described in detail below with reference to the drawings. The following description of embodiments is illustrative in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0015] Figure 1 shows a conductive film 1 according to an embodiment of the present disclosure. The conductive film 1 shown in Figure 1 is used, for example, as an anti-fogging heater attached to a camera or sensor for autonomous driving. The conductive film 1 shown in Figure 1 is placed over the entire surface of the windshield FG in an automobile 100, for example. Specifically, the conductive film 1 is attached to the windshield FG via an adhesive (not shown), such as OCA.

[0016] Note that the conductive film 1 according to the embodiment of the present disclosure is not limited to the use of the heater illustrated in FIG. 1, and can be widely applied to various technical fields such as touch sensors, liquid crystal display devices, organic electroluminescence display devices (OLEDs), micro LED display devices, solar cell devices, heater devices, antenna devices, electromagnetic shielding sheets, and the like.

[0017] In the following description, the side where the later-described first insulator 3 shown in FIG. 2 is located (the lower side of the paper surface of FIG. 2) is defined as the "lower side" of the conductive film 1, and the side where the later-described second insulator 4 is located (the upper side of the paper surface of FIG. 2) is defined as the "upper side" of the conductive film 1, and the positional relationship of each element constituting the conductive film 1 is determined. Note that such a positional relationship is independent of the actual up-and-down direction in the device or apparatus on which the conductive film 1 is mounted.

[0018] (Insulator) As shown in FIGS. 1 and 2, the conductive film 1 includes an insulator 2. The insulator 2 has transparency.

[0019] Note that the conductive film 1 does not necessarily have to have transparency. For example, when the conductive film 1 is attached to a housing not shown, it may be difficult to distinguish between the housing and the conductive film 1 in terms of appearance. In such a case, the conductive film 1 may have the same color as the housing. Further, when the conductive film 1 does not have transparency, the visibility of the wiring is also suppressed.

[0020] The insulator 2 is formed in a sheet shape. The thickness of the insulator 2 is, for example, 25 μm or more and 200 μm or less.

[0021] As shown in FIG. 2, the insulator 2 has a first insulator 3 and a second insulator 4.

[0022] The first insulator 3 is made of a transparent resin material. Examples of transparent resin materials include PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PC (polycarbonate), COP (cycloolefin polymer), COC (cycloolefin copolymer), and PMMA (polymethyl methacrylate resin). However, the first insulator 3 does not necessarily have to be transparent.

[0023] The second insulator 4 is laminated on top of the first insulator 3. The second insulator 4 is made of a resin material that is both insulating and permeable. The thickness of the second insulator 4 is greater than the depth of the groove 5 (described later). The second insulator 4 does not necessarily have to be transparent.

[0024] (Mizobe) As shown in Figure 2, a groove 5 is provided on the upper surface of the insulator 2 (second insulator 4). The groove 5 has a bottomed shape, recessed from the upper surface of the second insulator 4 in the thickness direction of the second insulator 4. The depth of the groove 5 is set to, for example, 0.2 μm or more and 5.0 μm or less.

[0025] The groove 5 has a bottom surface 6, a first groove side surface 7a, and a second groove side surface 7b. Here, "groove side surface" refers to a surface of the insulator 2 that forms the groove 5 and is not parallel to the top surface of the insulator 2.

[0026] In this embodiment, for the sake of explanation, the side of the groove 5 located on the left side of Figure 2 will be referred to as the "first groove side," and the side of the groove 5 located on the right side of Figure 2 will be referred to as the "second groove side."

[0027] Each of the first groove side surface 7a and the second groove side surface 7b is formed in a tapered shape, widening from the bottom surface 6 of the groove 5 toward the opening 8 of the groove 5. Specifically, the first groove side surface 7a is inclined to the left side of the plane of Figure 2 toward upward (towards the opening 8) from the groove 5 in the thickness direction of the insulator 2. The second groove side surface 7b is inclined to the right side of the plane of Figure 2 toward upward (towards the opening 8) from the groove 5 in the thickness direction of the insulator 2. As a result, in this embodiment, the groove width dimension GW1 at the opening 8 of the groove 5 is larger than the width dimension GW2 at the bottom surface 6 of the groove 5.

[0028] The groove width dimension GW1 of the groove 5 is, for example, 0.5 μm or more and 20 μm or less. In the groove 5 exemplified in Figure 2, the depth dimension GH and the groove width dimension GW1 are set to be approximately the same size. The aspect ratio of the groove 5 shown in Figure 2 (the value obtained by dividing the depth dimension GH by the groove width dimension GW1) is, for example, 0.1 or more.

[0029] Incidentally, Figure 2 shows a state in which no other layer, such as an adhesive layer, is laminated on the upper surface of the second insulator 4. However, depending on the usage of the conductive film 1, it is possible that another layer may be laminated on the upper surface of the second insulator 4 (see Modification Example 4 described later). Taking such cases into consideration, the concept of the opening 8 in the groove 5 includes a state in which another layer, such as an adhesive layer (not shown), is laminated on the upper surface of the second insulator 4, and that other layer substantially seals the opening 8.

