Wiring board and head mounted display

Abstract

A wiring board comprising a transparent substrate, and a mesh wiring layer that is disposed on the substrate. The wiring board has an electromagnetic wave transmission / reception function. The mesh wiring layer is configured as an electromagnetic-wave-transmitting / receiving portion and has wiring. In the planar shape of the wiring, a plurality of curved lines are connected. The curved lines are arcs or elliptic arcs.

Description

[Technical field]

[0001] An embodiment of the present disclosure relates to a wiring board and a head mounted display. [Background technology]

[0002] Currently, mobile terminal devices such as smartphones, tablets, and smart glasses (AR, MR, etc.) are becoming more functional, smaller, thinner, and lighter. These mobile terminal devices use multiple communication bands. For this reason, multiple antennas corresponding to the communication bands are required. For example, mobile terminal devices are equipped with multiple antennas such as a telephone antenna, a WiFi (Wireless Fidelity) antenna, a 3G (Generation) antenna, a 4G (Generation) antenna, a 5G (Generation) antenna, an LTE (Long Term Evolution) antenna, a Bluetooth (registered trademark) antenna, and an NFC (Near Field Communication) antenna. However, as mobile terminal devices become smaller, the space for mounting the antennas is limited, and the freedom of antenna design is narrowed. In addition, since the antennas are built into a limited space, the radio wave sensitivity is not necessarily satisfactory.

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

[0004] [Patent Document 1] JP 2011-66610 A [Patent Document 2] Patent No. 5636735 specification [Patent Document 3] Patent No. 5695947 specification

[0005] In the conventional film antenna, a region in which a conductive mesh layer (antenna pattern) is formed exists on a transparent substrate. When the wiring of the conductive mesh layer is arranged regularly and in a lattice pattern, a light streak (a light beam) depending on the direction of the wiring may be observed when observing a point light source. When a light beam is generated in this way, the visibility of images may be reduced in mobile terminal devices, etc.

[0006] One way to eliminate the light beams is to eliminate the periodicity of the wiring. However, if the periodicity of the wiring is eliminated, the wiring directions will vary, which may result in flickering due to light reflection.

[0007] An object of the present embodiment is to provide a wiring board and a head mounted display capable of suppressing a decrease in visibility due to light beams and suppressing flickering due to reflected light. DISCLOSURE OF THEINVENTION

[0008] A first aspect of the present disclosure is a wiring board comprising a transparent substrate and a mesh wiring layer disposed on the substrate, the wiring board having an electromagnetic wave transmitting and receiving function, the mesh wiring layer being configured as an electromagnetic wave transmitting and receiving unit and having wiring, the planar shape of the wiring being a shape formed by connecting a plurality of curves, and the curve being a circular arc or an elliptical arc.

[0009] A second aspect of the present disclosure is the wiring board according to the first aspect described above, wherein the mesh wiring layer has an aperture ratio of 94% or more.

[0010] A third aspect of the present disclosure is a wiring board according to the first aspect or the second aspect described above, wherein an opening is formed by being surrounded by the wiring, and the wiring surrounding the opening may have a shape obtained by connecting ends of chords of a plurality of the curves to each other, which may be a polygon, and the wiring may have a shape obtained by connecting a plurality of arcs cut at a central angle of 160° or more and 200° or less, and one side of the polygon may be composed of 2N (N is a natural number equal to or greater than 1) chords, and on the one side, among the division points obtained by dividing the one side into 2N equal parts, an M-th (M is a natural number equal to or greater than 1 and equal to or less than (2N-1)) division point counting from one end of the one side is defined as an M-th division point, and on the one side, among the connection points between the chords, an M-th connection point counting from the one end of the one side is defined as an M-th connection point, and the distance from the M-th division point to the M-th connection point may be 0.1 / N times or less the length of the one side.

[0011] A fourth aspect of the present disclosure is such that, in the wiring board according to the third aspect described above, a plurality of the openings may be formed, and the corners of the polygon may be irregularly arranged.

[0012] A fifth aspect of the present disclosure is a wiring board according to the first aspect described above, wherein an opening is formed by being surrounded by the wiring, and the wiring surrounding the opening may have a shape obtained by connecting ends of chords of a plurality of the curves to each other, which may be a square, and the wiring may have a shape obtained by connecting a plurality of arcs cut at a central angle of 160° or more and 200° or less, and one side of the square may be composed of 2N (N is a natural number greater than or equal to 1) chords, and on the one side, among the division points obtained by dividing the one side into 2N equal parts, the Mth (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) division point counting from one end of the side is defined as the Mth division point, and on the one side, among the connection points between the chords, the Mth connection point counting from the one end of the side is defined as the Mth connection point, and the distance from the Mth division point to the Mth connection point may be less than or equal to 0.1 / N times the length of the side.

