Wiring board

Abstract

The wiring substrate of this invention comprises a substrate and a mesh wiring layer. The wiring substrate has electromagnetic wave transmission and reception functions. 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 wiring. The planar shape of the openings is a polygon with opposite sides parallel to each other. The distance between the sides extending along a first direction in each opening is defined as d. The average value of the distance between the sides extending along the first direction in 100 consecutively adjacent openings or all openings is defined as D. At this time, more than 95% of the 100 openings or all openings satisfy the relationship 0.70D≦d≦0.98D, or satisfy the relationship 1.02D≦d≦1.30D.

Description

[Technical Field]

[0001] The embodiments of the present invention relate to a wiring board, a module, and an image display device. [Previous Technology]

[0002] Currently, there is a push to increase the functionality, miniaturization, thinness, and lightweighting of mobile terminal devices such as smartphones and tablets. These mobile terminal devices use multiple communication frequency bands. Therefore, multiple antennas corresponding to the communication frequency bands are required. For example, mobile terminal devices are equipped with multiple antennas, such as antennas for telephones, WiFi (Wireless Fidelity), 3G (Generation), 4G (Generation), LTE (Long Term Evolution), Bluetooth (trademark), and NFC (Near Field Communication). However, with the miniaturization of mobile terminal devices, the space for antenna installation is limited, reducing the freedom of antenna design. Furthermore, because the antenna is built into a limited space, the electromagnetic inductance may not be sufficient.

[0003] Therefore, a thin-film antenna capable of being mounted on the display area of ​​a mobile terminal device is being developed. This thin-film antenna is a transparent antenna on a transparent substrate with an antenna pattern formed thereon. The antenna pattern is formed from a mesh-like conductive layer. The conductive mesh layer includes conductive portions forming opaque conductive layers and multiple openings forming non-transparent conductive layers. [Prior Art Documents] [Patent Documents]

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

[0005] Furthermore, in previous thin-film antennas, there are both areas on the transparent substrate where an antenna pattern is formed and areas where no antenna pattern is formed. However, in mobile terminal devices equipped with thin-film antennas, the period of the conductive mesh layer (antenna pattern) may interfere with the period of the pixels, resulting in striped patterns (water ripples, interference stripes). In the case of water ripples, there is a risk of reduced image visibility in mobile terminal devices.

[0006] In order to eliminate water ripples, it is also considered to eliminate the periodicity of the antenna pattern. However, when eliminating the periodicity of the antenna pattern, various wiring directions will appear, which may cause flickering due to light reflection.

[0007] One of the objectives of this embodiment is to provide a wiring board, module and image display device that can suppress the generation of water ripples and suppress flickering caused by reflected light.

[0008] Furthermore, this embodiment provides a wiring board, module, and image display device capable of suppressing the generation of water ripples and flickering. [Summary of the Invention]

[0009] A first aspect of the present invention is a wiring substrate comprising: 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; the wiring substrate has electromagnetic wave transmission and reception 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 being a polygon with opposite sides parallel to each other, the distance between the sides extending along a first direction in each opening being d, and the average distance between the sides extending along the first direction in 100 consecutively adjacent openings or all openings being D, wherein more than 95% of the 100 openings or all openings satisfy 0.70D≦d≦0.98D The relationship is either 1.02D≦d≦1.30D or 1.02D≦d≦1.30D.

[0010] The second state of the present invention is the wiring board of the first state described above, wherein the 100 openings or more than 95% of all the openings may satisfy the relationship of 0.85D≦d≦0.98D, or satisfy the relationship of 1.02D≦d≦1.15D.

[0011] The third state sample of the present invention is the wiring board of the first state sample or the second state sample described above, wherein more than 95% of the 100 openings or all of the openings may satisfy the relationship of 0.90D≦d≦0.98D, or satisfy the relationship of 1.02D≦d≦1.10D.

[0012] The fourth state of the present invention is the wiring substrate of each of the states of the first to the third states described above, wherein the polygon may also be a quadrilateral.

[0013] The fifth state of the present invention is the wiring substrate of each of the states of the first to the third states described above, wherein the polygon may also be hexagonal.

[0014] The sixth state sample of the present invention is a wiring substrate of each of the first to fifth state samples described above, wherein the average value D can be more than 50 μm and less than 500 μm.

[0015] The seventh state sample of the present invention is a wiring substrate of each of the first to sixth states described above, wherein the line width of the wiring can be more than 0.5 μm and less than 3 μm.

[0016] The eighth state sample of the present invention is a wiring substrate of each of the first to seventh states described above, wherein the overall aperture ratio of the mesh wiring layer is 95% or more but less than 100%.

[0017] The ninth state sample of the present invention is a wiring substrate of each of the first to eighth states described above, wherein the sheet resistance value of the mesh wiring layer can be 4 Ω / □ or less.

[0018] The 10th state of the present invention is a wiring substrate of each of the states 1 to 9 described above, wherein the wiring substrate may have millimeter wave transceiver function, and the mesh wiring layer may be configured as an array antenna containing two or more antenna elements.

[0019] The 11th aspect of the present invention is the wiring board of the 10th aspect described above, wherein four or more antenna elements are provided, and the distance between the antenna elements is more than 1 mm and less than 5 mm.

[0020] The 12th state of the present invention is a wiring substrate of each of the states 1 to 11 described above, wherein a dummy wiring layer electrically independent of the mesh wiring layer may be provided around the mesh wiring layer.

[0021] The 13th aspect of the present invention is the wiring substrate of the 12th 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] The 14th state of the present invention is the wiring substrate of the 12th state or the 13th state described above, wherein two or more of the above-mentioned dummy wiring layers may be provided, and the aperture ratio of the above-mentioned mesh wiring layer and the above-mentioned dummy wiring layer may be increased in stages from the above-mentioned mesh wiring layer toward the above-mentioned dummy wiring layer away from the above-mentioned mesh wiring layer.

[0023] The 15th aspect of the present invention is a wiring substrate, comprising: a substrate including a first surface and a second surface located opposite to 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; the substrate is transparent, the mesh wiring layer having a transmission portion connected to the power supply portion and a transceiver portion connected to the transmission portion, the mesh wiring layer having wiring constituting the transmission portion and the transceiver portion, thereby being transparent by means of the above-mounted... The wiring surrounds and forms two or more openings. The planar shape of the openings is a polygon with opposite sides parallel to each other. When the distance between the sides extending along the first direction in each opening is d, and the average distance between the sides extending along the first direction in 100 consecutively adjacent openings or all of the openings is D, more than 95% of the 100 openings or all of the openings satisfy the relationship 0.70D≦d≦0.98D, or satisfy the relationship 1.02D≦d≦1.30D.

[0024] The 16th aspect of the present invention is a module comprising a wiring board as described in any one of the 1st to 15th aspects described above, and a feeder wire electrically connected to the wiring board.

[0025] The 17th aspect of the present invention is an image display device, which includes a module as described in the 16th aspect above, and a display device laminated on the wiring substrate of the module.

[0026] The 18th aspect of the present invention is a wiring substrate, comprising: 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; the wiring substrate has electromagnetic wave transceiver 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 the first wirings, wherein the intersection point of the first wirings and the second wirings is defined as A, the intersection point of a first regression line obtained from the plurality of intersection points A on the same first wiring and a second regression line obtained from the plurality of intersection points A on the same second wiring is defined as B, and the distance from the intersection point A to the nearest intersection point B along the width direction of the mesh wiring layer is defined as d. X, where d is the distance from the intersection point A to the nearest intersection point B along the length of the mesh wiring layer, Y is the average distance between 10 consecutively adjacent intersection points B in the width direction, DX is the average distance between 10 consecutively adjacent intersection points B in the length direction, and DY is the average distance between 10 consecutively adjacent intersection points B in the length direction, at least one of the following conditions must be satisfied at 9 or more of the 10 intersection points A that are closest to each of the 10 intersection points B: 0.02DX ≤ dX < 0.3DX and 0.02DY ≤ dY < 0.3DY.

[0027] The 19th aspect of the present invention is the wiring board of the 18th aspect described above, wherein at 9 or more of the 10 intersection points A that are closest to each of the 10 intersection points B, the relationship 0.02DX≦dX<0.3DX and the relationship 0.02DY≦dY<0.3DY are satisfied.

[0028] The 20th state sample of the present invention is the wiring substrate of the 18th state sample or the 19th state sample described above, wherein the average value DX and the average value DY can be 50 μm or more and 500 μm or less.

[0029] The 21st state sample of the present invention is a wiring substrate of each of the states 18 to 20 described above, wherein the line width of the first wiring and the line width of the second wiring can be 0.5 μm or more and 3 μm or less, respectively.

[0030] The 22nd aspect of the present invention is a wiring substrate of each aspect from aspect 18 to aspect 21 described above, wherein the overall aperture ratio of the mesh wiring layer is 95% or more but less than 100%.

[0031] The 23rd state sample of the present invention is the wiring substrate of each of the states 18 to 22 described above, wherein the sheet resistance value of the mesh wiring layer can be 4 Ω / □ or less.

[0032] The 24th state of the present invention is the wiring board of each state from the 18th state to the 23rd state, wherein the angle between the first regression line and the second regression line can be more than 30° and less than 150°.

[0033] The 25th state of the present invention is the wiring substrate of each of the states 18 to 24 described above, wherein the wiring substrate may have millimeter wave transceiver function, and the mesh wiring layer may be configured as an array antenna containing two or more antenna elements.

[0034] The 26th aspect of the present invention is the wiring board of the 25th aspect described above, wherein four or more antenna elements are provided, and the distance between the antenna elements is more than 1 mm and less than 5 mm.

[0035] The 27th state of the present invention is a wiring substrate of each of the states 18 to 26 described above, wherein a dummy wiring layer electrically independent of the mesh wiring layer may be provided around the mesh wiring layer.

[0036] The 28th aspect of the present invention is the wiring substrate of 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] The 29th embodiment of the present invention is the wiring substrate of the 27th embodiment or the 28th embodiment described above, wherein a plurality of the above-described dummy wiring layers may be provided, and the aperture ratio of the above-described mesh wiring layer and the above-described dummy wiring layer may be increased in stages from the above-described mesh wiring layer toward the above-described dummy wiring layer away from the above-described mesh wiring layer.

[0038] The 30th aspect of the present invention is a wiring board of the above-described 18th to 29th aspects, wherein a power supply portion electrically connected to the above-described mesh wiring layer may be provided. The mesh wiring layer may have a power transmission portion connected to the above-described power supply portion and a transceiver portion connected to the above-described power transmission portion. The transceiver portion may include a central portion and a peripheral portion located around the central portion. The distance dX of the peripheral portion may be less than the distance dX of the central portion, and the distance dY of the peripheral portion may be less than the distance dY of the central portion.

[0039] The 31st aspect of the present invention is the wiring board of the 30th aspect described above, wherein the distance dX of the peripheral portion can be more than 20% and less than 80% of the distance dX of the central portion, and the distance dY of the peripheral portion can be more than 20% and less than 80% of the distance dY of the central portion.

[0040] The 32nd embodiment of the present invention is a wiring board of the 30th embodiment or the 31st embodiment described above, wherein more than 50% of the area of ​​the power transmission section side in the central portion in the length direction is surrounded by the peripheral portion.

[0041] The 33rd state sample of the present invention is the wiring board of each of the states 30 to 32 described above, wherein the width of the peripheral portion can be more than twice the average value DX of the central portion.

[0042] The 34th aspect of the present invention is a wiring substrate, comprising: 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; the substrate is transparent, the mesh wiring layer having a transmission section connected to the power supply section and a transceiver section connected to the transmission section, the mesh wiring layer having a first wiring and a second wiring constituting the transmission section and the transceiver section, wherein the intersection point of the first wiring and the second wiring is designated as A, the intersection point of a first regression line obtained from a plurality of intersection points A on the same first wiring and a second regression line obtained from a plurality of intersection points A on the same second wiring is designated as B, and the distance from the intersection point A to the nearest intersection point B along the width direction of the mesh wiring layer is designated as d. X, where d is the distance from the intersection point A to the nearest intersection point B along the length of the mesh wiring layer, Y is the average distance between 10 consecutively adjacent intersection points B in the width direction, DX is the average distance between 10 consecutively adjacent intersection points B in the length direction, and DY is the average distance between 10 consecutively adjacent intersection points B in the length direction, at least one of the following conditions must be satisfied at 9 or more of the 10 intersection points A that are closest to each of the 10 intersection points B: 0.02DX ≤ dX < 0.3DX and 0.02DY ≤ dY < 0.3DY.

[0043] The 35th aspect of the present invention is a module comprising: a wiring board as described in any one of the 18th to 34th aspects described above; and a feed line electrically connected to the wiring board.

[0044] The 36th aspect of the present invention is an image display device comprising: a module as described in the 35th aspect above; and a display device having a wiring substrate deposited on the module.

[0045] The 37th aspect of the present invention is the image display device of the 36th aspect described above, wherein the display device may have a plurality of pixels repeatedly arranged along the width direction and the length direction, the average value DX may be (N-0.05) times or less (N is a natural number) and (N+0.05) times or more of the distance between the pixels in the width direction, and the average value DY may be (M-0.05) times or less (M is a natural number) and (M+0.05) times or more of the distance between the pixels in the length direction.

[0046] The 38th aspect of the present invention is the image display device of the 37th aspect described above, wherein the average value DX is more than (N-0.2) times and less than (N+0.2) times the distance between the pixels in the width direction.

[0047] The 39th state of the present invention is the same as the image display device of the 37th state or the 38th state described above, wherein the average value DY can be more than (M-0.2) times and less than (M+0.2) times the distance between the pixels in the length direction.

[0048] The 40th state of the present invention is the same as the image display device of each of the 37th to 39th states described above, wherein N and M can be natural numbers of 1 to 6 respectively.

[0049] The 41st embodiment of the present invention is a wiring substrate comprising a substrate and a mesh wiring layer disposed on the substrate. The substrate is transparent, and the mesh wiring layer has a plurality of intersections and wirings located between each intersection. An opening is formed by the plurality of wirings surrounding the opening. When calculating the ratio of the length of the wirings between the intersections to the shortest distance between the intersections for each of the plurality of wirings surrounding the opening, the average value is 1.01 times or more and 1.82 times or less. Transparency means that the transmittance of light with wavelengths of 400 nm to 700 nm is 85% or more.

[0050] The 42nd embodiment of the present invention is the wiring substrate of the 41st embodiment described above, wherein the line width of the wiring can be 0.1 μm or more and 5.0 μm or less.

[0051] The 43rd state sample of the present invention is the wiring substrate of the 41st state sample or the 42nd state sample described above, wherein the planar shape of the wiring can be a sine curve.

[0052] The 44th state of the present invention is a wiring substrate of each of the 41st to 43rd states described above, wherein the non-periodic planar structure constituting the mesh wiring layer may be a Voronoi pattern.

[0053] The 45th state of the present invention is a wiring substrate of each of the states 41 to 43 described above, wherein the non-periodic planar structure constituting the mesh wiring layer can be formed by randomly displacing the periodically arranged intersections in various directions at a distance smaller than a predetermined distance.

[0054] The 46th state sample of the present invention is a wiring substrate of each of the 41st to 45th states described above, wherein the overall aperture ratio of the mesh wiring layer is 96% or more but less than 100%.

[0055] The 47th state of the present invention is a wiring substrate of each of the states 41 to 46 described above, wherein a dummy wiring layer electrically independent of the mesh wiring layer may be provided around the mesh wiring layer.

[0056] The 48th aspect of the present invention is a module comprising: a wiring board as described in any one of the 41st to 47th aspects; and a feed line electrically connected to the wiring board.

[0057] The 49th aspect of the present invention is an image display device, which includes a module as described in the 48th aspect above.

[0058] The 50th aspect of the present invention is the image display device of the 49th aspect described above, wherein the mesh wiring layer can function as an antenna.

[0059] The 51st aspect of the present invention is the image display device of the 49th aspect or the 50th aspect described above, wherein the wiring board 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 an embodiment of the present invention, the generation of water ripples can be suppressed, and the flickering caused by reflected light can be suppressed.

[0061] Furthermore, according to an embodiment of the present invention, both the generation of water ripples and the generation of flickering can be suppressed.

Implementation Method

[0063] (First Embodiment) First, the first embodiment will be described using Figures 1 to 9. Figures 1 to 9 are diagrams illustrating this embodiment.

[0064] The following figures are schematic representations. Therefore, for ease of understanding, the size and shape of each part are appropriately exaggerated. Furthermore, modifications can be made appropriately without departing from the technical concept. Moreover, in the following figures, the same symbols are sometimes used to label the same parts, and some detailed descriptions are omitted. Also, the dimensions and material names of the components described in this specification are examples of embodiments and are not limited to them; appropriate selections can be made. In this specification, terms describing specific shapes or geometric conditions, such as parallel or orthogonal, perpendicular, etc., are interpreted in addition to their strict meanings, including substantially the same state.

[0065] In the following embodiments, "X direction" refers to a direction parallel to one side of the image display device. "Y direction" refers to a direction perpendicular to the X direction and parallel to the other side of the image display device. "Z direction" refers to a direction perpendicular to both the X and Y directions and parallel to the thickness direction of the image display device. "Front side" refers to the side facing the observer in the Z direction, which is the side with the light-emitting surface of the image display device. "Back side" refers to the side facing the observer in the Z direction, which is the side opposite to the side with the light-emitting surface of the image display device. Furthermore, in this embodiment, the mesh wiring layer 20 is described as an example of a mesh wiring layer with radio wave transceiver function (i.e., functioning as an antenna), but the mesh wiring layer 20 may also not have radio wave transceiver function.

[0066] Referring to Figures 1 and 2, the configuration of the image display device of this embodiment will be described.

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

[0068] The wiring board 10 includes a substrate 11, a mesh wiring layer 20, and a power supply section 40. As shown in FIG2, 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 mesh wiring layers 20 are disposed on the first surface 11a of the substrate 11. Furthermore, a power supply section 40 is electrically connected to each mesh wiring layer 20. Moreover, a communication module 63 is disposed on the negative side in the Z direction relative to the display device 61. The image display device laminate 70, the display device 61, and the communication module 63 are housed within a housing 62.

[0069] In the image display device 60 shown in Figures 1 and 2, communication can be achieved by transmitting and receiving radio waves of a specified frequency via the communication module 63. The communication module 63 may also include any one of the following: millimeter-wave antenna, telephone antenna, WiFi antenna, 3G antenna, 4G antenna, 5G antenna, LTE antenna, Bluetooth antenna, NFC antenna, etc. Examples of such image display devices 60 include smartphones, tablets, and other mobile terminal devices.

[0070] As shown in FIG2, the image display device 60 has a light-emitting surface 64. The image display device 60 includes a wiring board 10 located on the side of the light-emitting surface 64 (i.e., the positive side in the Z direction) relative to the display device 61, and a communication module 63 located on the opposite side of the light-emitting surface 64 (i.e., the negative side in the Z direction) relative to the display device 61.