[0030] (wiring) As shown in Figure 1, the conductive film 1 comprises a plurality of wirings 10. The wirings 10 are formed in the shape of fine wires. The line width of the wirings 10 is, for example, 0.5 μm or more and 20 μm or less.

[0031] The wiring 10 is formed in a straight line. The wiring 10 extends diagonally with respect to the X and Y directions shown in Figure 1. Multiple wirings 10 are arranged with space between them.

[0032] Note that the wiring 10 is not limited to being straight. For example, although not shown in the figures, the wiring 10 may be formed in a curved shape. Also, a plurality of wirings 10 may include both straight wirings 10 and curved wirings 10. Furthermore, the wiring 10 may extend in the X and Y directions as shown in Figure 1.

[0033] The conductive film 1 comprises a plurality of cells 11. Each cell 11 is formed in a closed manner by a plurality of wirings 10. In this embodiment, the cells 11 have a rhombus shape. However, the shape of the cells 11 is not limited to a rhombus shape, and may be other polygonal shapes (triangle, square, etc.) or circular shapes.

[0034] (conductor) As shown in Figure 2, the wiring 10 has a conductor 12. The conductor 12 is embedded in the groove 5. The conductor 12 is laminated, for example, to an adhesion layer 13 and a seed layer 14 provided within the groove 5. Note that the adhesion layer 13 and seed layer 14 are not shown in Figures 3 and 4.

[0035] The adhesion layer 13 is an element that ensures the adhesion of the seed layer 14 to the groove 5. The adhesion layer 13 is a metal layer composed of 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 adhesion layer 13 may be a single layer or a laminate of multiple layers with different compositions. The adhesion layer 13 is deposited in a thin film form on the bottom surface 6, the first groove side surface 7a, and the second groove side surface 7b in the groove 5, for example, by vapor deposition or sputtering.

[0036] The seed layer 14 has the function of bonding the conductor 12 to the adhesion layer 13. Specifically, in this embodiment, the seed layer 14 functions as a cathode for laminating a plating layer, which will be described later and may contain copper (Cu), onto the adhesion layer 13 during an electroplating process to form the conductor 12. The seed layer 14 is laminated onto the adhesion layer 13 in a thin film form by, for example, vapor deposition or sputtering.

[0037] The conductor 12 is made of a conductive metal such as copper (Cu). The conductor 12 is formed by electroplating, electroless plating, vacuum deposition, etc. When electroplating is performed, the conductor 12 and the seed layer 14 are formed integrally. As a result, the interface between the conductor 12 and the seed layer 14 may become indistinguishable. Although copper (Cu) is suitable as the main component of the wiring 10, other metals (e.g., silver, gold, nickel, aluminum) may also be included.

[0038] As shown in Figures 2 to 4, the upper surface 12a of the conductor 12 has a first surface 15, a second surface 16, and a third surface 17.

[0039] (front page) As shown in Figure 2, the first surface 15 is positioned approximately in the center of the groove 5 in the groove width direction (left-right direction shown in Figure 2). Specifically, the first surface 15 is positioned between the second surface 16 on the left and the third surface 17 on the right in the groove width direction. Also, the first surface 15 faces the same direction as the bottom surface 6 of the groove 5.

[0040] The width dimension S1 of the first surface 15 is smaller than the groove width dimension GW1 of the groove 5. Preferably, the width dimension S1 of the first surface 15 is 50% or more and 90% or less of the groove width dimension GW1 of the groove 5.

[0041] The first surface 15 is formed in a substantially planar shape. As illustrated in Figure 2, the first surface 15 may be slightly curved downwards. Alternatively, although not shown, the first surface 15 may be slightly curved upwards. Furthermore, the first surface 15 may be formed in a completely planar shape, without curving upwards or downwards.

[0042] As shown in Figure 3, the left end portion 15L of the first surface 15 is located near the first groove surface 7a in the groove width direction. The left end portion 15L of the first surface 15 is spaced apart from the first groove surface 7a in the groove width direction.

[0043] As shown in Figure 4, the right end 15R of the first surface 15 is located near the second groove surface 7b in the groove width direction. The right end 15R of the first surface 15 is spaced apart from the second groove surface 7b in the groove width direction.

[0044] By the way, in order to suppress the problems of the conventional technology described above (visibility of wiring), it is conceivable to form a different form from the embodiments of this disclosure, for example, by forming minute uneven shapes (not shown) on the first surface 15. Specifically, one can imagine a form in which minute uneven shapes are formed on the first surface 15 by pressing a roller (not shown) with a roughened surface against the first surface 15 of the conductor 12 and the second insulator 4.

