Wiring board, module and image display device

Abstract

This wiring substrate comprises a substrate and a mesh wiring layer. The wiring substrate has an electromagnetic wave transmission / reception function. The substrate has transparency. The mesh wiring layer is configured as an antenna, and has wires. Two or more openings are formed by being surrounded by the wires. The planar shape of each of the openings is a polygon in which opposing sides are paralleled to each other. The distances between the sides extending in a first direction in the respective openings are each denoted as d. The average value of the distances between the sides extending in the first direction in 100 sequentially adjacent openings or all of the openings is denoted as D. In this case, at least 95% of openings, of the 100 openings or all of the openings, satisfy the relationship of 0.70D≤d≤0.98D or the relationship of 1.02D≤d≤1.30D.

Description

[Technical Field]

[0001] An embodiment of the present disclosure relates to a wiring board, a module, and an image display device. [Background technology]

[0002] Currently, mobile terminal devices such as smartphones and tablets are becoming increasingly sophisticated, smaller, thinner, and lighter. These mobile terminal devices use multiple communication bands. Therefore, multiple antennas corresponding to the communication bands are required. For example, mobile terminal devices are equipped with multiple antennas, such as a telephone antenna, a Wi-Fi (Wireless Fidelity) antenna, a 3G (Generation) antenna, a 4G (Generation) antenna, an LTE (Long Term Evolution) antenna, a Bluetooth (registered trademark) antenna, and an NFC (Near Field Communication) antenna. However, as mobile terminal devices become smaller, the space available for antenna installation is limited, limiting the degree of freedom in antenna design. Furthermore, because antennas are built into a limited space, radio wave sensitivity is not always satisfactory.

[0003] For this reason, a film antenna that can be mounted in the display area of ​​a mobile terminal device has been developed. This film antenna is a transparent antenna in which an antenna pattern is formed on a transparent substrate. The antenna pattern is formed by a mesh-like conductive mesh layer. The conductive mesh layer includes a conductive portion as a formed portion of an opaque conductive layer and a large number of openings as a non-formed portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-66610 [Patent Document 2] Patent No. 5636735 specification [Patent Document 3] Patent No. 5695947 specification

[0005] In conventional film antennas, both areas where an antenna pattern is formed and areas where an antenna pattern is not formed exist on a transparent substrate. However, in mobile terminal devices and the like equipped with the film antenna, the period of the conductive mesh layer (antenna pattern) and the period of the pixels may interfere with each other, resulting in striped patterns (moiré, interference fringes). When moiré occurs, the visibility of images on the mobile terminal devices and the like may be reduced.

[0006] One way to eliminate moire is to eliminate the periodicity of the antenna pattern. However, if the periodicity of the antenna pattern is eliminated, the direction of the wiring will vary, which could result in flickering due to light reflection.

[0007] An object of the present embodiment is to provide a wiring board, a module, and an image display device that can suppress the occurrence of moire and also suppress flickering due to reflected light.

[0008] Moreover, the present embodiment provides a wiring board, a module, and an image display device that can suppress both the occurrence of moire and the occurrence of flicker. DISCLOSURE OF THE INVENTION

[0009] A first aspect of the present disclosure comprises a substrate including a first surface and a second surface located on the opposite side of the first surface, and a mesh wiring layer disposed on the first surface of the substrate, wherein the wiring substrate has an electromagnetic wave transmitting and receiving function, the substrate is transparent, the mesh wiring layer is configured as an antenna and has wiring, and two or more openings are formed by being surrounded by the wiring, the planar shape of the openings is a polygon with opposing sides parallel to each other, and when a distance between sides extending in a first direction in each opening is d and an average value of the distance between sides extending in the first direction in 100 consecutively adjacent openings or all of the openings is D, 95% or more of the openings 0.70D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.30D This is a wiring board that satisfies the following relationship.

[0010] A second aspect of the present disclosure is a wiring substrate according to the first aspect, wherein 95% or more of the 100 openings or all of the openings are 0.85D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.15D The following relationship may be satisfied.

[0011] A third aspect of the present disclosure is a wiring substrate according to the first aspect or the second aspect, wherein 95% or more of the openings among the 100 openings or all of the openings are 0.90D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.10D The following relationship may be satisfied.

[0012] A fourth aspect of the present disclosure is the wiring board according to each of the first to third aspects described above, wherein the polygon may be a rectangle.

[0013] A fifth aspect of the present disclosure is the wiring board according to each of the first to third aspects described above, wherein the polygon may be a hexagon.

[0014] A sixth aspect of the present disclosure is such that, in the wiring board according to each of the first to fifth aspects described above, the average value D may be 50 μm or more and 500 μm or less.

[0015] A seventh aspect of the present disclosure is a wiring board according to each of the first to sixth aspects described above, wherein the wiring has a line width of 0.5 μm or more and 3 μm or less.

[0016] An eighth aspect of the present disclosure is such that, in the wiring board according to each of the first to seventh aspects described above, the mesh wiring layer may have an overall aperture ratio of 95% or more and less than 100%.

[0017] A ninth aspect of the present disclosure is such that, in the wiring board according to each of the first to eighth aspects described above, the mesh wiring layer may have a sheet resistance of 4 Ω / □ or less.

[0018] A tenth aspect of the present disclosure is a wiring board according to each of the first to ninth aspects described above, wherein the wiring board may have a millimeter wave transmission / reception function, and the mesh wiring layer may be configured as an array antenna including two or more antenna elements.

[0019] An eleventh aspect of the present disclosure is the wiring board according to the tenth aspect described above, wherein four or more antenna elements may be provided, and the distance between the antenna elements may be 1 mm or more and 5 mm or less.

[0020] A twelfth aspect of the present disclosure is that, in a wiring substrate according to each of the first aspect to the eleventh aspect described above, a dummy wiring layer electrically independent from the mesh wiring layer may be provided around the mesh wiring layer.

[0021] A thirteenth aspect of the present disclosure is a wiring board according to the twelfth aspect described above, wherein the dummy wiring layer may include two or more dummy wirings, and the dummy wirings may extend parallel to the wirings.

[0022] A fourteenth aspect of the present disclosure is that in a wiring board according to the twelfth aspect or the thirteenth aspect described above, two or more dummy wiring layers may be provided, and the aperture ratios of the mesh wiring layer and the dummy wiring layer may increase stepwise from the mesh wiring layer to the dummy wiring layer farther from the mesh wiring layer.

[0023] A fifteenth aspect of the present disclosure comprises a substrate including a first surface and a second surface located on the opposite side of the first surface, a mesh wiring layer disposed on the first surface of the substrate, and a power supply portion electrically connected to the mesh wiring layer, wherein the substrate is transparent, and the mesh wiring layer has a transmission portion connected to the power supply portion and a transceiver portion connected to the transmission portion, and the mesh wiring layer has wiring constituting the transmission portion and the transceiver portion, and two or more openings are formed by being surrounded by the wiring, and the planar shape of the openings is a polygon with opposing sides parallel to each other, and when a distance between sides extending in a first direction in each opening is d and an average value of the distance between sides extending in the first direction in 100 consecutively adjacent openings or all of the openings is D, then 95% or more of the openings are 0.70D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.30D This is a wiring board that satisfies the following relationship.

[0024] A sixteenth aspect of the present disclosure is a module comprising a wiring board according to any one of the first to fifteenth aspects described above and a power supply line electrically connected to the wiring board.

[0025] A seventeenth aspect of the present disclosure is an image display device including the module according to the sixteenth aspect described above, and a display device stacked on the wiring substrate of the module.

[0026] An eighteenth aspect of the present disclosure includes a substrate including a first surface and a second surface located opposite to the first surface, and a mesh wiring layer disposed on the first surface of the substrate, wherein the wiring substrate has an electromagnetic wave transmitting and receiving function, the substrate is transparent, the mesh wiring layer is configured as an antenna, and has a plurality of first wirings and a plurality of second wirings intersecting with the first wirings, an intersection of the first wirings and the second wirings is defined as A, an intersection of a first regression line obtained from the plurality of intersections A located on the same first wirings is defined as B, and a distance along a width direction of the mesh wiring layer from the intersection A to the closest intersection B is defined as d X The distance from the intersection point A to the nearest intersection point B along the longitudinal direction of the mesh wiring layer is d Y The average value of the pitches of the 10 adjacent intersections B in the width direction is D X The average value of the pitches of the 10 adjacent intersections B in the longitudinal direction is D Y When the intersections A are closest to each of the 10 intersections B, at least 9 of the 10 intersections A are 0.02D X ≦d X <0.3D X The relationship, and 0.02D Y ≦d Y <0.3D Y This is a wiring board that satisfies at least one of the following relationships.

[0027] A nineteenth aspect of the present disclosure is the wiring board according to the eighteenth aspect, wherein, among the ten intersections A that are respectively closest to each of the ten intersections B, nine or more of the intersections A are 0.02D X ≦d X <0.3D X The relationship, and 0.02D Y ≦d Y <0.3D Y The following relationship may be satisfied.

[0028] A twentieth aspect of the present disclosure is a wiring board according to the eighteenth aspect or the nineteenth aspect, wherein the average value D X and average value D Y may be 50 μm or more and 500 μm or less.

[0029] A 21st aspect of the present disclosure is a wiring board according to each of the 18th to 20th aspects described above, wherein the line width of the first wiring and the line width of the second wiring may each be 0.5 μm or more and 3 μm or less.

[0030] A 22nd aspect of the present disclosure is a wiring board according to each of the 18th to 21st aspects described above, wherein the overall aperture ratio of the mesh wiring layer may be 95% or more and less than 100%.

[0031] A twenty-third aspect of the present disclosure is the wiring board according to each of the eighteenth to twenty-second aspects described above, wherein the mesh wiring layer has a sheet resistance of 4 Ω / □ or less.

[0032] A 24th aspect of the present disclosure is a wiring board according to each of the 18th aspect to the 23rd aspect described above, wherein the angle between the first regression line and the second regression line may be greater than or equal to 30° and less than or equal to 150°.

[0033] A 25th aspect of the present disclosure is a wiring board according to each of the above-mentioned 18th aspect to the above-mentioned 24th aspect, wherein the wiring board may have a millimeter wave transmission / reception function, and the mesh wiring layer may be configured as an array antenna including two or more antenna elements.

[0034] A 26th aspect of the present disclosure is a wiring board according to the 25th aspect described above, wherein four or more antenna elements may be provided, and the distance between the antenna elements may be 1 mm or more and 5 mm or less.

[0035] A 27th aspect of the present disclosure is that, in a wiring substrate according to each of the above-mentioned 18th aspect to the above-mentioned 26th aspect, a dummy wiring layer electrically independent from the mesh wiring layer may be provided around the mesh wiring layer.

[0036] A 28th aspect of the present disclosure is a wiring board according to the 27th aspect described above, wherein the dummy wiring layer may include a plurality of dummy wirings, and the dummy wirings may extend parallel to the first wiring or the second wiring.

[0037] A 29th aspect of the present disclosure is that, in a wiring substrate according to the 27th aspect or the 28th aspect described above, multiple dummy wiring layers may be provided, and the aperture ratios of the mesh wiring layer and the dummy wiring layer may gradually increase from the mesh wiring layer to the dummy wiring layer farther from the mesh wiring layer.

[0038] A 30th aspect of the present disclosure is that the wiring board according to each of the above-described 18th to 29th aspects may further include a power supply unit electrically connected to the mesh wiring layer, and the mesh wiring layer may have a power transmission unit connected to the power supply unit and a transceiver unit connected to the power transmission unit, and the transceiver unit may include a central portion and a peripheral portion located around the central portion, and the distance d X is the distance d in the central portion Xand the distance d Y is the distance d in the central portion Y It may be smaller than

[0039] A thirty-first aspect of the present disclosure is a wiring board according to the thirtieth aspect, wherein the distance d X is the distance d in the central portion X and the distance d Y is the distance d in the central portion Y It may be 20% or more and 80% or less of the above.

[0040] A 32nd aspect of the present disclosure is a wiring board according to either the 30th aspect or the 31st aspect described above, wherein in the longitudinal direction, 50% or more of the area of ​​the central portion on the transmission section side may be surrounded by the peripheral portion.

[0041] A thirty-third aspect of the present disclosure is a wiring board according to any one of the thirtieth to thirty-second aspects, wherein the width of the peripheral portion is less than the average value D X It may be twice or more.

[0042] A 34th aspect of the present disclosure includes a substrate including a first surface and a second surface located opposite to the first surface, and a mesh wiring layer disposed on the first surface of the substrate, wherein the substrate is transparent, and the mesh wiring layer has a transmission section connected to the power supply section and a transceiver section connected to the transmission section, the mesh wiring layer has first wiring and second wiring constituting the transmission section and the transceiver section, an intersection of the first wiring and the second wiring is defined as A, an intersection of a first regression line obtained from a plurality of the intersections A located on the same first wiring with a second regression line obtained from a plurality of the intersections A located on the same second wiring is defined as B, and a distance along a width direction of the mesh wiring layer from the intersection A to the closest intersection B is defined as d XThe distance from the intersection point A to the nearest intersection point B along the longitudinal direction of the mesh wiring layer is d Y The average value of the pitches of the 10 adjacent intersections B in the width direction is D X The average value of the pitches of the 10 adjacent intersections B in the longitudinal direction is D Y When the intersections A are closest to each of the 10 intersections B, at least 9 of the 10 intersections A are 0.02D X ≦d X <0.3D X The relationship, and 0.02D Y ≦d Y <0.3D Y The wiring board satisfies at least one of the following relationships.

[0043] A 35th aspect of the present disclosure is a module comprising a wiring board according to any one of the 18th aspect to the 34th aspect described above and a power supply line electrically connected to the wiring board.

[0044] A thirty-sixth aspect of the present disclosure is an image display device including the module according to the thirty-fifth aspect described above, and a display device stacked on the wiring substrate of the module.

[0045] A thirty-seventh aspect of the present disclosure is an image display device according to the thirty-sixth aspect, wherein the display device may have a plurality of pixels repeatedly arranged along the width direction and the length direction, and the average value D X may be equal to or smaller than (N-0.05) times (N is a natural number) and equal to or larger than (N+0.05) times the pitch of the pixels in the width direction, and the average value D Y may be equal to or smaller than (M-0.05) times (M is a natural number) the pixel pitch in the longitudinal direction, and may be equal to or larger than (M+0.05) times.

[0046] A thirty-eighth aspect of the present disclosure is the image display device according to the thirty-seventh aspect, wherein the average value D X may be equal to or greater than (N-0.2) times and equal to or less than (N+0.2) times the pixel pitch in the width direction.

[0047] A thirty-ninth aspect of the present disclosure is an image display device according to the thirty-seventh aspect or the thirty-eighth aspect, wherein the average value D Y may be equal to or greater than (M-0.2) times and equal to or less than (M+0.2) times the pixel pitch in the longitudinal direction.

[0048] A fortieth aspect of the present disclosure is an image display device according to each of the above-mentioned thirty-seventh to thirty-ninth aspects, wherein N and M may each be a natural number between 1 and 6, inclusive.

[0049] A forty-first aspect of the present disclosure is a wiring substrate comprising: a substrate; and a mesh wiring layer disposed on the substrate, the substrate being transparent, the mesh wiring layer having a plurality of intersections and wires located between the intersections, an opening being formed by being surrounded by the plurality of wires, and an average value of a ratio of the length of the wires between the intersections to the shortest distance between the intersections for each of the plurality of wires surrounding the opening being 1.01 to 1.82. "Transparent" means that the transmittance of light having a wavelength of 400 nm to 700 nm is 85% or more.

[0050] A forty-second aspect of the present disclosure is the wiring board according to the forty-first aspect described above, wherein the wiring may have a line width of 0.1 μm or more and 5.0 μm or less.

[0051] A forty-third aspect of the present disclosure is the wiring board according to the forty-first aspect or the forty-second aspect, wherein the planar shape of the wiring is a sine curve.

[0052] A 44th aspect of the present disclosure is a wiring board according to each of the above-mentioned 41st to 43rd aspects, wherein the non-periodic planar structure constituting the mesh wiring layer may be a Voronoi pattern.

[0053] A 45th aspect of the present disclosure is that, in a wiring substrate according to each of the above-mentioned 41st to 43rd aspects, the non-periodic planar structure constituting the mesh wiring layer may be formed by randomly displacing periodically arranged intersections in various directions by a distance smaller than a predetermined distance.

[0054] A 46th aspect of the present disclosure is a wiring board according to each of the above-mentioned 41st to 45th aspects, wherein the overall aperture ratio of the mesh wiring layer may be 96% or more and less than 100%.

[0055] A 47th aspect of the present disclosure is that, in a wiring substrate according to each of the above-mentioned 41st aspect to the above-mentioned 46th aspect, a dummy wiring layer electrically independent from the mesh wiring layer may be provided around the mesh wiring layer.

[0056] A 48th aspect of the present disclosure is a module comprising a wiring board according to any one of the 41st to 47th aspects described above and a power supply line electrically connected to the wiring board.

[0057] A forty-ninth aspect of the present disclosure is an image display device including the module according to the forty-eighth aspect described above.

[0058] A fiftieth aspect of the present disclosure is the image display device according to the forty-ninth aspect, wherein the mesh wiring layer may function as an antenna.

[0059] A 51st aspect of the present disclosure is an image display device according to the 49th aspect or the 50th aspect described above, wherein the wiring substrate may further have a power supply section electrically connected to the mesh wiring layer, and the mesh wiring layer may include a transmission section connected to the power supply section and a transceiver section connected to the transmission section.

[0060] According to the embodiments of the present disclosure, it is possible to suppress the occurrence of moire and also suppress flickering due to reflected light.

[0061] Furthermore, according to the embodiment of the present disclosure, it is possible to suppress both the occurrence of moire and flickering. [Brief explanation of the drawings]

[0062] [Figure 1] FIG. 1 is a plan view showing an image display device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view (cross-sectional view taken along line II-II in FIG. 1) showing the image display device according to the first embodiment. [Figure 3] FIG. 3 is a plan view showing pixels of the display device of the image display device according to the first embodiment. [Figure 4] FIG. 4 is a plan view showing the wiring board according to the first embodiment. [Figure 5A] FIG. 5A is an enlarged plan view showing a mesh wiring layer of the wiring board according to the first embodiment. [Figure 5B] FIG. 5B is an enlarged plan view showing the mesh wiring layer of the wiring board according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view (cross-sectional view taken along line VI-VI in FIG. 5A) showing the wiring board according to the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view (cross-sectional view taken along line VII-VII in FIG. 5A) showing the wiring board according to the first embodiment. [Figure 8] FIG. 8 is a perspective view showing a mesh wiring layer of the wiring board according to the first embodiment. [Figure 9]9(a) to 9(f) are cross-sectional views showing the method for manufacturing the wiring board according to the first embodiment. [Figure 10] FIG. 10 is a plan view showing a wiring board according to a first modified example. [Figure 11] FIG. 11 is an enlarged plan view showing a wiring board according to a first modified example. [Figure 12] FIG. 12 is a plan view showing a wiring board according to a second modified example. [Figure 13] FIG. 13 is an enlarged plan view showing a wiring board according to a second modified example. [Figure 14] FIG. 14 is an enlarged plan view showing a mesh wiring layer of a wiring board according to a third modified example. [Figure 15] FIG. 15 is a plan view showing a wiring board according to a fourth modified example. [Figure 16] FIG. 16 is an enlarged plan view showing a wiring board according to a fourth modified example. [Figure 17] FIG. 17 is an enlarged plan view showing a mesh wiring layer of a wiring board according to a fifth modified example. [Figure 18] FIG. 18 is an enlarged plan view showing the mesh wiring layer of the wiring board according to Comparative Example A1. [Figure 19] FIG. 19 is an enlarged plan view showing the mesh wiring layer of the wiring board according to Comparative Example A2. [Figure 20] FIG. 20 is an enlarged plan view showing the mesh wiring layer of the wiring board according to Comparative Example A3. [Figure 21] FIG. 21 is an enlarged plan view showing a mesh wiring layer of a wiring board according to the second embodiment. [Figure 22] 22 is an enlarged plan view (enlarged view of part XXII in FIG. 21) showing the mesh wiring layer of the wiring board according to the second embodiment. [Figure 23] FIG. 23 is a cross-sectional view (cross-sectional view taken along line XXIII-XXIII in FIG. 21) showing the wiring board according to the second embodiment. [Figure 24] FIG. 24 is a cross-sectional view (cross-sectional view taken along line XXIV-XXIV in FIG. 21) showing the wiring board according to the second embodiment. [Figure 25] FIG. 25 is a plan view showing a wiring board according to a first modified example. [Figure 26] FIG. 26 is an enlarged plan view showing a wiring board according to a first modified example. [Figure 27] FIG. 27 is an enlarged plan view showing a wiring board according to a second modified example. [Figure 28] FIG. 28 is a plan view showing a wiring board according to a third modified example. [Figure 29] FIG. 29 is a plan view showing a wiring board according to a third embodiment. [Figure 30] 30 is an enlarged plan view showing a mesh wiring layer of a wiring board according to a third embodiment (an enlarged view of a portion XXX in FIG. 29). [Figure 31] 31(a)-(c) are enlarged plan views showing the wiring. [Figure 32] 32 is a cross-sectional view showing the wiring board according to the third embodiment (a cross-sectional view taken along line XXXII-XXXII in FIG. 30). [Figure 33] 33(a) to 33(f) are cross-sectional views showing a method for manufacturing a wiring substrate according to a third embodiment. [Figure 34] FIG. 34 is a plan view showing an image display device according to a third embodiment. [Figure 35] FIG. 35 is an enlarged plan view showing a mesh wiring layer of a wiring board according to a first modified example. [Figure 36] FIG. 36 is a plan view showing a wiring board according to a second modified example. [Figure 37] 37 is an enlarged plan view showing a mesh wiring layer of a wiring board according to a second modified example (an enlarged view of a portion XXXVII in FIG. 36). DETAILED DESCRIPTION OF THE INVENTION

[0063] (First embodiment) First, a first embodiment will be described with reference to Figures 1 to 9. Figures 1 to 9 are diagrams showing this embodiment.