[0071] The display device 61 includes, for example, an organic EL (Electro Luminescence) display device. The display device 61 has a plurality of pixels P (see FIG3) repeatedly arranged along a first direction (e.g., the Y direction) and a second direction (e.g., the X direction). Details regarding the pixels P will be described below.

[0072] The display device 61 may also include, for example, a metal layer (not shown), a support substrate, a resin substrate, a thin film transistor (TFT), and an organic EL layer. A touch sensor (not shown) may also be disposed on the display device 61. Furthermore, a wiring substrate 10 is disposed on the display device 61 via a second transparent bonding layer 96. Moreover, the display device 61 is not limited to an organic EL display device. For example, the display device 61 may also be other display devices with its own light-emitting function, or a micro-LED display device including a micro-LED (Light Emitting Diode) element. Additionally, the display device 61 may also be a liquid crystal display device including a liquid crystal.

[0073] A cover glass 75 is disposed on the wiring substrate 10 via a first transparent adhesive layer 95. Furthermore, a decorative film (not shown) and a polarizing plate may also 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. The first transparent adhesive layer 95 is located on the first surface 11a side of the substrate 11. The first transparent adhesive layer 95 has optical transparency and can be an OCA (Optical Clear Adhesive) layer. An OCA layer is, for example, a layer made as follows: First, a liquid curable adhesive composition containing a polymeric compound is coated onto a release film such as polyethylene terephthalate (PET). Then, it is cured using, for example, ultraviolet light (UV) to obtain an OCA sheet. After the OCA sheet is adhered to an object, the release film is peeled off, thereby obtaining the aforementioned OCA layer. The material of the first transparent adhesive layer 95 can be an acrylic resin, a silicone resin, or a urethane resin, etc. In particular, the first transparent adhesive layer 95 can also contain an acrylic resin. In this case, it is preferable that the second transparent adhesive layer 96 comprises an acrylic resin. This can substantially eliminate the difference in refractive index between the first transparent adhesive layer 95 and the second transparent adhesive layer 96, and more reliably suppress the reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96.

[0075] The transmittance of visible light of the first transparent adhesive layer 95 can be 85% or more, preferably 90% or more. Furthermore, there is no particular upper limit to the transmittance of visible light of the first transparent adhesive layer 95; for example, it can be 100% or less. By setting the transmittance of visible light of the first transparent adhesive layer 95 to the above range, the transparency of the image display device laminate 70 can be improved, making it easier to see the display device 61 of the image display device 60. Furthermore, visible light refers to light with a wavelength of 400 nm to 700 nm. Also, a transmittance of visible light of 85% or more means that when measuring the absorbance of the component to be measured (e.g., the first transparent adhesive layer 95), the transmittance is 85% or more in the entire wavelength range of 400 nm to 700 nm. The absorbance measurement can be performed using a known spectrophotometer (e.g., a spectrometer manufactured by Nippon Spectrophotometer Co., Ltd.: V-670).

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

[0077] As described above, the wiring board 10 includes: a substrate 11, which is transparent; and a mesh wiring layer 20 disposed on a first surface 11a of the substrate 11. Two or more mesh wiring layers 20 are disposed on the first surface 11a of the substrate 11, spaced apart from each other. A power supply section 40 is electrically connected to the mesh wiring layer 20. The power supply section 40 is electrically connected to the communication module 63 via a power supply wire (not shown). Furthermore, a portion of the wiring board 10 is not disposed between the first transparent bonding layer 95 and the second transparent bonding layer 96, but protrudes outward from between the first transparent bonding layer 95 and the second transparent bonding layer 96 (i.e., the negative side in the Y direction). Specifically, the area in the wiring board 10 where the power supply section 40 is disposed protrudes outward. This allows for easy electrical connection between the power supply section 40 and the communication module 63. On the other hand, the area in the wiring substrate 10 where the mesh wiring layer 20 is disposed is located between the first transparent bonding layer 95 and the second transparent bonding layer 96. Furthermore, details regarding the wiring substrate 10 will be described below.

[0078] The second transparent adhesive layer 96 is an adhesive layer that connects the display device 61 directly or indirectly to the wiring substrate 10. The second transparent adhesive layer 96 is located on the second surface 11b of the substrate 11. Like the first transparent adhesive layer 95, the second transparent adhesive layer 96 has optical transparency and can be an OCA (Optical Clear Adhesive) layer. The material of the second transparent adhesive layer 96 can be acrylic resin, silicone resin, or urethane resin, etc. In particular, the second transparent adhesive layer 96 can also contain 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 visible light reflection at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96.

[0079] The transmittance of visible light (i.e., light with wavelengths between 400 nm and 700 nm) of the second transparent adhesive layer 96 can be 85% or more, preferably 90% or more. Furthermore, there is no particular upper limit to the transmittance of visible light of the second transparent adhesive layer 96, for example, it can be 100% or less. By setting the transmittance of visible light of the second transparent adhesive layer 96 to the above range, the transparency of the laminate 70 for the image display device can be improved, making it easier to see the display device 61 of the image display device 60.

[0080] In this image display device 60, the difference between the refractive index of the substrate 11 and the refractive index of the first transparent adhesive layer 95 is 0.1 or less, preferably 0.05 or less. Furthermore, the difference between the refractive index of the substrate 11 and the refractive index of the second transparent adhesive layer 96 is 0.1 or less, preferably 0.05 or less. Moreover, the difference between the refractive index of the first transparent adhesive layer 95 and the refractive index of the second transparent adhesive layer 96 is preferably 0.1 or less, more preferably 0.05 or less. For example, when the materials of the first transparent adhesive layer 95 and the second transparent adhesive layer 96 are 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 fluoropolymers, silicone resins, polyolefin resins, polyester resins, acrylic resins, polycarbonate resins, polyimide resins, and cellulose resins.

[0081] By controlling the difference between the refractive index of the substrate 11 and the refractive index of the first transparent adhesive layer 95 to below 0.1, the reflection of visible light at the interface B1 between the substrate 11 and the first transparent adhesive layer 95 can be suppressed, making it difficult for an observer to see the substrate 11 with the naked eye. Furthermore, by controlling the difference between the refractive index of the substrate 11 and the refractive index of the second transparent adhesive layer 96 to below 0.1, the reflection of visible light at the interface B2 between the substrate 11 and the second transparent adhesive layer 96 can be suppressed, making it difficult for an observer to see the substrate 11 with the naked eye. Moreover, by controlling the difference between the refractive index of the first transparent adhesive layer 95 and the second transparent adhesive layer 96 to below 0.1, the reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96 can be suppressed. Therefore, it is possible to make it difficult for an observer to see the first transparent adhesive layer 95 and the second transparent adhesive layer 96 with the naked eye.

[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. In this way, the difference in refractive index between the first transparent adhesive layer 95 and the second transparent adhesive layer 96 can be smaller, thereby suppressing the reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96.

[0083] In Figure 2, the thickness of 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 can be at least 1.5 times the thickness T1 of the substrate 11, preferably at least 2 times, and more preferably at least 2.5 times. By sufficiently increasing the thickness T3 of the first transparent adhesive layer 95 or the thickness T4 of the second transparent adhesive layer 96 relative to 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 area overlapping with the substrate 11, absorbing the thickness of the substrate 11. This suppresses the generation of a step difference 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 discern the presence of the substrate 11.

[0084] The thickness of 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 less than 10 times the thickness T1 of the substrate 11, and more preferably less than 5 times. 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 excessively thick, thus enabling a thinner overall thickness of the image display device 60.

[0085] In Figure 2, the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 can 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 can be at least 1.5 times, preferably at least 2.0 times, the thickness T1 of the substrate 11. That is, the total 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 at least 3 times the thickness T1 of the substrate 11. By sufficiently increasing the total thickness T3 and T4 of the first transparent adhesive layer 95 and the second transparent adhesive layer 96 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 area overlapping with the substrate 11. In this way, 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 suppress the generation of a step difference at the periphery of the substrate 11 in the first transparent adhesive layer 95 or the second transparent adhesive layer 96, so that the observer cannot easily perceive 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 can be less than 5 times the thickness T1 of the substrate 11, preferably less than 3 times. This ensures that the thicknesses T3 and T4 of both the first transparent adhesive layer 95 and the second transparent adhesive layer 96 do not become excessively thick, allowing for a thinner overall thickness of the image display device 60.

[0087] Specifically, the thickness T1 of the substrate 11 can be, for example, 2 μm or more, or 10 μm or more, 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 the second wiring 22 below the mesh wiring layer 20 are less prone to deformation. Furthermore, the thickness T1 of the substrate 11 can be, for example, 200 μm or less, or 50 μm or less, preferably 25 μm or less. By setting the thickness T1 of the substrate 11 to 200 μm or less, the step difference generated at the periphery of the substrate 11 at the first transparent adhesive layer 95 and the second transparent adhesive layer 96 can be suppressed, thereby making it difficult for an observer to discern the presence of the substrate 11. Furthermore, by setting the thickness T1 of the substrate 11 to less than 50 μm, it is possible to further suppress the generation of step difference between the first transparent adhesive layer 95 and the second transparent adhesive layer 96 at the periphery of the substrate 11, thereby making it more difficult for the observer to identify 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, preferably 20 μm or more. The thickness T3 of the first transparent adhesive layer 95 may be, for example, 500 μm or less, preferably 300 μm or less, and even more preferably 250 μm or less. The thickness T4 of the second transparent adhesive layer 96 may be, for example, 15 μm or more, preferably 20 μm or more. The thickness T4 of the second transparent adhesive layer 96 may be, for example, 500 μm or less, preferably 300 μm or less, and even more preferably 250 μm or less.

[0089] Referring again to Figure 2, the cover glass 75 is disposed directly or indirectly on the first transparent adhesive layer 95. The cover glass 75 is a glass component that allows light to pass through. The cover glass 75 is plate-shaped, and its shape may be rectangular when viewed from above. The thickness of the cover glass 75 may be, for example, 200 μm to 1000 μm, preferably 300 μm to 700 μm. The length of the cover glass 75 in the longitudinal direction (i.e., the Y direction) may be, for example, 20 mm to 500 mm, ideally 100 mm to 200 mm. The length of the cover glass 75 in the short side direction (i.e., the X direction) may be 20 mm to 500 mm, ideally 50 mm to 100 mm.

[0090] As shown in Figure 1, the image display device 60 is generally rectangular in shape when viewed from above, with its length direction parallel to the Y direction and its short side direction parallel to the X direction. The length L4 of the image display device 60 in the length direction (i.e., the Y direction) can be selected, for example, within the range of 20 mm to 500 mm, ideally between 100 mm and 200 mm. The length L5 of the image display device 60 in the short side direction (i.e., the X direction) can be selected, for example, within the range of 20 mm to 500 mm, ideally between 50 mm and 100 mm. Furthermore, the planar shape of the image display device 60 can also be a rectangle with rounded corners.

[0091] Next, with reference to FIG3, the pixel P of the display device 61 will be described.

[0092] Figure 3 is a top view showing an example of the configuration of pixel P and its subpixels S. Furthermore, in Figure 3, the subpixel S marked with "R" represents a subpixel S emitting red light. The subpixel S marked with "G" represents a subpixel S emitting green light. The subpixel S marked with "B" represents a subpixel S emitting blue light.

[0093] The display device 61 has a plurality of pixels P regularly arranged along the width direction (i.e., the X direction) and length direction (i.e., the Y direction) of the mesh wiring layer 20. The plurality of pixels P are arranged with a fixed spacing PX in the X direction, and the spacing PX can be, for example, in the range of about 50 μm to 200 μm. Also, the plurality of pixels P are arranged with a fixed spacing PY in the Y direction, and the spacing PY can be, for example, in the range of about 50 μm to 200 μm.

[0094] Each pixel P comprises a plurality of subpixels S. Each subpixel S comprises an OLED (Organic Light Emitting Diode) capable of emitting light of a corresponding color. In the example shown in FIG3, each pixel P comprises a subpixel S capable of emitting three colors of light (i.e., red, green, and blue). The subpixels S comprised of each pixel P are arranged in both the X and Y directions. In the example shown in FIG3, the subpixel S emitting green light is arranged in the X direction, separated from the subpixels emitting red light and blue light. Furthermore, the subpixels emitting red light and blue light are arranged separated from each other in the Y direction.

[0095] Furthermore, there is no particular limitation on the type (i.e., emission color) and number of sub-pixels S contained in each pixel P. For example, each pixel P may contain sub-pixels S capable of emitting two or more colors of light. Also, there is no particular limitation on the relative positional relationship between the sub-pixels S within each pixel P. For example, within each pixel P, the sub-pixels S may be arranged only along either the X or Y direction. The sub-pixels S within each pixel P may also be arranged close to or densely packed together.

[0096] Thus, each sub-pixel S constitutes a light-emitting element. Each pixel P is composed of a set of multiple sub-pixels S constituting a repeating unit. Furthermore, the arrangement of pixel P and sub-pixels S is not limited to the example shown in FIG3. Pixel P and sub-pixels S can also be arranged in any shape. For example, in the example shown in FIG3, each pixel P within a square contains one sub-pixel S of each color (i.e., red, green, and blue). However, the shape of each pixel P is not necessarily limited to a square. Also, each pixel P may contain multiple sub-pixels S of each color.

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

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

[0099] The substrate 11 is generally rectangular in shape when viewed from above. In the illustrated example, its length direction is parallel to the X direction, and its short side direction is parallel to the Y direction. The substrate 11 is transparent and generally flat, and its thickness is generally uniform. The length L1 of the substrate 11 in the length direction (i.e., the Y direction) of the image display device 60 can be selected, for example, in the range of 2 mm to 300 mm, 10 mm to 200 mm, or 100 mm to 200 mm. The length L2 of the substrate 11 in the short side direction (i.e., the X direction) of the image display device 60 can be selected, for example, in the range of 2 mm to 300 mm, 3 mm to 100 mm, or 50 mm to 100 mm. Furthermore, the planar shape of the substrate 11 can also be a rectangle with rounded corners.

[0100] The material of the substrate 11 may be any material that is transparent and electrically insulating in the visible light region. Preferably, the substrate 11 is made of organic insulating materials such as polyester resin, acrylic resin, polycarbonate resin, polyimide resin, polyolefin resin, cellulose resin, or fluoropolymer. Polyester resin may be polyethylene terephthalate, etc. Acrylic resin may be polymethyl methacrylate, etc. Polyolefin resin may be cyclic olefin polymers, etc. Cellulose resin may be triacetyl cellulose, etc. Fluoropolymer materials may be PTFE (polytetrafluoroethylene) or PFA (perfluoroalkoxy alkanes), etc. For example, cyclic olefin polymers (such as ZF-16 manufactured by Zeon Corporation of Japan) or polynorbornene polymers (manufactured by Sumitomo Bakelite Corporation) may also be used as the substrate 11 material. Furthermore, the material of the substrate 11 can be glass or ceramic, depending on the application. Moreover, the illustration shows an example of the substrate 11 being composed of a single layer, but it is not limited to this; it can also be a structure obtained from multiple substrates or laminated layers. Additionally, the substrate 11 can be a film-like component or a plate-like component.

[0101] The dielectric loss factor of the substrate 11 may be 0.002 or less, preferably 0.001 or less. Furthermore, the dielectric loss factor of the substrate 11 does not have a particular lower limit and may be set to be greater than 0. By having the dielectric loss factor of the substrate 11 within the above range, especially when the electromagnetic waves (e.g., millimeter waves) transmitted and received by the mesh wiring layer 20 are high frequency, the loss of gain (i.e., the reduction in sensitivity) associated with the transmission and reception of electromagnetic waves can be reduced.

[0102] The relative permittivity of the substrate 11 is preferably 2 or higher and 10 or lower. Having a relative permittivity of 2 or higher increases the options for the material of the substrate 11. Furthermore, having a relative permittivity of 10 or lower reduces the loss of gain (sensitivity) associated with the transmission and reception of electromagnetic waves. That is, when the relative permittivity of the substrate 11 increases, the thickness of the substrate 11 has a greater impact on electromagnetic wave propagation. Also, when electromagnetic wave propagation is adversely affected, the dielectric loss factor of the substrate 11 increases, and the loss of gain associated with the transmission and reception of electromagnetic waves increases. In contrast, having a relative permittivity of 10 or lower reduces the impact of the thickness of the substrate 11 on electromagnetic wave propagation. 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 caused by the transmission and reception of electromagnetic waves can be reduced.

[0103] The dielectric loss factor and relative permittivity of the substrate 11 can be determined according to IEC 62562. Specifically, firstly, a test piece is prepared by cutting out the portion of the substrate 11 before the formation of the mesh wiring layer 20. The dimensions of the test piece are set to a width of 10 mm to 20 mm and a length of 50 mm to 100 mm. Then, the dielectric loss factor or relative permittivity is determined according to IEC 62562.

[0104] In this embodiment, the substrate 11 is transparent. In this specification, "transparent" means that the transmittance of visible light (i.e., light with a wavelength of 400 nm to 700 nm) is 85% or more. The transmittance of visible light of the substrate 11 may be 85% or more, preferably 90% or more. Furthermore, there is no particular upper limit to the transmittance of visible light of the substrate 11, for example, it may be 100% or less. By setting the transmittance of visible light of the substrate 11 to the above range, the transparency of the wiring substrate 10 can be improved, making it easier to see the display device 61 of the image display device 60.

[0105] In this embodiment, the mesh wiring layer 20 is composed of an antenna pattern that functions as an antenna. The mesh wiring layer 20 can also be configured as an array antenna comprising two or more antenna elements (radiating elements (hereinafter, the front end portion 20b)). When the mesh wiring layer 20 is configured as an array antenna, the performance of millimeter-wave antennas with high transmit and receive linearity can be improved. Furthermore, an array antenna refers to an antenna in which a plurality of antenna elements are regularly arranged, and the excitation amplitude and phase of the elements can be controlled independently.

[0106] Two or more mesh wiring layers 20 are formed on the substrate 11. Preferably, four or more mesh wiring layers 20 are provided. In this case, four or more antenna elements (hereinafter referred to as the front end portion 20b) are provided in the wiring substrate 10. In the illustrated example, four mesh wiring layers 20 are formed on the substrate 11 (see Figure 1). Also, as shown in Figure 4, the mesh wiring layers 20 may not exist on the entire surface of the substrate 11, but only in a portion of the substrate 11. Each mesh wiring layer 20 may have the same shape as each other. In this case, it is preferable that the error of the length (i.e., the length in the Y direction) La and the error of the width (the length in the X direction) Wa of each mesh wiring layer 20 are both within 10%. This can effectively improve the performance of millimeter-wave antennas.

[0107] The mesh wiring layer 20 has a base-side portion (i.e., a power transmission portion) 20a on the side of the power supply section 40, and a front-side portion (i.e., a transceiver portion) 20b connected to the base-side portion 20a. The base-side portion 20a is connected to the power supply section 40. The shape of the base-side portion 20a and the shape of the front-side portion 20b are both approximately rectangular when viewed from above. In this case, the length (i.e., the distance in the Y direction) of the front-side portion 20b is longer than the length (i.e., the distance in the Y direction) of the base-side portion 20a, and the width (i.e., the distance in the X direction) of the front-side portion 20b is wider than the width (i.e., the distance in the X direction) of the base-side portion 20a.