[0045] A problem with this embodiment, which differs from the embodiments of this disclosure, is that the physical load on the insulator 2 by the roller becomes large. This problem limits the selection of constituent materials for the insulator 2. In particular, for the second insulator 4 having grooves 5, the selection of a material that can withstand the direct physical load by the roller is limited. As a result, it becomes difficult to obtain a suitable conductive film 1.

[0046] Alternatively, instead of using the rollers described above, it is conceivable to form minute irregularities on the first surface 15 of the conductor 12 by etching or oxidation. However, etching or oxidation may dissolve the constituent metals (such as copper) of the conductor 12. In such cases, this could lead to an excessive increase in the electrical resistance of the conductor 12.

[0047] From this viewpoint, in the embodiments of the present disclosure, it is not necessary to provide minute irregular shapes on the first surface 15.

[0048] (Second side) As shown in Figures 2 and 3, the second surface 16 of this embodiment is located closer to the first groove side surface 7a than the left end 15L of the first surface 15 in the groove width direction. The second surface 16 is continuous with the first surface 15. The second surface 16 is formed, for example, by etching.

[0049] The width dimension S2 of the second surface 16 is smaller than the width dimension S1 of the first surface 15. Preferably, the width dimension S2 of the second surface 16 is 1% or more and 30% or less of the width dimension S1 of the first surface 15.

[0050] The second surface 16 is inclined downward from the first surface 15 toward the first groove side surface 7a. Specifically, the surface direction of the second surface 16 is inclined counterclockwise by a first angle θ1 with respect to the surface direction of the first surface 15 (hereinafter referred to as the "first inclination direction"). As a result, the second surface 16 faces in a different direction from the orientation of the first surface 15.

[0051] The "first angle" mentioned above corresponds to the angle obtained when the left end 15L of the first surface 15 is rotated counterclockwise by θ1 (see Figure 3) from the left end 15L toward the first groove side surface 7a located below the first surface 15. In other words, the first angle θ1 is the angle between the imaginary line VL1 and the imaginary line VL2. The first angle θ1 is, for example, between 10° and 90°.

[0052] Here, the imaginary line VL1 shown in Figure 3 virtually indicates the reference position of the first surface 15. Specifically, in a cross-sectional view, the imaginary line VL1 is a straight line that passes through the point corresponding to the interface between the first surface 15 and the second surface 16 and is parallel to the upper surface of the second insulator 4. The imaginary line VL2 shown in Figure 3 is an imaginary line that is inclined counterclockwise by a first angle θ1 relative to the imaginary line VL1. In a cross-sectional view, the imaginary line VL2 is a straight line connecting the point corresponding to the interface between the first surface 15 and the second surface 16 and the point corresponding to the interface between the second surface 16 and the first side portion 18.

[0053] Furthermore, the "plane direction of the first surface 15" mentioned above corresponds to the extension direction of the virtual line VL1 shown in Figure 3. The "first inclination direction" mentioned above corresponds to the extension direction of the virtual line VL2 shown in Figure 3.

[0054] As shown in Figures 2 and 3, for example, when light (hereinafter referred to as "incident light IL") is incident from the upper outside of the conductive film 1 toward the upper surface 12a of the conductor 12, the incident light IL incident on the substantially planar first surface 15 is specularly reflected toward the opposite direction of incidence (see reflected light RL1 shown in Figure 2). In contrast, since the second surface 16 is inclined downward from the first surface 15 toward the first groove side surface 7a, the incident light IL incident on the second surface 16 is reflected toward a direction different from the direction of reflected light RL1 (see Figure 2) on the first surface 15. Specifically, the incident light IL incident on the second surface 16 is reflected as reflected light RL2 shown in Figure 3 toward a direction different from the direction of reflected light RL1 on the first surface 15. As a result, specular reflection of the incident light IL toward the top of the conductive film 1 is suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous. That is, the visibility of the wiring 10 is suppressed. Therefore, visibility as a conductive film 1 can be ensured.

[0055] Furthermore, the second surface 16 of this embodiment has a curved shape that bulges toward the side where the first groove side surface 7a is located. The second surface 16 illustrated in Figures 2 and 3 bulges toward the side where the first groove side surface 7a is located, closer to the opening 8 on the left side. Specifically, the second surface 16 bulges toward a direction perpendicular to the first inclination direction described above.

[0056] On the curved second surface 16, the incident light IL incident on the second surface 16 is diffusely reflected in a direction different from the reflection direction of the incident light IL on the first surface 15 (the direction of the reflected light RL1 shown in Figure 2) (see the reflected light RL2 shown in Figure 3). As a result, specular reflection of the incident light IL towards the conductive film 1 is further suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous, and the visibility of the wiring 10 is suppressed.