[0013] A sixth aspect of the present disclosure is a wiring board according to the first aspect described above, wherein an opening is formed by being surrounded by the wiring, and the wiring surrounding the opening may have a shape obtained by connecting ends of chords of a plurality of the curves to each other, which may be a square, and the wiring may have a shape obtained by connecting a plurality of arcs cut at a central angle of 80° or more and 100° or less, and one side of the square may be composed of 2N (N is a natural number greater than or equal to 1) chords, and on the one side, among the division points obtained by dividing the one side into 2N equal parts, the Mth (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) division point counting from one end of the side is defined as the Mth division point, and on the one side, among the connection points between the chords, the Mth connection point counting from the one end of the side is defined as the Mth connection point, and the distance from the Mth division point to the Mth connection point may be less than or equal to 0.1 / N times the length of the side.

[0014] A seventh aspect of the present disclosure is that, in a wiring board according to each of the first aspect to the fifth aspect described above, the curve may be an arc cut at a central angle of 180°, and in a wiring board according to the first aspect or the sixth aspect described above, the curve may be an arc cut at a central angle of 90°.

[0015] An eighth aspect of the present disclosure is a wiring board according to the first aspect described above, wherein an opening is formed by being surrounded by the wiring, and the wiring surrounding the opening may have a shape obtained by connecting ends of chords of a plurality of the curves to each other, which may be a rhombus, and the wiring may have a shape obtained by connecting a plurality of arcs cut at a central angle of 160° or more and 200° or less, and one side of the rhombus may be composed of 2N (N is a natural number greater than or equal to 1) chords, and on the one side, among the division points obtained by dividing the one side into 2N equal parts, the Mth (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) division point counting from one end of the side is defined as an Mth division point, and on the one side, among the connection points between the chords, the Mth connection point counting from the one end of the side is defined as an Mth connection point, and the distance from the Mth division point to the Mth connection point may be 0.1 / N times or less the length of the side.

[0016] A ninth aspect of the present disclosure is a wiring board according to the first aspect described above, wherein an opening is formed by being surrounded by the wiring, and the wiring surrounding the opening may have a shape obtained by connecting ends of chords of a plurality of the curves to each other, which may be a regular hexagon, and the wiring may have a shape obtained by connecting a plurality of arcs cut at a central angle of 160° or more and 200° or less, and one side of the regular hexagon may be composed of 2N (N is a natural number greater than or equal to 1) chords, and on the one side, among the division points obtained by dividing the side into 2N equal parts, the Mth (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) division point counting from one end of the side is defined as the Mth division point, and on the one side, among the connection points between the chords, the Mth connection point counting from the one end of the side is defined as the Mth connection point, and the distance from the Mth division point to the Mth connection point may be less than or equal to 0.1 / N times the length of the side.

[0017] A tenth aspect of the present disclosure is directed to a wiring board according to the first aspect described above, wherein an opening is formed by being surrounded by the wiring, and the wiring surrounding the opening may have a shape obtained by connecting ends of chords of a plurality of the curves to each other, which may be a polygon, and the wiring may have a shape obtained by connecting a plurality of arcs cut at a central angle of 80° or more and 100° or less, and one side of the polygon may be composed of 2N (N is a natural number greater than or equal to 1) chords, and among the division points on the one side obtained by dividing the one side into 2N equal parts, the Mth (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) division point counting from one end of the side is defined as an Mth division point, and among the connection points between the chords on the one side, the Mth connection point counting from the one end of the side is defined as an Mth connection point, and the distance from the Mth division point to the Mth connection point may be less than or equal to 0.1 / N times the length of the side.

[0018] An eleventh aspect of the present disclosure is the wiring board according to the tenth aspect described above, wherein the polygon may be a rhombus or a hexagon.

[0019] A twelfth aspect of the present disclosure is such that, in the wiring board according to each of the first aspect to the eleventh aspect described above, N may be 1.

[0020] A thirteenth aspect of the present disclosure is a wiring board according to any one of the first to twelfth aspects described above, wherein the wiring board has a function of transmitting and receiving radio waves at a frequency of 1 GHz or higher.

[0021] A fourteenth aspect of the present disclosure is the wiring board according to any one of the first to thirteenth aspects described above, wherein the mesh wiring layer has an electromagnetic wave shielding function.

[0022] A fifteenth aspect of the present disclosure is such that, in a wiring board according to each of the first aspect to the fourteenth aspect described above, when the wiring board is bent 180° around a cylinder having a diameter of 1 mm and then straightened ten times, the increase in resistance value of the mesh wiring layer may be 10% or less.