[0064] The figures shown below are schematic diagrams. Therefore, the size and shape of each part are appropriately exaggerated for ease of understanding. Furthermore, appropriate modifications can be made within the scope of the technical concept. In the figures shown below, the same parts are denoted by the same reference numerals, and some detailed descriptions may be omitted. Furthermore, the numerical values, such as dimensions, and material names of each component described in this specification are examples of embodiments, and are not limited to these and may be selected and used as appropriate. In this specification, terms specifying shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are interpreted not only to mean their strict meanings but also to include substantially the same state.

[0065] In the following embodiments, the "X direction" refers to a direction parallel to one side of the image display device. The "Y direction" refers to a direction perpendicular to the X direction and parallel to another side of the image display device. The "Z direction" refers to a direction perpendicular to both the X direction and the Y direction and parallel to the thickness direction of the image display device. The "front surface" refers to the surface on the positive side of the Z direction, which is the light-emitting surface side of the image display device and faces the viewer. The "rear surface" refers to the surface on the negative side of the Z direction, which is the surface opposite to the light-emitting surface of the image display device and the surface facing the viewer. Note that in this embodiment, the mesh wiring layer 20 is described as having a radio wave transmitting and receiving function (i.e., a function as an antenna), but the mesh wiring layer 20 does not necessarily have a radio wave transmitting and receiving function.

[0066] The configuration of the image display device according to this embodiment will be described with reference to FIGS.

[0067] As shown in FIGS. 1 and 2, an image display device 60 according to this embodiment includes a wiring substrate 10 and a display device 61 laminated on the wiring substrate 10.

[0068] The wiring board 10 has a substrate 11, a mesh wiring layer 20, and a power supply unit 40. As shown in FIG. 2, the substrate 11 includes a first surface 11a and a second surface 11b located on the opposite side of the first surface 11a. Two or more (plural) mesh wiring layers 20 are arranged on the first surface 11a of the substrate 11. Each mesh wiring layer 20 is electrically connected to a power supply unit 40. Furthermore, a communication module 63 is arranged on the negative side in the Z direction relative to the display device 61. The laminate 70 for an image display device, the display device 61, and the communication module 63 are housed in a housing 62.

[0069] 1 and 2, radio waves of a predetermined frequency can be transmitted and received via a communication module 63, enabling communication. The communication module 63 may include any of a millimeter wave antenna, a telephone antenna, a Wi-Fi antenna, a 3G antenna, a 4G antenna, a 5G antenna, an LTE antenna, a Bluetooth (registered trademark) antenna, an NFC antenna, etc. Examples of such an image display device 60 include mobile terminal devices such as smartphones and tablets.

[0070] 2, the image display device 60 has a light-emitting surface 64. The image display device 60 includes a wiring board 10 located on the light-emitting surface 64 side (i.e., the positive side in the Z direction) of the display device 61, and a communication module 63 located on the opposite side of the light-emitting surface 64 of the display device 61 (i.e., the negative side in the Z direction).

[0071] The display device 61 is, for example, an organic EL (Electro Luminescence) display device. The display device 61 has a plurality of pixels P (see FIG. 3) repeatedly arranged along a first direction (for example, the Y direction) and a second direction (for example, the X direction). Details of the pixels P will be described later.

[0072] The display device 61 may include, for example, a metal layer, a support substrate, a resin substrate, a thin film transistor (TFT), and an organic EL layer, all of which are not shown. A touch sensor, all of which are not shown, may be disposed on the display device 61. A wiring substrate 10 is disposed on the display device 61 via a second transparent adhesive layer 96. The display device 61 is not limited to an organic EL display device. For example, the display device 61 may be another display device that has the function of emitting light itself, or may be a micro LED display device including micro LED elements. The display device 61 may also be a liquid crystal display device including liquid crystal.

[0073] A cover glass 75 is disposed on the wiring substrate 10 via a first transparent adhesive layer 95. Note that a decorative film and a polarizing plate (not shown) may be disposed between the first transparent adhesive layer 95 and the cover glass 75.

[0074] The first transparent adhesive layer 95 is an adhesive layer that directly or indirectly bonds the wiring substrate 10 to the cover glass 75. This first transparent adhesive layer 95 is located on the first surface 11a side of the substrate 11. The first transparent adhesive layer 95 is optically transparent and may be an OCA (Optical Clear Adhesive) layer. The OCA layer is a layer prepared, for example, as follows: First, a liquid curable adhesive layer composition containing a polymerizable compound is applied to a release film such as polyethylene terephthalate (PET). Next, the composition is cured using, for example, ultraviolet (UV) light to obtain an OCA sheet. After the OCA sheet is attached to an object, the release film is peeled off and removed to obtain the OCA layer. The material of the first transparent adhesive layer 95 may be an acrylic resin, a silicone resin, a urethane resin, or the like. In particular, the first transparent adhesive layer 95 may contain an acrylic resin. In this case, it is preferable that the second transparent adhesive layer 96 contains an acrylic resin. This substantially eliminates the difference in refractive index between the first transparent adhesive layer 95 and the second transparent adhesive layer 96, and more reliably suppresses reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96.

[0075] The first transparent adhesive layer 95 may have a visible light transmittance of 85% or more, preferably 90% or more. There is no particular upper limit to the visible light transmittance of the first transparent adhesive layer 95, but it may be, for example, 100% or less. By setting the visible light transmittance of the first transparent adhesive layer 95 within the above range, the transparency of the laminate 70 for an image display device can be increased, making it easier to view the display device 61 of the image display device 60. Visible light refers to light with a wavelength of 400 nm or more and 700 nm or less. A visible light transmittance of 85% or more means that, when the absorbance of the member to be measured (e.g., the first transparent adhesive layer 95) is measured, the transmittance is 85% or more over the entire wavelength range of 400 nm or more and 700 nm or less. The absorbance can be measured using a known spectrophotometer (e.g., a V-670 spectrometer manufactured by JASCO Corporation).

[0076] As described above, the wiring substrate 10 is disposed on the light-emitting surface 64 side of the display device 61. In this case, the wiring substrate 10 is located between the first transparent adhesive layer 95 and the second transparent adhesive layer 96. More specifically, a portion of the substrate 11 of the wiring substrate 10 is disposed in a portion of the region between the first transparent adhesive layer 95 and the second transparent adhesive layer 96. In this case, the first transparent adhesive layer 95, the second transparent adhesive layer 96, the display device 61, and the cover glass 75 each have a larger area than the substrate 11 of the wiring substrate 10. In this way, by disposing the substrate 11 of the wiring substrate 10 in a portion of the image display device 60 rather than over the entire surface in a plan view, the overall thickness of the image display device 60 can be reduced.

[0077] As described above, the wiring substrate 10 includes a transparent substrate 11 and a mesh wiring layer 20 disposed on the first surface 11a of the substrate 11. Two or more (plural) mesh wiring layers 20 are disposed spaced apart from each other on the first surface 11a of the substrate 11. The mesh wiring layer 20 is electrically connected to the power supply unit 40. The power supply unit 40 is electrically connected to the communication module 63 via a power supply line (not shown). A portion of the wiring substrate 10 is not disposed between the first transparent adhesive layer 95 and the second transparent adhesive layer 96, but protrudes outward (i.e., toward the negative Y-direction) from between the first transparent adhesive layer 95 and the second transparent adhesive layer 96. Specifically, the region of the wiring substrate 10 where the power supply unit 40 is provided protrudes outward. This facilitates electrical connection between the power supply unit 40 and the communication module 63. Meanwhile, the region of the wiring substrate 10 where the mesh wiring layer 20 is provided is located between the first transparent adhesive layer 95 and the second transparent adhesive layer 96. The details of the wiring board 10 will be described later.

[0078] The second transparent adhesive layer 96 is an adhesive layer that directly or indirectly adheres the display device 61 to the wiring substrate 10. This second transparent adhesive layer 96 is located on the second surface 11b side of the substrate 11. Like the first transparent adhesive layer 95, the second transparent adhesive layer 96 has optical transparency and may be an OCA (Optical Clear Adhesive) layer. The material of the second transparent adhesive layer 96 may be an acrylic resin, a silicone resin, a urethane resin, or the like. In particular, the second transparent adhesive layer 96 may contain an acrylic resin. This substantially eliminates the difference in refractive index between the first transparent adhesive layer 95 and the second transparent adhesive layer 96, thereby more reliably suppressing reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96.

[0079] The second transparent adhesive layer 96 may have a transmittance of 85% or more, and preferably 90% or more, for visible light (i.e., light with a wavelength of 400 nm or more and 700 nm or less). There is no particular upper limit to the visible light transmittance of the second transparent adhesive layer 96, but it may be, for example, 100% or less. By setting the visible light transmittance of the second transparent adhesive layer 96 to be within the above range, the transparency of the laminate 70 for an image display device can be increased, and the display device 61 of the image display device 60 can be made easier to view.

[0080] In this image display device 60, the difference in refractive index between the substrate 11 and the first transparent adhesive layer 95 is 0.1 or less, and preferably 0.05 or less. The difference in refractive index between the substrate 11 and the second transparent adhesive layer 96 is 0.1 or less, and preferably 0.05 or less. The difference in refractive index between the first transparent adhesive layer 95 and the second transparent adhesive layer 96 is preferably 0.1 or less, and more preferably 0.05 or less. For example, if the first transparent adhesive layer 95 and the second transparent adhesive layer 96 are made of acrylic resins with a refractive index of 1.49, the refractive index of the substrate 11 is set to 1.39 or more and 1.59 or less. Examples of such materials include fluororesins, silicone resins, polyolefin resins, polyester resins, acrylic resins, polycarbonate resins, polyimide resins, and cellulose resins.

[0081] Thus, by keeping the difference between the refractive index of the substrate 11 and the refractive index of the first transparent adhesive layer 95 to 0.1 or less, reflection of visible light at the interface B1 between the substrate 11 and the first transparent adhesive layer 95 is suppressed, making the substrate 11 less visible to the naked eye of an observer. Furthermore, by keeping the difference between the refractive index of the substrate 11 and the refractive index of the second transparent adhesive layer 96 to 0.1 or less, reflection of visible light at the interface B2 between the substrate 11 and the second transparent adhesive layer 96 is suppressed, making the substrate 11 less visible to the naked eye of an observer. Furthermore, by keeping the difference between the refractive index of the first transparent adhesive layer 95 and the refractive index of the second transparent adhesive layer 96 to 0.1 or less, reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96 is suppressed. Therefore, the first transparent adhesive layer 95 and the second transparent adhesive layer 96 are less visible to the naked eye of an observer.

[0082] In particular, it is preferable that the material of the first transparent adhesive layer 95 and the material of the second transparent adhesive layer 96 are the same. This makes it possible to further reduce the difference in refractive index between the first transparent adhesive layer 95 and the second transparent adhesive layer 96, and suppress reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96.

[0083] 2, at least one of the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 may be 1.5 times or more, preferably 2 times or more, and more preferably 2.5 times or more, the thickness T1 of the substrate 11. By making the thickness T3 of the first transparent adhesive layer 95 or the thickness T4 of the second transparent adhesive layer 96 sufficiently thicker than the thickness T1 of the substrate 11, the first transparent adhesive layer 95 or the second transparent adhesive layer 96 deforms in the thickness direction in the region overlapping with the substrate 11, absorbing the thickness of the substrate 11. This makes it possible to prevent steps from occurring in the first transparent adhesive layer 95 or the second transparent adhesive layer 96 around the periphery of the substrate 11, making it difficult for an observer to perceive the presence of the substrate 11.

[0084] At least one of the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 is preferably 10 times or less, and more preferably 5 times or less, the thickness T1 of the substrate 11. This prevents the thickness T3 of the first transparent adhesive layer 95 or the thickness T4 of the second transparent adhesive layer 96 from becoming too thick, and allows the overall thickness of the image display device 60 to be thin.

[0085] 2, the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 may be the same. In this case, the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 may each be 1.5 times or more, and preferably 2.0 times or more, the thickness T1 of the substrate 11. That is, the sum of the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 (i.e., T3 + T4) is three times or more the thickness T1 of the substrate 11. In this way, by making the sum of the thicknesses T3 and T4 of the first transparent adhesive layer 95 and the second transparent adhesive layer 96 sufficiently thick relative to the thickness T1 of the substrate 11, the first transparent adhesive layer 95 and the second transparent adhesive layer 96 deform (shrink) in the thickness direction in the region overlapping with the substrate 11. As a result, the first transparent adhesive layer 95 and the second transparent adhesive layer 96 absorb the thickness of the substrate 11. Therefore, it is possible to prevent steps from occurring in the first transparent adhesive layer 95 or the second transparent adhesive layer 96 at the periphery of the substrate 11, making it difficult for an observer to notice the presence of the substrate 11.

[0086] When the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 are the same, the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 may each be five times or less, and preferably three times or less, the thickness T1 of the substrate 11. This prevents the thicknesses T3 and T4 of the first transparent adhesive layer 95 and the second transparent adhesive layer 96 from becoming too thick, and allows the overall thickness of the image display device 60 to be thin.

[0087] Specifically, the thickness T1 of the substrate 11 may be, for example, 2 μm or more, 10 μm or more, and preferably 15 μm or more. By setting the thickness T1 of the substrate 11 to 2 μm or more, the strength of the wiring substrate 10 can be maintained and the first wiring 21 and second wiring 22 (described later) of the mesh wiring layer 20 can be made less likely to deform. Furthermore, the thickness T1 of the substrate 11 may be, for example, 200 μm or less, 50 μm or less, and preferably 25 μm or less. Setting the thickness T1 of the substrate 11 to 200 μm or less prevents the first transparent adhesive layer 95 and the second transparent adhesive layer 96 from forming steps at the periphery of the substrate 11, making it difficult for an observer to recognize the presence of the substrate 11. Setting the thickness T1 of the substrate 11 to 50 μm or less further prevents the first transparent adhesive layer 95 and the second transparent adhesive layer 96 from forming steps at the periphery of the substrate 11, making it even more difficult for an observer to recognize the presence of the substrate 11.

[0088] The thickness T3 of the first transparent adhesive layer 95 may be, for example, 15 μm or more, and preferably 20 μm or more. The thickness T3 of the first transparent adhesive layer 95 may be, for example, 500 μm or less, and preferably 300 μm or less, and more preferably 250 μm or less. The thickness T4 of the second transparent adhesive layer 96 may be, for example, 15 μm or more, and preferably 20 μm or more. The thickness T4 of the second transparent adhesive layer 96 may be, for example, 500 μm or less, and preferably 300 μm or less, and more preferably 250 μm or less.

[0089] Referring again to FIG. 2, the cover glass 75 is disposed directly or indirectly on the first transparent adhesive layer 95. This cover glass 75 is a light-transmitting glass member. The cover glass 75 is plate-shaped, and the shape of the cover glass 75 may be rectangular in plan view. The thickness of the cover glass 75 may be, for example, 200 μm to 1000 μm, and preferably 300 μm to 700 μm. The length of the cover glass 75 in the longitudinal direction (i.e., Y direction) may be, for example, 20 mm to 500 mm, and preferably 100 mm to 200 mm. The length of the cover glass 75 in the lateral direction (i.e., X direction) may be, for example, 20 mm to 500 mm, and preferably 50 mm to 100 mm.

[0090] As shown in FIG. 1, the shape of the image display device 60 is generally rectangular in plan view, with its longitudinal direction parallel to the Y direction and its lateral direction parallel to the X direction. The length L4 of the image display device 60 in the longitudinal direction (i.e., the Y direction) can be selected, for example, from 20 mm to 500 mm, and preferably from 100 mm to 200 mm. The length L5 of the image display device 60 in the lateral direction (i.e., the X direction) can be selected, for example, from 20 mm to 500 mm, and preferably from 50 mm to 100 mm. The planar shape of the image display device 60 may also be a rectangle with rounded corners.

[0091] Next, the pixel P of the display device 61 will be described with reference to FIG.

[0092] Fig. 3 is a plan view showing an example of the arrangement of a pixel P and subpixels S included in the pixel P. In Fig. 3, subpixels S marked with "R" indicate subpixels S that emit red light. Subpixels S marked with "G" indicate subpixels S that emit green light. Subpixels S marked with "B" indicate subpixels S that emit blue light.

[0093] The display device 61 has a plurality of pixels P regularly arranged along the width direction (i.e., X direction) and the length direction (i.e., Y direction) of the mesh wiring layer 20. The plurality of pixels P are arranged at a constant pitch P in the X direction. X and their pitch is P X The pitch P may be, for example, in the range of 50 μm to 200 μm. Y and their pitch is P Y may be, for example, in the range of about 50 μm or more and 200 μm or less.

[0094] Each pixel P includes a plurality of subpixels S. Each subpixel S includes an OLED (organic light-emitting diode) capable of emitting light of a corresponding color. In the example shown in FIG. 3, each pixel P includes subpixels S capable of emitting light of three colors (i.e., red, green, and blue). The subpixels S included in each pixel P are aligned in both the X direction and the Y direction. In the example shown in FIG. 3, the subpixel S emitting green light is aligned in the X direction, spaced apart from the subpixel S emitting red light and the subpixel S emitting blue light. Furthermore, the subpixel S emitting red light and the subpixel S emitting blue light are aligned in the Y direction, spaced apart from each other.

[0095] The types (i.e., luminescent colors) and number of subpixels S included in each pixel P are not particularly limited. For example, each pixel P may include subpixels S capable of emitting two or four or more colors. Furthermore, the relative positional relationship between the subpixels S within each pixel P is also not particularly limited. For example, within each pixel P, the subpixels S may be arranged so as to be aligned only in either the X direction or the Y direction. The subpixels S within each pixel P may be arranged adjacent to or in close contact with each other.

[0096] In this way, each subpixel S constitutes an individual light-emitting element. Each pixel P is composed of a set of multiple subpixels S that form a repeating unit. The arrangement of the pixels P and subpixels S is not limited to the example shown in FIG. 3. The pixels P and subpixels S may be arranged in any shape. For example, in the example shown in FIG. 3, one subpixel S of each color (i.e., red, green, and blue) is included within each square pixel P. However, the shape of each pixel P is not necessarily limited to a square. Each pixel P may also include multiple subpixels S of each color.

[0097] Next, the configuration of the wiring board will be described with reference to Figures 4 to 7. Figures 4 to 7 are diagrams showing the wiring board according to this embodiment.

[0098] As shown in FIG. 4, the wiring board 10 according to this embodiment is a board used in the image display device 60 described above (see FIGS. 1 and 2). The wiring board 10 can be disposed on the light-emitting surface 64 side of the display device 61, between a first transparent adhesive layer 95 and a second transparent adhesive layer 96. As described above, the wiring board 10 has a transparent substrate 11 and a mesh wiring layer 20 disposed on the substrate 11. The mesh wiring layer 20 is electrically connected to a power supply unit 40.