[0057] Furthermore, in this embodiment, the second surface 16 is located closer to the first groove side surface 7a than the left end 15L of the first surface 15 in the groove width direction. Due to this positional relationship of the second surface 16, the overall width of the first surface 15, which is continuous in the groove width direction, becomes smaller than the groove width of the groove portion 5. As a result, the degree to which incident light IL is specularly reflected across the entire upper surface 12a of the conductor 12 is reduced. Consequently, the apparent line width of the wiring 10 becomes smaller. Therefore, the visibility of the wiring 10 can be suppressed.

[0058] (Third side) As shown in Figures 2 and 4, the third surface 17 is located on the opposite side of the first surface 15 from the second surface 16. Specifically, in this embodiment, the third surface 17 is located closer to the second groove side surface 7b than the right end 15R of the first surface 15 in the groove width direction. The third surface 17 is continuous with the first surface 15. The third surface 17 is formed, for example, by etching.

[0059] The width dimension S3 of the third surface 17 is smaller than the width dimension S1 of the first surface 15. Preferably, the width dimension S3 of the third surface 17 is 1% or more and 30% or less of the width dimension S1 of the first surface 15.

[0060] The third surface 17 is inclined downward from the first surface 15 toward the second groove side surface 7b. Specifically, the surface direction of the third surface 17 is inclined clockwise by a second angle θ2 with respect to the surface direction of the first surface 15 (hereinafter referred to as the "second inclination direction"). As a result, the third surface 17 faces in a different direction from the first surface 15.

[0061] The "second angle" mentioned above corresponds to the angle obtained when the rightmost edge 15R of the first surface 15 is rotated clockwise by θ2 (see Figure 4) from the rightmost edge 12R toward the second groove side surface 7b located below the first surface 15. In other words, the second angle θ2 is the angle between the imaginary line VL1 and the imaginary line VL3. The second angle θ2 is, for example, between 10° and 90°.

[0062] Here, the imaginary line VL3 shown in Figure 4 is an imaginary line that is inclined clockwise by a second angle θ2 relative to the imaginary line VL1. In a cross-sectional view, the imaginary line VL3 is a straight line connecting the point corresponding to the interface between the first surface 15 and the third surface 17 and the point corresponding to the interface between the third surface 17 and the second side portion 19.

[0063] Furthermore, the "second inclination direction" mentioned above corresponds to the extension direction of the imaginary line VL2 shown in Figure 4. Note that the second angle θ2 may be the same magnitude as the first angle θ1. Alternatively, the second angle θ2 may be a different magnitude from the first angle θ1.

[0064] As shown in Figures 2 and 4, the third surface 17 is inclined downward from the first surface 15 toward the second groove side surface 7b. Therefore, incident light IL incident on the third surface 17 is reflected in a direction different from the direction of reflected light RL1 (see Figure 2) on the first surface 15 (see reflected light RL3 shown in Figure 4). As a result, specular reflection of incident light IL toward the conductive film 1 is suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous. In other words, the visibility of the wiring 10 is suppressed. Furthermore, because the upper surface of the conductor 12 has both a second surface 16 and a third surface 17, the visibility of the wiring 10 is further suppressed.

[0065] Furthermore, the third surface 17 of this embodiment has a curved shape that bulges toward the side where the second groove side surface 7b is located. The third surface 17 illustrated in Figures 2 and 4 bulges toward the vicinity of the right-side opening 8 where the second groove side surface 7b is located. Specifically, the third surface 17 bulges toward a direction perpendicular to the second inclination direction described above.

[0066] On the curved third surface 17, the incident light IL incident on the third surface 17 is diffusely reflected in a direction different from the reflection direction of the incident light IL on the first surface 15 (the direction of the reflected light RL1 shown in Figure 2) (see the reflected light RL3 shown in Figure 4). As a result, specular reflection of the incident light IL towards the conductive film 1 is further suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous, and the visibility of the wiring 10 is suppressed.

[0067] Furthermore, in this embodiment, the third surface 17 is located closer to the second groove side surface 7b than the right end 15R of the first surface 15 in the groove width direction. Due to this positional relationship of the third surface 17, the overall width of the first surface 15 that is continuous in the groove width direction becomes smaller than the groove width of the groove portion 5. As a result, the degree to which incident light IL is specularly reflected as the upper surface 12a of the conductor 12 is reduced. Consequently, the apparent line width of the wiring 10 becomes smaller. Therefore, the visibility of the wiring 10 can be suppressed.

[0068] (First side) As shown in Figure 3, the conductor 12 has a first side portion 18. The first side portion 18 is formed, for example, by etching.

[0069] The first side portion 18 is located on the left side of the conductor 12. The first side portion 18 is located below the second surface 16. The first side portion 18 is continuous with the second surface 16. In this embodiment, the first side portion 18 is located on the left side of the conductor 12, between approximately the center in the vertical direction and the second surface 16.