[0023] A sixteenth aspect of the present disclosure is that, in a wiring board according to each of the first aspect to the fifteenth aspect described above, a dummy wiring layer electrically independent from the mesh wiring layer may be provided around the mesh wiring layer.

[0024] A seventeenth aspect of the present disclosure is that in a wiring board according to each of the first aspect to the sixteenth aspect described above, a plurality of the dummy wiring layers may be provided, and the aperture ratio of the mesh wiring layer and the dummy wiring layer may gradually increase from the mesh wiring layer to the dummy wiring layer farther from the mesh wiring layer.

[0025] An 18th aspect of the present disclosure is a head-mounted display comprising a frame and a transparent display device attached to the frame, the display device having a first substrate, a wiring board according to any one of the first to 17th aspects described above provided on the first substrate, and a display unit provided between the first substrate and the wiring board.

[0026] According to the embodiments of the present disclosure, it is possible to suppress the decrease in visibility due to the light beams and to suppress flickering due to reflected light. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view showing a head mounted display according to an embodiment. [Diagram 2] FIG. 2 is a front view (view taken in the direction of the arrow II in FIG. 1) showing the head mounted display according to the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view (cross-sectional view taken along line III-III in FIG. 2) showing the display device of the head mounted display according to the embodiment. [Figure 4] FIG. 4 is a plan view showing the wiring board according to the embodiment. [Diagram 5] FIG. 5 is an enlarged plan view showing a mesh wiring layer of the wiring board according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view (a cross-sectional view taken along line VI-VI in FIG. 5) showing the wiring board according to the embodiment. [Figure 7] FIG. 7 is a cross-sectional view (cross-sectional view taken along line VII-VII in FIG. 5) showing the wiring board according to the embodiment. [Figure 8A] FIG. 8A is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. [Figure 8B] FIG. 8B is a cross-sectional view showing the method for manufacturing the wiring board according to the embodiment. [Figure 8C] FIG. 8C is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. [Figure 8D] FIG. 8D is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. [Figure 8E] FIG. 8E is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. [Figure 8F] FIG. 8F is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. [Figure 9]FIG. 9 is an enlarged plan view showing a wiring board according to a first modified example. [Figure 10A] FIG. 10A is an enlarged plan view showing a wiring board according to a second modified example. [Figure 10B] FIG. 10B is an enlarged plan view showing another example of the wiring board according to the second modified example. [Figure 11] FIG. 11 is an enlarged plan view showing a wiring board according to a third modified example. [Figure 12A] FIG. 12A is an enlarged plan view showing a wiring board according to a fourth modified example. [Figure 12B] FIG. 12B is an enlarged plan view showing another example of the wiring board according to the fourth modified example. [Figure 13] FIG. 13 is an enlarged plan view showing a wiring board according to a fifth modified example. [Figure 14] FIG. 14 is an enlarged plan view showing another example of the wiring board according to the fifth modified example. [Figure 15] FIG. 15 is an enlarged plan view showing another example of the wiring board according to the fifth modified example. [Figure 16] FIG. 16 is a plan view showing a wiring board according to a sixth modified example. [Figure 17] FIG. 17 is an enlarged plan view showing a wiring board according to a sixth modified example. [Figure 18] FIG. 18 is a plan view showing a wiring board according to a seventh modified example. [Figure 19] FIG. 19 is an enlarged plan view showing a wiring board according to a seventh modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] First, one embodiment will be described with reference to Figures 1 to 8F. Figures 1 to 8F are diagrams showing this embodiment.

[0029] The figures shown below are schematic diagrams. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, the present invention can be modified appropriately without departing from the technical concept. In each of the figures shown below, the same parts are given the same reference numerals, and some detailed explanations may be omitted. In addition, the numerical values ​​such as dimensions of each member and the material names described in this specification are examples of embodiments, and are not limited thereto, and can be appropriately selected and used. In this specification, terms that specify shapes and geometric conditions, such as parallel, orthogonal, and vertical, are interpreted to include substantially the same state in addition to their strict meanings.

[0030] In the following embodiments, the "X direction" refers to a direction parallel to one side of the substrate. The "Y direction" refers to a direction perpendicular to the X direction and parallel to another side of the substrate. The "Z direction" refers to a direction perpendicular to both the X direction and the Y direction and parallel to the thickness direction of the substrate. The "front surface" refers to the surface on the positive side of the Z direction that faces the wearer. The "back surface" refers to the surface on the negative side of the Z direction that is opposite to the surface facing the wearer.

[0031] First, the configuration of a head mounted display (hereinafter, simply referred to as HMD) according to the present embodiment will be described with reference to Figures 1 to 3. The HMD according to the present embodiment is a transmission type (see-through type) HMD.