[0099] The shape of the substrate 11 is approximately rectangular in plan view. In the illustrated example, its longitudinal direction is parallel to the X direction, and its lateral direction is parallel to the Y direction. The substrate 11 is transparent and approximately flat, and its thickness is approximately uniform overall. The length L1 of the substrate 11 in the longitudinal direction (i.e., Y direction) of the image display device 60 can be selected, for example, from 2 mm to 300 mm, from 10 mm to 200 mm, or from 100 mm to 200 mm. The length L2 of the substrate 11 in the lateral direction (i.e., X direction) of the image display device 60 can be selected, for example, from 2 mm to 300 mm, from 3 mm to 100 mm, or from 50 mm to 100 mm. The planar shape of the substrate 11 may be a rectangle with rounded corners.

[0100] The material of the substrate 11 may be any material as long as it is transparent in the visible light range and has electrical insulation properties. The substrate 11 is preferably made of an organic insulating material such as a polyester resin, an acrylic resin, a polycarbonate resin, a polyimide resin, a polyolefin resin, a cellulose resin, or a fluororesin material. The polyester resin may be polyethylene terephthalate or the like. The acrylic resin may be polymethyl methacrylate or the like. The polyolefin resin may be cycloolefin polymer or the like. The cellulose resin may be triacetyl cellulose or the like. The fluororesin material may be PTFE or PFA or the like. For example, the substrate 11 may be made of an organic insulating material such as cycloolefin polymer (e.g., ZF-16 manufactured by Nippon Zeon Co., Ltd.) or polynorbornene polymer (manufactured by Sumitomo Bakelite Co., Ltd.). The substrate 11 may also be made of glass, ceramics, or the like, depending on the application. While the substrate 11 is illustrated as being made of a single layer, the substrate 11 is not limited thereto and may have a structure in which multiple base materials or layers are stacked. Furthermore, the substrate 11 may be a film-like member or a plate-like member.

[0101] The dielectric loss tangent of the substrate 11 may be 0.002 or less, and preferably 0.001 or less. There is no particular lower limit to the dielectric loss tangent of the substrate 11, but it may be greater than 0. When the dielectric loss tangent of the substrate 11 is in the above range, particularly when the electromagnetic waves (e.g., millimeter waves) transmitted and received by the mesh wiring layer 20 are high frequency, the gain loss (i.e., reduction in sensitivity) associated with the transmission and reception of the electromagnetic waves can be reduced.

[0102] The relative dielectric constant of the substrate 11 is preferably 2 or more and 10 or less. When the relative dielectric constant of the substrate 11 is 2 or more, the options for materials for the substrate 11 are increased. Furthermore, when the relative dielectric constant of the substrate 11 is 10 or less, the loss of gain (sensitivity) associated with the transmission and reception of electromagnetic waves can be reduced. That is, when the relative dielectric constant of the substrate 11 is increased, the influence of the thickness of the substrate 11 on the propagation of electromagnetic waves increases. Furthermore, when there is an adverse effect on the propagation of electromagnetic waves, the dielectric loss tangent of the substrate 11 increases, which can increase the loss of gain associated with the transmission and reception of electromagnetic waves. In contrast, when the relative dielectric constant of the substrate 11 is 10 or less, the influence of the thickness of the substrate 11 on the propagation of electromagnetic waves can be reduced. Therefore, the loss of gain associated with the transmission and reception of electromagnetic waves can be reduced. In particular, when the electromagnetic waves (e.g., millimeter waves) transmitted and received by the mesh wiring layer 20 are high frequency, the loss of gain associated with the transmission and reception of electromagnetic waves can be reduced.

[0103] The dielectric loss tangent and relative dielectric constant of the substrate 11 can be measured in accordance with IEC 62562. Specifically, first, a test piece is prepared by cutting out a portion of the substrate 11 where the mesh wiring layer 20 is not formed. The dimensions of the test piece are a width of 10 mm to 20 mm and a length of 50 mm to 100 mm. Next, the dielectric loss tangent or relative dielectric constant is measured in accordance with IEC 62562.

[0104] In this embodiment, substrate 11 is transparent. In this specification, "transparent" means that the transmittance of visible light (i.e., light having a wavelength of 400 nm or more and 700 nm or less) is 85% or more. Substrate 11 may have a visible light transmittance of 85% or more, and preferably 90% or more. There is no particular upper limit to the visible light transmittance of substrate 11, but it may be, for example, 100% or less. By setting the visible light transmittance of substrate 11 to be within the above range, the transparency of wiring board 10 can be increased, and display device 61 of image display device 60 can be made easier to view.

[0105] In this embodiment, the mesh wiring layer 20 is made up of an antenna pattern that functions as an antenna. This mesh wiring layer 20 may be configured as an array antenna including two or more antenna elements (radiating elements (tip side portion 20b, described later)). When the mesh wiring layer 20 is configured as an array antenna in this way, it is possible to improve the millimeter wave antenna performance for transmitting and receiving millimeter waves with high linearity. Note that an array antenna is an antenna in which multiple antenna elements are regularly arranged and in which the amplitude and phase of the excitation of the elements can be independently controlled.

[0106] Two or more (plural) mesh wiring layers 20 are formed on the substrate 11. It is preferable that four or more mesh wiring layers 20 are provided. In this case, four or more antenna elements (tip side portions 20b described later) are provided on the wiring substrate 10. In the illustrated example, four mesh wiring layers 20 are formed on the substrate 11 (see FIG. 1). Also, as shown in FIG. 4, the mesh wiring layer 20 may not be present on the entire surface of the substrate 11, but may be present only in a partial region on the substrate 11. Each mesh wiring layer 20 may have the same shape. In this case, each mesh wiring layer 20 has a length L (i.e., length in the Y direction) of the tip side portion 20b described later. a Error and width (length in X direction) W a It is preferable that the error of each of these is within 10%, which can effectively improve the performance of the millimeter wave antenna.

[0107] The mesh wiring layer 20 has a base end portion (i.e., a power transmission portion) 20a on the power supply unit 40 side, and a tip end portion (i.e., a transmitter / receiver portion) 20b connected to the base end portion 20a. The base end portion 20a is connected to the power supply unit 40. The base end portion 20a and the tip end portion 20b each have a substantially rectangular shape in a plan view. In this case, the length (i.e., the distance in the Y direction) of the tip end portion 20b is longer than the length (i.e., the distance in the Y direction) of the base end portion 20a, and the width (i.e., the distance in the X direction) of the tip end portion 20b is wider than the width (i.e., the distance in the X direction) of the base end portion 20a.

[0108] The tip end portion 20b of the mesh wiring layer 20 corresponds to a predetermined frequency band. That is, the tip end portion 20b has a length (length in the Y direction) L a The length L of the tip portion 20b corresponds to a specific frequency band. a The mesh wiring layer 20 may be compatible with a millimeter wave antenna, a telephone antenna, a WiFi antenna, a 3G antenna, a 4G antenna, a 5G antenna, an LTE antenna, a Bluetooth (registered trademark) antenna, an NFC antenna, or the like. The lengths of the tip portions 20b may be different from each other, and each may correspond to a different frequency band. Alternatively, if the wiring board 10 does not have a radio wave transmission / reception function, each mesh wiring layer 20 may perform functions such as a hovering function, fingerprint authentication, a heater, and noise reduction (shielding). The hovering function refers to a function that allows a user to operate the display without directly touching it.

[0109] The length L of the tip portion 20b in the Y direction is equal to the length L of the tip portion 20b in the X direction. a The width W of the tip portion 20b in the X direction can be selected, for example, in the range of 1 mm to 100 mm. a In particular, when the mesh wiring layer 20 is a millimeter wave antenna, the length L of the tip side portion 20b can be selected within a range of, for example, 1 mm or more and 100 mm or less.a When the mesh wiring layer 20 is a millimeter wave antenna, the length L of the tip side portion 20b can be selected from the range of 1 mm or more, more preferably 1.5 mm or more. a can be selected in the range of 10 mm or less, more preferably 5 mm or less.

[0110] In such a mesh wiring layer 20, the distance between the antenna elements is preferably 1 mm or more and 5 mm or less. 20b The distance D between the tip end portions 20b (see FIG. 4) is preferably 1 mm or more and 5 mm or less. 20b By making the distance D between the tip side portions 20b equal to or greater than 1 mm, unintended interference of electromagnetic waves between the antenna elements can be suppressed. 20b By making the distance D between the tip side portions 20b equal to or less than 5 mm, it is possible to reduce the size of the entire array antenna formed by the mesh wiring layer 20. For example, when the mesh wiring layer 20 is a millimeter wave antenna of 28 GHz, the distance D between the tip side portions 20b is equal to or less than 5 mm. 20b In addition, when the mesh wiring layer 20 is a millimeter wave antenna of 60 GHz, the distance D between the tip side portions 20b may be 3.5 mm. 20b may be 1.6 mm.

[0111] The mesh wiring layer 20 has a pattern shape in which metal wires are arranged in a lattice or mesh shape. This pattern shape is repeatedly arranged in the X direction and the Y direction. That is, the mesh wiring layer 20 has a pattern shape consisting of a portion (i.e., first wirings 21) extending in a first direction (e.g., Y direction) and a portion (i.e., second wirings 22) extending in a second direction (e.g., X direction).

[0112] As shown in FIG. 5A, the mesh wiring layer 20 has wiring. In this embodiment, the mesh wiring layer 20 has two or more wirings. Specifically, the mesh wiring layer 20 has a plurality of first wirings (i.e., wirings) 21 and a plurality of second wirings (i.e., wirings) 22 connecting the plurality of first wirings 21. The plurality of first wirings 21 and the plurality of second wirings 22 are integrated as a whole to form a lattice or mesh shape. Each of the first wirings 21 extends linearly in the Y direction. Each of the second wirings 22 extends linearly in the X direction, which is a direction perpendicular to the first wirings 21.

[0113] In the mesh wiring layer 20, two or more openings 23 are formed by being surrounded by the first wirings 21 and the second wirings 22. Specifically, in the mesh wiring layer 20, a plurality of openings 23 are formed by being surrounded by the first wirings 21 adjacent to each other and the second wirings 22 adjacent to each other. Note that in this specification, an opening refers to a region surrounded by wirings (the first wirings 21 and the second wirings 22) in which there are no wirings connecting the wirings that make up the region. Specifically, in the example shown in FIG. 5B, openings 23A to 23E each constitute one opening 23. In other words, for example, the combined region of openings 23A and 23B does not constitute one opening 23.

[0114] Furthermore, the first wirings 21 and the second wirings 22 are arranged irregularly relative to each other. Specifically, the multiple first wirings 21 are arranged parallel to each other, and the pitch P1 between them is irregular. The pitch P1 may be, for example, in the range of 0.01 mm or more and 1 mm or less. The multiple second wirings 22 are arranged parallel to each other, and the pitch P2 between them is irregular. The pitch P2 may be, for example, in the range of 0.01 mm or more and 1 mm or less.

[0115] As described above, in the present embodiment, the pitch P1 of the plurality of first wirings 21 and the pitch P2 of the plurality of second wirings 22 are both irregular. This makes it possible to reduce the pitch of moire patterns that occur due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P of the display device 61 to a level that is not visible to the naked eye. Furthermore, as described above, the first wirings 21 are arranged parallel to each other, and the second wirings 22 are arranged parallel to each other. Therefore, even when the pitches P1 and P2 are irregular, flickering caused by reflection of visible light by the mesh wiring layer 20 can be suppressed.

[0116] The planar shape of each opening 23 is a polygon with opposing sides parallel to each other. In this embodiment, the first wirings 21 are arranged parallel to each other, and the second wirings 22 are arranged parallel to each other, so the planar shape of each opening 23 is a quadrangle (i.e., a rectangle) with opposing sides parallel to each other. The transparent substrate 11 is exposed from each opening 23. This can increase the transparency of the wiring substrate 10 as a whole.

[0117] As shown in FIG. 5A, the distance between the sides extending in a predetermined direction (first direction) in each opening 23 is defined as d. The average value of the distances d between the sides extending in the predetermined direction in 100 consecutive adjacent openings 23 is defined as D. In this embodiment, 95% or more of the 100 openings 23 are 0.70D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.30D The relationship is satisfied. As described above, in this embodiment, the pitch P1 of the plurality of first wirings 21 and the pitch P2 of the plurality of second wirings 22 are irregular. Therefore, the side-to-side distances d of 100 consecutively adjacent openings 23 may differ from one another. In this case, it is preferable that the side-to-side distances d of 100 consecutively adjacent openings 23 have three or more different values. In this specification, "100 consecutively adjacent openings" means that, in all of the 100 openings 23, an opening 23 is adjacent to at least one of the other openings 23 that make up the 100 openings 23.

[0118] The "100 consecutively adjacent openings" may be selected, for example, as follows. First, as shown in FIG. 5B, an arbitrary opening 23A is selected. Next, an arbitrary opening 23B adjacent to opening 23A is selected. In the illustrated example, opening 23B is adjacent to opening 23A on the positive side in the X direction. Next, an arbitrary opening 23C adjacent to at least one of openings 23A and 23B is selected. In the illustrated example, opening 23C is adjacent to opening 23B on the positive side in the Y direction. Next, an arbitrary opening 23D adjacent to at least one of openings 23A, 23B, and 23C is selected. In the illustrated example, opening 23D is adjacent to opening 23A on the positive side in the Y direction and adjacent to opening 23C on the negative side in the X direction. Next, an arbitrary opening 23E adjacent to at least one of openings 23A, 23B, 23C, and 23D is selected. In the illustrated example, opening 23E is adjacent to opening 23D on the negative side in the X direction. In this manner, 100 openings 23 may be selected.

[0119] Furthermore, when the number of openings 23 in wiring board 10 is less than 100, the average value of the distances d between the sides extending in a predetermined direction in all openings 23 may be set to D. Even in this case, 95% or more of all openings 23 may be 0.70D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.30D This relationship is satisfied.

[0120] Here, as described above, the planar shape of opening 23 is a rectangle. In this case, the planar shape of opening 23 has two pairs of sides extending parallel to each other. The sides of the first pair (i.e., one pair) extend in a first direction (e.g., the X direction), and the sides of the second pair (i.e., the other pair) extend in a second direction (e.g., the Y direction) different from the first direction. In other words, when the planar shape of opening 23 is a 2N-polygon (where N is a natural number greater than or equal to 2), the planar shape of opening 23 has N pairs of sides extending parallel to each other. The sides of each pair extend in a different direction from the sides of the other pairs. That is, the sides of the Mth pair (M is a natural number greater than or equal to 1 and less than or equal to N) extend in the Mth direction, which is different from the direction in which the sides of the other pairs extend.

[0121] For this reason, in this embodiment, the distance between the sides of each opening 23 extending in the M-th direction is set to d M The distance between the sides of 100 adjacent openings 23 is d M The average value of D M When this is the case, of the 100 openings 23, 95% or more of the openings 23 are 0.70D M ≦d M ≦0.98D M Does it satisfy the relationship 1.02D M ≦d M ≦1.30D M The following relationship is satisfied.

[0122] In addition, when the number of openings 23 in the wiring board 10 is less than 100, the distance d between the sides extending in the M-th direction in all of the openings 23 is M The average value of D M In this case, 95% or more of all the openings 23 may be 0.70DM ≦d M ≦0.98D M Does it satisfy the relationship 1.02D M ≦d M ≦1.30D M This relationship is satisfied.

[0123] Specifically, for example, as shown in FIG. 5A, the distance between the sides extending in the longitudinal direction (i.e., the Y direction) of the first wiring 21 is defined as d1. The average value of the distances between the sides d1 in 100 consecutively adjacent openings 23 or in all openings 23 is defined as D1. In this embodiment, of the 100 openings 23 or all openings 23, 95% or more of the openings 23 are 0.70D1≦d1≦0.98D1 Does it satisfy the relationship 1.02D1≦d1≦1.30D1 This satisfies the relationship: The pitch of moire patterns that occur due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P of the display device 61 can be reduced to an extent that is not visible to the naked eye.

[0124] That is, in the above-described image display device 60, the mesh wiring layer 20 of the wiring substrate 10 is disposed so as to overlap the pixels P of the display device 61 in the Z direction. Therefore, moire may occur due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P. In contrast, in the present embodiment, of the above-described 100 openings 23 or all of the openings 23, 95% or more of the openings 23 satisfy the relationship 0.70D1≦d1≦0.98D1 or the relationship 1.02D1≦d1≦1.30D1. As a result, when viewed from the Z direction, the first wirings 21 and the pixels P are disposed irregularly in the X direction. Therefore, the pitch of moire occurring due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P can be made small enough to be invisible to the naked eye. Furthermore, since the wiring substrate 10 satisfies the above relationship, the size of the openings 23 in the mesh wiring layer 20 does not vary, and the mesh wiring layer 20 can be made difficult to see with the naked eye.

[0125] Similarly, for example, the distance between the sides extending in the longitudinal direction (i.e., the X direction) of the second wiring 22 is defined as d2. The average value of the distances between the sides d2 in 100 consecutively adjacent openings 23 or in all openings 23 is defined as D2. In this embodiment, of the 100 openings 23 or all openings 23, 95% or more of the openings 23 are 0.70D2≦d2≦0.98D2 Does it satisfy the relationship 1.02D2≦d2≦1.30D2 The above relationship is satisfied. As a result, when viewed from the Z direction, the second wirings 22 and the pixels P are arranged irregularly in the Y direction. Therefore, the pitch of the moire pattern that occurs due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P can be made small enough to be invisible to the naked eye. Furthermore, since the wiring substrate 10 satisfies the above relationship, there is no variation in the size of the openings 23 in the mesh wiring layer 20, making it difficult to see the mesh wiring layer 20 with the naked eye.

[0126] Furthermore, in this embodiment, it is preferable that 95% or more of the openings 23 among the 100 openings 23 or all of the openings 23 satisfy the relationship 0.85D≦d≦0.98D or the relationship 1.02D≦d≦1.15D. This makes it possible to further reduce the pitch of moire patterns that occur due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P. Furthermore, since it is possible to reduce the variation in size of the openings 23 within the mesh wiring layer 20, it is possible to make the mesh wiring layer 20 less visible.

[0127] Furthermore, in this embodiment, it is more preferable that 95% or more of the above-described 100 openings 23 or all of the openings 23 satisfy the relationship 0.90D≦d≦0.98D or the relationship 1.02D≦d≦1.10D. This further reduces the pitch of moire patterns that occur due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P. In addition, since the variation in size of the openings 23 within the mesh wiring layer 20 can be further reduced, the mesh wiring layer 20 can be made even more difficult to see.

[0128] The side-to-side distances d1, d2 of each opening 23 may be, for example, in the range of 35 μm or more and 650 μm or less. The average value D (i.e., the average values ​​D1, D2) may be 50 μm or more and 500 μm or less. When the average value D is 50 μm or more, it is possible to prevent the aperture ratio At of the mesh wiring layer 20, which will be described later, from becoming small, and the transparency of the wiring substrate 10 can be ensured. When the average value D is 500 μm or less, it is possible to prevent the sheet resistance value of the mesh wiring layer 20 from becoming too high, and it is possible to maintain its antenna characteristics. Note that, although the first wirings 21 and the second wirings 22 are orthogonal to each other, this is not a limitation, and they may intersect each other at an acute angle or an obtuse angle.

[0129] As shown in FIG. 6, each first wiring 21 has a shape such that a cross section perpendicular to its longitudinal direction (i.e., X-direction cross section) is substantially rectangular or substantially square. In this case, the cross-sectional shape of the first wiring 21 is substantially uniform along the longitudinal direction of the first wiring 21 (i.e., Y-direction). As shown in FIG. 7, each second wiring 22 has a cross section perpendicular to its longitudinal direction (i.e., Y-direction cross section) that is substantially rectangular or substantially square, and has substantially the same shape as the cross-sectional shape (i.e., X-direction cross section) of the first wiring 21 described above. In this case, the cross-sectional shape of the second wiring 22 is substantially uniform along the longitudinal direction of the second wiring 22 (i.e., X-direction). The cross-sectional shapes of the first wiring 21 and the second wiring 22 do not necessarily have to be substantially rectangular or substantially square. For example, the cross-sectional shape of the first wiring 21 and the cross-sectional shape of the second wiring 22 may be an approximately trapezoid in which the front side (i.e., the positive side in the Z direction) is narrower than the back side (i.e., the negative side in the Z direction), or a shape in which the side surfaces located on both sides in the longitudinal direction are curved.