[0108] The front end portion 20b of the mesh wiring layer 20 corresponds to a specified frequency band. That is, the length (length in the Y direction) La of the front end portion 20b is a length corresponding to a specific frequency band. Furthermore, the lower the frequency of the corresponding frequency band, the longer the length La of the front end portion 20b. In addition to corresponding to millimeter-wave antennas, the mesh wiring layer 20 can also correspond to any of the following: telephone antennas, WiFi antennas, 3G antennas, 4G antennas, 5G antennas, LTE antennas, Bluetooth antennas, NFC antennas, etc. Furthermore, multiple front end portions 20b can have different lengths, each corresponding to a different frequency band. Alternatively, when the wiring board 10 does not have radio wave transceiver functions, each mesh wiring layer 20 can also perform functions such as hovering, fingerprint authentication, heating, and noise cancellation (shielding). Furthermore, the hover function refers to the ability to operate the device even without directly touching the display.

[0109] The length direction of the front-end portion 20b is parallel to the X direction, and its short side direction is parallel to the Y direction. The length La in the Y direction of the front-end portion 20b can be selected, for example, within the range of 1 mm to 100 mm. The width Wa in the X direction of the front-end portion 20b can be selected, for example, within the range of 1 mm to 100 mm. In particular, when the mesh wiring layer 20 is a millimeter-wave antenna, the length La of the front-end portion 20b can be selected within the range of 1 mm or more, and more preferably 1.5 mm or more. When the mesh wiring layer 20 is a millimeter-wave antenna, the length La of the front-end portion 20b can be selected within the range of 10 mm or less, and more preferably 5 mm or less.

[0110] In this mesh wiring layer 20, the distance between antenna elements is preferably 1 mm or more and 5 mm or less. That is, the distance D 20b between the front-end portions 20b (see Figure 4) is preferably 1 mm or more and 5 mm or less. By ensuring that the distance D 20b between the front-end portions 20b is 1 mm or more, unwanted interference of electromagnetic waves between antenna elements can be suppressed. By ensuring that the distance D 20b between the front-end portions 20b is 5 mm or less, the overall size of the array antenna formed by the mesh wiring layer 20 can be reduced. For example, when the mesh wiring layer 20 is a 28 GHz millimeter-wave antenna, the distance D 20b between the front-end portions 20b can be 3.5 mm. Furthermore, when the mesh wiring layer 20 is a 60 GHz millimeter-wave antenna, the distance D 20b between the front-end portions 20b can be 1.6 mm.

[0111] The mesh wiring layer 20 has a pattern shape in which the metal wires are arranged in a grid or mesh pattern. The pattern shape is repeated in the X and Y directions. That is, the mesh wiring layer 20 has a pattern shape including a portion extending along a first direction (e.g., the Y direction) (i.e., the first wiring 21) and a portion extending along a second direction (e.g., the X direction) (i.e., the second wiring 22).

[0112] As shown in FIG5A, 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 integrally formed into a grid or mesh shape. Each first wiring 21 extends in a straight line along the Y direction. Each second wiring 22 extends in a straight line along the X direction, which is orthogonal to the first wiring 21.

[0113] In the mesh wiring layer 20, two or more openings 23 are formed by being surrounded by the first wiring 21 and the second wiring 22. Specifically, in the mesh wiring layer 20, a plurality of openings 23 are formed by being surrounded by adjacent first wiring 21 and adjacent second wiring 22. Furthermore, in this specification, an opening refers to a region surrounded by wirings (first wiring 21 and second wiring 22) where there are no wirings connecting the wirings that form that region. Specifically, in the example shown in FIG5B, opening 23A or opening 23E is each one opening 23. In other words, for example, the region obtained by merging openings 23A and 23B is not one opening 23.

[0114] Furthermore, the first wiring 21 and the second wiring 22 are irregularly arranged. Specifically, a plurality of first wirings 21 are arranged parallel to each other, and their spacing P1 is irregular. The spacing P1 may, for example, be in the range of 0.01 mm to 1 mm. A plurality of second wirings 22 are arranged parallel to each other, and their spacing P2 is irregular. The spacing P2 may, for example, be in the range of 0.01 mm to 1 mm.

[0115] Thus, in this embodiment, the distance P1 between the plurality of first wirings 21 and the distance P2 between the plurality of second wirings 22 are irregular. This reduces the distance between the ripples caused by 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 imperceptible 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 spacings P1 and P2 are irregular, flicker caused by the 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 opposite sides parallel to each other. In this embodiment, the first wiring 21 is arranged parallel to each other, and the second wiring 22 is arranged parallel to each other. Therefore, the planar shape of each opening 23 is a quadrilateral (i.e., a rectangle) with opposite sides parallel to each other. The transparent substrate 11 is exposed from each opening 23. This improves the overall transparency of the wiring substrate 10.

[0117] As shown in FIG. 5A, the distance between the edges extending in a predetermined direction (first direction) of each opening 23 is denoted as d. Furthermore, the average value of the distances d between the edges extending in the predetermined direction of 100 consecutively adjacent openings 23 is denoted as D. In this embodiment, more than 95% of the 100 openings 23 satisfy the relationship 0.70D≦d≦0.98D, or the relationship 1.02D≦d≦1.30D. Here, as described above, in this embodiment, the distances P1 between the plurality of first wirings 21 and P2 between the plurality of second wirings 22 are irregular. Therefore, the distances d between the edges of 100 consecutively adjacent openings 23 may be different. In this case, it is preferable that the values ​​of the distances d between the edges of 100 consecutively adjacent openings 23 are three or more. Furthermore, in this specification, "100 consecutive adjacent openings" means that among all 100 openings 23, each opening 23 is adjacent to at least one of the other openings 23 constituting the 100 openings 23.

[0118] The "100 consecutively adjacent openings" can also be selected in the following manner, for example. First, as shown in FIG5B, any opening 23A is selected. Next, any opening 23B adjacent to opening 23A is selected. In the illustrated example, opening 23B is adjacent to opening 23A on the positive side of the X direction. Then, any 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 of the Y direction. Next, any 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 of the Y direction and adjacent to opening 23C on the negative side of the X direction. Next, select any opening 23E that is adjacent to at least one of openings 23A, 23B, 23C, and 23D. In the example shown, opening 23E is adjacent to opening 23D on the negative side of the X direction. Alternatively, 100 openings 23 can be selected in this manner.

[0119] Furthermore, when the number of openings 23 in the wiring board 10 is less than 100, the average value of the distance d between the edges of all openings 23 extending in a predetermined direction can be set as D. In this case, more than 95% of all openings 23 satisfy the relationship 0.70D≦d≦0.98D, or satisfy the relationship 1.02D≦d≦1.30D.

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

[0121] Therefore, in this embodiment, when the distance between the edges of each opening 23 extending along the M-th direction is set as dM, and the average value of the distance between the edges dM in 100 consecutively adjacent openings 23 is set as DM, more than 95% of the openings 23 satisfy the relationship 0.70DM≦dM≦0.98DM, or satisfy the relationship 1.02DM≦dM≦1.30DM.

[0122] Furthermore, when the number of openings 23 in the wiring board 10 is less than 100, the average value of the distance dM between the edges extending along the M-th direction of all openings 23 can be set as DM. In this case, more than 95% of all openings 23 also satisfy the relationship 0.70DM≦dM≦0.98DM, or satisfy the relationship 1.02DM≦dM≦1.30DM.

[0123] Specifically, for example, as shown in FIG5A, the distance between the edges extending along the length direction (i.e., the Y direction) of the first wiring 21 is set as d1. Furthermore, the average value of the distances d1 between the edges of 100 consecutively adjacent openings 23 or all openings 23 is set as D1. In this embodiment, more than 95% of the 100 openings 23 or all openings 23 satisfy the relationship 0.70D1≦d1≦0.98D1, or the relationship 1.02D1≦d1≦1.30D1. This reduces the distance between the ripples caused by 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 imperceptible to the naked eye.

[0124] That is, in the image display device 60 described above, the mesh wiring layer 20 of the wiring substrate 10 is arranged to overlap with the pixel P of the display device 61 in the Z direction. Therefore, water ripples may be generated due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P. In contrast, in this embodiment, more than 95% of the 100 openings 23 or all the openings 23 satisfy the relationship 0.70D 1≦d 1≦0.98D 1, or satisfy the relationship 1.02D 1≦d 1≦1.30D 1. Therefore, when viewed from the Z direction, the first wiring 21 and the pixel P are irregularly arranged in the X direction. Therefore, the distance between the ripples caused by the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P can be reduced to a level that is not visible to the naked eye. Furthermore, by satisfying the above relationship in the wiring substrate 10, the size of the opening 23 in the mesh wiring layer 20 will not deviate, thereby making the mesh wiring layer 20 difficult to see with the naked eye.

[0125] Similarly, for example, the distance between the edges extending along the length direction (i.e., the X direction) of the second wiring 22 is set as d2. Furthermore, the average value of the distances d2 between the edges of 100 consecutively adjacent openings 23 or all openings 23 is set as D2. In this embodiment, more than 95% of the 100 openings 23 or all openings 23 satisfy the relationship 0.70D2≦d2≦0.98D2, or the relationship 1.02D2≦d2≦1.30D2. Therefore, when viewed from the Z direction, the second wiring 22 and the pixel P are irregularly arranged in the Y direction. Thus, the distance between the ripples caused by the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P can be reduced to a level that is imperceptible to the naked eye. Furthermore, by satisfying the above relationship through the wiring substrate 10, the size of the opening 23 in the mesh wiring layer 20 will not deviate, thereby making the mesh wiring layer 20 difficult to see with the naked eye.

[0126] Furthermore, in this embodiment, it is preferable that 95% or more of the 100 openings 23 or all the openings 23 satisfy the relationship 0.85D≦d≦0.98D, or satisfy the relationship 1.02D≦d≦1.15D. This allows for a smaller distance between the ripples caused by the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P. Furthermore, it reduces the size deviation of the openings 23 within the mesh wiring layer 20, thus making the mesh wiring layer 20 less visible.

[0127] Furthermore, in this embodiment, it is preferable that more than 95% of the 100 openings 23 or all the openings 23 satisfy the relationship 0.90D≦d≦0.98D, or satisfy the relationship 1.02D≦d≦1.10D. This makes the distance between the ripples caused by the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P smaller. Furthermore, it can further reduce the size deviation of the openings 23 within the mesh wiring layer 20, thus making the mesh wiring layer 20 less visible.

[0128] Furthermore, the side distances d1 and d2 of each opening 23 can be, for example, in the range of 35 μm to 650 μm. The average value D (i.e., the average values ​​D1 and D2) can be 50 μm to 500 μm. By having an average value D of 50 μm or more, the aperture ratio At of the mesh wiring layer 20 can be suppressed from decreasing, thereby ensuring the transparency of the wiring substrate 10. By having an average value D of 500 μm or less, the sheet resistance of the mesh wiring layer 20 can be suppressed from becoming too large, thereby maintaining its antenna characteristics. Furthermore, each first wiring 21 and each second wiring 22 are orthogonal to each other, but not limited to this, they can also intersect each other at acute or obtuse angles.

[0129] As shown in FIG. 6, each first wiring 21 has a cross-section perpendicular to its length direction (i.e., the X-direction cross-section) that is approximately rectangular or approximately square. In this case, the cross-sectional shape of the first wiring 21 is approximately uniform along the length direction (i.e., the Y-direction) of the first wiring 21. As shown in FIG. 7, each second wiring 22 has a cross-section perpendicular to its length direction (i.e., the Y-direction cross-section) that is approximately rectangular or approximately square, and has a shape that is approximately the same as the cross-sectional shape (i.e., the X-direction cross-section) of the first wiring 21. In this case, the cross-sectional shape of the second wiring 22 is approximately uniform along the length direction (i.e., the X-direction) of the second wiring 22. The cross-sectional shapes of the first wiring 21 and the second wiring 22 do not necessarily have to be approximately rectangular or approximately square. For example, the cross-sectional shape of the first wiring 21 and the cross-sectional shape of the second wiring 22 can also be a roughly trapezoidal shape with the front side (i.e., the positive side in the Z direction) narrower than the back side (i.e., the negative side in the Z direction), or a shape with curved sides on both sides in the length direction.

[0130] In this embodiment, the linewidth W1 of the first wiring 21 (see Figure 6) and the linewidth W2 of the second wiring 22 (see Figure 7) are not particularly limited and can be appropriately selected according to the application. Here, the linewidth W1 of the first wiring 21 is the length in the X direction, and the linewidth W2 of the second wiring 22 is the length in the Y direction. For example, the linewidth W1 of the first wiring 21 can be 0.5 μm or more and 3 μm or less. By having the linewidth W1 of the first wiring 21 be 0.5 μm or more, the conductivity of the wiring substrate 10 can be improved. By having the linewidth W1 of the first wiring 21 be 3.0 μm or less, even in the case of water ripples, the density of the water ripples can be made lighter. The linewidth W1 of the first wiring 21 can be selected in the range of 0.5 μm or more, and preferably 1.0 μm or more. The linewidth W1 of the first wiring 21 can be selected within the range of 3.0 μm or less, preferably 2.0 μm or less. Furthermore, the linewidth W2 of the second wiring 22 can be 0.5 μm or more and 3 μm or less. By having the linewidth W2 of the second wiring 22 be 0.5 μm or more, the conductivity of the wiring substrate 10 can be improved. By having the linewidth W2 of the second wiring 22 be 3.0 μm or less, even in the event of water ripples, the density of the ripples can be reduced. The linewidth W2 of the second wiring 22 can be selected within the range of 0.5 μm or more, preferably 1.0 μm or more. The linewidth W2 of the second wiring 22 can be selected within the range of 3.0 μm or less, preferably 2.0 μm or less.

[0131] The height H1 of the first wiring 21 (see Figure 6) and the height H2 of the second wiring 22 (see Figure 7) are not particularly limited and can be appropriately selected according to the application. Here, the height H1 of the first wiring 21 and the height H2 of the second wiring 22 are the 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 in a range of, for example, 0.1 μm or more, 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 in a range of, for example, 5.0 μm or less, preferably 2.0 μm or less.

[0132] The materials for the first wiring 21 and the second wiring 22 can be any conductive metallic material. In this embodiment, the material for the first wiring 21 and the second wiring 22 is copper, but it is not limited to this. The materials for the first wiring 21 and the second wiring 22 may be, for example, metallic materials such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or alloys containing such metals. Furthermore, the first wiring 21 and the second wiring 22 may be plating layers formed by electrolytic plating.

[0133] The overall aperture ratio At of the mesh wiring layer 20 can be, for example, in the range of 87% or more but less than 100%. By setting the overall aperture ratio At of the mesh wiring layer 20 to this range, the conductivity and transparency of the wiring substrate 10 can be ensured. Preferably, the overall aperture ratio At of the mesh wiring layer 20 is 95% or more but less than 100%, or 96% or more but less than 100%. This ensures the conductivity of the wiring substrate 10 and improves its transparency. Furthermore, the aperture ratio refers to the percentage (%) of the area of ​​the open region to the unit area of ​​a specified area (e.g., the entire area of ​​the mesh wiring layer 20). The open region refers to the area where the substrate 11 is exposed without metal portions such as the first wiring 21 and the second wiring 22.

[0134] The sheet resistance of the mesh wiring layer 20 can 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 improved. Furthermore, radiation efficiency refers to the ratio of how much power input to a single unit of the mesh wiring layer 20 is radiated.

[0135] The sheet resistance value (Ω / □) of the mesh wiring layer 20 can be obtained as follows. That is, the resistance value R between the two ends 20e1 and 20e2 (see Figure 8) along the length direction (Y direction) of the mesh wiring layer 20 is actually measured. Then, by dividing this resistance value R by the ratio of the length La to the width Wa of the mesh wiring layer 20 (La / Wa), the sheet resistance value Rs (Ω / □) of the mesh wiring layer 20 can be obtained. That is, the sheet resistance value Rs = R × Wa / La.

[0136] By setting the sheet resistance value of the mesh wiring layer 20 to 4 Ω / □ or less, the radiation efficiency of a single mesh wiring layer 20 can be improved, thereby enhancing the performance of the mesh wiring layer 20 as an antenna. Furthermore, the width Wa and heights H1 and H2 of the mesh wiring layer 20 can be minimized as much as possible within the range that satisfies the aforementioned sheet resistance value. Therefore, the aperture ratio At of the mesh wiring layer 20 can be increased, making the mesh wiring layer 20 less visible.

[0137] Furthermore, although not shown in the figure, a protective layer can also be formed on the surface of the substrate 11 in such a way as to cover the mesh wiring layer 20. The protective layer protects the mesh wiring layer 20 and is formed to cover at least the mesh wiring layer 20 in the substrate 11. As the material of the protective layer, colorless and transparent insulating resins such as poly(methyl)acrylate, poly(ethyl)acrylate and other acrylic resins, modified resins and copolymers thereof, polyester, polyvinyl alcohol, polyvinyl acetate, polyvinyl alcohol acetal, polyvinyl alcohol butyral and other polyethylene resins and copolymers thereof, polyurethane, epoxy resin, polyamide, chlorinated polyolefin and other such materials can be used.

[0138] Referring again to FIG4, a power supply section 40 is electrically connected to the mesh wiring layer 20. The power supply section 40 is composed of a generally rectangular conductive thin plate-shaped member. The length direction of the power supply section 40 is parallel to the X direction, and the short side direction of the power supply section 40 is parallel to the Y direction. Furthermore, the power supply section 40 is disposed at the end of the substrate 11 in the length direction (i.e., the negative end in the Y direction). The material of the power supply section 40 may be, for example, metals such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or alloys containing such metals. The power supply section 40 is electrically connected to the communication module 63 of the image display device 60 via a power supply wire (not shown) when the wiring substrate 10 is assembled into the image display device 60 (refer to FIG1 and FIG2). Furthermore, the power supply section 40 is disposed on the first surface 11a of the substrate 11, but is not limited thereto; a portion or all of the power supply section 40 may also be located further outward than the periphery of the substrate 11. Alternatively, the power supply section 40 can be flexibly formed so that it wraps around the side or back of the image display device 60. In this case, the power supply section 40 can also be electrically connected to the communication module 63 on the side or back of the image display device 60.

[0139] Next, with reference to FIG9(a)-(f), the manufacturing method of the wiring board 10 of this embodiment will be described.

[0140] First, as shown in FIG9(a), a substrate 11 comprising a first surface 11a and a second surface 11b located on the opposite side of the first surface 11a is prepared. The substrate 11 is transparent.