[0070] The first side portion 18 is positioned with a first gap D1 between it and the first groove surface 7a in the groove width direction. The first gap D1 gradually increases as the distance between the first groove surface 7a and the first side portion 18 increases from the lower end to the upper end of the first side portion 18. The upper limit of the first gap D1 is, for example, 20% of the dimension GW1. Although not shown in the figures, the first side portion 18 does not necessarily have to be spaced apart from the first groove surface 7a in the groove width direction.

[0071] The first side portion 18 is positioned with a first gap D1 between it and the first groove side surface 7a in the groove width direction. As a result, when viewing the upper surface of the conductor 12 from above the conductive film 1, the line width of the wiring 10 (dimension LW1 shown in Figure 2) appears smaller than the groove width of the groove portion 5 (dimension GW1 shown in Figure 2). In other words, the line width of the wiring 10 appears smaller. This makes it possible to suppress the visibility of the wiring 10.

[0072] (Second side) As shown in Figure 4, the conductor 12 has a second side portion 19. The second side portion 19 is formed, for example, by etching.

[0073] The second side portion 19 is located on the right side of the conductor 12. The second side portion 19 is located below the third surface 17. The second side portion 19 is continuous with the third surface 17. In this embodiment, the second side portion 19 is located on the right side of the conductor 12, between approximately the center in the vertical direction and the third surface 17.

[0074] The second side portion 19 is positioned with a second gap D2 between it and the second groove surface 7b in the groove width direction. The second gap D2 gradually increases as the distance between the second groove surface 7b and the second side portion 19 increases from the lower end to the upper end of the second side portion 19. The upper limit of the second gap D2 is, for example, 20% of the dimension GW1. Although not shown in the figures, the second side portion 19 does not necessarily have to be spaced apart from the second groove surface 7b in the groove width direction.

[0075] The second side portion 19 is positioned with a second gap D2 between it and the second groove side surface 7b in the groove width direction. As a result, when viewing the upper surface of the conductor 12 from above the conductive film 1, the line width of the wiring 10 (dimension LW1 shown in Figure 2) appears smaller than the groove width of the groove portion 5 (dimension GW1 shown in Figure 2). In other words, the line width of the wiring 10 appears smaller. This suppresses the visibility of the wiring 10. Furthermore, the presence of the first side portion 18 and the second side portion 18 in the conductor 12 further suppresses the visibility of the wiring 10.

[0076] (Blackened layer) As shown in Figures 2 to 4, the wiring 10 includes a blackened layer 20. The blackened layer 20 has the function of making the wiring 10 invisible when viewed from the top surface of the insulator 2. As will be described later, the blackened layer 20 may be omitted as appropriate depending on the usage conditions of the conductive film 1, if it does not particularly affect the visibility of the conductive film 1.

[0077] The blackened layer 20 is laminated on the upper surface of the conductor 12. From the viewpoint of suppressing the electrical resistance of the wiring 10, the thickness of the blackened layer 20 is preferably, for example, 3 nm or more and 50 nm or less.

[0078] In this embodiment, the blackened layer 20 consists of a first blackened layer 21, a second blackened layer 22, and a third blackened layer 23.

[0079] The first blackening layer 21 is formed on the first surface 15 of the conductor 12. The second blackening layer 22 is formed on the second surface 16 of the conductor 12. The first blackening layer 21 and the second blackening layer 22 make it possible to prevent the portions of the wiring 10 corresponding to the first surface 15 and the second surface 16 of the conductor 12 from being visible from outside the conductive film 1.

[0080] Furthermore, the third blackening layer 23 is formed on the third surface 17 of the conductor 12. This makes it possible to prevent the portion of the wiring 10 corresponding to the third surface 17 of the conductor 12 from being visible from outside the conductive film 1.

[0081] Furthermore, by including the first blackening layer 21, the second blackening layer 22, and the third blackening layer 23 in the wiring 10, the entire upper surface of the wiring 10 can be made invisible.

[0082] Although not shown in the figures, the blackened layer 20 may also have a fourth blackened layer formed on the first side portion 18 and a fifth blackened layer formed on the second side portion 19.

[0083] [Modified Example 1 of the Embodiment] In the above embodiment, the second surface 16 was shown to have a curved shape that bulges toward the side where the first groove side surface 7a is located, but the embodiment is not limited to this. For example, as shown in Modification 1 in Figure 5, the second surface 16 may have a planar shape.

[0084] Even in this modified example 1, the planar second surface 16 is inclined downward from the first surface 15 toward the first groove side surface 7a. Therefore, incident light IL incident on the second surface 16 is reflected in a direction different from the reflection direction of incident light IL on the first surface 15 (see reflected light RL2 shown in Figure 5). As a result, specular reflection of incident light IL toward directly upwards on the conductive film 1 is suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous. In other words, the visibility of the wiring 10 is suppressed.