[0130] In the present embodiment, the line width W1 of the first wiring 21 (see FIG. 6) and the line width W2 of the second wiring 22 (see FIG. 7) are not particularly limited and can be appropriately selected depending on the application. Here, the line width W1 of the first wiring 21 is the length in the X direction, and the line width W2 of the second wiring 22 is the length in the Y direction. For example, the line width W1 of the first wiring 21 may be 0.5 μm or more and 3 μm or less. When the line width W1 of the first wiring 21 is 0.5 μm or more, the conductivity of the wiring substrate 10 can be increased. When the line width W1 of the first wiring 21 is 3.0 μm or less, even if moire occurs, the density of the moire can be reduced. The line width W1 of the first wiring 21 can be selected in a range of 0.5 μm or more, and preferably 1.0 μm or more. The line width W1 of the first wiring 21 can be selected in a range of 3.0 μm or less, and preferably 2.0 μm or less. Furthermore, the line width W2 of the second wiring 22 may be 0.5 μm or more and 3 μm or less. When the line width W2 of the second wiring 22 is 0.5 μm or more, the conductivity of the wiring substrate 10 can be increased. When the line width W2 of the second wiring 22 is 3.0 μm or less, even if moire occurs, the density of the moire can be reduced. The line width W2 of the second wiring 22 can be selected in a range of 0.5 μm or more, and is preferably 1.0 μm or more. The line width W2 of the second wiring 22 can be selected in a range of 3.0 μm or less, and is preferably 2.0 μm or less.

[0131] The height H1 of the first wiring 21 (see FIG. 6) and the height H2 of the second wiring 22 (see FIG. 7) are not particularly limited and can be appropriately selected depending on the application. Here, the height H1 of the first wiring 21 and the height H2 of the second wiring 22 are each lengths in the Z direction. The height H1 of the first wiring 21 and the height H2 of the second wiring 22 can each be selected, for example, from a range of 0.1 μm or more, and preferably 0.2 μm or more. The height H1 of the first wiring 21 and the height H2 of the second wiring 22 can each be selected, for example, from a range of 5.0 μm or less, and preferably 2.0 μm or less.

[0132] The material of the first wiring 21 and the second wiring 22 may be any conductive metal material. In the present embodiment, the material of the first wiring 21 and the second wiring 22 is copper, but is not limited to this. The material of the first wiring 21 and the second wiring 22 may be, for example, a metal material such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or an alloy containing these metals. Furthermore, the first wiring 21 and the second wiring 22 may be a plating layer formed by electrolytic plating.

[0133] The overall aperture ratio At of the mesh wiring layer 20 may be, for example, in the range of 87% or more and less than 100%. By setting the overall aperture ratio At of the mesh wiring layer 20 in this range, the conductivity and transparency of the wiring substrate 10 can be ensured. The overall aperture ratio At of the mesh wiring layer 20 is preferably 95% or more and less than 100%, or 96% or more and less than 100%. This allows the transparency of the wiring substrate 10 to be increased while ensuring the conductivity of the wiring substrate 10. The aperture ratio refers to the ratio (%) of the area of ​​the open region to the unit area of ​​a predetermined region (for example, the entire region of the mesh wiring layer 20). The open region refers to a region where no metal parts such as the first wiring 21 and the second wiring 22 are present and the substrate 11 is exposed.

[0134] The sheet resistance of the mesh wiring layer 20 may be 4 Ω / □ or less. By setting the sheet resistance to 4 Ω / □ or less, the performance of the mesh wiring layer 20 can be maintained. Specifically, the radiation efficiency of the mesh wiring layer 20 as an antenna can be increased. The radiation efficiency refers to the ratio indicating how much power input to a single mesh wiring layer 20 is radiated.

[0135] The sheet resistance (Ω / □) of the mesh wiring layer 20 can be calculated as follows: e1 , 20 e2 (See FIG. 8) . Then, the resistance value R is measured by dividing the length L of the mesh wiring layer 20 by the resistance value R. a and width W a Ratio to (L a / W a) to obtain the sheet resistance R s (Ω / □) can be calculated. That is, the sheet resistance R s =R×W a / L a This becomes:

[0136] In this way, by setting the sheet resistance value of the mesh wiring layer 20 to 4Ω / □ or less, the radiation efficiency of the mesh wiring layer 20 alone can be increased, and the performance of the mesh wiring layer 20 as an antenna can be improved. a In addition, the heights H1 and H2 can be minimized as much as possible. This makes it possible to increase the aperture ratio At of the mesh wiring layer 20, and makes it possible to make the mesh wiring layer 20 less visible.

[0137] Although not shown, a protective layer may be formed on the surface of substrate 11 so as to cover mesh wiring layer 20. The protective layer protects mesh wiring layer 20 and is formed so as to cover at least mesh wiring layer 20 of substrate 11. Examples of materials that can be used for the protective layer include acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate, modified resins thereof, copolymers thereof, polyvinyl resins such as polyester, polyvinyl alcohol, polyvinyl acetate, polyvinyl acetal, and polyvinyl butyral, copolymers thereof, polyurethane, epoxy resin, polyamide, and chlorinated polyolefin, and other colorless and transparent insulating resins.

[0138] Referring again to FIG. 4 , the power supply unit 40 is electrically connected to the mesh wiring layer 20. The power supply unit 40 is made of a substantially rectangular conductive thin plate member. The longitudinal direction of the power supply unit 40 is parallel to the X direction, and the lateral direction of the power supply unit 40 is parallel to the Y direction. The power supply unit 40 is disposed at the longitudinal end of the substrate 11 (i.e., the end on the negative side in the Y direction). The power supply unit 40 may be made of, for example, a metal material such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or an alloy containing these metals. When the wiring substrate 10 is incorporated into the image display device 60 (see FIGS. 1 and 2 ), the power supply unit 40 is electrically connected to the communication module 63 of the image display device 60 via a power supply line (not shown). Note that the power supply unit 40 is provided on the first surface 11 a of the substrate 11, but this is not limiting. Part or all of the power supply unit 40 may be located outside the periphery of the substrate 11. Furthermore, by forming power supply unit 40 to be flexible, power supply unit 40 may be configured to wrap around the side or back surface of image display device 60. In this case, power supply unit 40 may be electrically connected to communication module 63 on the side or back surface of image display device 60.

[0139] Next, a method for manufacturing the wiring board 10 according to this embodiment will be described with reference to FIGS.

[0140] 9(a), a substrate 11 is prepared, which includes a first surface 11a and a second surface 11b located on the opposite side of the first surface 11a. The substrate 11 is transparent.

[0141] Next, on the first surface 11a of the substrate 11, the mesh wiring layer 20 and the power supply section 40 electrically connected to the mesh wiring layer 20 are formed.

[0142] 9(b), first, metal foil 51 is laminated over substantially the entire first surface 11a of substrate 11. In this embodiment, the thickness of metal foil 51 may be 0.1 μm or more and 5.0 μm or less. In this embodiment, metal foil 51 may contain copper.

[0143] 9(c), a photo-curable insulating resist 52 is applied to almost the entire surface of the metal foil 51. Examples of the photo-curable insulating resist 52 include organic resins such as acrylic resins and epoxy resins.

[0144] 9(d), an insulating layer 54 is formed by photolithography. In this case, the photo-curable insulating resist 52 is patterned by photolithography to form the insulating layer 54 (i.e., a resist pattern). At this time, the insulating layer 54 is formed so that the metal foil 51 corresponding to the first wiring 21 and the second wiring 22 is exposed.

[0145] 9(e), the metal foil 51 located on the first surface 11a of the substrate 11 in the portion not covered with the insulating layer 54 is removed. At this time, the metal foil 51 is etched so as to expose the first surface 11a of the substrate 11 by wet treatment using ferric chloride, cupric chloride, a strong acid such as sulfuric acid or hydrochloric acid, persulfate, hydrogen peroxide, an aqueous solution of these, or a combination of these.

[0146] 9(f), the insulating layer 54 is removed by wet treatment using a permanganate solution, N-methyl-2-pyrrolidone, an acid or alkaline solution, or dry treatment using oxygen plasma.

[0147] In this manner, a wiring board 10 is obtained that includes the substrate 11 and the mesh wiring layer 20 provided on the first surface 11a of the substrate 11. In this case, the mesh wiring layer 20 includes the first wiring 21 and the second wiring 22. At this time, the power supply unit 40 may be formed by a part of the metal foil. Alternatively, a flat power supply unit 40 may be separately prepared and electrically connected to the mesh wiring layer 20.

[0148] Then, by laminating the display device 61 on the wiring substrate 10 via the first transparent adhesive layer 95 and the second transparent adhesive layer 96, an image display device 60 is obtained, which includes the wiring substrate 10 and the display device 61 laminated on the wiring substrate 10.

[0149] Next, the operation of this embodiment having the above configuration will be described.

[0150] 1 and 2, the wiring board 10 is incorporated into an image display device 60 having a display device 61. At this time, the wiring board 10 is placed on the display device 61. The mesh wiring layer 20 of the wiring board 10 is electrically connected to a communication module 63 of the image display device 60 via the power supply unit 40. In this way, radio waves of a predetermined frequency can be transmitted and received via the mesh wiring layer 20, and communication can be performed using the image display device 60.

[0151] As described above, in the image display device 60, the mesh wiring layer 20 of the wiring substrate 10 is disposed so as to overlap the pixels P of the display device 61 in the Z direction. Therefore, moire may occur due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P.

[0152] In contrast to this, in the present embodiment, when the distance between the sides extending in a predetermined direction in each opening 23 is d and the average value of the distances d between the sides extending in the predetermined direction in 100 consecutively adjacent openings 23 or in all openings 23 is D, 95% or more of the openings 23 out of the 100 openings 23 or all openings 23 0.70D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.30D The relationship is satisfied. As a result, when viewed from the Z direction, the first wirings 21, the second wirings 22, and the pixels P are arranged irregularly. Therefore, the pitch of the moire pattern that occurs due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P can be made small enough to be invisible to the naked eye. Furthermore, since the wiring substrate 10 satisfies the above relationship, there is no variation in the size of the openings 23 in the mesh wiring layer 20, making it difficult to see the mesh wiring layer 20 with the naked eye.

[0153] Furthermore, according to the present embodiment, two or more openings 23 are formed by being surrounded by the first wiring 21 and the second wiring 22, and the planar shape of the openings 23 is a polygon with opposing sides parallel to each other. In other words, the first wirings 21 extend linearly in a planar view and are arranged parallel to each other, and the second wirings 22 extend linearly in a planar view and are arranged parallel to each other. This can suppress flicker caused by reflection of visible light by the mesh wiring layer 20. Furthermore, because the first wirings 21 and the like extend linearly in a planar view and are arranged parallel to each other, the overall length of the first wirings 21 and the like can be shortened compared to when the first wirings 21 and the like are curved in a planar view. This can reduce the sheet resistance of the mesh wiring layer 20 and maintain its antenna characteristics.

[0154] Furthermore, according to this embodiment, wiring board 10 includes substrate 11 and mesh wiring layer 20 disposed on substrate 11. Substrate 11 is transparent. Mesh wiring layer 20 has a conductor portion as a forming portion of an opaque conductive layer and a mesh pattern formed by numerous openings 23. This ensures the transparency of wiring board 10. As a result, when wiring board 10 is placed on display device 61, display device 61 can be seen through openings 23 of mesh wiring layer 20, and visibility of display device 61 is not hindered.

[0155] Next, modified examples of the wiring board will be described.

[0156] Figures 10 and 11 show a first modified example of the wiring board. The modified example shown in Figures 10 and 11 differs in that a dummy wiring layer 30 is provided around the mesh wiring layer 20, but other configurations are substantially the same as the embodiment shown in Figures 1 to 9 described above. In Figures 10 and 11, the same parts as those in the embodiment shown in Figures 1 to 9 are given the same reference numerals and detailed description thereof will be omitted.

[0157] 10, a dummy wiring layer 30 is provided along the periphery of the mesh wiring layer 20. Unlike the mesh wiring layer 20, this dummy wiring layer 30 does not substantially function as an antenna.

[0158] As shown in FIG. 11, the dummy wiring layer 30 is composed of repeated dummy wirings 30a having a predetermined pattern shape. That is, the dummy wiring layer 30 includes a plurality of dummy wirings 30a, and each dummy wiring 30a is electrically independent from the mesh wiring layer 20 (i.e., the first wirings 21 and the second wirings 22). The plurality of dummy wirings 30a are regularly arranged throughout the dummy wiring layer 30. The plurality of dummy wirings 30a are spaced apart from each other in the planar direction and are arranged to protrude above the substrate 11. That is, each dummy wiring 30a is electrically independent from the mesh wiring layer 20, the power supply section 40, and other dummy wirings 30a. The shape of each dummy wiring 30a is approximately L-shaped in plan view.

[0159] In this case, the dummy wiring 30a has a shape in which a portion of the pattern shape of the mesh wiring layer 20 described above is missing. This makes it difficult to visually recognize the difference between the mesh wiring layer 20 and the dummy wiring layer 30, and makes the mesh wiring layer 20 arranged on the substrate 11 less visible. As shown in FIG. 11 , the dummy wiring 30a extends parallel to the first wiring 21 or the second wiring 22. Specifically, the dummy wiring 30a includes a first portion 31a extending parallel to the first wiring 21 and a second portion 32a extending parallel to the second wiring 22. In this way, the dummy wiring 30a extending parallel to the first wiring 21 or the second wiring 22 makes the mesh wiring layer 20 arranged on the substrate 11 even less visible. The aperture ratio of the dummy wiring layer 30 may be the same as or different from the aperture ratio of the mesh wiring layer 20, but is preferably close to the aperture ratio of the mesh wiring layer 20.

[0160] In this modification, as shown in FIG. 11, the distance between the portions of the dummy wirings 30a extending in a predetermined direction is set to d a In addition, the distance d between the portions extending in a predetermined direction in 100 sets of consecutively adjacent dummy wirings 30a is a The average value of D a In this modification, of the 100 sets of dummy wirings 30a, 95% or more of the dummy wirings 30a are 0.70D a ≦d a ≦0.98D a Does it satisfy the relationship 1.02D a ≦d a ≦1.30D a This allows the pitch of moire patterns that occur due to the regularity (periodicity) of the dummy wirings 30a and the regularity (periodicity) of the pixels P of the display device 61 to be reduced to an extent that is not visible to the naked eye. Note that the one direction may be the X direction or the Y direction.

[0161] In addition, in the wiring board 10, when the number of sets of dummy wirings 30a is less than 100, the distance d between the portions extending in a predetermined direction in all the dummy wirings 30a is a The average value of D a In this case, 95% or more of all the dummy wirings 30a may be 0.70D a ≦d a ≦0.98D a Does it satisfy the relationship 1.02D a ≦d a ≦1.30D a The following relationship may be satisfied.

[0162] In the example shown in FIG. 11, the distance d between the first portions 31a is a d a1 In this case, the distance d a1 The average value of D a1 When the above equation is satisfied, 95% or more of the 100 sets of dummy wirings 30a or all of the dummy wirings 30a are 0.70D a1 ≦d a1 ≦0.98D a1 Does it satisfy the relationship 1.02D a1 ≦d a1 ≦1.30D a1 The following relationship may be satisfied.

[0163] Similarly, the distance d between the second portions 32a a d a2 In this case, the distance d a2 The average value of D a2 When the above equation is satisfied, 95% or more of the 100 sets of dummy wirings 30a or all of the dummy wirings 30a are 0.70D a2≦d a2 ≦0.98D a2 Does it satisfy the relationship 1.02D a2 ≦d a2 ≦1.30D a2 The following relationship may be satisfied.

[0164] In this modification, 95% or more of the 100 sets of dummy wirings 30a or all of the dummy wirings 30a are 0.85D a ≦d a ≦0.98D a The relationship is satisfied, or 1.02D a ≦d a ≦1.15D a Furthermore, in this modification, of the 100 sets of dummy wirings 30a or all of the dummy wirings 30a, 95% or more of the dummy wirings 30a satisfy the relationship of 0.90D. a ≦d a ≦0.98D a The relationship is satisfied, or 1.02D a ≦d a ≦1.10D a It is more preferable that the following relationship is satisfied.

[0165] As in this modification, the dummy wiring layer 30 that is electrically independent from the mesh wiring layer 20 is provided around the mesh wiring layer 20, thereby making the outer edge of the mesh wiring layer 20 unclear. This makes it possible to make the mesh wiring layer 20 less visible on the surface of the image display device 60, and makes it difficult for a user of the image display device 60 to recognize the mesh wiring layer 20 with the naked eye.

[0166] Figures 12 and 13 show a second modified example of the wiring board. The modified example shown in Figures 12 and 13 differs in that two or more dummy wiring layers 30A, 30B having different aperture ratios are provided around the mesh wiring layer 20, but other configurations are substantially the same as the embodiment shown in Figures 1 to 11 described above. In Figures 12 and 13, the same parts as those shown in Figures 1 to 11 are given the same reference numerals, and detailed description thereof will be omitted.

[0167] 12, two or more (two in this case) dummy wiring layers 30A, 30B (i.e., a first dummy wiring layer 30A and a second dummy wiring layer 30B) having different aperture ratios are provided along the periphery of the mesh wiring layer 20. Specifically, the first dummy wiring layer 30A is arranged along the periphery of the mesh wiring layer 20, and the second dummy wiring layer 30B is arranged along the periphery of the first dummy wiring layer 30A. Unlike the mesh wiring layer 20, these dummy wiring layers 30A, 30B do not substantially function as antennas.

[0168] As shown in FIG. 13, the first dummy wiring layer 30A is composed of repeated dummy wirings 30a1 having a predetermined pattern. The second dummy wiring layer 30B is composed of repeated dummy wirings 30a2 having a predetermined pattern. That is, the dummy wiring layers 30A and 30B each include a plurality of dummy wirings 30a1 and 30a2, and each of the dummy wirings 30a1 and 30a2 is electrically independent from the mesh wiring layer 20. The dummy wirings 30a1 and 30a2 are regularly arranged throughout the dummy wiring layers 30A and 30B, respectively. The dummy wirings 30a1 and 30a2 are spaced apart from each other in the planar direction and protrude above the substrate 11. Each of the dummy wirings 30a1 and 30a2 is electrically independent from the mesh wiring layer 20, the power supply section 40, and the other dummy wirings 30a1 and 30a2. The dummy wirings 30a1 and 30a2 each have a substantially L-shape in plan view.

[0169] In this case, the dummy wirings 30a1 and 30a2 have a shape in which a portion of the pattern shape of the mesh wiring layer 20 described above is missing. This makes it difficult to visually recognize the difference between the mesh wiring layer 20 and the first dummy wiring layer 30A, and the difference between the first dummy wiring layer 30A and the second dummy wiring layer 30B, making it difficult to see the mesh wiring layer 20 arranged on the substrate 11. As shown in FIG. 13 , the dummy wirings 30a1 and 30a2 extend parallel to the first wiring 21 or the second wiring 22. Specifically, the dummy wiring 30a1 includes a first portion 31a1 extending parallel to the first wiring 21 and a second portion 32a1 extending parallel to the second wiring 22. The dummy wiring 30a2 includes a first portion 31a2 extending parallel to the first wiring 21 and a second portion 32a2 extending parallel to the second wiring 22.

[0170] The area of ​​each dummy wiring 30a1 in the first dummy wiring layer 30A is larger than the area of ​​each dummy wiring 30a2 in the second dummy wiring layer 30B. In this case, the line width of each dummy wiring 30a1 is the same as the line width of each dummy wiring 30a2, but this is not limited to this, and the line width of each dummy wiring 30a1 may be wider than the line width of each dummy wiring 30a2. Note that other configurations of the dummy wirings 30a1 and 30a2 are similar to the configuration of the dummy wiring 30a in the first modified example, so detailed description will be omitted here.

[0171] In this modification, it is preferable that the aperture ratios of the mesh wiring layer 20 and the two or more dummy wiring layers 30A, 30B increase stepwise from the mesh wiring layer 20 toward the dummy wiring layers 30A, 30B farther from the mesh wiring layer 20. In other words, it is preferable that the aperture ratio of each dummy wiring layer gradually increase from that closer to the mesh wiring layer 20 to that farther away. In this case, it is preferable that the aperture ratio of the first dummy wiring layer 30A is greater than that of the mesh wiring layer 20. It is preferable that the aperture ratio of the second dummy wiring layer 30B is greater than that of the first dummy wiring layer 30A. This makes it possible to further obscure the outer edges of the mesh wiring layer 20 and the dummy wiring layers 30A, 30B. This makes it possible to make the mesh wiring layer 20 even less visible on the surface of the image display device 60.