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

[0142] At this time, firstly, as shown in FIG9(b), a metal foil 51 is deposited over approximately the entire area of ​​the first surface 11a of the substrate 11. In this embodiment, the thickness of the metal foil 51 may be 0.1 μm or more and 5.0 μm or less. In this embodiment, the metal foil 51 may contain copper.

[0143] Next, as shown in FIG9(c), a photocurable insulating resist 52 is supplied to approximately the entire surface area of ​​the metal foil 51. Examples of the photocurable insulating resist 52 include organic resins such as acrylic resins and epoxy resins.

[0144] Next, as shown in FIG9(d), an insulating layer 54 is formed using photolithography. In this case, the photocurable insulating resist 52 is patterned using photolithography to form the insulating layer 54 (i.e., the resist pattern). At this time, the insulating layer 54 is formed in such a way that the metal foil 51 corresponding to the first wiring 21 and the second wiring 22 is exposed.

[0145] Next, as shown in FIG9(e), the metal foil 51 on the first surface 11a of the substrate 11, in the portion not covered by the insulating layer 54, is removed. At this time, the metal foil 51 is etched by performing a wet treatment using strong acids such as ferric chloride, copper chloride, sulfuric acid, hydrochloric acid, persulfate, hydrogen peroxide or aqueous solutions thereof, or combinations thereof, in a manner that exposes the first surface 11a of the substrate 11.

[0146] Next, as shown in FIG9(f), the insulating layer 54 is removed. In this case, the insulating layer 54 on the metal foil 51 is removed by performing a wet treatment using a permanganate solution or N-methyl-2-pyrrolidone, an acid or alkaline solution, or a dry treatment using oxygen plasma.

[0147] In this manner, a wiring substrate 10 having a substrate 11 and a mesh wiring layer 20 disposed on a first surface 11a of the substrate 11 can be obtained. In this case, the mesh wiring layer 20 includes a first wiring 21 and a second wiring 22. At this time, the power supply section 40 can also be formed from a portion of a metal foil. Alternatively, a flat plate-shaped power supply section 40 can be prepared separately and electrically connected to the mesh wiring layer 20.

[0148] Subsequently, the display device 61 is deposited on the wiring substrate 10 via the first transparent bonding layer 95 and the second transparent bonding layer 96, thereby obtaining an image display device 60 having the wiring substrate 10 and the display device 61 deposited on the wiring substrate 10.

[0149] Next, the function of this embodiment including this configuration will be described.

[0150] As shown in Figures 1 and 2, the wiring board 10 is assembled into the image display device 60, which has a display device 61. At this time, the wiring board 10 is disposed on the display device 61. The mesh wiring layer 20 of the wiring board 10 is electrically connected to the communication module 63 of the image display device 60 via the power supply section 40. In this way, radio waves of a specified frequency can be transmitted and received via the mesh wiring layer 20, thereby enabling communication using the image display device 60.

[0151] As described above, in the image display device 60, the mesh wiring layer 20 of the wiring board 10 is arranged to overlap with the pixel P of the display device 61 in the Z direction. Therefore, water ripples may be generated due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P.

[0152] In contrast, in this embodiment, when the distance between the edges extending in a predetermined direction in each opening 23 is set as d, and the average value of the distance d between the edges extending in a predetermined direction in 100 consecutively adjacent openings 23 or all openings 23 is set as D, more than 95% of the openings 23 in the 100 openings 23 or all openings 23 satisfy the relationship 0.70D≦d≦0.98D, or satisfy the relationship 1.02D≦d≦1.30D. Therefore, when viewed from the Z direction, the first wiring 21 and the second wiring 22 are irregularly arranged with the pixel P. Thus, the distance between the ripples caused by the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P can be reduced to a level that is not visible to the naked eye. Furthermore, by satisfying the above relationship through the wiring substrate 10, the size of the opening 23 in the mesh wiring layer 20 will not deviate, thereby making the mesh wiring layer 20 difficult to see with the naked eye.

[0153] Furthermore, according to this 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 opposite sides parallel to each other. In other words, the first wiring 21 extends in a straight line and is arranged parallel to each other when viewed from above, and the second wiring 22 extends in a straight line and is arranged parallel to each other when viewed from above. Therefore, flicker caused by the reflection of visible light by the mesh wiring layer 20 can be suppressed. Furthermore, by having the first wiring 21 extend in a straight line and be arranged parallel to each other when viewed from above, for example, compared to the case where the first wiring 21 is curved when viewed from above, the overall length of the first wiring 21, etc., can be shortened. Therefore, the sheet resistance value of the mesh wiring layer 20 can be reduced, thereby maintaining its antenna characteristics.

[0154] Furthermore, according to this embodiment, the wiring board 10 includes a substrate 11 and a mesh wiring layer 20 disposed on the substrate 11. The substrate 11 is transparent. Furthermore, the mesh wiring layer 20 has a mesh pattern formed by conductor portions that are formed as opaque conductive layers and a plurality of openings 23. Therefore, the transparency of the wiring board 10 is ensured. Thus, when the wiring board 10 is disposed on the display device 61, the display device 61 can be viewed through the openings 23 of the mesh wiring layer 20 without obstructing the visibility of the display device 61.

[0155] Next, we will explain a variation of the wiring board.

[0156] Figures 10 and 11 show a first variation of the wiring board. The difference between the variation shown in Figures 10 and 11 is that a dummy wiring layer 30 is provided around the mesh wiring layer 20; the other configurations are substantially the same as those shown in Figures 1 to 9 above. In Figures 10 and 11, the same symbols are used for the parts that are the same as those shown in Figures 1 to 9, and detailed descriptions are omitted.

[0157] In the wiring board 10 shown in FIG10, a dummy wiring layer 30 is provided around the mesh wiring layer 20. The dummy wiring layer 30 is different from the mesh wiring layer 20 and does not actually function as an antenna.

[0158] As shown in Figure 11, the dummy wiring layer 30 is composed of repeating dummy wirings 30a with a prescribed pattern shape. That is, the dummy wiring layer 30 includes a plurality of dummy wirings 30a, each of which is electrically independent from the mesh wiring layer 20 (i.e., the first wiring 21 and the second wiring 22). Furthermore, the plurality of dummy wirings 30a are regularly arranged throughout the entire area of ​​the dummy wiring layer 30. The plurality of dummy wirings 30a are spaced apart from each other in the planar direction and are prominently arranged on 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 when viewed from above.

[0159] In this case, the dummy wiring 30a has a shape in which a portion of the pattern of the aforementioned mesh wiring layer 20 is missing. This makes it difficult to visually distinguish the difference between the mesh wiring layer 20 and the dummy wiring layer 30, thereby making it difficult to see the mesh wiring layer 20 disposed on the substrate 11. As shown in FIG11, 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. By extending the dummy wiring 30a parallel to the first wiring 21 or the second wiring 22, it is even more difficult to see the mesh wiring layer 20 disposed on the substrate 11. The aperture ratio of the dummy wiring layer 30 can be the same as or different from that of the mesh wiring layer 20, but it is preferable to be close to the aperture ratio of the mesh wiring layer 20.

[0160] In this variation, as shown in FIG11, the distance between the portions extending in a predetermined direction of each dummy wiring 30a is defined as da. Furthermore, the average value of the distances da between the portions extending in a predetermined direction of 100 consecutively adjacent groups of dummy wirings 30a is defined as Da. In this variation, more than 95% of the dummy wirings 30a in the 100 groups satisfy the relationship 0.70Da≦da≦0.98Da, or the relationship 1.02Da≦da≦1.30Da. This reduces the distance between the ripples caused by the regularity (periodicity) of the dummy wirings 30a and the regularity (periodicity) of the pixels P of the display device 61 to a level imperceptible to the naked eye. Furthermore, one direction can be either the X direction or the Y direction.

[0161] Furthermore, when the number of groups of dummy wirings 30a in the wiring board 10 is less than 100, the average value of the distance da between the portions of all dummy wirings 30a extending in a specified direction can be set as Da. In this case, similarly, more than 95% of all dummy wirings 30a can satisfy the relationship 0.70Da≦da≦0.98Da, or satisfy the relationship 1.02Da≦da≦1.30Da.

[0162] Furthermore, in the example shown in Figure 11, the distance da between the first part 31a is set as da1. In this case, when the average value of the distance da1 among 100 consecutively adjacent groups of dummy wirings 30a or all dummy wirings 30a is set as Da1, more than 95% of the dummy wirings 30a among the 100 groups of dummy wirings 30a or all dummy wirings 30a can satisfy the relationship 0.70Da1≦da1≦0.98Da1, or satisfy the relationship 1.02Da1≦da1≦1.30Da1.

[0163] Similarly, the distance da between the two parts 32a is set as da2. In this case, when the average value of the distance da2 among the 100 consecutively adjacent groups of dummy wirings 30a or all dummy wirings 30a is set as Da2, more than 95% of the dummy wirings 30a among the 100 groups of dummy wirings 30a or all dummy wirings 30a can satisfy the relationship 0.70Da2≦da2≦0.98Da2, or satisfy the relationship 1.02Da2≦da2≦1.30Da2.

[0164] Furthermore, in this variation, it is preferable that more than 95% of the 100 sets of dummy wiring 30a or all dummy wiring 30a satisfy the relationship 0.85D a≦da≦0.98D a, or satisfy the relationship 1.02D a≦da≦1.15D a. Moreover, in this variation, it is even more preferable that more than 95% of the 100 sets of dummy wiring 30a or all dummy wiring 30a satisfy the relationship 0.90D a≦da≦0.98D a, or satisfy the relationship 1.02D a≦da≦1.10D a.

[0165] As in this variation, by providing a dummy wiring layer 30 that is electrically independent of the mesh wiring layer 20 around the mesh wiring layer 20, the outer edge of the mesh wiring layer 20 can be made unclear. This makes the mesh wiring layer 20 less visible on the surface of the image display device 60, thereby making it difficult for the user of the image display device 60 to visually identify the mesh wiring layer 20.

[0166] Figures 12 and 13 show a second variation of the wiring board. The difference between the variation shown in Figures 12 and 13 is that two or more dummy wiring layers 30A and 30B with different aperture ratios are provided around the mesh wiring layer 20. The other configurations are generally the same as those shown in Figures 1 to 11 above. In Figures 12 and 13, the parts that are the same as those shown in Figures 1 to 11 are marked with the same symbols, and detailed descriptions are omitted.

[0167] In the wiring board 10 shown in FIG12, two or more (in this case, two) dummy wiring layers 30A and 30B with different aperture ratios are disposed around the mesh wiring layer 20 (i.e., the first dummy wiring layer 30A and the second dummy wiring layer 30B). Specifically, the first dummy wiring layer 30A is disposed around the mesh wiring layer 20, and the second dummy wiring layer 30B is disposed around the first dummy wiring layer 30A. These dummy wiring layers 30A and 30B are different from the mesh wiring layer 20 and do not actually function as antennas.

[0168] As shown in Figure 13, the first dummy wiring layer 30A is composed of repeating dummy wirings 30a1 with a prescribed pattern shape. The second dummy wiring layer 30B is composed of repeating dummy wirings 30a2 with a prescribed pattern shape. That is, dummy wiring layers 30A and 30B each contain a plurality of dummy wirings 30a1 and 30a2, and each dummy wiring 30a1 and 30a2 is electrically independent from the mesh wiring layer 20. Furthermore, the dummy wirings 30a1 and 30a2 are regularly arranged throughout the entire area of ​​the dummy wiring layers 30A and 30B, respectively. Each dummy wiring 30a1 and 30a2 is spaced apart from each other in the planar direction and protrudes onto the substrate 11. Each dummy wiring 30a1 and 30a2 is electrically independent from the mesh wiring layer 20, the power supply section 40, and other dummy wirings 30a1 and 30a2. The shape of each dummy wiring 30a1 and 30a2 is roughly L-shaped when viewed from above.

[0169] In this case, the dummy wirings 30a1 and 30a2 have a shape in which a portion of the pattern of the mesh wiring layer 20 is missing. This makes it difficult to visually distinguish the differences between the mesh wiring layer 20 and the first dummy wiring layer 30A, and between the first dummy wiring layer 30A and the second dummy wiring layer 30B, thereby making it difficult to see the mesh wiring layer 20 disposed on the substrate 11. As shown in FIG13, 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] Furthermore, 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 linewidth of each dummy wiring 30a1 is the same as the linewidth of each dummy wiring 30a2, but it is not limited to this; the linewidth of each dummy wiring 30a1 may also be wider than the linewidth of each dummy wiring 30a2. Furthermore, the other configurations of the dummy wirings 30a1 and 30a2 are the same as the configuration of the dummy wiring 30a in the first variation example; therefore, detailed explanation is omitted here.

[0171] In this variation, the aperture ratio of the mesh wiring layer 20 and the two or more dummy wiring layers 30A and 30B preferably increases progressively from the mesh wiring layer 20 toward the dummy wiring layers 30A and 30B that are farther away from the mesh wiring layer 20. In other words, the aperture ratio of each dummy wiring layer preferably increases gradually from the one closer to the mesh wiring layer 20 toward the one farther away from the mesh wiring layer 20. In this case, the aperture ratio of the first dummy wiring layer 30A is preferably greater than the aperture ratio of the mesh wiring layer 20. The aperture ratio of the second dummy wiring layer 30B is preferably greater than the aperture ratio of the first dummy wiring layer 30A. This makes the outer edges of the mesh wiring layer 20 and the dummy wiring layers 30A and 30B less clear. Therefore, it makes the mesh wiring layer 20 less visible on the surface of the image display device 60.

[0172] By configuring dummy wiring layers 30A and 30B, which are electrically independent of the mesh wiring layer 20, the outer edge of the mesh wiring layer 20 becomes less distinct. This makes the mesh wiring layer 20 less visible on the surface of the image display device 60, thus making it difficult for users of the image display device 60 to visually identify the mesh wiring layer 20. Furthermore, three or more dummy wiring layers with different aperture ratios can be provided around the mesh wiring layer 20.

[0173] Figure 14 shows a third variation of the wiring board. The variation shown in Figure 14 differs in the planar shape of the mesh wiring layer 20, but the other components are largely the same as those shown in Figures 1 to 13 above. In Figure 14, the same symbols are used to mark the parts that are the same as those shown in Figures 1 to 13, and detailed descriptions are omitted.

[0174] Figure 14 is an enlarged top view of the mesh wiring layer 20 in the third variation. In Figure 14, the first wiring 21 and the second wiring 22 intersect at an angle (i.e., not at a right angle), and the shape of each opening 23 is rhomboid in the top view. The first wiring 21 and the second wiring 22 are not parallel to either the X direction or the Y direction, but either the first wiring 21 or the second wiring 22 may be parallel to either the X direction or the Y direction.

[0175] Figures 15 and 16 show a fourth variation of the wiring board. The difference between the variation shown in Figures 15 and 16 lies in the planar shape of the mesh wiring layer 20 and the presence of two or more dummy wiring layers 30A and 30B with different aperture ratios around the mesh wiring layer 20. Other configurations are largely the same as those shown in Figures 1 to 14. In Figures 15 and 16, the same symbols are used for the parts that are the same as those shown in Figures 1 to 14, and detailed descriptions are omitted.

[0176] Figures 15 and 16 are enlarged top views of the mesh wiring layer 20 of the fourth variation. In Figures 15 and 16, similar to the mesh wiring layer 20 of the third variation shown in Figure 14, the first wiring 21 and the second wiring 22 intersect at an angle (i.e., not at a right angle), and the shape of each opening 23 is rhomboid in top view. The first wiring 21 and the second wiring 22 are not parallel to either the X direction or the Y direction, but either the first wiring 21 or the second wiring 22 may be parallel to either the X direction or the Y direction.

[0177] Furthermore, in the wiring board 10 shown in FIG15 and FIG16, similarly to the wiring board 10 of the second variation shown in FIG12 and FIG13, two or more (in this case, two) dummy wiring layers 30A and 30B with different opening ratios are provided around the mesh wiring layer 20 (i.e., the first dummy wiring layer 30A and the second dummy wiring layer 30B).

[0178] As shown in Figure 16, in this variation, the dummy wirings 30a1 and 30a2 also extend parallel to either the first wiring 21 or the second wiring 22. Specifically, 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 at an angle (i.e., not at a right angle). 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 at an angle (i.e., not at a right angle). The other configurations of the first dummy wiring layer 30A and the second dummy wiring layer 30B are the same as those of the first dummy wiring layer 30A and the second dummy wiring layer 30B in the second variation example. Therefore, detailed descriptions are omitted here.

[0179] Figure 17 shows the fifth variation of the wiring board. The variation shown in Figure 17 differs in the planar shape of the opening 23, but the other components are largely the same as those shown in Figures 1 to 16 above. In Figure 17, the same symbols are used to mark the parts that are the same as those shown in Figures 1 to 16, and detailed descriptions are omitted.

[0180] In the wiring substrate 10 shown in FIG17, the planar shape of the opening 23 is hexagonal. In this variation, the first wiring 21 includes a first portion 24 and a second portion 25 that intersect each other at an incline (i.e., not at right angles). The first portion 24 and the second portion 25 are not parallel to the X direction and the Y direction, respectively.

[0181] Part 1 24 and Part 2 25 are arranged irregularly. Specifically, a plurality of Part 1 24s are arranged parallel to each other, and their spacing P 1a is irregular. The spacing P 1a may, for example, be in the range of 0.01 mm to 1 mm. A plurality of Part 2 25s are arranged parallel to each other, and their spacing P 1b is irregular. The spacing P 1b may, for example, be in the range of 0.01 mm to 1 mm.

[0182] Thus, the distances P1a between the plurality of first portions 24 and the distances P1b between the plurality of second portions 25 are irregular. This reduces the distance between the ripples caused by 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 imperceptible to the naked eye. Furthermore, 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, even when the spacings P1a and P1b are irregular, flicker caused by the reflection of visible light by the mesh wiring layer 20 can be suppressed.

[0183] Furthermore, in this variation example, the planar shape of the opening 23 is described as hexagonal, but the planar shape of the opening 23 may also be octagonal or a polygon with more than ten corners.

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

[0185] (Example A1) A wiring substrate 10 having the configuration shown in FIG. 5A was fabricated. That is, a wiring substrate 10 in which the first wiring 21 and the second wiring 22 are irregularly arranged. In this case, a polyethylene terephthalate substrate with a thickness of 100 μm was used as the substrate of the wiring substrate 10. Furthermore, copper wiring with 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 La of the front end side portion 20b of the mesh wiring layer 20 is 3.5 mm and the width Wa is 4.2 mm.

[0186] In the wiring board 10 of Embodiment A1, the distance between the edges of the opening 23 extending along the length direction (i.e., the Y direction) of the first wiring 21 is set as d. In this case, the average value D of the distance d between the edges of 100 consecutively adjacent openings 23 in the Y direction is 100 μm. Furthermore, among the 100 openings 23, 100 openings 23 satisfy the relationship 0.70D≦d≦0.98D (hereinafter simply referred to as Equation 1), or satisfy the relationship 1.02D≦d≦1.30D (hereinafter simply referred to as Equation 2).