[0085] [Modification of Embodiment 2] In the above embodiment, the third surface 17 was shown to have a curved shape that bulges outward from the first surface 15 toward the side where the second groove side surface 7b is located, but the embodiment is not limited to this. For example, as shown in Modification 2 in Figure 6, the third surface 17 may have a planar shape.

[0086] Even in this modified example 2, the planar third surface 17 is inclined downward from the first surface 15 toward the second groove side surface 7b. Therefore, incident light IL incident on the third surface 17 is reflected in a direction different from the reflection direction of incident light IL on the first surface 15 (see reflected light RL3 shown in Figure 6). As a result, specular reflection of incident light IL toward directly upwards on the conductive film 1 is suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous. In other words, the visibility of the wiring 10 is suppressed.

[0087] [Modification of Embodiment 3] In the above embodiment, the groove 5 is shown in a configuration where the depth dimension GH and the groove width dimension GW1 are approximately the same size, but the embodiment is not limited to this. For example, as shown in Modification 3 in Figure 7, the depth dimension GH and the groove width dimension GW1 may be different from each other.

[0088] In the groove 5 shown in Figure 7, the groove width dimension GW1 is greater than the depth dimension GH. Specifically, the aspect ratio of the groove 5 shown in Figure 7 is, for example, 0.1 or greater. The groove width dimension GW1 of the groove 5 shown in Figure 7 is, for example, 0.5 μm or more and 50 μm or less.

[0089] Even in Modification 3, the upper surface 12a of the conductor 12 embedded in the groove 5 has a second surface 16 and a third surface 17. Therefore, even in the configuration according to Modification 3, the visibility of the wiring 10 is suppressed, similar to the embodiment described above. Thus, even in the configuration according to Modification 3, the visibility of the conductive film 1 can be ensured.

[0090] [Modification of Embodiment 4] In the above embodiment (see Figure 2) and the above modifications 1 to 3, a state in which no other layer is laminated on the upper surface of the second insulator 4 is shown, but the embodiment is not limited to this. For example, as shown in Figure 8, depending on the usage of the conductive film 1, another layer such as an adhesive layer (hereinafter simply referred to as "another layer 30") may be laminated on the upper surface of the second insulator 4. Note that in Figure 8, for the sake of illustration, the dimensions shown in Figure 2 have been omitted.

[0091] In the configuration shown in Figure 8, the separate layer 30 is in close contact with the upper surface of the wiring 10 (the upper surface of the blackened layer 20). The separate layer 30 may also be embedded in all or part of the gap corresponding to the first spacing D1. Similarly, the separate layer 30 may also be embedded in all or part of the gap corresponding to the second spacing D2.

[0092] [Modification of Embodiment 5] In the above embodiment (see Figure 2) and the above modifications 1 to 4, the first surface 15 is shown to be planar, but the invention is not limited to this form. For example, as shown in Figure 9, recesses 40, 40 may be provided on the surface of the first surface 15. Each recess 40 extends along the direction of extension of the wiring 10. By providing these recesses 40, the incident light IL on the first surface 15 is diffusely reflected by the recesses 40. Therefore, specular reflection of the incident light IL toward the conductive film 1 is further suppressed across the entire upper surface 12a of the conductor 12. As a result, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous, and the visibility of the wiring 10 is suppressed.

[0093] The recess 40 has a first recessed portion 41 and a second recessed portion 42. The distance between the first recessed portion 41 and the second surface 16 (see dimension SD1 in Figure 9) is approximately the same as the distance between the second recessed portion 42 and the third surface 17 (see dimension SD2 in Figure 9).

[0094] [Other embodiments] In the above embodiment and its modifications, the first groove side surface 7a and the second groove side surface 7b are shown to be tapered, but the embodiment is not limited to this form. That is, the first groove side surface 7a and the second groove side surface 7b do not have to be tapered. Specifically, the surface direction of the first groove side surface 7a and the second groove side surface 7b may extend straight in the vertical direction (perpendicular to the bottom surface 6) from the bottom surface 6 of the groove 5 to the opening 8 of the groove 5 (not shown). In this case, the groove width dimension GW1 at the opening 8 of the groove 5 is approximately the same as the width dimension GW2 at the bottom surface 6 of the groove 5. Even with such a configuration, the second surface 16 and the third surface 17 can suppress the visibility of the wiring 10.

[0095] In the above embodiment and its modifications, the upper surface 12a of the conductor 12 is shown to have a first surface 15, a second surface 16, and a third surface 17, but it is not limited to this embodiment. For example, the upper surface 12a of the conductor 12 may have only the first surface 15 and the second surface 16. Alternatively, the upper surface 12a of the conductor 12 may have only the first surface 15 and the third surface 17. In other words, as long as the upper surface 12a of the conductor 12 has at least one of the second surface 16 and the third surface 17, the visibility of the wiring 10 can be suppressed, similar to the above embodiment.