[0172] In this way, by arranging the dummy wiring layers 30A and 30B electrically independent from the mesh wiring layer 20, the outer edge of the mesh wiring layer 20 can be made more unclear. This makes it possible to make the mesh wiring layer 20 less visible on the surface of the image display device 60, and makes it difficult for a user of the image display device 60 to recognize the mesh wiring layer 20 with the naked eye. Note that three or more dummy wiring layers having different aperture ratios may be provided around the mesh wiring layer 20.

[0173] Figure 14 shows a third modified example of the wiring board. The modified example shown in Figure 14 differs in the planar shape of the mesh wiring layer 20, but other configurations are substantially the same as those shown in Figures 1 to 13 described above. In Figure 14, the same parts as those shown in Figures 1 to 13 are given the same reference numerals, and detailed explanations will be omitted.

[0174] 14 is an enlarged plan view showing a mesh wiring layer 20 according to a third modified example. In Fig. 14, the first wirings 21 and the second wirings 22 intersect at an angle (i.e., not at a right angle), and the shape of each opening 23 is a rhombus in plan view. The first wirings 21 and the second wirings 22 are not parallel to either the X direction or the Y direction, but either one of the first wirings 21 and the second wirings 22 may be parallel to the X direction or the Y direction.

[0175] Figures 15 and 16 show a fourth modified example of the wiring board. The modified example shown in Figures 15 and 16 differs in the planar shape of the mesh wiring layer 20 and in the provision of two or more dummy wiring layers 30A, 30B with different aperture ratios around the mesh wiring layer 20, but the other configurations are substantially the same as those shown in Figures 1 to 14 described above. In Figures 15 and 16, the same parts as those shown in Figures 1 to 14 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0176] 15 and 16 are enlarged plan views showing a mesh wiring layer 20 according to a fourth modified example. In Fig. 15 and 16, similar to the mesh wiring layer 20 according to the third modified example shown in Fig. 14, the first wirings 21 and the second wirings 22 intersect obliquely (i.e., not at a right angle), and the shape of each opening 23 is a rhomb in plan view. The first wirings 21 and the second wirings 22 are not parallel to either the X direction or the Y direction, but either one of the first wirings 21 and the second wirings 22 may be parallel to the X direction or the Y direction.

[0177] Furthermore, in the wiring board 10 shown in Figures 15 and 16, similar to the wiring board 10 according to the second modified example shown in Figures 12 and 13, two or more (two in this case) dummy wiring layers 30A, 30B (i.e., a first dummy wiring layer 30A and a second dummy wiring layer 30B) having different aperture ratios are provided along the periphery of the mesh wiring layer 20.

[0178] As shown in FIG. 16, in this modification, the dummy wirings 30a1 and 30a2 also extend parallel to the first wiring 21 or the second wiring 22. Specifically, the dummy wiring 30a1 includes a first portion 31a1 extending parallel to the first wiring 21 and a second portion 32a1 extending parallel to the second wiring 22. The first portion 31a1 and the second portion 32a1 intersect obliquely (i.e., not at a right angle). The dummy wiring 30a2 includes a first portion 31a2 extending parallel to the first wiring 21 and a second portion 32a2 extending parallel to the second wiring 22. The first portion 31a2 and the second portion 32a2 intersect obliquely (i.e., not at a right angle). Other configurations of the first dummy wiring layer 30A and the second dummy wiring layer 30B are similar to the configurations of the first dummy wiring layer 30A and the second dummy wiring layer 30B in the second modified example, and therefore detailed description thereof will be omitted here.

[0179] Fig. 17 shows a fifth modified example of the wiring board. The modified example shown in Fig. 17 differs in the planar shape of the opening 23, but other configurations are substantially the same as the embodiment shown in Figs. 1 to 16 described above. In Fig. 17, the same parts as those shown in Figs. 1 to 16 are given the same reference numerals, and detailed description thereof will be omitted.

[0180] 17, the planar shape of the opening 23 is hexagonal. In this modification, the first wiring 21 includes a first portion 24 and a second portion 25 that intersect with each other obliquely (i.e., at a non-right angle). The first portion 24 and the second portion 25 are not parallel to either the X direction or the Y direction.

[0181] The first portions 24 and the second portions 25 are irregularly arranged relative to each other. Specifically, the first portions 24 are arranged parallel to each other at a pitch P 1a The pitch P is irregular. 1a The second portions 25 are arranged parallel to each other, and the pitch P 1b The pitch P is irregular. 1b may be, for example, in the range of 0.01 mm or more and 1 mm or less.

[0182] In this way, the pitch P of the plurality of first portions 24 1a and the pitch P of the plurality of second portions 25 1b and are irregular. This allows the pitch of moire generated due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P of the display device 61 to be reduced to a level that is not visible to the naked eye. Also, as described above, the first portions 24 are arranged parallel to each other, and the second portions 25 are arranged parallel to each other. Therefore, the pitch P 1a , P 1b Even if the mesh wiring layer 20 is irregular, flickering caused by the reflection of visible light by the mesh wiring layer 20 can be suppressed.

[0183] In this modified example, the planar shape of the opening 23 is a hexagon, but the planar shape of the opening 23 may be an octagon, or a polygon having ten or more corners.

[0184] [Example] Next, a specific example of this embodiment will be described.

[0185] (Example A1) A wiring board 10 having the configuration shown in FIG. 5A was fabricated. That is, a wiring board 10 was fabricated in which the first wirings 21 and the second wirings 22 were irregularly arranged relative to each other. In this case, a substrate made of polyethylene terephthalate and having a thickness of 100 μm was used as the substrate for the wiring board 10. Furthermore, copper wiring having a line width of 1.0 μm and a height of 1.0 μm was used as the first wirings 21 and the second wirings 22. At this time, the length L of the tip side portion 20b of the mesh wiring layer 20 was a is 3.5 mm, and the width W a was 4.2 mm.

[0186] In the wiring board 10 according to Example A1, the distance between the sides of the openings 23 that extend in the longitudinal direction of the first wiring 21 (i.e., the Y direction) was defined as d. In this case, the average value D of the distance between the sides d for 100 openings 23 that are adjacent to each other in the Y direction was 100 μm. 0.70D≦d≦0.98D (hereinafter simply referred to as Equation 1) 1.02D≦d≦1.30D The number of openings 23 that satisfied the above relationship (hereinafter also simply referred to as Equation 2) was 100.

[0187] In wiring board 10 according to Example A1, the difference in aperture ratio between adjacent 1000 μm square regions was 0.5% or less.

[0188] Next, the visibility of the wiring board 10 was confirmed. At this time, first, the presence or absence of moire was confirmed. At this time, the wiring board 10 was first superimposed on the display device 61 shown in FIG. 3 and observed. In the display device 61, the pitch P of the pixels P was X is 60 μm, and the pitch P of the pixel P Y The moire pattern was 60 μm. Then, with the display device 61 emitting white light, the wiring board 10 was visually observed from a distance of 300 mm to check for the presence or absence of moire.

[0189] The presence or absence of flickering was also confirmed. First, a blackboard was placed on the back side of wiring board 10 (i.e., the negative side in the Z direction). Next, light was irradiated from the front side of wiring board 10 (i.e., the positive side in the Z direction) using a high-intensity light. At this time, the light was irradiated from a direction inclined with respect to the normal direction of first surface 11a of substrate 11. Then, wiring board 10 was visually observed from a distance of 300 mm to confirm the presence or absence of flickering.

[0190] Next, the sheet resistance value (Ω / □) of the mesh wiring layer 20 in the wiring substrate 10 was measured. e1 , 20 e2 The resistance value R between the mesh wiring layer 20 and the length L of the mesh wiring layer 20 was measured. a and width W a Ratio to (L a / W a ) to obtain the sheet resistance R s (Ω / □) was calculated.

[0191] (Example A2) A wiring board 10 having the configuration shown in FIG. 15 was fabricated. That is, a wiring board 10 was fabricated in which the first wirings 21 and the second wirings 22 were arranged irregularly relative to each other. In this case, a substrate made of polyethylene terephthalate and having a thickness of 100 μm was used as the substrate for the wiring board 10. Furthermore, copper wiring having a line width of 1.0 μm and a height of 1.0 μm was used as the first wirings 21 and the second wirings 22. At this time, the length L of the tip side portion 20b of the mesh wiring layer 20 was a is 3.5 mm, and the width W a was 4.2 mm.

[0192] In wiring board 10 according to Example A2, the distance between the sides of openings 23 that extend in the longitudinal direction of first wiring 21 was defined as d. In this case, the average value D of the distances between the sides d for 100 openings 23 that are adjacent to each other in the Y direction was 100 μm. Of the 100 openings 23, 100 openings 23 satisfied formula 1 or formula 2.

[0193] In wiring board 10 according to Example A2, the difference in aperture ratio between adjacent 1000 μm square regions was 0.5% or less.

[0194] Next, in the same manner as in Example A1, the visibility of the wiring substrate 10 was confirmed, and the sheet resistance value of the mesh wiring layer 20 was measured.

[0195] (Comparative Example A1) A wiring board 100 having the configuration shown in FIG. 18 was fabricated. That is, a wiring board 100 was fabricated in which the first wirings 21 and the second wirings 22 were regularly arranged relative to one another. Specifically, a wiring board 100 was fabricated in which the first wirings 21 and the second wirings 22 were arranged at approximately equal intervals relative to one another. In this case, a substrate made of polyethylene terephthalate and having a thickness of 100 μm was used as the substrate for the wiring board 100. Furthermore, copper wiring having a line width of 1.0 μm and a height of 1.0 μm was used as the first wirings 21 and the second wirings 22. At this time, the length L of the tip side portion 20b of the mesh wiring layer 20 was a is 3.5 mm, and the width W a was 4.2 mm.

[0196] In wiring substrate 100 according to comparative example A1, the distance between the sides of openings 23 that extend in the longitudinal direction of first wiring 21 was defined as d. In this case, the average value D of the distances d between the sides was 100 μm. Furthermore, of the 100 openings 23, 0 openings 23 satisfied formula 1 or formula 2.

[0197] In wiring board 100 according to comparative example A1, the difference in aperture ratio between adjacent 1000 μm square regions was 0.5% or less.

[0198] Next, in the same manner as in Example A1, the visibility of the wiring substrate 100 was checked, and the sheet resistance value of the mesh wiring layer 20 was measured.

[0199] (Comparative example A2) A wiring board 100 having the configuration shown in FIG. 19 was fabricated. That is, a wiring board 100 was fabricated in which the planar shape of the opening 23 was a rectangle with opposing sides not parallel to each other. In this case, a substrate made of polyethylene terephthalate and having a thickness of 100 μm was used as the substrate for the wiring board 100. Furthermore, copper wiring having a line width of 1.0 μm and a height of 1.0 μm was used as the first wiring 21 and the second wiring 22. At this time, the length L of the tip side portion 20b of the mesh wiring layer 20 was a is 3.5 mm, and the width W a was 4.2 mm.

[0200] In the wiring substrate 100 according to Comparative Example A2, the average side-to-side distance was 100 μm. The side-to-side distance was measured on a virtual line extending along the longitudinal direction (X direction) of the tip portion 20b (see FIG. 4) of the mesh wiring layer 20, and drawn at an arbitrarily selected position.

[0201] In wiring board 100 according to comparative example A2, the difference in aperture ratio between adjacent 1000 μm square regions was 0.5% or less.

[0202] Next, in the same manner as in Example A1, the visibility of the wiring substrate 100 was checked, and the sheet resistance value of the mesh wiring layer 20 was measured.

[0203] (Comparative example A3) A wiring board 100 having the configuration shown in FIG. 20 was fabricated. That is, a wiring board 100 was fabricated in which the planar structure formed by the wiring 200 of the mesh wiring layer 20 was a Voronoi pattern. In this case, a substrate made of polyethylene terephthalate and having a thickness of 100 μm was used as the substrate for the wiring board 100. Furthermore, copper wiring having a line width of 1.0 μm and a height of 1.0 μm was used as the wiring 200. At this time, the length L of the tip side portion 20b of the mesh wiring layer 20 was ais 3.5 mm, and the width W a was 4.2 mm.

[0204] In the wiring substrate 100 according to Comparative Example A3, the average side-to-side distance was 100 μm. The side-to-side distance was measured on a virtual line extending along the longitudinal direction (X direction) of the tip portion 20b (see FIG. 4) of the mesh wiring layer 20, and drawn at an arbitrarily selected position.

[0205] In wiring board 100 according to comparative example A3, the difference in aperture ratio between adjacent 1000 μm square regions was 0.5% or less.

[0206] Next, in the same manner as in Example A1, the visibility of the wiring substrate 100 was checked, and the sheet resistance value of the mesh wiring layer 20 was measured.

[0207] The results are shown in Table 1.

[0208] [Table 1]

[0209] The number in the "number" column in Table 1 means the number of openings 23 that satisfy formula 1 or formula 2 out of 100 openings 23.

[0210] In Table 1, "A" means that the results were excellent, and "B" means that the results were poor. Specifically, in the "Moiré" column of Table 1, "A" means that no moiré was observed, and "B" means that moiré was observed. In the "Flickering" column of Table 1, "A" means that no flickering due to reflected light was observed, and "B" means that flickering due to reflected light was observed. In the "Aperture Ratio" column of Table 1, "A" means that the difference in aperture ratio was 0.5% or less. In the "Sheet Resistance" column of Table 1, "A" means that the sheet resistance was equal to or less than a predetermined value, and "B" means that the sheet resistance was greater than a predetermined value.

[0211] As a result, moire was observed in the wiring board 100 according to Comparative Example A1, as shown in Table 1. In contrast, no moire was observed in the wiring boards 10 according to Examples A1 and A2.

[0212] As shown in Table 1, flickering due to reflected light occurred in the wiring boards 100 according to Comparative Examples A2 and A3. In contrast, flickering due to reflected light was not observed in the wiring boards 10 according to Examples A1 and A2.

[0213] As described above, it was found that wiring board 10 according to the present embodiment can suppress the occurrence of moire and also suppress flickering due to reflected light.

[0214] As shown in Table 1, in the wiring boards 10 according to Examples A1 and A2, the unevenness in the aperture ratio could be reduced, similar to the wiring board 100 according to Comparative Example A1. That is, even when the first wirings 21, etc. were arranged irregularly, the unevenness in the aperture ratio could be reduced, similar to the wiring board 100 in which the first wirings 21, etc. were arranged regularly.

[0215] As shown in Table 1, in the wiring boards 10 according to Examples A1 and A2, the sheet resistance of the mesh wiring layer 20 could be kept below a predetermined value, as in the wiring board 100 according to Comparative Example A1. In this case, the sheet resistance of the mesh wiring layer 20 of the wiring boards 10 according to Examples A1 and A2 was equivalent to the sheet resistance of the mesh wiring layer 20 of the wiring board 100 according to Comparative Example A1. That is, in the wiring boards 10 according to Examples A1 and A2, the first wirings 21, etc. are arranged irregularly, but the length of the first wirings 21, etc. is not changed compared to when the first wirings 21, etc. are arranged regularly. As a result, even when the first wirings 21, etc. are arranged irregularly, the sheet resistance of the mesh wiring layer 20 could be made equivalent to the sheet resistance of the mesh wiring layer 20 of the wiring board 100 in which the first wirings 21, etc. are arranged regularly. Therefore, in wiring boards 10 according to Examples A1 and A2, the radiation efficiency of mesh wiring layer 20 as an antenna could be increased, similar to wiring board 100 in which first wirings 21 and the like are regularly arranged.

[0216] (Second embodiment) Next, one embodiment will be described with reference to Figures 21 to 24. Figures 21 to 24 are diagrams showing this embodiment. In Figures 21 to 24, the same parts as those in the first embodiment shown in Figures 1 to 20 are given the same reference numerals, and detailed descriptions thereof may be omitted.

[0217] In this embodiment, each of the first wirings 21 and second wirings 22 extends linearly in a direction that is not parallel to either the longitudinal direction (i.e., Y direction) or the width direction (i.e., X direction) of the mesh wiring layer 20. That is, the first wirings 21 and second wirings 22 are not parallel to either the X direction or the Y direction. Note that either one of the first wirings 21 and second wirings 22 may be parallel to the X direction or the Y direction.

[0218] In this embodiment, multiple openings 23 are formed by being surrounded by adjacent first wirings 21 and adjacent second wirings 22. Each opening 23 has a generally rhombic shape in plan view. The transparent substrate 11 is exposed from each opening 23. This can increase the transparency of the wiring substrate 10 as a whole.

[0219] As shown in FIGS. 21 and 22, the intersections A between the first wiring 21 and the second wiring 22 are defined as A. In this case, the intersections A between the first wiring 21 and the second wiring 22 are irregularly arranged. That is, the pitch of the first wiring 21 and the pitch of the second wiring 22 are both irregular. Specifically, because the intersections A are irregularly arranged, the orientations of the first wirings 21 extending between the intersections A are irregular relative to each other. Similarly, the orientations of the second wirings 22 extending between the intersections A are irregular relative to each other. This makes it possible to reduce the pitch of moire patterns that occur due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P of the display device 61 to a level that is not visible to the naked eye.

[0220] That is, in the above-described image display device 60, the mesh wiring layer 20 of the wiring substrate 10 is arranged so as to overlap the pixels P of the display device 61 in the Z direction. Therefore, moire may occur due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P. In contrast, in the present embodiment, the intersections A are arranged irregularly. As a result, the first wirings 21 and the second wirings 22 and the pixels P are arranged irregularly. Therefore, the pitch of the moire that occurs due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P can be made small enough to be invisible to the naked eye.

[0221] 21 and 22, a regression line obtained from a plurality of intersection points A located on the same first wiring 21 is defined as a first regression line 21x. Similarly, a regression line obtained from a plurality of intersection points A located on the same second wiring 22 is defined as a second regression line 22x. The intersection point between the first regression line 21x and the second regression line 22x is defined as B. Here, the regression line refers to a line obtained by approximating the position data of each intersection point A located on the same first wiring 21 in a planar view using the least squares method.

[0222] 22, the distance from the intersection A to the closest intersection B along the width direction (i.e., the X direction) of the mesh wiring layer 20 is defined as d X The distance from the intersection point A to the closest intersection point B along the longitudinal direction of the mesh wiring layer 20 (i.e., the Y direction) is defined as d Y In addition, the pitch P of 10 adjacent intersections B in the width direction of the mesh wiring layer 20 is 1X The average value of D X The pitch P of 10 adjacent intersections B in the longitudinal direction of the mesh wiring layer 20 is 1Y The average value of D Y In this embodiment, among the 10 intersections A that are closest to each of the 10 intersections B, at least 9 intersections A are 0.02D X ≦d X <0.3D X The relationship, and 0.02D Y ≦d Y <0.3D Y At least one of the relationships is satisfied. This makes it possible to prevent the variation in the pitch of the first wirings 21 and the variation in the pitch of the second wirings 22 from becoming too large. This makes it possible to prevent flicker caused by the reflection of visible light by the mesh wiring layer 20. Furthermore, since the wiring substrate 10 satisfies the above relationships, there is no variation in the size of the openings 23 in the mesh wiring layer 20, making it difficult for the mesh wiring layer 20 to be seen with the naked eye. Here, the distance d X , d y In this case, the distances d at the 10 closest intersections A to each of the 10 intersections B can be different. X , d y It is preferable that the value of be three or more different values.

[0223] Furthermore, for each of the 10 intersections B, of the 10 intersections A closest to each other, at least 9 intersections A are 0.02D X ≦d X <0.3D X The relationship, and 0.02D Y ≦d Y <0.3D Y The above relationship is satisfied. By satisfying both of the above relationships, it is possible to more effectively prevent the variation in the pitch of the first wirings 21 and the variation in the pitch of the second wirings 22 from becoming too large. Therefore, it is possible to more effectively prevent the flicker caused by the reflection of visible light by the mesh wiring layer 20. Furthermore, by the wiring substrate 10 satisfying both of the above relationships, it is possible to further reduce the variation in the size of the openings 23, making it even more difficult to see the mesh wiring layer 20 with the naked eye.