[0187] In the wiring board 10 of Example A1, the difference in aperture ratio of the 1000 μm square regions that are continuous with each other is less than 0.5%.

[0188] Next, the visibility of the wiring board 10 is checked. First, the presence or absence of water ripples is checked. First, the wiring board 10 is superimposed on the display device 61 shown in FIG. 3 for observation. In the display device 61, the distance between pixels PX is 60 μm, and the distance between pixels PY is 60 μm. Furthermore, with the display device 61 emitting white light, the wiring board 10 is visually observed from a distance of 300 mm to check for the presence or absence of water ripples.

[0189] Next, the presence or absence of flickering is checked. First, a black panel is placed on the back side (i.e., the negative side in the Z direction) of the wiring board 10. Then, a high-brightness lamp is used to illuminate the front side (i.e., the positive side in the Z direction) of the wiring board 10. The light is then illuminated in a direction inclined relative to the normal direction of the first surface 11a of the substrate 11. Next, the wiring board 10 is visually observed from a distance of 300 mm to check for flickering.

[0190] Next, the sheet resistance value (Ω / □) of the mesh wiring layer 20 in the wiring board 10 is measured. At this time, firstly, the resistance value R between the two ends 20e1 and 20e2 (see Figure 8) in the length direction (Y direction) of the mesh wiring layer 20 is measured. A digital multimeter (CUSTOM Corporation, CDM-2000D) is used as the measuring instrument. Then, the sheet resistance value Rs (Ω / □) of the mesh wiring layer 20 is obtained by dividing the resistance value R by the ratio of the length La to the width Wa of the mesh wiring layer 20 (La / Wa).

[0191] (Example A2) A wiring substrate 10 having the configuration shown in FIG. 15 was fabricated. That is, a wiring substrate 10 in which the first wiring 21 and the second wiring 22 are irregularly arranged. In this case, a polyethylene terephthalate substrate with a thickness of 100 μm was used as the substrate of the wiring substrate 10. Furthermore, copper wiring with 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 La of the front end portion 20b of the mesh wiring layer 20 is 3.5 mm and the width Wa is 4.2 mm.

[0192] In the wiring board 10 of Embodiment A2, the distance between the edges of the openings 23 extending along the length direction of the first wiring 21 is set as d. In this case, the average value D of the distance d between the edges of 100 consecutively adjacent openings 23 in the Y direction is 100 μm. Furthermore, among the 100 openings 23, 100 openings 23 satisfy Formula 1 or Formula 2.

[0193] In the wiring board 10 of Example A2, the difference in aperture ratio of the 1000 μm square regions that are continuous with each other is less than 0.5%.

[0194] Subsequently, in the same manner as in Example A1, the visibility of the wiring board 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 in which the first wiring 21 and the second wiring 22 are regularly arranged with each other was fabricated. Specifically, a wiring board 100 in which the first wiring 21 and the second wiring 22 are arranged at approximately equal intervals was fabricated. In this case, a polyethylene terephthalate substrate with a thickness of 100 μm was used as the substrate of the wiring board 100. Furthermore, copper wiring with 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 La of the front end side portion 20b of the mesh wiring layer 20 was 3.5 mm and the width Wa was 4.2 mm.

[0196] In the wiring board 100 of Comparative Example A1, the distance between the edges of the opening 23 extending along the length direction of the first wiring 21 is set as d. In this case, the average value D of the distance between the edges d is 100 μm. Also, among the 100 openings 23, there are 0 openings 23 that satisfy Formula 1 or Formula 2.

[0197] In the wiring board 100 of Comparative Example A1, the difference in aperture ratio of the 1000 μm square regions that are continuous with each other is less than 0.5%.

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

[0199] (Comparative Example A2) A wiring substrate 100 having the configuration shown in FIG19 was fabricated. That is, a wiring substrate 100 having an opening 23 having a planar shape of a quadrilateral with opposite sides not parallel to each other was fabricated. In this case, a polyethylene terephthalate substrate with a thickness of 100 μm was used as the substrate of the wiring substrate 100. Furthermore, copper wiring with 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 La of the front end side portion 20b of the mesh wiring layer 20 was 3.5 mm and the width Wa was 4.2 mm.

[0200] In the wiring substrate 100 of Comparative Example A2, the average value of the edge distance is 100 μm. At this time, the edge distance is measured on an imaginary line extending along the length direction (X direction) of the front end side portion 20b of the mesh wiring layer 20 (see Figure 4) and drawn to an arbitrarily selected position.

[0201] In the wiring board 100 of Comparative Example A2, the difference in aperture ratio of consecutive 1000 μm square regions is 0.5% or less.

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

[0203] (Comparative Example A3) A wiring substrate 100 having the configuration shown in FIG20 was fabricated. That is, a wiring substrate 100 having a Voronoi pattern as the planar structure of the wiring 200 formed by the mesh wiring layer 20 was fabricated. In this case, a polyethylene terephthalate substrate with a thickness of 100 μm was used as the substrate of the wiring substrate 100. Furthermore, copper wiring with 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 La of the front end portion 20b of the mesh wiring layer 20 was 3.5 mm and the width Wa was 4.2 mm.

[0204] In the wiring substrate 100 of Comparative Example A3, the average value of the edge distance is 100 μm. At this time, the edge distance is measured on an imaginary line extending along the length direction (X direction) of the front end side portion 20b of the mesh wiring layer 20 (see Figure 4) and drawn to an arbitrarily selected position.

[0205] In the wiring board 100 of Comparative Example A3, the difference in aperture ratio of consecutive 1000 μm square regions is less than 0.5%.

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

[0207] The results above are shown in Table 1.

[0208] [Table 1] Planar shape (construction) Average value D (μm) Number water ripples blinking Slot ratio Thin film resistance value Example A1 quadrilateral 100 100 A A A A Example A2 hexagon 100 100 A A A A Comparative Example A1 quadrilateral 100 0 B A A A Comparative Example A2 quadrilateral - - A B A B Comparative Example A3 Voronoi pattern - - A B A B

[0209] The number in the "Number" column of Table 1 refers to the number of openings 23 that satisfy Equation 1 or Equation 2 out of 100 openings 23.

[0210] In Table 1, "A" indicates a very good result, and "B" indicates a poor result. Specifically, in the "Ripple" column of Table 1, "A" indicates that ripples could not be detected, and "B" indicates that ripples were present. In the "Flicker" column of Table 1, "A" indicates that flicker caused by reflected light could not be detected, and "B" indicates that flicker was caused by reflected light. In the "Aperture Ratio" column of Table 1, "A" indicates that the difference in aperture ratio is less than 0.5%. In the "Sheet Resistance Value" column of Table 1, "A" indicates that the sheet resistance value is below the specified value, and "B" indicates that the sheet resistance value is greater than the specified value.

[0211] As a result, as shown in Table 1, water ripples were generated in the wiring board 100 of Comparative Example A1. In contrast, water ripples were not observed in the wiring boards 10 of Examples A1 and A2.

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

[0213] Thus, it can be seen that the wiring board 10 of this embodiment can suppress the generation of water ripples and suppress the flickering caused by reflected light.

[0214] As shown in Table 1, the wiring board 10 of Examples A1 and A2, like the wiring board 100 of Comparative Example A1, can reduce the unevenness of the aperture ratio. That is, even when the first wiring 21 and the like are irregularly arranged, the unevenness of the aperture ratio can be reduced in the same way as when the wiring board 100 is regularly arranged.

[0215] As shown in Table 1, the wiring board 10 of Embodiments A1 and A2, like the wiring board 100 of Comparative Example A1, can make the sheet resistance value of the mesh wiring layer 20 below a predetermined value. In this case, the sheet resistance value of the mesh wiring layer 20 of the wiring board 10 of Embodiments A1 and A2 is the same as the sheet resistance value of the mesh wiring layer 20 of the wiring board 100 of Comparative Example A1. That is, in the wiring board 10 of Embodiments A1 and A2, although the first wiring 21 and the like are irregularly arranged, the length of the first wiring 21 and the like does not change compared to the case where the first wiring 21 and the like are regularly arranged. Therefore, even when the first wiring 21 is irregularly arranged, the sheet resistance value of the mesh wiring layer 20 can be made the same as that of the mesh wiring layer 20 of the wiring substrate 100 with the first wiring 21 regularly arranged. Thus, the wiring substrate 10 of Embodiments A1 and A2, like the wiring substrate 100 with the first wiring 21 regularly arranged, can improve the radiation efficiency of the mesh wiring layer 20 as an antenna.

[0216] (Second Embodiment) Next, an embodiment will be described using Figures 21 to 24. Figures 21 to 24 are diagrams illustrating this embodiment. In Figures 21 to 24, the same symbols are used for the parts that are the same as those in the first embodiment shown in Figures 1 to 20, and detailed descriptions are omitted.

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

[0218] In this embodiment, a plurality of openings 23 are formed by being surrounded by adjacent first wiring 21 and adjacent second wiring 22. The planar shape of each opening 23 is approximately rhomboid when viewed from above. The transparent substrate 11 is exposed from each opening 23. This improves the overall transparency of the wiring substrate 10.

[0219] As shown in Figures 21 and 22, the intersection point of the first wiring 21 and the second wiring 22 is designated as A. In this case, the intersection point A of the first wiring 21 and the second wiring 22 is irregularly arranged. That is, the distance between the first wiring 21 and the distance between the second wiring 22 are both irregular. Specifically, since the intersection point A is irregularly arranged, the directions of the first wiring 21 extending between each intersection point A are irregular relative to each other. Similarly, the directions of the second wiring 22 extending between each intersection point A are irregular relative to each other. In this way, the distance between the ripples caused by 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 a level that is not visible to the naked eye.

[0220] That is, in the image display device 60 described above, the mesh wiring layer 20 of the wiring substrate 10 is arranged to overlap with the pixel P of the display device 61 in the Z direction. Therefore, water ripples may be generated due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P. In contrast, in this embodiment, the intersection point A is irregularly arranged. As a result, the first wiring 21 and the second wiring 22 are irregularly arranged with the pixel P. Therefore, the distance between the water ripples generated by the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P can be reduced to a level that is not visible to the naked eye.

[0221] As shown in Figures 21 and 22, the regression line obtained from a plurality of intersection points A located on the same first line 21 is designated as the first regression line 21x. Similarly, the regression line obtained from a plurality of intersection points A located on the same second line 22 is designated as the second regression line 22x. Furthermore, the intersection point of the first regression line 21x and the second regression line 22x is designated as B. Here, the regression line refers to the line obtained by approximating the top-view positional data of each intersection point A located on the same first line 21 using the least squares method.

[0222] Furthermore, as shown in FIG22, the distance from intersection point A to the nearest intersection point B along the width direction (i.e., the X direction) of the mesh wiring layer 20 is denoted as dX. The distance from intersection point A to the nearest intersection point B along the length direction (i.e., the Y direction) of the mesh wiring layer 20 is denoted as dY. The average distance P1X between 10 consecutively adjacent intersection points B in the width direction of the mesh wiring layer 20 is denoted as DX. The average distance P1Y between 10 consecutively adjacent intersection points B in the length direction of the mesh wiring layer 20 is denoted as DY. In this embodiment, at least one of the following relationships is satisfied: 0.02DX ≤ dX < 0.3DX, and 0.02DY ≤ dY < 0.3DY, at 9 or more of the 10 intersection points A closest to each of the 10 intersection points B: dX ≤ dX < 0.3DY. This suppresses excessive deviations in the spacing between the first wiring 21 and the second wiring 22. Consequently, flickering caused by the reflection of visible light by the mesh wiring layer 20 is suppressed. Furthermore, by satisfying the above relationship in the wiring substrate 10, the size of the opening 23 within the mesh wiring layer 20 does not deviate, making the mesh wiring layer 20 difficult to see with the naked eye. Here, the distances dX and dy at the 10 intersection points A closest to each of the 10 intersection points B can be different. In this case, it is preferable that the values ​​of the distances dX and dy at the 10 intersection points A closest to each of the 10 intersection points B are three or more different values.

[0223] Furthermore, at 9 or more of the 10 intersection points A closest to each of the 10 intersection points B, the relationships 0.02DX≦dX<0.3DX and 0.02DY≦dY<0.3DY are satisfied. By satisfying these two relationships, the deviations in the spacing between the first wiring 21 and the spacing between the second wiring 22 can be more effectively suppressed. Therefore, flickering caused by the reflection of visible light by the mesh wiring layer 20 can be more effectively suppressed. Furthermore, by satisfying the above two relationships on the wiring substrate 10, the deviation in the size of the opening 23 can be further reduced, thereby making the mesh wiring layer 20 less visible to the naked eye.

[0224] The average value DX of the distance between intersection points B and P1X, and the average value DY of the distance between intersection points B and P1Y, can be 50 μm or more and 500 μm or less. By having an average value DX and an average value DY of 50 μm or more, the aperture ratio At of the mesh wiring layer 20 can be suppressed from decreasing, thereby ensuring the transparency of the wiring substrate 10. By having an average value DX and an average value DY of 500 μm or less, the sheet resistance of the mesh wiring layer 20 can be suppressed from becoming too large, thereby maintaining its antenna characteristics.

[0225] The average value DX of the distance P1X between intersection points B can be less than (N-0.05) times (N is a natural number (not 0)) and more than (N+0.05) times the distance PX between pixels P in the width direction. This reduces the distance between the ripples caused by the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P to a level that is imperceptible to the naked eye. That is, when viewed from the Z direction, the intersection points A and pixels P are irregularly arranged in the X direction. Therefore, the distance between the ripples caused by the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixels P can be reduced to a level that is imperceptible to the naked eye.

[0226] The average value DX of the distance between intersection points B and P1X is preferably more than (N-0.2) times and less than (N+0.2) times the distance between pixels P in the width direction. This prevents the average value DX from becoming too small even when, for example, N becomes small. Therefore, it is possible to prevent the aperture ratio At of the mesh wiring layer 20 from becoming small, thereby ensuring the transparency of the wiring substrate 10. Furthermore, even when, for example, N becomes large, it is possible to prevent the average value DX from becoming too large. Therefore, it is possible to prevent the sheet resistance value of the mesh wiring layer 20 from becoming too large, thereby maintaining its antenna characteristics.

[0227] The average value DX of the distance P1X between intersection points B can be 50 μm or more and 500 μm or less. By having an average value DX of 50 μm or more, the aperture ratio At of the mesh wiring layer 20 can be suppressed from decreasing, thereby ensuring the transparency of the wiring substrate 10. By having an average value DX of 500 μm or less, the sheet resistance of the mesh wiring layer 20 can be suppressed from becoming too large, thereby maintaining its antenna characteristics.

[0228] The average value DY of the distance P1Y between intersection points B can be less than (M-0.05) times (M is a natural number) and more than (M+0.05) times the distance PY between pixels P in the length direction. Therefore, when viewed from the Z direction, the intersection points A and pixels P are irregularly arranged in the Y direction. Thus, the distance between the water ripples caused by the regularity of the mesh wiring layer 20 and the regularity of the pixels P can be reduced to a level that is imperceptible to the naked eye.

[0229] The average value DY of the distance P1Y between intersection points B is preferably more than (M-0.2) times and less than (M+0.2) times the distance PY between pixels P in the length direction. This prevents the average value DY from becoming too small even when, for example, M becomes small. Therefore, the aperture ratio At of the mesh wiring layer 20 can be prevented from decreasing, thereby ensuring the transparency of the wiring substrate 10. Furthermore, even when, for example, M becomes large, the average value DY can be prevented from becoming too large. Therefore, the sheet resistance value of the mesh wiring layer 20 can be prevented from becoming too large, thereby maintaining its antenna characteristics.

[0230] The average value DY of the distance P1Y between intersection points B can be 50 μm or more and 500 μm or less. By having an average value DY of 50 μm or more, the aperture ratio At of the mesh wiring layer 20 can be suppressed from decreasing, thereby ensuring the transparency of the wiring substrate 10. By having an average value DY of 500 μm or less, the sheet resistance of the mesh wiring layer 20 can be suppressed from becoming too large, thereby maintaining its antenna characteristics.

[0231] N and M are preferably natural numbers between 1 and 6. By using natural numbers less than 6 for N and M, it is possible to suppress the average value DX of the distance between intersection points B and P1X and the average value DY of the distance between intersection points B and P1Y from becoming too large. Therefore, it is possible to suppress the excessive resistance value of the mesh wiring layer 20, thereby maintaining its antenna characteristics.

[0232] The angle θ between the first regression line 21x and the second regression line 22x is preferably 30° to 150°. This prevents the angle between the first wiring 21 and the second wiring 22 from becoming too small or too large. Therefore, when forming the mesh wiring layer 20, the first wiring 21 and the second wiring 22 can be easily formed.

[0233] As shown in FIG23, in this embodiment, each first wiring 21 also has a cross-section perpendicular to its length direction that is approximately rectangular or approximately square. In this case, the cross-sectional shape of the first wiring 21 is approximately uniform throughout the entire first wiring 21. As shown in FIG24, in this embodiment, each second wiring 22 also has a cross-section perpendicular to its length direction that is approximately rectangular or approximately square, having a shape approximately the same as the cross-sectional shape of the first wiring 21 described above. In this case, the cross-sectional shape of the second wiring 22 is approximately uniform throughout the entire second wiring 22. The cross-sectional shapes of the first wiring 21 and the second wiring 22 do not necessarily have to be approximately rectangular or approximately square. For example, the cross-sectional shapes of the first wiring 21 and the second wiring 22 may also be approximately trapezoidal with the front side (i.e., the positive side in the Z direction) narrower than the back side (i.e., the negative side in the Z direction), or shapes with curved sides on both sides in the length direction.

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

[0235] The wiring board 10 of this embodiment can be manufactured, for example, by the method shown in FIG9(a)-(f).

[0236] Subsequently, the display device 61 is deposited on the wiring substrate 10 via the first transparent bonding layer 95 and the second transparent bonding layer 96, thereby obtaining an image display device 60 having the wiring substrate 10 and the display device 61 deposited on the wiring substrate 10.

[0237] Next, the function of this embodiment including this configuration will be described.

[0238] In this embodiment, the wiring board 10 is also incorporated into the image display device 60 having a display device 61 (see Figures 1 and 2). In this case, the wiring board 10 is disposed on the display device 61. The mesh wiring layer 20 of the wiring board 10 is electrically connected to the communication module 63 of the image display device 60 via a power supply section 40. In this manner, radio waves of a predetermined frequency can be transmitted and received via the mesh wiring layer 20, thereby enabling communication using the image display device 60.

[0239] As described above, in the image display device 60, the mesh wiring layer 20 of the wiring board 10 is arranged to overlap with the pixel P of the display device 61 in the Z direction. Therefore, water ripples may be generated due to the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P.