[0096] In the above embodiment and its modifications, the conductor 12 is shown to have a first side portion 18 and a second side portion 19, but it is not limited to this embodiment. For example, the conductor 12 may have only the first side portion 18. Alternatively, the conductor 12 may have only the second side portion 19. In other words, as long as the conductor 12 has at least one of the first side portion 18 and the second side portion 19, the visibility of the wiring 10 can be suppressed, similar to the above embodiment.

[0097] Furthermore, the conductor 12 does not necessarily have to have both the first side portion 18 and the second side portion 19. In other words, if the effects obtained by the second surface 16 and the third surface 17 described above are sufficient in the conductive film 1, both the first side portion 18 and the second side portion 19 may be omitted.

[0098] In the above embodiments and their modifications, a form having a blackened layer 20 (first blackened layer 21, second blackened layer 22, and third blackened layer 23) is shown, but the embodiment is not limited to this form. That is, if it does not particularly affect the visibility of the conductive film 1, the blackened layer 20 may be omitted as appropriate depending on the usage conditions of the conductive film 1.

[0099] [summary] As a first disclosure, the conductive film 1 comprises an insulator 2 having a groove 5 that opens upward, and wiring 10 having a conductor 12 embedded in the groove 5. The upper surface of the conductor 12 has a first surface 15 and a second surface 16 that slopes downward from the first surface 15 toward the side surface of the groove 5 (first groove side surface 7a).

[0100] In the first disclosure, incident light IL incident on the first surface 15 is specularly reflected in the opposite direction to the direction of incidence. In contrast, since the second surface 16 is inclined downward from the first surface 15 toward the first groove side surface 7a, incident light IL incident on the second surface 16 is reflected in a direction different from the direction of reflected light RL1 (see Figure 2) on the first surface 15 (see reflected light RL2 shown in Figure 3 or Figure 5). As a result, specular reflection of incident light IL toward directly upwards on the conductive film 1 is suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous. That is, the visibility of the wiring 10 is suppressed. Therefore, the visibility of the conductive film 1 can be ensured.

[0101] As a second disclosure, the second surface 16 has a curved shape that bulges toward the side where the side surface of the groove 5 is located.

[0102] In this second disclosure, on the curved second surface 16, the incident light IL incident on the second surface 16 is diffusely reflected in a direction different from the reflection direction of the incident light IL on the first surface 15 (see Figure 2) (see reflected light RL2 shown in Figure 3). As a result, specular reflection of the incident light IL towards the conductive film 1 is further suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous, and the visibility of the wiring 10 is suppressed.

[0103] As a third disclosure, the second surface 16 has a planar shape.

[0104] Even in this third disclosure, the planar second surface 16 is inclined downward from the first surface 15 toward the first groove side surface 7a. Therefore, incident light IL incident on the second surface 16 is reflected in a direction different from the reflection direction of incident light IL on the first surface 15. As a result, specular reflection of incident light IL toward directly upwards on the conductive film 1 is suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous. Therefore, the visibility of the wiring 10 can be suppressed.

[0105] As a fourth disclosure, the wiring 10 includes a first blackened layer 21 and a second blackened layer 22. The first blackened layer 21 is formed on the first surface 15 of the conductor 12. The second blackened layer 22 is formed on the second surface 16 of the conductor 12.

[0106] In this fourth disclosure, the first blackening layer 21 and the second blackening layer 22 make it possible to prevent the portions of the wiring 10 corresponding to the first surface 15 and the second surface 16 of the conductor 12 from being visible from outside the conductive film 1.

[0107] As a fifth disclosure, the conductor 12 has a first side portion 18 that is continuous with the second surface 16. The first side portion 18 is positioned with a first gap D1 between it and the side surface of the groove portion 5 (first groove side surface 7a) in the groove width direction.

[0108] In this fifth disclosure, the first side portion 18 is positioned with a first gap D1 between it and the first groove side surface 7a in the groove width direction, so that when the upper surface 12a of the conductor 12 is viewed from above the conductive film 1, the line width of the wiring 10 appears smaller than the groove width of the groove portion 5. As a result, the line width of the wiring 10 can be made to appear smaller. Therefore, the visibility of the wiring 10 can be suppressed.

[0109] As a sixth disclosure, the upper surface 12a of the conductor 12 further has a third surface 17 that is located on the opposite side of the second surface 16 with respect to the first surface 15 and is inclined downward from the first surface 15 toward the side surface of the groove 5 (the second groove side surface 7b).

[0110] In this sixth disclosure, incident light IL incident on the third surface 17 is reflected in a direction different from the direction of reflected light RL1 (see Figure 2) on the first surface 15 (see reflected light RL3 shown in Figure 4 or Figure 6). As a result, specular reflection of the incident light IL toward directly upwards on the conductive film 1 is suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous. In other words, the visibility of the wiring 10 can be suppressed. Furthermore, since the upper surface 12a of the conductor 12 has both a second surface 16 and a third surface 17, the visibility of the wiring 10 can be further suppressed.