[0224] Pitch P of intersection point B 1X Average value of D X and the pitch P of intersection B 1Y Average value of D Y The average value D may be 50 μm or more and 500 μm or less. X and average value DY When the average value D is 50 μm or more, it is possible to prevent the aperture ratio At of the mesh wiring layer 20, which will be described later, from becoming small, and the transparency of the wiring board 10 can be ensured. X and average value D Y By making the thickness 500 μm or less, it is possible to prevent the sheet resistance value of the mesh wiring layer 20 from becoming too high, and to maintain the antenna characteristics.

[0225] Pitch P of intersection point B 1X Average value of D X is the pitch P of pixels P in the width direction X The intersecting point A and the pixel P are arranged in a random order in the X direction when viewed from the Z direction. ...

[0226] Pitch P of intersection point B 1X Average value of D X is the pitch P of pixels P in the width direction X It is preferable that the average value D X Therefore, it is possible to prevent the aperture ratio At of the mesh wiring layer 20, which will be described later, from becoming too small, and the transparency of the wiring substrate 10 can be ensured. X Therefore, the sheet resistance value of the mesh wiring layer 20 can be prevented from becoming too large, and the antenna characteristics can be maintained.

[0227] Pitch P of intersection point B 1XAverage value of D X The average value D may be 50 μm or more and 500 μm or less. X When the average value D is 50 μm or more, it is possible to prevent the aperture ratio At of the mesh wiring layer 20, which will be described later, from becoming small, and the transparency of the wiring board 10 can be ensured. X By making the thickness 500 μm or less, it is possible to prevent the sheet resistance value of the mesh wiring layer 20 from becoming too high, and to maintain the antenna characteristics.

[0228] Pitch P of intersection point B 1Y Average value of D Y is the pitch P of pixels P in the longitudinal direction Y The distance between the intersections A and the pixels P may be equal to or smaller than (M-0.05) times (M is a natural number) and may be equal to or larger than (M+0.05). As a result, when viewed from the Z direction, the intersections A and the pixels P are arranged irregularly in the Y direction. Therefore, the pitch of the moire pattern generated due to the regularity of the mesh wiring layer 20 and the regularity of the pixels P can be made small enough to be invisible to the naked eye.

[0229] Pitch P of intersection point B 1Y Average value of D Y is the pitch P of pixels P in the longitudinal direction Y It is preferable that the average value D is (M-0.2) times or more and (M+0.2) times or less. Y Therefore, it is possible to prevent the aperture ratio At of the mesh wiring layer 20, which will be described later, from becoming too small, and the transparency of the wiring substrate 10 can be ensured. Y Therefore, the sheet resistance value of the mesh wiring layer 20 can be prevented from becoming too large, and the antenna characteristics can be maintained.

[0230] Pitch P of intersection point B 1Y Average value of D Y The average value D may be 50 μm or more and 500 μm or less. YWhen the average value D is 50 μm or more, it is possible to prevent the aperture ratio At of the mesh wiring layer 20, which will be described later, from becoming small, and the transparency of the wiring board 10 can be ensured. Y By making the thickness 500 μm or less, it is possible to prevent the sheet resistance value of the mesh wiring layer 20 from becoming too high, and to maintain the antenna characteristics.

[0231] It is preferable that N and M are each a natural number of 1 or more and 6 or less. When N and M are each a natural number of 6 or less, the pitch P of the intersection points B 1X Average value of D X and the pitch P of intersection B 1Y Average value of D Y Therefore, the sheet resistance value of the mesh wiring layer 20 can be prevented from becoming too large, and the antenna characteristics can be maintained.

[0232] The angle θ between the first regression line 21x and the second regression line 22x is preferably 30° or more and 150° or less. This makes it possible to prevent the angle between the first wiring 21 and the second wiring 22 from becoming too small or too large. This makes it easier to form the first wiring 21 and the second wiring 22 when forming the mesh wiring layer 20.

[0233] As shown in FIG. 23 , in this embodiment, each first wiring 21 has a cross section perpendicular to its longitudinal direction that is substantially rectangular or square. In this case, the cross section of the first wiring 21 is substantially uniform throughout the first wiring 21. As shown in FIG. 24 , in this embodiment, each second wiring 22 has a cross section perpendicular to its longitudinal direction that is substantially rectangular or square, and has substantially the same shape as the cross section of the first wiring 21 described above. In this case, the cross section of the second wiring 22 is substantially uniform throughout the second wiring 22. The cross sections of the first wiring 21 and the second wiring 22 do not necessarily have to be substantially rectangular or square. For example, the cross sections of the first wiring 21 and the second wiring 22 may be substantially trapezoidal in which the front side (i.e., the positive side in the Z direction) is narrower than the back side (i.e., the negative side in the Z direction), or may have curved side surfaces on both longitudinal sides.

[0234] In this embodiment, the line width W1 (see Figure 23) of the first wiring 21 is the width in a cross section perpendicular to its longitudinal direction, and the line width W2 (see Figure 24) of the second wiring 22 is the width in a cross section perpendicular to its longitudinal direction.

[0235] The wiring board 10 according to this embodiment can be fabricated, for example, by the method shown in FIGS. 9(a) to 9(f).

[0236] Then, by laminating the display device 61 on the wiring substrate 10 via the first transparent adhesive layer 95 and the second transparent adhesive layer 96, an image display device 60 is obtained, which includes the wiring substrate 10 and the display device 61 laminated on the wiring substrate 10.

[0237] Next, the operation of this embodiment having the above configuration will be described.

[0238] In this embodiment as well, the wiring board 10 is incorporated into an image display device 60 (see FIGS. 1 and 2) having a display device 61. At this time, the wiring board 10 is placed on the display device 61. The mesh wiring layer 20 of the wiring board 10 is electrically connected to a communication module 63 of the image display device 60 via the power supply unit 40. In this way, radio waves of a predetermined frequency can be transmitted and received via the mesh wiring layer 20, and communication can be performed using the image display device 60.

[0239] As described above, in the image display device 60, the mesh wiring layer 20 of the wiring substrate 10 is disposed so as to overlap the pixels P of the display device 61 in the Z direction. Therefore, moire may occur due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P.

[0240] In contrast to this, in this embodiment, the intersection of the first wiring 21 and the second wiring 22 is defined as A, the intersection of a first regression line 21x obtained from a plurality of intersections A located on the same first wiring 21 with a second regression line 22x obtained from a plurality of intersections A located on the same second wiring 22 is defined as B, and the distance along the width direction of the mesh wiring layer 20 from the intersection A to the closest intersection B is defined as d X The distance from the intersection point A to the closest intersection point B along the longitudinal direction of the mesh wiring layer 20 is d Y The pitch P of ten adjacent intersections B in the width direction of the mesh wiring layer 20 is 1X The average value of D X The pitch P of ten adjacent intersections B in the longitudinal direction of the mesh wiring layer 20 is 1Y The average value of D Y Then, for each of the 10 intersections B, among the 10 closest intersections A, at least 9 intersections A are 0.02D X ≦d X <0.3D X The relationship, and 0.02D Y ≦d Y <0.3D Y At least one of the following relationships is satisfied. This allows the intersections A to be arranged irregularly. That is, the first wirings 21, the second wirings 22, and the pixels P can be arranged irregularly. Therefore, the pitch of moire patterns generated due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P can be made small enough to be invisible to the naked eye. Furthermore, since the wiring substrate 10 satisfies the above relationship, it is possible to prevent variations in the pitch of the first wirings 21 and the pitch of the second wirings 22 from becoming too large. Therefore, it is possible to suppress flicker caused by reflection of visible light by the mesh wiring layer 20. Furthermore, since the wiring substrate 10 satisfies the above relationship, there is no variation in the size of the openings 23 in the mesh wiring layer 20, making it difficult for the mesh wiring layer 20 to be visible to the naked eye.

[0241] Furthermore, according to the present embodiment, as described above, the intersections A can be arranged irregularly, and therefore the orientation of the first wirings 21 extending between the intersections A and the orientation of the second wirings 22 extending between the intersections A are irregular. As a result, the lengths of the first wirings 21 and the second wirings 22 can be increased compared to when the first wirings 21 and the like extend linearly in a planar view. This improves adhesion between the first wirings 21 and the second wirings 22 of the mesh wiring layer 20 and the substrate 11. In this case, when a protective layer (not shown) for protecting the mesh wiring layer 20 is provided on the mesh wiring layer 20, adhesion between the mesh wiring layer 20 and the protective layer can be improved. This prevents the first wirings 21 and the second wirings 22 from peeling off from the substrate 11 even when the wiring substrate 10 is bent. Furthermore, breakage of the first wirings 21 and the second wirings 22 can also be prevented.

[0242] Furthermore, according to this embodiment, wiring board 10 includes substrate 11 and mesh wiring layer 20 disposed on substrate 11. Substrate 11 is transparent. Mesh wiring layer 20 has a conductor portion as a forming portion of an opaque conductive layer and a mesh pattern formed by numerous openings 23. This ensures the transparency of wiring board 10. As a result, when wiring board 10 is placed on display device 61, display device 61 can be seen through openings 23 of mesh wiring layer 20, and visibility of display device 61 is not hindered.

[0243] Next, modified examples of the wiring board will be described.

[0244] Figures 25 and 26 show a first modified example of a wiring board. The modified example shown in Figures 25 and 26 differs in that a dummy wiring layer 30 is provided around the mesh wiring layer 20, and other configurations are substantially the same as the embodiment shown in Figures 21 to 24 described above. In Figures 25 and 26, the same parts as those in the embodiment shown in Figures 21 to 24 are given the same reference numerals, and detailed explanations thereof will be omitted.

[0245] 25, a dummy wiring layer 30 is provided along the periphery of the mesh wiring layer 20. Unlike the mesh wiring layer 20, this dummy wiring layer 30 does not substantially function as an antenna.

[0246] As shown in FIG. 26, the dummy wiring layer 30 is composed of repeated dummy wirings 30a having a predetermined pattern shape. That is, the dummy wiring layer 30 includes a plurality of dummy wirings 30a, and each dummy wiring 30a is electrically independent from the mesh wiring layer 20 (i.e., the first wirings 21 and the second wirings 22). The plurality of dummy wirings 30a are regularly arranged throughout the dummy wiring layer 30. The plurality of dummy wirings 30a are spaced apart from each other in the planar direction and are arranged to protrude above the substrate 11. That is, each dummy wiring 30a is electrically independent from the mesh wiring layer 20, the power supply section 40, and other dummy wirings 30a. The shape of each dummy wiring 30a is an inverted V-shape in plan view.

[0247] In this case, the dummy wiring 30a has a shape in which a portion of the pattern shape of the mesh wiring layer 20 described above is missing. This makes it difficult to visually recognize the difference between the mesh wiring layer 20 and the dummy wiring layer 30, and makes the mesh wiring layer 20 arranged on the substrate 11 less visible. As shown in FIG. 26 , the dummy wiring 30a extends parallel to the first wiring 21 or the second wiring 22. Specifically, the dummy wiring 30a includes a first portion 31a extending parallel to the first wiring 21 and a second portion 32a extending parallel to the second wiring 22. In this way, the dummy wiring 30a extending parallel to the first wiring 21 or the second wiring 22 makes the mesh wiring layer 20 arranged on the substrate 11 even less visible. The aperture ratio of the dummy wiring layer 30 may be the same as or different from the aperture ratio of the mesh wiring layer 20, but is preferably close to the aperture ratio of the mesh wiring layer 20. Here, "parallel to the first wiring" means that the angle θ1 between the first portion 31a and the first regression line 21x is 5° or less. Also, "parallel to the second wiring" means that the angle θ2 between the second portion 32a and the second regression line 22x is 5° or less.

[0248] As in this modification, the dummy wiring layer 30 that is electrically independent from the mesh wiring layer 20 is provided around the mesh wiring layer 20, thereby making the outer edge of the mesh wiring layer 20 unclear. This makes it possible to make the mesh wiring layer 20 less visible on the surface of the image display device 60, and makes it difficult for a user of the image display device 60 to recognize the mesh wiring layer 20 with the naked eye.

[0249] Fig. 27 shows a second modified example of the wiring board. The modified example shown in Fig. 27 differs in that two or more dummy wiring layers 30A, 30B having different aperture ratios are provided around the mesh wiring layer 20, but the other configurations are substantially the same as those shown in Figs. 21 to 26 described above. In Fig. 27, the same parts as those shown in Figs. 21 to 26 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0250] 15, in the wiring substrate 10, a plurality of (two in this case) dummy wiring layers 30A, 30B (i.e., a first dummy wiring layer 30A and a second dummy wiring layer 30B) having different aperture ratios are provided along the periphery of the mesh wiring layer 20. Specifically, the first dummy wiring layer 30A is arranged along the periphery of the mesh wiring layer 20, and the second dummy wiring layer 30B is arranged along the periphery of the first dummy wiring layer 30A. Unlike the mesh wiring layer 20, these dummy wiring layers 30A, 30B do not substantially function as antennas.

[0251] As shown in FIG. 27, the first dummy wiring layer 30A is composed of repeated dummy wirings 30a1 having a predetermined pattern. The second dummy wiring layer 30B is composed of repeated dummy wirings 30a2 having a predetermined pattern. That is, the dummy wiring layers 30A and 30B each include a plurality of dummy wirings 30a1 and 30a2, and each of the dummy wirings 30a1 and 30a2 is electrically independent from the mesh wiring layer 20. The dummy wirings 30a1 and 30a2 are regularly arranged throughout the dummy wiring layers 30A and 30B, respectively. The dummy wirings 30a1 and 30a2 are spaced apart from each other in the planar direction and protrude above the substrate 11. Each of the dummy wirings 30a1 and 30a2 is electrically independent from the mesh wiring layer 20, the power supply section 40, and the other dummy wirings 30a1 and 30a2. The shape of each of the dummy wirings 30a1 and 30a2 is an inverted V-shape in plan view.

[0252] In this case, the dummy wirings 30a1 and 30a2 have a shape in which a portion of the pattern shape of the mesh wiring layer 20 described above is missing. This makes it difficult to visually recognize the difference between the mesh wiring layer 20 and the first dummy wiring layer 30A, and the difference between the first dummy wiring layer 30A and the second dummy wiring layer 30B, making it difficult to see the mesh wiring layer 20 arranged on the substrate 11. As shown in FIG. 27 , the dummy wirings 30a1 and 30a2 extend parallel to the first wiring 21 or the second wiring 22. Specifically, the dummy wiring 30a1 includes a first portion 31a1 extending parallel to the first wiring 21 and a second portion 32a1 extending parallel to the second wiring 22. The dummy wiring 30a2 includes a first portion 31a2 extending parallel to the first wiring 21 and a second portion 32a2 extending parallel to the second wiring 22.

[0253] The area of ​​each dummy wiring 30a1 in the first dummy wiring layer 30A is larger than the area of ​​each dummy wiring 30a2 in the second dummy wiring layer 30B. In this case, the line width of each dummy wiring 30a1 is the same as the line width of each dummy wiring 30a2, but this is not limited to this, and the line width of each dummy wiring 30a1 may be wider than the line width of each dummy wiring 30a2. Note that other configurations of the dummy wirings 30a1 and 30a2 are similar to the configuration of the dummy wiring 30a in the first modified example, so detailed description will be omitted here.

[0254] In this modification, it is preferable that the aperture ratios of the mesh wiring layer 20 and the two or more dummy wiring layers 30A, 30B increase stepwise from the mesh wiring layer 20 toward the dummy wiring layers 30A, 30B farther from the mesh wiring layer 20. In other words, it is preferable that the aperture ratio of each dummy wiring layer gradually increase from that closer to the mesh wiring layer 20 to that farther away. In this case, it is preferable that the aperture ratio of the first dummy wiring layer 30A is greater than that of the mesh wiring layer 20. It is preferable that the aperture ratio of the second dummy wiring layer 30B is greater than that of the first dummy wiring layer 30A. This makes it possible to further obscure the outer edges of the mesh wiring layer 20 and the dummy wiring layers 30A, 30B. This makes it possible to make the mesh wiring layer 20 even less visible on the surface of the image display device 60.

[0255] In this way, by arranging the dummy wiring layers 30A and 30B electrically independent from the mesh wiring layer 20, the outer edge of the mesh wiring layer 20 can be made more unclear. This makes it possible to make the mesh wiring layer 20 less visible on the surface of the image display device 60, and makes it difficult for a user of the image display device 60 to recognize the mesh wiring layer 20 with the naked eye. Note that three or more dummy wiring layers having different aperture ratios may be provided around the mesh wiring layer 20.

[0256] Figure 28 shows a third modified example of the wiring board. The modified example shown in Figure 28 differs in that the tip portion 20b includes a central portion 20c and a peripheral portion 20d located around the central portion 20c, but other configurations are substantially the same as those shown in Figures 21 to 27 described above. In Figure 28, the same parts as those shown in Figures 21 to 27 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0257] 28, the tip side portion (i.e., the transmitting / receiving portion) 20b includes a central portion 20c and a peripheral portion 20d located around the central portion 20c. Here, in the peripheral portion 20d, the distance d X (See FIG. 22) is the distance d X In addition, in the peripheral portion 20d, the distance d Y (See FIG. 22) is the distance d Y is smaller than the value of the sheet resistance in the peripheral portion 20d. This reduces the sheet resistance in the peripheral portion 20d. This effectively increases the radiation efficiency of the mesh wiring layer 20 as an antenna. That is, since the peripheral portion 20d is located closer to the base end portion 20a than the central portion 20c, the current density in the peripheral portion 20d is higher than the current density in the central portion 20c. This reduces the sheet resistance in the peripheral portion 20d where the current density is higher, thereby effectively increasing the radiation efficiency of the mesh wiring layer 20 as an antenna.

[0258] In this modification, the distance d in the peripheral portion 20d X is the distance d in the central portion 20c X It is preferable that the distance d in the peripheral portion 20d is 20% or more and 80% or less. Y is the distance d in the central portion 20c Y The distance d in the peripheral portion 20d is preferably 20% or more and 80% or less. X , d Y is the distance d X , d YBy making the distance d at least 20% of the distance d at the peripheral portion 20d, the intersection points A can be arranged irregularly. Therefore, the pitch of the moire pattern generated due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P can be made small enough to be invisible to the naked eye. Also, the boundary between the central portion 20c and the peripheral portion 20d can be made unclear. X , d Y is the distance d X , d Y By making the thickness 80% or less, the sheet resistance value in the peripheral portion 20d can be effectively reduced.

[0259] In the illustrated example, only the region of the central portion 20c on the base end portion 20a side is surrounded by the peripheral portion 20d. In this case, 50% or more of the region of the central portion 20c on the base end portion 20a side in the longitudinal direction (i.e., Y direction) of the mesh wiring layer 20 may be surrounded by the peripheral portion 20d. This can effectively improve the radiation efficiency of the mesh wiring layer 20 as an antenna. Note that the entire periphery of the central portion 20c may be surrounded by the peripheral portion 20d.

[0260] The width W3 of the peripheral portion 20d is the pitch P of the intersections B in the central portion 20c. 1X (See Figure 22) X It is preferable that the width W3 of the peripheral portion 20d is at least twice as large as the width W1 of the peripheral portion 20d. This widens the area where the sheet resistance can be reduced. Therefore, the sheet resistance can be effectively reduced in the area where the current density is high. Note that the width W3 of the peripheral portion 20d refers to the distance in the X direction in the part of the peripheral portion 20d that extends in the Y direction, and refers to the distance in the Y direction in the part of the peripheral portion 20d that extends in the X direction.

[0261] As in this modification, the distance d X , d Y is the distance d X , d YSince the sheet resistance value at the peripheral portion 20d is smaller than the value at the surface periphery 20c, the radiation efficiency of the mesh wiring layer 20 as an antenna can be effectively improved.

[0262] [Example] Next, a specific example of this embodiment will be described.

[0263] Example B1 A wiring board 10 having the configuration shown in FIG. 21 was fabricated. That is, a wiring board 10 was fabricated in which the first wirings 21 and the second wirings 22 were arranged irregularly relative to each other. In this case, a substrate made of polyethylene terephthalate and having a thickness of 100 μm was used as the substrate for the wiring board 10. Furthermore, copper wiring having a line width of 1.0 μm and a height of 1.0 μm was used as the first wirings 21 and the second wirings 22. At this time, the length L of the tip side portion 20b of the mesh wiring layer 20 was a is 3.5 mm, and the width W a was 4.2 mm.