[0240] In contrast, in this embodiment, the intersection point of the first wiring 21 and the second wiring 22 is set as A, the intersection point of the first regression line 21x obtained from a plurality of intersection points A on the same first wiring 21 and the second regression line 22x obtained from a plurality of intersection points A on the same second wiring 22 is set as B, the distance from intersection point A to the nearest intersection point B along the width direction of the mesh wiring layer 20 is set as dX, the distance from intersection point A to the nearest intersection point B along the length direction of the mesh wiring layer 20 is set as dY, the average value of the distance P1X between 10 consecutively adjacent intersection points B in the width direction of the mesh wiring layer 20 is set as DX, and the average value of the distance P1X between 10 consecutively adjacent intersection points B in the length direction of the mesh wiring layer 20 is set as DX. When the average value of 1Y is set to DY, at least one of the following relationships is satisfied: 0.02DX ≤ dX < 0.3DX, and 0.02DY ≤ dY < 0.3DY, at least 9 of the 10 intersection points A closest to each of the 10 intersection points B. This allows for irregular configuration of intersection points A. That is, the first wiring 21 and the second wiring 22 can be irregularly configured with respect to pixel P. Therefore, the spacing between the ripples caused by the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of pixel P can be reduced to a level imperceptible to the naked eye. Furthermore, by satisfying the above relationships in the wiring substrate 10, the deviations in the spacing between the first wiring 21 and the second wiring 22 can be suppressed from becoming excessive. Therefore, flickering caused by the reflection of visible light by the mesh wiring layer 20 can be suppressed. Furthermore, by satisfying the above relationship through the wiring substrate 10, the size of the opening 23 in the mesh wiring layer 20 will not deviate, making the mesh wiring layer 20 difficult to see with the naked eye.

[0241] Furthermore, according to this embodiment, as described above, the intersection points A can be irregularly arranged, thus the directions of the first wiring 21 extending between intersection points A and the second wiring 22 extending between intersection points A are irregular. This allows, for example, a longer length for the first wiring 21 and the second wiring 22 compared to the case where the first wiring 21 extends in a straight line when viewed from above. Therefore, the adhesion between the first wiring 21 and the second wiring 22 of the mesh wiring layer 20 and the substrate 11 can be improved. In this case, when a protective layer (not shown) protecting the mesh wiring layer 20 is provided on the mesh wiring layer 20, the adhesion between the mesh wiring layer 20 and the protective layer can be improved. Therefore, even in cases where the wiring substrate 10 is bent, the peeling of the first wiring 21 and the second wiring 22 from the substrate 11 can be suppressed. Furthermore, it can also suppress wire breakage in the first wiring 21 and the second wiring 22.

[0242] Furthermore, according to this embodiment, the wiring board 10 includes a substrate 11 and a mesh wiring layer 20 disposed on the substrate 11. The substrate 11 is transparent. Furthermore, the mesh wiring layer 20 has a mesh pattern formed by conductor portions that are formed as opaque conductive layers and a plurality of openings 23. Therefore, the transparency of the wiring board 10 is ensured. Thus, when the wiring board 10 is disposed on the display device 61, the display device 61 can be viewed through the openings 23 of the mesh wiring layer 20 without obstructing the visibility of the display device 61.

[0243] Next, we will explain a variation of the wiring board.

[0244] Figures 25 and 26 show a first variation of the wiring board. The difference between the variation shown in Figures 25 and 26 is that a dummy wiring layer 30 is provided around the mesh wiring layer 20; the other configurations are largely the same as those shown in Figures 21 to 24 above. In Figures 25 and 26, the parts that are the same as those shown in Figures 21 to 24 are labeled with the same symbols, and detailed descriptions are omitted.

[0245] In the wiring board 10 shown in FIG25, a dummy wiring layer 30 is provided around the mesh wiring layer 20. The dummy wiring layer 30 is different from the mesh wiring layer 20 and does not actually function as an antenna.

[0246] As shown in FIG26, the dummy wiring layer 30 is composed of repeating dummy wirings 30a with a prescribed pattern shape. That is, the dummy wiring layer 30 includes a plurality of dummy wirings 30a, each of which is electrically independent from the mesh wiring layer 20 (i.e., the first wiring 21 and the second wiring 22). Furthermore, the plurality of dummy wirings 30a are regularly arranged throughout the entire area of ​​the dummy wiring layer 30. The plurality of dummy wirings 30a are spaced apart from each other in the planar direction and are prominently arranged on 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 an inverted V-shape when viewed from above.

[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 is missing. This makes it difficult to visually distinguish the difference between the mesh wiring layer 20 and the dummy wiring layer 30, thereby making it difficult to see the mesh wiring layer 20 disposed on the substrate 11. As shown in FIG26, 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. By extending the dummy wiring 30a parallel to the first wiring 21 or the second wiring 22, it is even more difficult to see the mesh wiring layer 20 disposed on the substrate 11. The aperture ratio of the dummy wiring layer 30 may be the same as or different from that of the mesh wiring layer 20, but it is preferable to have an aperture ratio close to that of the mesh wiring layer 20. Here, "parallel to the first wiring" means that the angle θ1 formed by the first part 31a and the first regression line 21x is 5° or less. Similarly, "parallel to the second wiring" means that the angle θ2 formed by the second part 32a and the second regression line 22x is 5° or less.

[0248] By providing a dummy wiring layer 30, electrically independent of the mesh wiring layer 20, around the mesh wiring layer 20 as in this variation, the outer edge of the mesh wiring layer 20 can be made unclear. This makes the mesh wiring layer 20 less visible on the surface of the image display device 60, thus making it difficult for users of the image display device 60 to visually identify the mesh wiring layer 20.

[0249] Figure 27 shows a second variation of the wiring board. The difference in the variation shown in Figure 27 is that two or more dummy wiring layers 30A and 30B with different aperture ratios are provided around the mesh wiring layer 20. The other configurations are generally the same as those shown in Figures 21 to 26 above. In Figure 27, the parts that are the same as those shown in Figures 21 to 26 are marked with the same symbols, and detailed descriptions are omitted.

[0250] In this variation, similar to the example shown in FIG15, a plurality of dummy wiring layers 30A and 30B (i.e., the first dummy wiring layer 30A and the second dummy wiring layer 30B) with different aperture ratios are provided around the mesh wiring layer 20 in the wiring substrate 10. Specifically, the first dummy wiring layer 30A is arranged around the mesh wiring layer 20, and the second dummy wiring layer 30B is arranged around the first dummy wiring layer 30A. These dummy wiring layers 30A and 30B are different from the mesh wiring layer 20 and do not actually function as antennas.

[0251] As shown in Figure 27, the first dummy wiring layer 30A is composed of repeating dummy wirings 30a1 with a prescribed pattern shape. The second dummy wiring layer 30B is composed of repeating dummy wirings 30a2 with a prescribed pattern shape. That is, dummy wiring layers 30A and 30B each contain a plurality of dummy wirings 30a1 and 30a2, each dummy wiring 30a1 and 30a2 being electrically independent from the mesh wiring layer 20. Furthermore, the dummy wirings 30a1 and 30a2 are regularly arranged throughout the entire area of ​​the dummy wiring layers 30A and 30B, respectively. Each dummy wiring 30a1 and 30a2 is spaced apart from each other in the planar direction and protrudes onto the substrate 11. Each dummy wiring 30a1 and 30a2 is electrically independent from the mesh wiring layer 20, the power supply section 40, and other dummy wirings 30a1 and 30a2. The shape of each dummy wiring 30a1 and 30a2 is roughly an inverted V-shape when viewed from above.

[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 is missing. This makes it difficult to visually distinguish the differences between the mesh wiring layer 20 and the first dummy wiring layer 30A, and the differences between the first dummy wiring layer 30A and the second dummy wiring layer 30B, thereby making it difficult to see the mesh wiring layer 20 disposed on the substrate 11. As shown in FIG27, 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] Furthermore, 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 linewidth of each dummy wiring 30a1 is the same as the linewidth of each dummy wiring 30a2, but it is not limited to this; the linewidth of each dummy wiring 30a1 may also be wider than the linewidth of each dummy wiring 30a2. Furthermore, the other configurations of the dummy wirings 30a1 and 30a2 are the same as the configuration of the dummy wiring 30a in the first variation example, therefore, detailed descriptions are omitted here.

[0254] In this variation, the aperture ratio of the mesh wiring layer 20 and the two or more dummy wiring layers 30A and 30B preferably increases progressively from the mesh wiring layer 20 toward the dummy wiring layers 30A and 30B that are farther away from the mesh wiring layer 20. In other words, the aperture ratio of each dummy wiring layer preferably increases gradually from the one closer to the mesh wiring layer 20 toward the one farther away from the mesh wiring layer 20. In this case, the aperture ratio of the first dummy wiring layer 30A is preferably greater than the aperture ratio of the mesh wiring layer 20. The aperture ratio of the second dummy wiring layer 30B is preferably greater than the aperture ratio of the first dummy wiring layer 30A. This makes the outer edges of the mesh wiring layer 20 and the dummy wiring layers 30A and 30B less clear. Therefore, it makes the mesh wiring layer 20 less visible on the surface of the image display device 60.

[0255] By configuring dummy wiring layers 30A and 30B, which are electrically independent of the mesh wiring layer 20, the outer edge of the mesh wiring layer 20 becomes less distinct. This makes the mesh wiring layer 20 less visible on the surface of the image display device 60, thus making it difficult for users of the image display device 60 to visually identify the mesh wiring layer 20. Furthermore, three or more dummy wiring layers with different aperture ratios can be provided around the mesh wiring layer 20.

[0256] Figure 28 shows a third variation of the wiring board. The difference in the variation shown in Figure 28 is that the front end portion 20b includes a central portion 20c and a peripheral portion 20d surrounding the central portion 20c. Other configurations are substantially the same as those shown in Figures 21 to 27. In Figure 28, the same symbols are used for the parts that are the same as those shown in Figures 21 to 27, and detailed descriptions are omitted.

[0257] In the wiring board 10 shown in FIG28, the front end portion (i.e., the transceiver portion) 20b includes a central portion 20c and a peripheral portion 20d surrounding the central portion 20c. Here, in the peripheral portion 20d, the aforementioned distance dX (see FIG22) is smaller than the distance dX at the central portion 20c. Also, in the peripheral portion 20d, the aforementioned distance dY (see FIG22) is smaller than the distance dY at the central portion 20c. This reduces the sheet resistance value at the peripheral portion 20d. Therefore, the radiation efficiency of the mesh wiring layer 20, which serves as an antenna, can be effectively improved. That is, the peripheral portion 20d is located closer to the base end portion 20a than the central portion 20c, therefore, the current density at the peripheral portion 20d is higher than the current density at the central portion 20c. Therefore, by reducing the resistance value of the thin film at the peripheral portion 20d where the current density increases, the radiation efficiency of the mesh wiring layer 20, which serves as an antenna, can be effectively improved.

[0258] In this variation, the distance dX at the peripheral portion 20d is preferably 20% to 80% of the distance dX at the central portion 20c. Also, the distance dY at the peripheral portion 20d is preferably 20% to 80% of the distance dY at the central portion 20c. By ensuring that the distances dX and dY at the peripheral portion 20d are 20% or more of the distances dX and dY at the central portion 20c, the intersection point A can be irregularly arranged. Therefore, the distance between the ripples caused by the regularity (periodicity) of the mesh wiring layer 20 and the regularity (periodicity) of the pixel P can be reduced to a level that is imperceptible to the naked eye. Furthermore, the boundary between the central portion 20c and the peripheral portion 20d can be made less distinct. By ensuring that the distances dX and dY at the periphery 20d are less than 80% of the distances dX and dY at the central part 20c, the sheet resistance at the periphery 20d can be effectively reduced.

[0259] In the illustrated example, in the central portion 20c, only the area on the base-end side 20a side is surrounded by the peripheral portion 20d. In this case, it is also possible that more than 50% of the area on the base-end side 20a side of the central portion 20c is surrounded by the peripheral portion 20d in the longitudinal direction (i.e., the Y direction) of the mesh wiring layer 20. This can effectively improve the radiation efficiency of the mesh wiring layer 20 as an antenna. Furthermore, it is also possible that the entire circumference of the central portion 20c is surrounded by the peripheral portion 20d.

[0260] The width W3 of the peripheral portion 20d is preferably more than twice the average value DX of the distances P1X (see Figure 22) between the intersection points B in the central portion 20c. This expands the area where the sheet resistance can be reduced. Therefore, the sheet resistance in areas with high current density can be effectively reduced. Furthermore, the width W3 of the peripheral portion 20d refers to the distance in the X direction for the portion extending along the Y direction in the peripheral portion 20d, and the distance in the Y direction for the portion extending along the X direction in the peripheral portion 20d.

[0261] By making the distances dX and dY in the peripheral portion 20d smaller than those in the central portion 20c, as in this variation, the sheet resistance value in the peripheral portion 20d can be reduced. This effectively improves the radiation efficiency of the mesh wiring layer 20, which serves as an antenna.

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

[0263] (Example B1) A wiring substrate 10 having the configuration shown in FIG21 was fabricated. That is, a wiring substrate 10 in which the first wiring 21 and the second wiring 22 are irregularly arranged relative to each other was fabricated. In this case, a polyethylene terephthalate substrate with a thickness of 100 μm was used as the substrate of the wiring substrate 10. Furthermore, copper wiring with 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 La of the front end portion 20b of the mesh wiring layer 20 is 3.5 mm and the width Wa is 4.2 mm.

[0264] In the wiring substrate 10 of Embodiment B1, the average distance DX between 10 consecutively adjacent intersection points B in the width direction (i.e., the X direction) of the mesh wiring layer 20 is 70 μm. Furthermore, the average distance DY between 10 consecutively adjacent intersection points B in the length direction (i.e., the Y direction) of the mesh wiring layer 20 is 130 μm.

[0265] When the distance from intersection point A to the nearest intersection point B along the width direction of the mesh wiring layer 20 is set as dX, at 9 or more of the 10 intersection points A that are closest to each of the 10 intersection points B (hereinafter, simply referred to as "9 or more intersection points A"), the relationship 0.02DX≦dX≦0.1DX is satisfied.

[0266] Furthermore, when the distance from intersection point A to the nearest intersection point B along the length direction of the mesh wiring layer 20 is set as dY, at more than 9 intersection points A, the relationship 0.02DY≦dY≦0.1DY is satisfied.

[0267] In the wiring board 10 of Example B1, the difference in aperture ratio of the 1000 μm square regions that are continuous with each other is less than 0.5%.

[0268] Next, the visibility of the wiring board 10 is checked. First, the presence or absence of water ripples is checked. First, the wiring board 10 is superimposed on the display device 61 shown in FIG. 3 for observation. In the display device 61, the distance between pixels PX is 60 μm, and the distance between pixels PY is 60 μm. Furthermore, with the display device 61 emitting white light, the wiring board 10 is visually observed from a distance of 300 mm to check for the presence or absence of water ripples.

[0269] Next, the presence or absence of flicker is checked. First, a black panel is placed on the back side (i.e., the negative side in the Z direction) of the wiring board 10. Then, a high-brightness lamp is used to illuminate the front side (i.e., the positive side in the Z direction) of the wiring board 10. The light is then illuminated in a direction inclined relative to the normal direction of the first surface 11a of the substrate 11. Next, the wiring board 10 is visually observed from a distance of 300 mm to check for flicker.

[0270] Next, the sheet resistance value (Ω / □) of the mesh wiring layer 20 in the wiring board 10 is measured. At this time, firstly, the resistance value R between the two ends 20e1 and 20e2 (see Figure 8) in the length direction (Y direction) of the mesh wiring layer 20 is measured. A digital multimeter (CUSTOM Corporation, CDM-2000D) is used as the measuring instrument. Then, the sheet resistance value Rs (Ω / □) of the mesh wiring layer 20 is obtained by dividing the resistance value R by the ratio of the length La to the width Wa of the mesh wiring layer 20 (La / Wa).

[0271] (Example B2) Except that the average value DX is 130 μm and the average value DY is 270 μm, the visibility of the wiring board 10 was confirmed in the same manner as in Example B1, and the sheet resistance value of the mesh wiring layer 20 was measured.

[0272] (Example B3) At 9 or more intersection points A, the relationship 0.02DX≦dX≦0.05DX is satisfied, and at 9 or more intersection points A, the relationship 0.02DY≦dY≦0.05DY is satisfied. Otherwise, the visibility of the wiring board 10 is confirmed in the same manner as in Example B1, and the sheet resistance value of the mesh wiring layer 20 is measured.

[0273] (Example B4) At 9 or more intersection points A, the relationship 0.25DX≦dX≦0.29DX is satisfied, and at 9 or more intersection points A, the relationship 0.25DY≦dY≦0.29DY is satisfied. Otherwise, the visibility of the wiring board 10 is confirmed in the same manner as in Example B1, and the sheet resistance value of the mesh wiring layer 20 is measured.

[0274] (Comparative Example B1) At more than 9 intersection points A, dX = 0, at more than 9 intersection points A, dY = 0, the average value DX is 100 μm, and the average value DY is 100 μm. Otherwise, in the same manner as in Example B1, the visibility of the wiring board 10 is confirmed, and the sheet resistance value of the mesh wiring layer 20 is measured.

[0275] (Comparative Example B2) At 9 or more intersection points A, the relationship 0.00DX≦dX≦0.02DX is satisfied, and at 9 or more intersection points A, the relationship 0.00DY≦dY≦0.02DY is satisfied. Otherwise, the visibility of the wiring board 10 is confirmed in the same manner as in Example B1, and the sheet resistance value of the mesh wiring layer 20 is measured.

[0276] (Comparative Example B3) At more than 9 intersection points A, the relationship 0.30DX≦dX is satisfied, and at more than 9 intersection points A, the relationship 0.30DY≦dY is satisfied. Otherwise, in the same manner as in Example B1, the visibility of the wiring board 10 is confirmed, and the sheet resistance value of the mesh wiring layer 20 is measured.

[0277] (Comparative Example B4) A wiring substrate 100 having the configuration shown in FIG20 was fabricated. That is, a wiring substrate 100 having a planar structure of the wiring 200 forming the mesh wiring layer 20 with a Voronoi pattern was fabricated. In this case, a polyethylene terephthalate substrate with a thickness of 100 μm was used as the substrate of the wiring substrate 100. Furthermore, copper wiring with 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 La of the front end side portion 20b of the mesh wiring layer 20 was 3.5 mm and the width Wa was 4.2 mm.

[0278] In the wiring substrate 100 of Comparative Example B4, the average value of the edge distance is 100 μm. At this time, the edge distance is measured on an imaginary line extending along the length direction (X direction) of the front end side portion 20b of the mesh wiring layer 20 (see Figure 4) and drawn to an arbitrarily selected position.

[0279] In the wiring board 100 of Comparative Example B4, the difference in aperture ratio of consecutive 1000 μm square regions is less than 0.5%.