[0111] As a seventh disclosure, the third surface 17 has a curved shape that bulges toward the side where the side surface of the groove 5 (the second groove side surface 7b) is located.

[0112] In this seventh disclosure, on the curved third surface 17, incident light IL incident on the third surface 17 is diffusely reflected in a direction different from the reflection direction of incident light IL on the first surface 15 (see Figure 2) (see reflected light RL3 shown in Figure 4). As a result, specular reflection of incident light IL towards the conductive film 1 is further suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous, and the visibility of the wiring 10 is suppressed.

[0113] As the eighth disclosure, the third surface 17 has a planar shape.

[0114] Even in this eighth disclosure, the planar third surface 17 is inclined downward from the first surface 15 toward the second groove side surface 7b. Therefore, incident light IL incident on the third surface 17 is reflected in a direction different from the reflection direction of incident light IL on the first surface 15 (see Figure 2) (see reflected light RL3 shown in Figure 6). As a result, specular reflection of incident light IL toward directly upwards on the conductive film 1 is suppressed across the entire upper surface 12a of the conductor 12. Consequently, the wiring 10 provided on the upper side of the conductive film 1 becomes less conspicuous. Therefore, the visibility of the wiring 10 can be suppressed.

[0115] As a ninth disclosure, the wiring 10 further includes a third blackening layer 23. The third blackening layer 23 is formed on the third surface 17.

[0116] In this ninth disclosure, in the wiring 10, the portion of the conductor 12 corresponding to the third surface 17 can be made invisible from outside the conductive film 1. Furthermore, in a configuration in which the wiring 10 includes all of the first blackening layer 21, the second blackening layer 22, and the third blackening layer 23, the entire upper surface of the wiring 10 can be made invisible.

[0117] As a tenth disclosure, the conductor 12 has a second side portion 19 that is continuous with the third surface 17. The second side portion 19 is positioned with a second gap D2 between it and the side surface of the groove portion 5 (second groove side surface 7b) in the groove width direction.

[0118] In this tenth disclosure, the second side portion 19 is positioned with a second gap D2 between it and the second groove side surface 7b in the groove width direction, so that when the upper surface 12a of the conductor 12 is viewed from above the conductive film 1, the line width of the wiring 10 appears smaller than the groove width of the groove portion 5. As a result, the line width of the wiring 10 can be made to appear smaller. Therefore, the visibility of the wiring 10 can be suppressed. Furthermore, if the conductor 12 has both the first side portion 18 and the second side portion 19, the visibility of the wiring 10 can be suppressed even further. [Industrial applicability]

[0119] This disclosure is applicable to industrial use as a conductive film. [Explanation of Symbols]

[0120] 1: Conductive film 2: Insulator 3: First insulator 4: Second insulator 5: Groove 6: Bottom 7a: First groove side 7b: Side of the second groove 8:Aperture 10: Wiring 11: Cell 12: Conductors 15: Front page 16:Second side 17:Third side 18: First side 19: Second side 20: Blackened layer 21: First blackening layer 22: Second blackening layer 23: Third Blackening Layer 30: Another layer 40: Indentation 41: First depression 42: Second depression

Claims

1. An insulator having a groove that opens upward, The groove portion comprises a wiring having a conductor, The upper surface of the conductor has a first surface and a second surface that slopes downward from the first surface toward the side surface of the groove. Conductive film.

2. In the conductive film according to claim 1, The second surface is a conductive film having a curved shape that bulges toward the side where the groove portion is located.

3. In the conductive film according to claim 1, The second surface is a conductive film having a planar shape.

4. In the conductive film according to any one of claims 1 to 3, The wiring includes a first blackened layer and a second blackened layer, The first blackened layer is formed on the first surface, The second blackened layer is a conductive film formed on the second surface.

5. In the conductive film according to any one of claims 1 to 4, The conductor has a first side portion that is continuous with the second surface, The first side portion is a conductive film that is arranged with a first gap between it and the side surface of the groove in the groove width direction.

6. In the conductive film according to any one of claims 1 to 5, A conductive film wherein the upper surface of the conductor further has a third surface that is located on the opposite side of the second surface to the first surface and slopes downward from the first surface toward the side surface of the groove.

7. In the conductive film according to claim 6, The third surface is a conductive film having a curved shape that bulges toward the side where the groove portion is located.

8. In the conductive film according to claim 6, The third surface is a conductive film having a planar shape.

9. In the conductive film according to any one of claims 6 to 8, The aforementioned wiring further includes a third blackened layer, The third blackened layer is a conductive film formed on the third surface.

10. In the conductive film according to any one of claims 6 to 9, The conductor has a second side portion that is continuous with the third surface, The second side portion is a conductive film, which is arranged in the groove width direction with a second gap between it and the side surface of the groove.

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