[0264] In the wiring board 10 according to Example B1, the pitch P of 10 adjacent intersections B in the width direction (i.e., the X direction) of the mesh wiring layer 20 is 1X Average value of D X The pitch P of the ten intersections B adjacent to each other in the longitudinal direction of the mesh wiring layer 20 (i.e., the Y direction) was 70 μm. 1Y The average value of D Y was 130 μm.

[0265] The distance from the intersection point A to the closest intersection point B along the width direction of the mesh wiring layer 20 is defined as d X When this is the case, for each of the 10 intersections B, of the 10 closest intersections A, at least 9 intersections A (hereinafter simply referred to as "9 or more intersections A"), 0.02D X ≦d X ≦0.1D X It was a fulfilling relationship.

[0266] The distance from the intersection point A to the closest intersection point B along the longitudinal direction of the mesh wiring layer 20 is defined as d Y Then, for nine or more intersections A, 0.02D Y ≦d Y ≦0.1D Y It was a fulfilling relationship.

[0267] In wiring board 10 according to Example B1, the difference in aperture ratio between adjacent 1000 μm square regions was 0.5% or less.

[0268] Next, the visibility of the wiring board 10 was confirmed. At this time, first, the presence or absence of moire was confirmed. At this time, the wiring board 10 was first superimposed on the display device 61 shown in FIG. 3 and observed. In the display device 61, the pitch P of the pixels P was X is 60 μm, and the pitch P of the pixel P Y The moire pattern was 60 μm. Then, with the display device 61 emitting white light, the wiring board 10 was visually observed from a distance of 300 mm to check for the presence or absence of moire.

[0269] The presence or absence of flickering was also confirmed. First, a blackboard was placed on the back side of wiring board 10 (i.e., the negative side in the Z direction). Next, light was irradiated from the front side of wiring board 10 (i.e., the positive side in the Z direction) using a high-intensity light. At this time, the light was irradiated from a direction inclined with respect to the normal direction of first surface 11a of substrate 11. Then, wiring board 10 was visually observed from a distance of 300 mm to confirm the presence or absence of flickering.

[0270] Next, the sheet resistance value (Ω / □) of the mesh wiring layer 20 in the wiring substrate 10 was measured. e1 , 20 e2 The resistance value R between the mesh wiring layer 20 and the length L of the mesh wiring layer 20 was measured. a and width W a Ratio to (La / W a ) to obtain the sheet resistance R s (Ω / □) was calculated.

[0271] (Example B2) Average value D X The average value D Y The visibility of the wiring board 10 was confirmed and the sheet resistance of the mesh wiring layer 20 was measured in the same manner as in Example B1, except that the thickness of the mesh wiring layer 20 was 270 μm.

[0272] (Example B3) At nine or more intersections A, 0.02D X ≦d X ≦0.05D X The relationship was fulfilled. At nine or more intersections A, 0.02D Y ≦d Y ≦0.05D Y The visibility of the wiring board 10 was confirmed and the sheet resistance of the mesh wiring layer 20 was measured in the same manner as in Example B1, except that the following relationship was satisfied.

[0273] (Example B4) At nine or more intersections A, 0.25D X ≦d X ≦0.29D X The relationship was fulfilled. At nine or more intersections A, 0.25D Y ≦d Y ≦0.29D Y The visibility of the wiring board 10 was confirmed and the sheet resistance of the mesh wiring layer 20 was measured in the same manner as in Example B1, except that the following relationship was satisfied.

[0274] (Comparative Example B1) At nine or more intersections A, d X = 0, and at nine or more intersections A, d Y =0, the average value D X was 100 μm, and the average value D Y The visibility of the wiring board 10 was confirmed and the sheet resistance of the mesh wiring layer 20 was measured in the same manner as in Example B1, except that the thickness of the mesh wiring layer 20 was 100 μm.

[0275] (Comparative example B2) At nine or more intersections A, 0.00D X ≦d X ≦0.02D X The relationship was fulfilled. At nine or more intersections A, 0.00D Y ≦d Y ≦0.02D Y The visibility of the wiring board 10 was confirmed and the sheet resistance of the mesh wiring layer 20 was measured in the same manner as in Example B1, except that the following relationship was satisfied.

[0276] (Comparative Example B3) At nine or more intersections A, 0.30D X ≦d X The relationship was fulfilled. At nine or more intersections A, 0.30D Y ≦d Y The visibility of the wiring board 10 was confirmed and the sheet resistance of the mesh wiring layer 20 was measured in the same manner as in Example B1, except that the following relationship was satisfied.

[0277] (Comparative example B4) A wiring board 100 having the configuration shown in FIG. 20 was fabricated. That is, a wiring board 100 was fabricated in which the planar structure formed by the wiring 200 of the mesh wiring layer 20 was a Voronoi pattern. In this case, a substrate made of polyethylene terephthalate and having a thickness of 100 μm was used as the substrate for the wiring board 100. Furthermore, copper wiring having a line width of 1.0 μm and a height of 1.0 μm was used as the wiring 200. At this time, the length L of the tip side portion 20b of the mesh wiring layer 20 was a is 3.5 mm, and the width W a was 4.2 mm.

[0278] In the wiring substrate 100 according to Comparative Example B4, the average side-to-side distance was 100 μm. The side-to-side distance was measured on a virtual line extending along the longitudinal direction (X direction) of the tip portion 20b (see FIG. 4) of the mesh wiring layer 20, and drawn at an arbitrarily selected position.

[0279] In wiring board 100 according to Comparative Example B4, the difference in aperture ratio between adjacent 1000 μm square regions was 0.5% or less.

[0280] Next, in the same manner as in Example B1, the visibility of the wiring substrate 100 was checked, and the sheet resistance value of the mesh wiring layer 20 was measured.

[0281] The results are shown in Tables 2 to 4.

[0282] [Table 2]

[0283] [Table 3]

[0284] [Table 4]

[0285] In Table 4, "A" means that the result was excellent, "B" means that the result was good, and "C" means that the result was poor. Specifically, in the "Moiré" column of Table 4, "A" means that no moiré was observed, and "B" means that moiré was observed. In the "Flicker" column of Table 4, "A" means that no flicker due to reflected light was observed, and "B" means that flicker due to reflected light was observed. In the "Aperture Ratio" column of Table 4, "A" means that the difference in aperture ratio was 0.5% or less. In the "Sheet Resistance" column of Table 4, "A" means that the sheet resistance was equal to or less than a predetermined value, "B" means that the sheet resistance was greater than a predetermined value, and "C" means that the sheet resistance was significantly greater than a predetermined value.

[0286] As a result, moire patterns were observed in the wiring boards 100 according to Comparative Examples B1 and B2, as shown in Table 4. In contrast, no moire patterns were observed in the wiring boards 10 according to Examples B1 to B4.

[0287] As shown in Table 4, flickering due to reflected light occurred in the wiring boards 100 of Comparative Examples B3 and B4. In contrast, flickering due to reflected light was not observed in the wiring boards 10 of Examples B1 to B4.

[0288] As described above, it was found that wiring board 10 according to the present embodiment can suppress the occurrence of moire and also suppress flickering due to reflected light.

[0289] As shown in Table 4, in the wiring boards 10 according to Examples B1 to B4, the unevenness in the aperture ratio could be reduced, similar to the wiring board 100 according to Comparative Example B1. That is, even when the first wirings 21, etc. were arranged irregularly, the unevenness in the aperture ratio could be reduced, similar to the wiring board 100 in which the first wirings 21, etc. were arranged regularly.

[0290] As shown in Table 4, in the wiring boards 10 according to Examples B1 to B4, the sheet resistance of the mesh wiring layer 20 could be kept below a predetermined value, similar to the wiring board 100 according to Comparative Example B1. In this case, the sheet resistance of the mesh wiring layer 20 of the wiring boards 10 according to Examples B1 to B4 was equivalent to the sheet resistance of the mesh wiring layer 20 of the wiring board 100 according to Comparative Example B1. That is, in the wiring boards 10 according to Examples B1 to B4, the first wirings 21, etc. are irregularly arranged, but the length of the first wirings 21, etc. is unchanged compared to when the first wirings 21, etc. are regularly arranged. As a result, even when the first wirings 21, etc. are irregularly arranged, the sheet resistance of the mesh wiring layer 20 could be made equivalent to the sheet resistance of the mesh wiring layer 20 of the wiring board 100 in which the first wirings 21, etc. are regularly arranged. Therefore, in wiring boards 10 according to Examples B1 to B4, the radiation efficiency of mesh wiring layer 20 as an antenna could be increased, similar to wiring board 100 in which first wirings 21 and the like are regularly arranged.

[0291] (Third embodiment) Next, a third embodiment will be described with reference to Figures 29 to 34. Figures 29 to 34 are diagrams showing this embodiment. In Figures 29 to 34, the same parts as those in the first embodiment shown in Figures 1 to 20 or the same parts as those in the second embodiment shown in Figures 21 to 28 are given the same reference numerals, and detailed descriptions thereof may be omitted.

[0292] In the following embodiments, the "X direction" refers to a direction parallel to one side of the substrate. The "Y direction" refers to a direction perpendicular to the X direction and parallel to another side of the substrate. The "Z direction" refers to a direction perpendicular to both the X and Y directions and parallel to the thickness direction of the wiring substrate. The "front surface" refers to the surface on the positive side of the Z direction, on which wiring is provided relative to the substrate. The "back surface" refers to the surface on the negative side of the Z direction, opposite to the surface on which wiring is provided relative to the substrate.

[0293] [Wiring board configuration] The configuration of the wiring board according to this embodiment will be described with reference to Figures 29 to 32. Figures 29 to 32 are diagrams showing the wiring board according to this embodiment.

[0294] 29, wiring board 10 according to the present embodiment is disposed on, for example, a display device 91 of an image display device 90 described later. Such wiring board 10 includes a transparent substrate 11 and a mesh wiring layer 20 disposed on substrate 11. In addition, a power supply unit 40 is electrically connected to mesh wiring layer 20.

[0295] In this embodiment, the mesh wiring layer 20 is made up of an antenna pattern region that functions as an antenna. In Fig. 29, a plurality of (three) mesh wiring layers 20 are formed on the substrate 11, and each corresponds to a different frequency band. That is, the plurality of mesh wiring layers 20 have a length (length in the Y direction) L a1 The lengths L of the mesh wiring layer 20 are different from each other and correspond to specific frequency bands. a1 is longer. When the wiring board 10 is disposed on, for example, a display device 91 of an image display device 90 (see FIG. 34 described later), each mesh wiring layer 20 may correspond to any of a telephone antenna, a WiFi antenna, a 3G antenna, a 4G antenna, a 5G antenna, a millimeter wave antenna, an LTE antenna, a Bluetooth (registered trademark) antenna, an NFC antenna, etc. When the wiring board 10 does not have a radio wave transmission / reception function, each mesh wiring layer 20 may perform functions such as hovering (a function that allows a user to operate the display without directly touching it), fingerprint authentication, a heater, noise reduction (shielding), etc. Furthermore, the mesh wiring layer 20 may not be present on the entire surface of the substrate 11, but may be present only in a partial region on the substrate 11.

[0296] Each mesh wiring layer 20 has a substantially rectangular shape in a plan view. The longitudinal direction of each mesh wiring layer 20 is parallel to the Y direction, and the lateral direction of each mesh wiring layer 20 is parallel to the X direction. The length L of each mesh wiring layer 20 in the longitudinal direction (Y direction) is a1 The width W of each mesh wiring layer 20 in the short side direction (X direction) can be selected, for example, in the range of 2 mm to 100 mm. a1 The length L of the mesh wiring layer 20 can be selected, for example, in the range of 1 mm to 10 mm. In particular, the mesh wiring layer 20 may be a millimeter wave antenna. When the mesh wiring layer 20 is a millimeter wave antenna, the length L of the mesh wiring layer 20 is a1 The width can be selected from the range of 1 mm to 10 mm, more preferably 1.5 mm to 5 mm. Note that, although Fig. 29 shows a shape in which the mesh wiring layer 20 functions as a monopole antenna, the shape is not limited to this, and the mesh wiring layer 20 can also be a dipole antenna, a loop antenna, a slot antenna, a microstrip antenna, a patch antenna, or the like.

[0297] In this embodiment, the mesh wiring layer 20 has a non-periodic planar structure. In the mesh wiring layer 20, metal wires are formed in an irregular lattice shape or an irregular mesh shape.

[0298] As shown in FIG. 30 , each mesh wiring layer 20 is composed of a plurality of intersections 240 and a plurality of wires 210. The wires 210 are located between each of the intersections 240. The wires 210 connect a pair of intersections 240. The intersections 240 are located at both ends of each wire 210 in the longitudinal direction. The plurality of intersections 240 and the plurality of wires 210 are integrated as a whole to form an irregular lattice shape or an irregular mesh shape. The wires 210 extend in an irregular direction without any fixed regularity. Furthermore, three to five wires 210 may be connected to one intersection 240.

[0299] Each mesh wiring layer 20 has a plurality of openings 23. Each opening 23 is formed by being surrounded by a plurality of wirings 210. Each opening 23 may be surrounded by 3 to 10 wirings 210. In this case, the arrangement pattern of the openings 23 is a random pattern. In this random pattern, there is no direction in which the openings 23 are arranged at a repeating period with a certain regularity. Furthermore, the plurality of intersections 240 are arranged in an irregular pattern without a certain regularity. The pitch P between the intersections 240 is 11 The distances between the intersections 240 are not uniform within the mesh wiring layer 20, but are varied. 11 The distance may be set to various values ​​within a range of, for example, 0.01 mm to 1 mm. From each opening 23, the substrate 11 having transparency is exposed.

[0300] In the mesh wiring layer 20, there is no direction in which the openings 23 have a repeating period. In this way, since there is no direction in which the openings 23 of the mesh wiring layer 20 are arranged at a repeating period with a certain regularity, moire that may occur when the wiring substrate 10 and, for example, the display device 91 of the image display device 90 are overlapped can be made less noticeable. Note that, in order to more effectively suppress moire, it is preferable that there is no direction in which the openings 23 have a repeating period over the entire region of the mesh wiring layer 20.

[0301] In FIG. 30, the non-periodic planar structure constituting the mesh wiring layer 20 may be a Voronoi pattern. Here, a Voronoi pattern (Voronoi diagram) refers to a pattern that can be created by dividing a point in a plane, when a plurality of arbitrary points (generator points) are arranged on the plane, based on which point the point is closest to. As will be explained below, strictly speaking, the wirings 210 do not connect the intersections 240 with each other in a straight line. However, in this specification, when it is assumed that the wirings 210 connect the intersections 240 with each other in a straight line, a Voronoi pattern is formed, and this is referred to as "the non-periodic planar structure being a Voronoi pattern."

[0302] 31(a) is an enlarged view showing one wiring 210 connecting a pair of intersections 240. As shown in FIG. 31(a), the wiring 210 does not connect the pair of intersections 240 in a straight line (the shortest distance). For each of the multiple wirings 210 surrounding each opening 23, the shortest distance L between the intersections 240 is min When the magnification of the length of the wiring 210 between the intersections 240 is calculated relative to the length of the wiring 210, the average value is 1.01 times or more and 1.82 times or less. This average value is preferably 1.05 times or more and 1.30 times or less. Here, the length of the wiring 210 refers to the length measured along the length direction of the wiring 210 from the line connecting the centers of the wiring 210 in the width direction. The planar shape of the wiring 210 may be a wavy curve. In other words, the wiring 210 is formed by a line segment L connecting a pair of intersections 240. s The wiring 210 intersects with each other at at least one point between the intersections 240, and preferably at two to ten points.

[0303] For example, assume that one opening 23 is surrounded by N wirings 210. Here, N may be 3 or more and 10 or less, as described above. In this case, for each of the N wirings 210, the shortest distance L between the intersections 240 is min The length L of the wiring 210 between the intersections 240 c Magnification (L c / L min ) is calculated. The N magnifications (M1, M2, ....M N ) average value ((M1+M2+···+M N ) / N) is 1.01 times or more and 1.82 times or less. c / L min ) is preferably 1.01 times or more and 1.82 times or less. However, for some of the N wirings 210, c / L min) does not have to be 1.01 times or more and 1.82 times or less, as long as the average value of the N magnifications is 1.01 times or more and 1.82 times or less. Furthermore, it is preferable that the average value is 1.01 times or more and 1.82 times or less for all of the openings 23 included in the mesh wiring layer 20. However, this is not limiting, and it is not necessary for the average value to be 1.01 times or more and 1.82 times or less for some of the openings 23 included in the mesh wiring layer 20. Specifically, it is preferable that the average value is 1.01 times or more and 1.82 times or less for 80% or more, 90% or more, 95% or more, or 99% or more of the openings 23 included in the mesh wiring layer 20.

[0304] 31(a), the planar shape of the wiring 210 is a sine curve. In this case, the amplitude A1 of the sine curve constituting the wiring 210 is the shortest distance L between the intersections 240. min The wavelength λ1 of the sine curve constituting the wiring 210 is the shortest distance L between the intersections 240. min The shortest distance L may be 0.16 times or more and 0.5 times or less, and is preferably 0.2 times or more and 0.33 times or less. min The value of the wavelength λ1 may be uniform among the multiple wirings 210 in the mesh wiring layer 20. min The value of the wavelength λ1 may be a natural number between 2 and 10. In FIG. 31(a), the shortest distance L min The value of the wavelength λ1 is 3. The amplitude A1 of the wiring 210 may be uniform among the plurality of wirings 210 in the mesh wiring layer 20. Alternatively, both the amplitude A1 and the wavelength λ1 of the wiring 210 may be uniform among the plurality of wirings 210 in the mesh wiring layer 20.

[0305] As shown in FIG. 31(b), the planar shape of the wiring 210 may be a wavy curve with variable amplitude and wavelength. Alternatively, the planar shape of the wiring 210 may be a wavy curve with one of the amplitude and wavelength being constant and the other of the amplitude and wavelength being variable. As shown in FIG. 31(c), the planar shape of the wiring 210 may be a sawtooth or jagged line with no curved portions. Alternatively, although not shown, the planar shape of the wiring 210 may be a Bezier curve or a curve formed by connecting multiple arcs.

[0306] In this way, for each of the plurality of wirings 210 surrounding each opening 23, the shortest distance L between the intersections 240 is min When the magnification of the length of the wiring 210 between the intersections 240 is calculated, the average value is 1.01 to 1.82 times. This makes it possible to suppress flickering when the mesh wiring layer 20 reflects light.

[0307] 32, each wiring 210 has a cross section perpendicular to its longitudinal direction that is substantially rectangular or square. In this case, the cross-sectional shape of the wiring 210 is substantially uniform along the longitudinal direction of the wiring 210. The cross-sectional shape of the wiring 210 may be the same among the multiple wirings 210 included in the mesh wiring layer 20. The cross-sectional shape of the wiring 210 does not necessarily have to be substantially rectangular or square, and may be, for example, a substantially trapezoidal shape in which the front side (positive side in the Z direction) is narrower than the back side (negative side in the Z direction), or a shape in which the side surfaces located on both sides in the width direction are curved.

[0308] In this embodiment, the line width W of the wiring 210 11 (See FIG. 32) is not particularly limited and can be appropriately selected depending on the application. For example, the line width W 11 The height H of the wiring 210 can be selected from the range of 0.1 μm to 5.0 μm, and may be set to 0.5 μm to 3.0 μm. 11 The height H of the wiring 210 (length in the Z direction, see FIG. 32) is not particularly limited and can be selected appropriately depending on the application. 11 For example, it may be 0.1 μm or more and 5.0 μm or less, or 0.2 μm or more and 2.0 μm or less.

[0309] The material of the wiring 210 may be any metal material having electrical conductivity. In the present embodiment, the material of the wiring 210 is copper, but is not limited to this. The material of the wiring 210 may be, for example, a metal material (including an alloy) such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel. The wiring 210 may also be a plating layer formed by electrolytic plating.

[0310] 29 again, power supply unit 40 is electrically connected to mesh wiring layer 20. When wiring substrate 10 is incorporated into image display device 90 (see FIG. 34), power supply unit 40 is electrically connected to wireless communication circuit 92 of image display device 90. Note that power supply unit 40 is provided on the surface of substrate 11, but this is not limiting, and part or all of power supply unit 40 may be located outside the periphery of substrate 11. Furthermore, power supply unit 40 may be formed to be flexible so that it can wrap around the side or back surface of image display device 90 and be electrically connected on the side or back surface.