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

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

[0282] [Table 2] Planar shape (construction) Average D X (μm) Average D Y (μm) Example B1 quadrilateral 70 130 Example B2 quadrilateral 130 270 Example B3 quadrilateral 70 130 Example B4 quadrilateral 70 130 Comparative Example B1 quadrilateral 100 100 Comparative Example B2 quadrilateral 70 130 Comparative Example B3 quadrilateral 70 130 Comparative Example B4 Voronoi pattern 100 (distance between sides) 100 (distance between sides)

[0283] [Table 3] Regarding the intersection point A of more than 9 points, "d" X " and "D X The relationship between Regarding the intersection point A of more than 9 points, "d" Y " and "D Y The relationship between Example B1 0.02D X ≦d X ≤0.1D X 0.02D Y ≦d Y ≤0.1D Y Example B2 0.02D X ≦d X ≤0.1D X 0.02D Y ≦d Y ≤0.1DY Example B3 0.02D X ≦d X ≤0.05D X 0.02D Y ≦d Y ≤0.05D Y Example B4 0.25D X ≦d X ≤0.29D X 0.25D Y ≦d Y ≤0.29D Y Comparative Example B1 d X =0 d Y =0 Comparative Example B2 0.00D X ≦d X ≤0.02D X 0.00D Y ≦d Y ≤0.02D Y Comparative Example B3 0.30D X ≦d X 0.30D≦d Y Comparative Example B4 - -

[0284] [Table 4] water ripples blinking Slot ratio Thin film resistance value Example B1 A A A A Example B2 A A A A Example B3 A A A A Example B4 A A A A Comparative Example B1 B A A A Comparative Example B2 B A A A Comparative Example B3 A B A C Comparative Example B4 A B A B

[0285] In Table 4, "A" indicates an excellent result, "B" indicates a good result, and "C" indicates a poor result. Specifically, in the "Ripple" column of Table 4, "A" indicates that ripples could not be detected, and "B" indicates that ripples were present. In the "Flicker" column of Table 4, "A" indicates that flickering caused by reflected light could not be detected, and "B" indicates that flickering was caused by reflected light. In the "Aperture Ratio" column of Table 4, "A" indicates that the difference in aperture ratio is less than 0.5%. In the "Sheet Resistance Value" column of Table 4, "A" indicates that the sheet resistance value is below the specified value, "B" indicates that the sheet resistance value is greater than the specified value, and "C" indicates that the sheet resistance value is significantly greater than the specified value.

[0286] As a result, as shown in Table 4, water ripples were generated in the wiring substrate 100 of Comparative Examples B1 and B2. In contrast, water ripples were not observed in the wiring substrate 10 of Examples B1 to B4.

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

[0288] Thus, it can be seen that in the wiring board 10 of this embodiment, the generation of water ripples can be suppressed, and the flickering caused by reflected light can be suppressed.

[0289] As shown in Table 4, the wiring board 10 of Examples B1 to B4, like the wiring board 100 of Comparative Example B1, can reduce the unevenness of the aperture ratio. That is, even when the first wiring 21 and the like are irregularly arranged, the unevenness of the aperture ratio can be reduced in the same way as when the wiring board 100 is regularly arranged.

[0290] As shown in Table 4, the wiring substrates 10 of Examples B1 to B4, like the wiring substrate 100 of Comparative Example B1, can achieve a sheet resistance value of the mesh wiring layer 20 below a predetermined value. In this case, the sheet resistance value of the mesh wiring layer 20 of the wiring substrates 10 of Examples B1 to B4 is the same as that of the mesh wiring layer 20 of the wiring substrate 100 of Comparative Example B1. That is, in the wiring substrates 10 of Examples B1 to B4, although the first wiring 21 and the like are irregularly arranged, the length of the first wiring 21 and the like does not change compared to the case where the first wiring 21 and the like are regularly arranged. Therefore, even when the first wiring 21 is irregularly arranged, the sheet resistance value of the mesh wiring layer 20 can be made the same as that of the mesh wiring layer 20 of the wiring substrate 100 with the first wiring 21 regularly arranged. Thus, the wiring substrate 10 of Embodiments B1 to B4, like the wiring substrate 100 with the first wiring 21 regularly arranged, can improve the radiation efficiency of the mesh wiring layer 20 as an antenna.

[0291] (Third Embodiment) Next, the third embodiment will be described using Figures 29 to 34. Figures 29 to 34 are diagrams illustrating this embodiment. In Figures 29 to 34, parts that are the same as those in the first embodiment shown in Figures 1 to 20 or the second embodiment shown in Figures 21 to 28 are labeled with the same symbols and detailed descriptions are omitted.

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

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

[0294] As shown in FIG29, the wiring board 10 of this embodiment is disposed, for example, on the display device 91 of the image display device 90 described below. This wiring board 10 includes a transparent substrate 11 and a mesh wiring layer 20 disposed on the substrate 11. Furthermore, a power supply section 40 is electrically connected to the mesh wiring layer 20.

[0295] In this embodiment, the mesh wiring layer 20 includes an antenna pattern area that functions as an antenna. In FIG29, a plurality of mesh wiring layers 20 (3 in total) are formed on the substrate 11, each corresponding to a different frequency band. That is, the length (length in the Y direction) La1 of the plurality of mesh wiring layers 20 is different from each other, each having a length corresponding to a specific frequency band. Furthermore, the lower the frequency of the corresponding frequency band, the longer the length La1 of the mesh wiring layer 20. When the wiring substrate 10 is disposed, for example, on the display device 91 of the image display device 90 (see FIG34 below), each mesh wiring layer 20 may correspond to any of the following: telephone antenna, WiFi antenna, 3G antenna, 4G antenna, 5G antenna, millimeter wave antenna, LTE antenna, Bluetooth antenna, NFC antenna, etc. When the wiring board 10 does not have radio wave transceiver function, each mesh wiring layer 20 can also perform functions such as hovering (the function that allows operation even if the user does not directly touch the display), fingerprint authentication, heater, and noise cancellation (shielding). Furthermore, the mesh wiring layer 20 may not exist on the entire surface of the substrate 11, but only in a portion of the substrate 11.

[0296] Each mesh wiring layer 20 is generally rectangular when viewed from above. The length direction of each mesh wiring layer 20 is parallel to the Y direction, and its short side direction is parallel to the X direction. The length La1 of each mesh wiring layer 20 in the length direction (Y direction) can be selected, for example, within the range of 2 mm to 100 mm. The width Wa1 of each mesh wiring layer 20 in the short side direction (X direction) can be selected, for example, within the range of 1 mm to 10 mm. In particular, the mesh wiring layer 20 can also be a millimeter-wave antenna. When the mesh wiring layer 20 is a millimeter-wave antenna, the length La1 of the mesh wiring layer 20 can be selected within the range of 1 mm to 10 mm, and more preferably 1.5 mm to 5 mm. Furthermore, Figure 29 shows the shape of the mesh wiring layer 20 when it functions as a monopole antenna, but it is not limited to this. It can also be configured as a dipole antenna, loop antenna, slot antenna, microstrip antenna, patch antenna, etc.

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

[0298] As shown in Figure 30, each mesh wiring layer 20 includes a plurality of intersections 240 and a plurality of wirings 210. Wirings 210 are located between intersections 240. Wirings 210 connect a pair of intersections 240 to each other. Intersections 240 are respectively located at both ends of the length direction of each wiring 210. The plurality of intersections 240 and the plurality of wirings 210 are integrally formed, creating an irregular grid shape or an irregular mesh shape. Each wiring 210 extends in an irregular direction without a fixed regularity. Alternatively, three to five wirings 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 also be surrounded by 3 to 10 wirings 210. In this case, the arrangement pattern of the openings 23 becomes a random pattern. There is no direction in this random pattern that is arranged with a fixed regularity of repetition. Furthermore, the plurality of intersections 240 are arranged in an irregular pattern without a fixed regularity. The distance between each intersection 240 and P 11 is not uniform within the mesh wiring layer 20, and various distances are used. For example, the distance between each intersection 240 and P 11 can be set to various distances within the range of 0.01 mm to 1 mm. The transparent substrate 11 is exposed from each opening 23.

[0300] In the mesh wiring layer 20, there is no opening 23 with a repeating periodic direction. By eliminating the direction in which the openings 23 of the mesh wiring layer 20 are arranged in a fixed, regular repeating period, the water ripples that may occur when the wiring substrate 10 overlaps with the display device 91 of, for example, the image display device 90, are less noticeable. Furthermore, to more effectively suppress water ripples, it is preferable that there is no opening 23 with a repeating periodic direction covering the entire area of ​​the mesh wiring layer 20.

[0301] In Figure 30, the non-periodic planar structure constituting the mesh wiring layer 20 can be a Voronoi pattern. Here, a Voronoi pattern (Voronoi diagram) refers to a pattern formed by dividing the points in a plane according to the nearest point when a plurality of arbitrary points (mother points) are arranged on the plane. Furthermore, as will be explained below, strictly speaking, the wirings 210 do not connect the intersection points 240 to each other in a straight line. However, in this specification, the assumption that the wirings 210 connect the intersection points 240 to each other in a straight line to form a Voronoi pattern is referred to as "non-periodic planar structure as Voronoi pattern".

[0302] Figure 31(a) is an enlarged view of a wiring 210 connecting a pair of intersection points 240. As shown in Figure 31(a), the wiring 210 does not connect the pair of intersection points 240 in a straight line (with the shortest distance). When the ratio of the length of the wiring 210 between the intersection points 240 to the shortest distance Lmin between the intersection points 240 is calculated for each of the plurality of wirings 210 surrounding each opening 23, the average value is more than 1.01 times and less than 1.82 times. This average value is preferably more than 1.05 times and less than 1.30 times. Here, the length of the wiring 210 refers to the length obtained by measuring the line connecting the center of the wiring 210 in the width direction along the length direction of the wiring 210. The planar shape of the wiring 210 may be a wavy curve. That is, the wiring 210 crosses at least one point between the intersection points 240 relative to the line segment L s that connects a pair of intersection points 240. Preferably, it crosses at more than two points but less than ten points. Furthermore, the wiring 210 preferably does not cross with other wirings 210.

[0303] For example, suppose an opening 23 is surrounded by N wirings 210. Here, N can be set to 3 or more but less than 10 as described above. In this case, for each of the N wirings 210, the ratio (Lc / Lmin) of the length Lc of the wirings 210 between the intersection points 240 to the shortest distance Lmin between the intersection points 240 is calculated. The average value of the ratios (M1, M2, ..., MN) of the N wirings calculated in this way ((M1 + M2 + ... + MN) / N) is more than 1.01 times and less than 1.82 times. Furthermore, for each of the N wirings 210 surrounding an opening 23, the above ratio (Lc / Lmin) is preferably more than 1.01 times and less than 1.82 times. However, even if the ratio (Lc / Lmin) of a portion of the N wirings 210 is not between 1.01 and 1.82, it is acceptable as long as the average ratio of the N wirings is between 1.01 and 1.82. Furthermore, it is preferable that the average ratio of all openings 23 included in the mesh wiring layer 20 is between 1.01 and 1.82. However, this is not a limitation; the average ratio for a portion of the openings 23 included in the mesh wiring layer 20 may also not be between 1.01 and 1.82. Specifically, it is preferable that the average ratio is between 1.01 and 1.82 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] In Figure 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 can be more than 0.02 times and less than 0.06 times the shortest distance Lmin between the intersection points 240, preferably more than 0.03 times and less than 0.05 times. The wavelength λ1 of the sine curve constituting the wiring 210 can be more than 0.16 times and less than 0.5 times the shortest distance Lmin between the intersection points 240, preferably more than 0.2 times and less than 0.33 times. Furthermore, the value of the shortest distance Lmin / wavelength λ1 can be set to be uniform among the plurality of wirings 210 within the mesh wiring layer 20. The value of the shortest distance Lmin / wavelength λ1 can be set to a natural number of more than 2 and less than 10. Furthermore, in Figure 31(a), the value of the shortest distance Lmin / wavelength λ1 is 3. Furthermore, the amplitude A1 of the wiring 210 can be set to be uniform among the plurality of wirings 210 within the mesh wiring layer 20. Alternatively, both the amplitude A1 and the wavelength λ1 of the wiring 210 can be set to be uniform among the plurality of wirings 210 within the mesh wiring layer 20.

[0305] As shown in Figure 31(b), the planar shape of wiring 210 can be a wavy curve with variable amplitude and wavelength. Alternatively, it can be a wavy curve where one of the amplitude and wavelength is fixed and the other is variable. Also, as shown in Figure 31(c), the planar shape of wiring 210 can be a jagged or irregular line without a curved portion. Alternatively, although not shown, the planar shape of wiring 210 can be a Bézier curve or a curve formed by splicing together multiple arcs.

[0306] Thus, when calculating the ratio of the length of the wiring 210 between the intersection points 240 to the shortest distance Lmin between the intersection points 240 for each of the plurality of wirings 210 surrounding each opening 23, the average value is more than 1.01 times and less than 1.82 times. In this way, flickering when the mesh wiring layer 20 reflects light can be suppressed.

[0307] As shown in Figure 32, the cross-section of each wiring 210 perpendicular to its length direction is approximately rectangular or approximately square. In this case, the cross-sectional shape of the wiring 210 is approximately uniform along the length direction of the wiring 210. The cross-sectional shape of the wiring 210 may be the same among the plurality of wirings 210 included in the mesh wiring layer 20. The cross-sectional shape of the wiring 210 does not necessarily have to be approximately rectangular or approximately square; for example, it may be approximately trapezoidal with the front side (positive side in the Z direction) narrower than the back side (negative side in the Z direction), or a shape with curved sides on both sides in the width direction.

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

[0309] The material of wiring 210 can be any conductive metallic material. In this embodiment, the material of wiring 210 is copper, but it is not limited to this. For example, the material of wiring 210 can be gold, silver, copper, platinum, tin, aluminum, iron, nickel, and other metallic materials (including alloys of the above-mentioned metallic materials). Furthermore, wiring 210 can be a plating layer formed by electrolytic plating.

[0310] Referring again to FIG29, the power supply section 40 is electrically connected to the mesh wiring layer 20. This power supply section 40 is electrically connected to the wireless communication circuit 92 of the image display device 90 when the wiring substrate 10 is assembled into the image display device 90 (see FIG34). Furthermore, the power supply section 40 is disposed on the surface of the substrate 11, but is not limited thereto; a portion or all of the power supply section 40 may be located further outward than the periphery of the substrate 11. Also, the power supply section 40 may be flexibly formed so that it can wrap around to the side or back of the image display device 90 and be electrically connected to the side or back.

[0311] [Manufacturing Method of Wiring Board] Next, the manufacturing method of the wiring board according to this embodiment will be described with reference to FIG33(a)-(f). FIG33(a)-(f) are cross-sectional views showing the manufacturing method of the wiring board according to this embodiment.

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

[0313] Subsequently, 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] At this point, firstly, as shown in FIG33(b), a metal foil 51 is deposited over approximately the entire surface area of ​​the substrate 11. In this embodiment, the thickness of the metal foil 51 may be 0.1 μm or more and 5.0 μm or less. In this embodiment, the metal foil 51 may contain copper.

[0315] Next, as shown in FIG33(c), a photocurable insulating resist 52 is supplied to approximately the entire surface area of ​​the metal foil 51. Examples of the photocurable insulating resist 52 include organic resins such as acrylic resins and epoxy resins.

[0316] Next, as shown in FIG33(d), an insulating layer 54 is formed by photolithography. In this case, the photocurable insulating resist 52 is patterned by photolithography to form an insulating layer 54 (resist pattern). At this time, the insulating layer 54 is formed in such a way that the metal foil 51 of the corresponding wiring 210 is exposed.

[0317] Next, as shown in FIG33(e), the metal foil 51 on the surface of the substrate 11 that is not covered by the insulating layer 54 is removed. At this time, the metal foil 51 is etched to expose the surface of the substrate 11 by performing a wet treatment using strong acids such as ferric chloride, copper chloride, sulfuric acid, hydrochloric acid, persulfate, hydrogen peroxide or aqueous solutions thereof, or combinations thereof.

[0318] Next, as shown in FIG33(f), the insulating layer 54 is removed. In this case, the insulating layer 54 on the metal foil 51 is removed by performing a wet treatment using a permanganate solution or N-methyl-2-pyrrolidone, an acid or alkaline solution, or a dry treatment using oxygen plasma.

[0319] In this manner, a wiring substrate 10 having a substrate 11 and a mesh wiring layer 20 disposed on the substrate 11 can be obtained. In this case, the mesh wiring layer 20 has a non-periodic planar structure. Furthermore, the mesh wiring layer 20 includes a plurality of wirings 210. At this time, a power supply section 40 can also be formed by a portion of the conductor 55. Alternatively, a flat plate-shaped power supply section 40 can be separately prepared and electrically connected to the mesh wiring layer 20.

[0320] [Function of this embodiment] Next, the function of the wiring board including this configuration will be described.

[0321] As shown in FIG34, 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 EL (Electro Luminescence) display device. The display device 91 may include, for example, a metal layer (not shown), a support substrate, a resin substrate, a thin-film transistor (TFT), and an organic EL layer. A touch sensor (not shown) may be disposed on the display device 91. Furthermore, the display device 91 is not limited to an organic EL display device. For example, the display device 91 may also be other display devices that have their own light-emitting function. The display device 91 may also be a micro-LED display device that includes micro-LED elements (light emitters). In addition, the display device 91 may also be a liquid crystal display device that includes liquid crystal. The wiring substrate 10 is disposed directly or indirectly on the display device 91. Examples of such image display devices 90 include smartphones, tablets, and other mobile terminal devices. The mesh wiring layer 20 of the wiring board 10 is electrically connected to the wireless communication circuit 92 of the image display device 90 via the power supply section 40. In this way, radio waves of a specified frequency can be transmitted and received via the mesh wiring layer 20, thereby enabling communication using the image display device 90. In this embodiment, an image display device 90 is also provided, which includes a display device 91 and a wiring board 10 disposed on the display device 91.

[0322] Furthermore, in this image display device 90, the mesh wiring layer 20 of the wiring board 10 is arranged to overlap with the pixels (not shown) of the display device 91 of the image display device 90 in the Z direction. In this case, if the wiring 210 of the mesh wiring layer 20 is regular (periodic), there is a risk that the regularity (periodicity) of the wiring 210 and the regularity (periodicity) of the pixels of the display device 91 may produce striped patterns (water ripples, interference stripes).

[0323] In contrast, in this embodiment, the mesh wiring layer 20 has a non-periodic planar structure. Therefore, when viewed from the Z direction, the wiring 210 of the mesh wiring layer 20 and the pixels of the display device 91 are irregularly arranged. Thus, water ripples caused by the regularity (periodicity) of the wiring 210 and the regularity (periodicity) of the pixels can be suppressed.

[0324] In particular, in this embodiment, the non-periodic planar structure constituting the mesh wiring layer 20 can be configured as a Voronoi pattern. This can more effectively suppress the generation of water ripples when the wiring substrate 10 is superimposed on the display device 91 in which pixels are arranged regularly (periodically).

[0325] On the other hand, since the mesh wiring layer 20 has a non-periodic planar structure, the wiring 210 is oriented in various directions. In this case, there is a risk that a phenomenon called flicker may occur due to the reflection of light irradiating the wiring substrate 10. It is believed that this flicker occurs because when a plurality of straight wirings 210 with a fixed or greater length are arranged, the direction of light reflected from the wiring 210 is oriented in several directions.

[0326] In contrast, in this embodiment, the wiring 210 does not connect the intersections 240 of the mesh wiring layer 20 in a straight line. That is, when calculating the ratio of the length of the wiring 210 between intersections 240 to the shortest distance Lmin between intersections 240 for each of the plurality of wirings 210 surrounding each opening 23, the average value is more than 1.01 times and less than 1.82 times. By making the length of the wiring 210 between intersections 240 longer than the shortest distance Lmin, the reflection direction is dispersed more finely. This reduces the aforementioned flicker.

[0327] In particular, in this embodiment, the planar shape of the wiring 210 can be a sine curve. In this case, the direction of light reflection by the wiring 210 can be further dispersed, which can further reduce flicker.

[0328] As explained above, according to this embodiment, the mesh wiring layer 20 has a non-periodic planar structure. Furthermore, when calculating the ratio of the length of the wiring 210 between intersection points 240 to the shortest distance Lmin between intersection points 240 for each of the plurality of wirings 210 surrounding each opening 23, the average value is more than 1.01 times and less than 1.82 times. This allows for the acquisition of a wiring substrate 10 that suppresses both the generation of water ripples and the generation of flickering.

[0329] Furthermore, in this embodiment, the linewidth of the wiring 210 can be 0.1 μm or more and 5.0 μm or less. This makes it difficult for the wiring 210 to be seen with the naked eye, thereby suppressing the reduction of visibility of the display device 91.

[0330] Furthermore, in this embodiment, the mesh wiring layer 20 may function as an antenna. In this case, the mesh wiring layer 20 serving as an antenna can be disposed on the front side of the image display device 90. Therefore, compared to the case where the antenna is built into the image display device 90, communication performance can be improved. Moreover, since a plurality of mesh wiring layers 20 serving as antennas can be disposed within the surface of the image display device 90, communication performance can be further improved.

[0331] Furthermore, in this embodiment, the example described is that the mesh wiring layer 20 functions as an antenna, but it is not limited to this. For example, the mesh wiring layer 20 can also perform functions such as hovering (the function that allows operation even if the user does not directly touch the display), fingerprint authentication, heating, and noise cancellation (shielding).

[0332] [Variation Example] Next, a variation example of the wiring board will be explained.

[0333] (First Variation) Figure 35 shows a first variation of the wiring board. The variation shown in Figure 35 differs in the non-periodic planar structure constituting the mesh wiring layer 20; other configurations are largely the same as those shown in Figures 29 to 34 above. In Figure 35, the same symbols are used for the parts with the same shape as those shown in Figures 29 to 34, and detailed descriptions are omitted.

[0334] In the wiring substrate 10 shown in FIG35, the mesh wiring layer 20 has an aperiodic planar structure (random intersection mesh). This aperiodic planar structure is formed by randomly displacing periodically arranged intersections in various directions at distances smaller than a predetermined distance. Furthermore, when calculating the ratio of the length of the wiring 210 between intersections 240 to the shortest distance Lmin between intersections 240 for each of the plurality of (4) wirings 210 surrounding each opening 23, the average value is more than 1.01 times and less than 1.82 times.

[0335] The pattern of the mesh wiring layer 20 shown in Figure 35 can be obtained in the following manner. First, for example, temporary wiring 210a is arranged in a manner in which a plurality of temporary intersections 24a are periodically arranged along a predetermined direction (e.g., the X direction and the Y direction). Then, each temporary intersection 24a is randomly displaced in various directions at a distance smaller than a predetermined distance (e.g., the shortest distance between adjacent temporary intersections 24a). Furthermore, the distance at which each temporary intersection 24a is displaced is also randomly varied.

[0336] Accordingly, the pattern of the mesh wiring layer 20 shown in FIG35 is created. In FIG35, the mesh wiring layer 20 has a plurality of intersections 240 and wirings 210 located between each intersection 240. When calculating the ratio of the length of the wirings 210 between intersections 240 to the shortest distance Lmin between intersections 240 for each of the plurality of (4) wirings 210 surrounding each opening 23, the average value is more than 1.01 times and less than 1.82 times. Furthermore, in this variation, the planar shape of the wirings 210 is a sine curve, but the planar shape of the wirings 210 can also be various shapes as described above. By arranging the wirings 210 in such an irregular manner with a plurality of intersections 240, the effect of reducing water ripples can be obtained.

[0337] In this variation, the mesh wiring layer 20 has a non-periodic planar structure. Furthermore, when calculating the ratio of the length of the wiring 210 between intersection points 240 to the shortest distance Lmin between intersection points 240 for each of the plurality (4) wirings 210 surrounding each opening 23, the average value is more than 1.01 times and less than 1.82 times. This allows for the acquisition of a wiring substrate 10 that suppresses both the generation of water ripples and the generation of flicker.

[0338] (Second Variation) Figures 36 and 37 show a second variation of the wiring board. The difference between the variation shown in Figures 36 and 37 is that a dummy wiring layer 30 is provided around the mesh wiring layer 20; the other configurations are largely the same as the embodiments shown in Figures 29 to 34 above. In Figures 36 and 37, the same symbols are used for the parts with the same shape as those shown in Figures 29 to 34, and detailed descriptions are omitted.

[0339] In the wiring board 10 shown in FIG36, a dummy wiring layer 30 is provided around the mesh wiring layer 20. The dummy wiring layer 30 is provided around the mesh wiring layer 20 except for the feed section 40 side. Furthermore, the dummy wiring layer 30 may also be provided throughout the entire circumference of the mesh wiring layer 20. This dummy wiring layer 30 differs from the mesh wiring layer 20 and does not actually function as an antenna.

[0340] As shown in Figure 37, the dummy wiring layer 30 has a non-periodic planar structure that is substantially the same as that of the mesh wiring layer 20, but with a shape in which a portion of its planar structure is missing. For example, in Figure 37, the dummy wiring layer 30 has the same Voronoi pattern as the mesh wiring layer 20. The dummy wiring layer 30 has a plurality of intersections 34 and wirings 31 located between each intersection 34. In this case, unlike the wirings 210 of the mesh wiring layer 20, each wiring 31 does not continuously connect the intersections 34, but rather a portion of each wiring 31 is missing. Thus, each wiring 31 is electrically independent from the mesh wiring layer 20, the power supply section 40, and other wirings 31. Furthermore, assuming that the aforementioned missing parts do not exist, when calculating the ratio of the length of the wiring 31 between the intersection points 34 to the shortest distance between the intersection points 34 for each of the plurality of wirings 31 surrounding each opening, the average value is more than 1.01 times and less than 1.82 times. Alternatively, it could be that some of the intersection points 34 are missing.

[0341] By having a partially missing shape that is substantially the same as the mesh wiring layer 20 in its non-periodic planar structure, the difference between the mesh wiring layer 20 and the dummy wiring layer 30 is not easily visually distinguished. This makes it difficult to see the mesh wiring layer 20 disposed on the substrate 11. The aperture ratio of the dummy wiring layer 30 can be greater than that of the mesh wiring layer 20.

[0342] By configuring a dummy wiring layer 30 that is electrically independent of the mesh wiring layer 20, the outer edge of the mesh wiring layer 20 can be made less clear. In this way, the mesh wiring layer 20 can be made less visible on the surface of the image display device 90, and the user of the image display device 90 can hardly identify the mesh wiring layer 20 with the naked eye.

[0343] [Example] Next, specific embodiments of the above embodiments will be described.

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

[0345] (Example C2) Except that the average amplitude of the sinusoidal curve of the wiring is set to 4 μm, the wiring substrate is manufactured in the same manner as in Example C1 (Example C2). When calculating the ratio of the length of the wiring between intersections (line length) to the shortest distance between intersections for each of the plurality of wirings surrounding each opening, the average value is 1.060.

[0346] (Example C3) Except that the average wavelength of the sinusoidal curve of the wiring is set to 25 μm, the wiring substrate is manufactured in the same manner as in Example C1 (Example C3). When calculating the ratio of the length of the wiring between intersections (line length) to the shortest distance between intersections for each of the plurality of wirings surrounding each opening, the average value is 1.060.

[0347] (Example C4) Except that the average amplitude of the sinusoidal curve of the wiring is set to 4 μm and the average wavelength is set to 25 μm, the wiring substrate is manufactured in the same manner as in Example C1 (Example C4). When calculating the ratio of the length of the wiring between intersections (line length) to the shortest distance between intersections for each of the plurality of wirings surrounding each opening, the average value is 1.217.

[0348] (Example C5) Except that the average amplitude of the sinusoidal curve of the wiring is set to 6 μm and the average wavelength is set to 16.7 μm, the wiring substrate is manufactured in the same manner as in Example C1 (Example C5). When calculating the ratio of the length of the wiring between intersections (line length) to the shortest distance between intersections for each of the plurality of wirings surrounding each opening, the average value is 1.811.

[0349] (Example C6) Except that the average value of the shortest distance between the intersections of the mesh wiring layer is set to 200 μm and the average amplitude of the sinusoidal curve of the wiring is set to 4 μm, the wiring substrate is manufactured in the same manner as in Example C1 (Example C6). When calculating the ratio of the length of the wiring between intersections (line length) to the shortest distance between intersections for each of the plurality of wirings surrounding each opening, the average value is 1.016.

[0350] (Example C7) The non-periodic planar structure of the mesh wiring layer is set as a Voronoi pattern, the average value of the shortest distance between the intersections of the mesh wiring layer is set to 200 μm, and the average amplitude of the sinusoidal curve of the wiring is set to 4 μm. Otherwise, the wiring substrate is fabricated in the same manner as in Example C1 (Example C7). When calculating the ratio of the length of the wiring between intersections (line length) to the shortest distance between intersections for each of the plurality of wirings surrounding each opening, the average value is 1.016.

[0351] (Comparative Example C1) Except that the average amplitude of the sinusoidal curve of the wiring was set to 1 μm, the wiring substrate was manufactured in the same manner as in Example C1 (Comparative Example C1). When calculating the ratio of the length of the wiring between intersections (line length) to the shortest distance between intersections for each of the plurality of wirings surrounding each opening, the average value was 1.004.

[0352] (Comparative Example C2) Except that the average wavelength of the sinusoidal curve of the wiring is set to 100 μm, the wiring substrate is manufactured in the same manner as in Example C1 (Comparative Example C2). When calculating the ratio of the length of the wiring between intersections (line length) to the shortest distance between intersections for each of the plurality of wirings surrounding each opening, the average value is 1.004.

[0353] (Comparative Example C3) Except that the average value of the shortest distance between the intersections of the mesh wiring layer is set to 200 μm and the average wavelength of the sinusoidal curve of the wiring is set to 100 μm, the wiring substrate is manufactured in the same manner as in Example C1 (Comparative Example C3). When calculating the ratio of the length of the wiring between intersections (line length) to the shortest distance between intersections for each of the plurality of wirings surrounding each opening, the average value is 1.004.

[0354] (Comparative Example C4) Except that the non-periodic planar structure of the mesh wiring layer is set as a Voronoi pattern and the average wavelength of the sinusoidal curve of the wiring is set to 100 μm, the wiring substrate is manufactured in the same manner as in Example C1 (Comparative Example C4). When calculating the ratio of the length of the wiring between intersections (line length) to the shortest distance between intersections for each of the plurality of wirings surrounding each opening, the average value is 1.004.

[0355] Next, the wiring boards of Examples C1-7 and Comparative Examples C1-4 were visually inspected to confirm whether the effects of reducing the generation of water ripples and flickering were achieved. Wiring boards with higher effects of reducing the generation of water ripples and flickering were marked as "high", and wiring boards with lower effects were marked as "low". The results are shown in Table 5.

[0356] [Table 5] Example type Average shortest distance between intersection points (μm) Average amplitude (μm) Average wavelength (μm) Average amplitude / shortest distance between average intersection points Average wavelength / shortest distance between average intersection points Average line length / shortest distance between average intersection points Water ripple and flicker reduction effect Example C1 random intersection 100 2 50 0.02 0.50 1.016 high Example C2 random intersection 100 4 50 0.04 0.50 1.060 high Example C3 random intersection 100 2 25 0.02 0.25 1.060 high Example C4 random intersection 100 4 25 0.04 0.25 1.217 high Example C5 random intersection 100 6 16.7 0.06 0.17 1.811 high Example C6 random intersection 200 4 50 0.02 0.25 1.016 high Example C7 Voronoi 200 4 50 0.02 0.25 1.016 high Comparative Example C1 random intersection 100 1 50 0.01 0.50 1.004 Low Comparative Example C2 random intersection 100 2 100 0.02 1.00 1.004 Low Comparative example C3 random intersection 200 2 100 0.01 0.50 1.004 Low Comparative Example C4 Voronoi 200 2 100 0.01 0.50 1.004 Low

[0357] Thus it is determined that the wiring board of Embodiment C1-7 is more effective in reducing the generation of water ripples and flickering compared to the wiring board of Comparative Example C1-4.

[0358] The plurality of constituent elements disclosed in the above embodiments and variations can also be appropriately combined as needed. Alternatively, some constituent elements can be deleted from all the constituent elements shown in the above embodiments and variations. [Simplified Explanation of the Diagram]

[0062] FIG1 is a top view of the image display device according to the first embodiment. FIG2 is a cross-sectional view of the image display device according to the first embodiment (cross-sectional view along line II-II of FIG1). FIG3 is a top view of the pixels of the image display device according to the first embodiment. FIG4 is a top view of the wiring board according to the first embodiment. FIG5A is an enlarged top view of the mesh wiring layer of the wiring board according to the first embodiment. FIG5B is an enlarged top view of the mesh wiring layer of the wiring board according to the first embodiment. FIG6 is a cross-sectional view of the wiring board according to the first embodiment (cross-sectional view along line VI-VI of FIG5A). FIG7 is a cross-sectional view of the wiring board according to the first embodiment (cross-sectional view along line VII-VII of FIG5A). FIG8 is a perspective view of the mesh wiring layer of the wiring board according to the first embodiment. FIG9(a)-(f) are cross-sectional views showing the manufacturing method of the wiring board according to the first embodiment. FIG10 is a top view of the wiring board of the first variation. Figure 11 is an enlarged top view of the wiring substrate of the first variation. Figure 12 is a top view of the wiring substrate of the second variation. Figure 13 is an enlarged top view of the wiring substrate of the second variation. Figure 14 is an enlarged top view of the mesh wiring layer of the wiring substrate of the third variation. Figure 15 is a top view of the wiring substrate of the fourth variation. Figure 16 is an enlarged top view of the wiring substrate of the fourth variation. Figure 17 is an enlarged top view of the mesh wiring layer of the wiring substrate of the fifth variation. Figure 18 is an enlarged top view of the mesh wiring layer of the wiring substrate of Comparative Example A1. Figure 19 is an enlarged top view of the mesh wiring layer of the wiring substrate of Comparative Example A2. Figure 20 is an enlarged top view of the mesh wiring layer of the wiring substrate of Comparative Example A3. Figure 21 is an enlarged top view of the mesh wiring layer of the wiring substrate of the second embodiment. Figure 22 is an enlarged top view of the mesh wiring layer of the wiring substrate of the second embodiment (enlarged view of part XXII in Figure 21). Figure 23 is a cross-sectional view of the wiring substrate of the second embodiment (cross-sectional view along line XXIII-XXIII in Figure 21). Figure 24 is a cross-sectional view of the wiring substrate of the second embodiment (cross-sectional view along line XXIV-XXIV in Figure 21). Figure 25 is a top view of the wiring substrate of the first variation. Figure 26 is an enlarged top view of the wiring substrate of the first variation. Figure 27 is an enlarged top view of the wiring substrate of the second variation. Figure 28 is a top view of the wiring substrate of the third variation. Figure 29 is a top view of the wiring substrate of the third embodiment. Figure 30 is an enlarged top view of the mesh wiring layer of the wiring substrate of the third embodiment (enlarged view of part XXX in Figure 29). Figures 31(a)-(c) are enlarged top views of the wiring, respectively. Figure 32 is a cross-sectional view of the wiring board of the third embodiment (cross-sectional view along line XXXII-XXXII of Figure 30).Figures 33(a)-(f) are cross-sectional views showing the manufacturing method of the wiring board according to the third embodiment. Figure 34 is a top view showing the image display device according to the third embodiment. Figure 35 is an enlarged top view showing the mesh wiring layer of the wiring board in the first variation. Figure 36 is a top view showing the wiring board in the second variation. Figure 37 is an enlarged top view showing the mesh wiring layer of the wiring board in the second variation (enlarged view of part XXXVII of Figure 36).

Claims

1. A wiring substrate comprising: 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; the wiring substrate having electromagnetic wave transmission and reception function, the substrate being transparent, the mesh wiring layer being configured as an antenna and having wiring, forming two or more openings by being surrounded by the wiring, the planar shape of the openings being a polygon with opposite sides parallel to each other, the distance between the sides extending along a first direction in each opening being set as d, and the average value of the distance between the sides extending along the first direction in 100 consecutively adjacent openings or all of the openings being set as D, wherein more than 95% of the 100 openings or all of the openings satisfy the relationship 0.70D≦d≦0.98D, or satisfy 1.02D≦d≦1.30D. The relationship between them.

2. The wiring board of claim 1, wherein more than 95% of the 100 openings or all of the openings satisfy the relationship 0.85D≦d≦0.98D, or the relationship 1.02D≦d≦1.15D.

3. The wiring board of claim 1, wherein more than 95% of the 100 openings or all of the openings satisfy the relationship 0.90D≦d≦0.98D, or the relationship 1.02D≦d≦1.10D.

4. The wiring board of claim 1, wherein the polygon is a quadrilateral.

5. The wiring board of claim 1, wherein the polygon is hexagonal.

6. The wiring board of claim 1, wherein the average value D is 50 μm or more and 500 μm or less.

7. The wiring board of claim 1, wherein the linewidth of the wiring is more than 0.5 μm and less than 3 μm.

8. The wiring substrate of claim 1, wherein the overall aperture ratio of the above-mentioned mesh wiring layer is 95% or more but less than 100%.

9. The wiring substrate of claim 1, wherein the sheet resistance of the aforementioned mesh wiring layer is 4 Ω / □ or less.

10. The wiring substrate of claim 1, wherein the wiring substrate has millimeter-wave transceiver function, and the mesh wiring layer is configured as an array antenna containing two or more antenna elements.

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

12. The wiring board of claim 1, wherein a dummy wiring layer electrically independent of the mesh wiring layer is provided around the mesh wiring layer.

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

14. The wiring board of claim 12, wherein two or more of the aforementioned dummy wiring layers are provided, and the aperture ratio of the aforementioned mesh wiring layer and the aforementioned dummy wiring layer increases in stages from the aforementioned mesh wiring layer toward the aforementioned dummy wiring layer away from the aforementioned mesh wiring layer.

Images