[0311] [Method of manufacturing wiring board] Next, a method for manufacturing a wiring board according to this embodiment will be described with reference to Figures 33(a) to 33(f), which are cross-sectional views illustrating the method for manufacturing a wiring board according to this embodiment.

[0312] As shown in FIG. 33(a), a transparent substrate 11 is prepared.

[0313] Next, a mesh wiring layer 20 having a non-periodic planar structure and including a plurality of wirings 210 is formed on the substrate 11 .

[0314] 33(b), first, metal foil 51 is laminated over substantially the entire surface of substrate 11. In this embodiment, the thickness of metal foil 51 may be 0.1 μm or more and 5.0 μm or less. In this embodiment, metal foil 51 may contain copper.

[0315] 33(c), a photo-curable insulating resist 52 is applied to almost the entire surface of the metal foil 51. Examples of the photo-curable insulating resist 52 include organic resins such as acrylic resins and epoxy resins.

[0316] 33(d), an insulating layer 54 is formed by photolithography. In this case, the photo-curable insulating resist 52 is patterned by photolithography to form the insulating layer 54 (resist pattern). At this time, the insulating layer 54 is formed so that the metal foil 51 corresponding to the wiring 210 is exposed.

[0317] 33(e), the metal foil 51 located on the surface of the substrate 11 in a portion not covered with the insulating layer 54 is removed. At this time, the metal foil 51 is etched so as to expose the surface of the substrate 11 by wet treatment using ferric chloride, cupric chloride, a strong acid such as sulfuric acid or hydrochloric acid, persulfate, hydrogen peroxide, an aqueous solution of these, or a combination of these.

[0318] 33(f), the insulating layer 54 is removed by wet treatment using a permanganate solution, N-methyl-2-pyrrolidone, an acid or alkaline solution, or dry treatment using oxygen plasma.

[0319] In this manner, wiring substrate 10 is obtained, which includes substrate 11 and mesh wiring layer 20 provided on substrate 11. In this case, mesh wiring layer 20 has an aperiodic planar structure. Mesh wiring layer 20 also includes a plurality of wires 210. In this case, power supply portion 40 may be formed by a portion of conductor 55. Alternatively, a flat-plate-shaped power supply portion 40 may be separately prepared and electrically connected to mesh wiring layer 20.

[0320] [Operation of this embodiment] Next, the operation of the wiring board having such a configuration will be described.

[0321] As shown in FIG. 34 , the wiring substrate 10 is incorporated into an image display device 90 having a display device (display) 91. The display device 91 may be, for example, an organic electroluminescence (EL) display device. The display device 91 may include, for example, a metal layer, a support substrate, a resin substrate, a thin film transistor (TFT), and an organic EL layer (not shown). A touch sensor (not shown) may be disposed on the display device 91. Note that the display device 91 is not limited to an organic EL display device. For example, the display device 91 may be another display device that has a light-emitting function. The display device 91 may be a micro LED display device including micro LED elements (light emitters). The display device 91 may also be a liquid crystal display device including liquid crystal. The wiring substrate 10 is disposed directly or indirectly on the display device 91. Examples of such an image display device 90 include mobile terminal devices such as smartphones and tablets. The mesh wiring layer 20 of the wiring substrate 10 is electrically connected to a wireless communication circuit 92 of the image display device 90 via a power supply unit 40. In this way, radio waves of a predetermined frequency can be transmitted and received via the mesh wiring layer 20, and communication can be performed using the image display device 90. In this embodiment, there is also provided an image display device 90 including such a display device 91 and a wiring substrate 10 arranged on the display device 91.

[0322] In such an image display device 90, the mesh wiring layer 20 of the wiring substrate 10 is disposed so as to overlap in the Z direction with pixels (not shown) of the display device 91 of the image display device 90. In this case, if the wirings 210 of the mesh wiring layer 20 are regular (periodic), a striped pattern (moiré, interference fringes) may occur due to the regularity (periodicity) of the wirings 210 and the regularity (periodicity) of the pixels of the display device 91.

[0323] In contrast to this, in the present embodiment, the mesh wiring layer 20 has an aperiodic planar structure. As a result, when viewed from the Z direction, the wires 210 of the mesh wiring layer 20 and the pixels of the display device 91 are arranged irregularly. This prevents moire from occurring due to the regularity (periodicity) of the wires 210 and the regularity (periodicity) of the pixels.

[0324] In particular, in this embodiment, the non-periodic planar structure constituting the mesh wiring layer 20 may be a Voronoi pattern. This makes it possible to more effectively suppress the occurrence of moire when the wiring substrate 10 is superimposed on a display device 91 in which pixels are regularly (periodically) arranged.

[0325] On the other hand, since the mesh wiring layer 20 has an aperiodic planar structure, the wiring 210 faces in various directions. In this case, there is a risk that a phenomenon called flickering will occur due to the reflection of light irradiated onto the wiring substrate 10. This flickering is thought to occur when multiple linear wirings 210 each having a certain length or longer are arranged, and the direction of light reflected by the wiring 210 faces in several directions.

[0326] In contrast to this, in this embodiment, the wiring 210 does not linearly connect the intersections 240 of the mesh wiring layer 20. That is, for each of the plurality of wirings 210 surrounding each opening 23, the shortest distance L between the intersections 240 is min When the magnification of the length of the wiring 210 between the intersections 240 is calculated for the shortest distance L min By making the length longer than the normal, the direction of reflection is more finely dispersed, which reduces the flickering mentioned above.

[0327] In particular, in this embodiment, the planar shape of the wiring 210 may be a sine curve. In this case, the direction of light reflection by the wiring 210 can be more finely dispersed, and flickering can be further reduced.

[0328] As described above, according to this embodiment, the mesh wiring layer 20 has a non-periodic planar structure. In addition, for each of the plurality of wirings 210 surrounding each opening 23, the shortest distance L between the intersections 240 is min When the magnification of the length of wiring 210 between intersections 240 is calculated relative to the length of the wiring 210, the average value is 1.01 to 1.82. This results in a wiring board 10 that suppresses both the occurrence of moire and flicker.

[0329] In this embodiment, the line width of the wiring 210 may be 0.1 μm or more and 5.0 μm or less, which makes the wiring 210 difficult to see with the naked eye, and reduces the decrease in visibility of the display device 91.

[0330] Furthermore, in this embodiment, the mesh wiring layer 20 may also function as an antenna. In this case, the mesh wiring layer 20 as an antenna can be disposed on the surface side of the image display device 90. This allows for improved communication performance compared to when an antenna is built into the image display device 90. Furthermore, since multiple mesh wiring layers 20 as antennas can be disposed within the surface of the image display device 90, communication performance can be further improved.

[0331] In the present embodiment, the mesh wiring layer 20 has been described as having an antenna function, but the present invention is not limited to this. The mesh wiring layer 20 may also have other functions, such as hovering (a function that allows the user to operate the display without directly touching it), fingerprint authentication, a heater, noise reduction (shielding), etc.

[0332] [Variations] Next, modified examples of the wiring board will be described.

[0333] (First Modification) Fig. 35 shows a first modified example of the wiring substrate. The modified example shown in Fig. 35 differs in the aperiodic planar structure constituting the mesh wiring layer 20, but other configurations are substantially the same as the embodiment shown in Figs. 29 to 34 described above. In Fig. 35, the same parts as those in the embodiment shown in Figs. 29 to 34 are given the same reference numerals, and detailed description thereof will be omitted.

[0334] In the wiring substrate 10 shown in FIG. 35, the mesh wiring layer 20 has a non-periodic planar structure (random intersection mesh). This non-periodic planar structure is formed by randomly displacing periodically arranged intersections in various directions by a distance smaller than a predetermined distance. In addition, for each of the multiple (four) wirings 210 surrounding each opening 23, the shortest distance L between the intersections 240 is min When the magnification of the length of the wiring 210 between the intersections 240 is calculated, the average value is 1.01 times or more and 1.82 times or less.

[0335] The pattern of the mesh wiring layer 20 shown in Figure 35 is obtained as follows. First, for example, temporary wiring 210a is arranged so that multiple temporary intersections 24a are periodically arranged along predetermined directions (e.g., the X direction and the Y direction). Next, each temporary intersection 24a is randomly displaced in various directions by a distance smaller than a predetermined distance (e.g., the shortest distance between adjacent temporary intersections 24a). The distance by which each temporary intersection 24a is displaced is also randomly changed.

[0336] As a result, the pattern of the mesh wiring layer 20 shown in Fig. 35 is created. In Fig. 35, the mesh wiring layer 20 has a plurality of intersections 240 and wires 210 located between the intersections 240. For each of the plurality of (four) wires 210 surrounding each opening 23, the shortest distance L between the intersections 240 is minWhen the magnification of the length of the wiring 210 between the intersections 240 relative to the intersections 240 is calculated, the average value is 1.01 to 1.82 times. In this modification, the planar shape of the wiring 210 is a sine curve, but the planar shape of the wiring 210 may be any of the various shapes described above. In this way, by arranging the wiring 210 so that the multiple intersections 240 are arranged irregularly, the effect of reducing moire can be obtained.

[0337] In this modification, the mesh wiring layer 20 has a non-periodic planar structure. In addition, for each of the multiple (four) wirings 210 surrounding each opening 23, the shortest distance L between the intersections 240 is min When the magnification of the length of wiring 210 between intersections 240 is calculated relative to the length of the wiring 210, the average value is 1.01 to 1.82. This results in a wiring board 10 that suppresses both the occurrence of moire and flicker.

[0338] (Second Modification) Figures 36 and 37 show a second modified example of the wiring board. The modified example shown in Figures 36 and 37 differs in that a dummy wiring layer 30 is provided around the mesh wiring layer 20, but other configurations are substantially the same as the embodiment shown in Figures 29 to 34 described above. In Figures 36 and 37, the same parts as those in the embodiment shown in Figures 29 to 34 are given the same reference numerals and detailed description thereof will be omitted.

[0339] In the wiring board 10 shown in FIG. 36, a dummy wiring layer 30 is provided along the periphery of the mesh wiring layer 20. The dummy wiring layer 30 is provided around the mesh wiring layer 20 except for the side of the power supply section 40. The dummy wiring layer 30 may be provided around the entire periphery of the mesh wiring layer 20. Unlike the mesh wiring layer 20, this dummy wiring layer 30 does not actually function as an antenna.

[0340] As shown in FIG. 37 , the dummy wiring layer 30 has a non-periodic planar structure substantially identical to that of the mesh wiring layer 20, but with portions of the planar structure missing. For example, in FIG. 37 , the dummy wiring layer 30 has a Voronoi pattern similar to that of the mesh wiring layer 20. The dummy wiring layer 30 has multiple intersections 34 and wires 31 located between the intersections 34. Unlike the wires 210 of the mesh wiring layer 20, each wire 31 does not continuously connect the intersections 34, but rather has portions missing. This allows each wire 31 to be electrically isolated from the mesh wiring layer 20, the power supply 40, and other wires 31. Assuming that the missing portions do not exist, the average ratio of the length of the wire 31 between the intersections 34 to the shortest distance between the intersections 34 for each of the multiple wires 31 surrounding each opening is 1.01 times or more and 1.82 times or less. Note that portions of each intersection 34 may be missing.

[0341] The dummy wiring layer 30 has a shape in which a part of the non-periodic planar structure is missing, which is substantially the same as that of the mesh wiring layer 20, making it difficult to visually recognize the difference between the mesh wiring layer 20 and the dummy wiring layer 30. This makes it possible to make the mesh wiring layer 20 arranged on the substrate 11 less visible. The aperture ratio of the dummy wiring layer 30 may be larger than the aperture ratio of the mesh wiring layer 20.

[0342] In this way, by arranging the dummy wiring layer 30 electrically independent from the mesh wiring layer 20, it is possible to make the outer edge of the mesh wiring layer 20 more unclear. This makes it difficult to see the mesh wiring layer 20 on the surface of the image display device 90, and makes it difficult for a user of the image display device 90 to recognize the mesh wiring layer 20 with the naked eye.

[0343] [Example] Next, a specific example of the above embodiment will be described.

[0344] Example C1 A wiring board (Example C1) comprising a substrate and a mesh wiring layer was fabricated. The non-periodic planar structure of the mesh wiring layer was a random intersection mesh. The average value of the shortest distance between intersections of the mesh wiring layer was 100 μm. The planar shape of the wiring was a sine curve. The average amplitude of the sine curve of the wiring was 2 μm, and the average wavelength was 50 μm. When the ratio of the length (line length) of the wiring between the intersections to the shortest distance between the intersections was calculated for each of the multiple wirings surrounding each opening, the average value was 1.016.

[0345] (Example C2) A wiring substrate (Example C2) was fabricated in the same manner as Example C1, except that the average amplitude of the sine curve of the wiring was set to 4 μm. For each of the multiple wirings surrounding each opening, the ratio of the length of the wiring between the intersections (line length) to the shortest distance between the intersections was calculated, and the average value was 1.060.

[0346] (Example C3) A wiring substrate (Example C3) was fabricated in the same manner as Example C1, except that the average wavelength of the sine curve of the wiring was set to 25 μm. For each of the multiple wirings surrounding each opening, the ratio of the length of the wiring between the intersections (line length) to the shortest distance between the intersections was calculated, and the average value was 1.060.

[0347] (Example C4) A wiring substrate (Example C4) was fabricated in the same manner as Example C1, except that the average amplitude of the sine curve of the wiring was 4 μm and the average wavelength was 25 μm. For each of the multiple wirings surrounding each opening, the ratio of the length of the wiring between the intersections (line length) to the shortest distance between the intersections was calculated, and the average value was 1.217.

[0348] (Example C5) A wiring substrate (Example C5) was fabricated in the same manner as Example C1, except that the average amplitude of the sine curve of the wiring was set to 6 μm and the average wavelength was set to 16.7 μm. For each of the multiple wirings surrounding each opening, the ratio of the length of the wiring between the intersections (line length) to the shortest distance between the intersections was calculated, and the average value was 1.811.

[0349] (Example C6) A wiring substrate (Example C6) was fabricated in the same manner as Example C1, except that the average value of the shortest distance between the intersections of the mesh wiring layer was 200 μm and the average amplitude of the sine curve of the wiring was 4 μm. When the ratio of the length of the wiring between the intersections (line length) to the shortest distance between the intersections was calculated for each of the multiple wirings surrounding each opening, the average value was 1.016.

[0350] (Example C7) A wiring substrate (Example C7) was fabricated in the same manner as Example C1, except that the non-periodic planar structure of the mesh wiring layer was a Voronoi pattern, the average value of the shortest distance between the intersections of the mesh wiring layer was 200 μm, and the average amplitude of the sine curve of the wiring was 4 μm. For each of the multiple wirings surrounding each opening, when the ratio of the length of the wiring between the intersections (line length) to the shortest distance between the intersections was calculated, the average value was 1.016 times.

[0351] (Comparative Example C1) A wiring substrate (Comparative Example C1) was fabricated in the same manner as in Example C1, except that the average amplitude of the sine curve of the wiring was set to 1 μm. For each of the multiple wirings surrounding each opening, the ratio of the length of the wiring between the intersections (line length) to the shortest distance between the intersections was calculated, and the average value was 1.004.

[0352] (Comparative Example C2) A wiring substrate (Comparative Example C2) was fabricated in the same manner as in Example C1, except that the average wavelength of the sine curve of the wiring was set to 100 μm. For each of the multiple wirings surrounding each opening, the ratio of the length of the wiring between the intersections (line length) to the shortest distance between the intersections was calculated, and the average value was 1.004.

[0353] (Comparative Example C3) A wiring substrate (Comparative Example C3) was fabricated in the same manner as in Example C1, except that the average value of the shortest distance between intersections of the mesh wiring layer was 200 μm and the average wavelength of the sine curve of the wiring was 100 μm. When the ratio of the length of the wiring between the intersections (line length) to the shortest distance between the intersections was calculated for each of the multiple wirings surrounding each opening, the average value was 1.004.

[0354] (Comparative example C4) A wiring substrate (Comparative Example C4) was fabricated in the same manner as in Example C1, except that the non-periodic planar structure of the mesh wiring layer was a Voronoi pattern and the average wavelength of the sine curve of the wiring was 100 μm. For each of the multiple wirings surrounding each opening, when the ratio of the length (line length) of the wiring between the intersections to the shortest distance between the intersections was calculated, the average value was 1.004.

[0355] Next, the wiring boards of Examples C1-7 and Comparative Examples C1-4 were visually inspected to determine whether they were effective in reducing both the occurrence of moire and flicker. Wiring boards that were highly effective in reducing both the occurrence of moire and flicker were rated "high," and wiring boards that were less effective were rated "low." The results are shown in Table 5.

[0356] [Table 5]

[0357] Thus, it was found that the wiring board of Example C1-7 was more effective in reducing both the occurrence of moire and flicker than the wiring board of Comparative Example C1-4.

[0358] It is also possible to combine the multiple components disclosed in the above-described embodiments and modifications as needed, or to delete some of the components disclosed in the above-described embodiments and modifications.

Claims

1. A wiring board, a substrate including a first surface and a second surface opposite the first surface; a mesh wiring layer disposed on the first surface of the substrate, the wiring board has an electromagnetic wave transmitting and receiving function, The substrate is transparent, the mesh wiring layer is configured as an antenna and has wiring, two or more openings are formed by being surrounded by the wiring, The planar shape of the opening is a polygon with opposing sides parallel to each other, The distance between the sides of each opening extending in the first direction is defined as d, When the average value of the distances between the sides extending in the first direction in 100 consecutively adjacent openings or in all of the openings is D, Of the 100 openings or all of the openings, 95% or more of the openings 0.70D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.30D A wiring board that satisfies the above relationship.

2. Of the 100 openings or all of the openings, 95% or more of the openings 0.85D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.15D The wiring board according to claim 1 , wherein the following relationship is satisfied:

3. Of the 100 openings or all of the openings, 95% or more of the openings 0.90D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.10D The wiring board according to claim 1 , wherein the following relationship is satisfied:

4. The wiring board according to claim 1 , wherein the polygon is a quadrangle.

5. The wiring board according to claim 1 , wherein the polygon is a hexagon.

6. The wiring board according to claim 1 , wherein the average value D is equal to or greater than 50 μm and equal to or less than 500 μm.

7. 2. The wiring board according to claim 1, wherein the wiring has a line width of 0.5 [mu]m or more and 3 [mu]m or less.

8. The wiring board according to claim 1 , wherein the mesh wiring layer has an overall aperture ratio of 95% or more and less than 100%.

9. The wiring board according to claim 1 , wherein the mesh wiring layer has a sheet resistance of 4Ω / □ or less.

10. 2. The wiring board according to claim 1, wherein the wiring board has a millimeter wave transmitting and receiving function, and the mesh wiring layer is configured as an array antenna including two or more antenna elements.

11. The wiring board according to claim 10 , wherein four or more of the antenna elements are provided, and the distance between the antenna elements is 1 mm or more and 5 mm or less.

12. 2. The wiring board according to claim 1, further comprising a dummy wiring layer provided around said mesh wiring layer and electrically independent from said mesh wiring layer.

13. 13. The wiring board according to claim 12, wherein the dummy wiring layer includes two or more dummy wirings, and the dummy wirings extend parallel to the wirings.

14. 13. The wiring board according to claim 12, wherein two or more dummy wiring layers are provided, and the aperture ratios of the mesh wiring layer and the dummy wiring layer increase stepwise from the mesh wiring layer toward the dummy wiring layer farther from the mesh wiring layer.

15. A wiring board, a substrate including a first surface and a second surface opposite the first surface; a mesh wiring layer disposed on the first surface of the substrate; a power supply portion electrically connected to the mesh wiring layer, The substrate is transparent, the mesh wiring layer has a transmission section connected to the power supply section and a transceiver section connected to the transmission section, the mesh wiring layer has wiring that constitutes the transmission unit and the transmission / reception unit, two or more openings are formed by being surrounded by the wiring, The planar shape of the opening is a polygon with opposing sides parallel to each other, The distance between the sides of each opening extending in the first direction is defined as d, When the average value of the distances between the sides extending in the first direction in 100 consecutively adjacent openings or in all of the openings is D, Of the 100 openings or all of the openings, 95% or more of the openings 0.70D≦d≦0.98D Does it satisfy the relationship 1.02D≦d≦1.30D A wiring board that satisfies the above relationship.

16. The wiring substrate according to any one of claims 1 to 15, a power supply line electrically connected to the wiring board.

17. A module according to claim 16; a display device stacked on the wiring substrate of the module.

Images