[0032] As shown in FIG. 1, the HMD 90 according to this embodiment includes a frame 91 and a transparent display device 95 attached to the frame 91. In this embodiment, the HMD 90 includes a display device 95 for the right eye and a display device 95 for the left eye, and is a so-called glasses-type HMD. The display device 95 for the right eye and the display device 95 for the left eye have substantially the same structure. The display devices 95 are synchronized with each other and are configured to display the same image on the left and right, or are configured to display corresponding images on the left and right. Furthermore, the two display devices 95 may be individually controllable, and the two display devices 95 may display different images from each other. The HMD 90 may be a so-called goggle-type HMD that includes a single display device 95.

[0033] A frame 91 of the HMD 90 has a rim 92 and a pair of temples 93 connected to the rim 92. Each display device 95 is fitted into the rim 92. In this embodiment, a wireless communication circuit 94a of the HMD 90 is provided on the rim 92.

[0034] Further, the pair of temples 93 are provided with a control unit 94b for controlling each display device 95. The control unit 94b may include an image display unit (not shown) that generates image light. In this embodiment, one control unit 94b is provided on each temple 93. The control unit 94b provided on the right temple 93 is configured to control the display device 95 for the right eye, and the control unit 94b provided on the left temple 93 is configured to control the display device 95 for the left eye.

[0035] Next, the display device 95 will be described. As shown in Fig. 2 and Fig. 3, the display device 95 has a first base material 96, a wiring board 10 provided on the first base material 96, and a display unit 97 provided between the first base material 96 and the wiring board 10. In this embodiment, the wiring board 10 covers the entire area of ​​the first base material 96. Although not shown, the wiring board 10 may cover only a portion of the first base material 96.

[0036] The material of the first base material 96 may be any material that has transparency in the visible light region. For example, a glass base material can be used as the first base material 96. In this embodiment, when the HMD 90 is worn by the wearer, the first base material 96 is disposed on the side farther from the wearer, and the wiring board 10 is disposed on the side closer to the wearer. That is, when the HMD 90 is worn by the wearer, the wiring board 10 is disposed between the first base material 96 and the wearer. As a result, even if the HMD 90 comes into contact with surrounding structures or other people when the wearer wears the HMD 90, for example, the wiring board 10 can be prevented from coming into contact with surrounding structures, etc. Therefore, the first directional wiring 21 and the second directional wiring 22 of the mesh wiring layer 20 of the wiring board 10, which will be described later, can be prevented from being disconnected due to contact with surrounding structures, etc. Note that when the HMD 90 is worn by the wearer, the first base material 96 may be disposed on the side closer to the wearer, and the wiring board 10 may be disposed on the side farther from the wearer.

[0037] Such a display device 95 may be a display device that projects an image using a prism or a hologram, or may be a display device that uses a transmissive liquid crystal display or the like.

[0038] The display unit 97 of the display device 95 may include a half mirror when the display device is a display device that projects an image. This half mirror is a member that superimposes external light in front of the display device 95 and image light from an image display unit (not shown) that generates image light. When the display device 95 is a display device using a transmissive liquid crystal display or the like, the half mirror is not necessary. The display unit 97 is configured so that the image display area is transparent when the image is not displayed, and the wearer can visually recognize the outside world by the light that transmits through the display unit 97. The wearer can visually recognize a virtual image (image) formed by the image light while visually recognizing the outside world. In the illustrated example, the display unit 97 is provided at a position overlapping approximately the center of the first base material 96 in a front view (see FIG. 2). However, the present invention is not limited to this, and the display unit 97 may be provided at a position overlapping any area of ​​the first base material 96 in a front view. The display unit 97 and the wiring board 10 may be disposed in an overlapping position without interfering with each other, or in a non-overlapping position.

[0039] Next, the configuration of the wiring board will be described with reference to Figures 4 to 7. Figures 4 to 7 are diagrams showing the wiring board according to the present embodiment.

[0040] The wiring board 10 according to the present embodiment is a board used in, for example, the above-mentioned HMD 90 (see FIGS. 1 to 3). Note that the wiring board 10 may also be used in, for example, mobile terminal devices such as smartphones and tablets.

[0041] The wiring board 10 can transmit and receive radio waves of a predetermined frequency (for example, a frequency of 1 GHz or more) and can perform communication. The wiring board 10 may be compatible with any of a millimeter wave antenna, a telephone antenna, a WiFi antenna, a 3G antenna, a 4G antenna, a 5G antenna, an LTE antenna, an Bluetooth (registered trademark) antenna, an NFC antenna, and the like. Alternatively, the wiring board 10 may have functions such as a gesture sensing function, a wireless power supply function, an anti-fogging function, a heater function, a hovering function (a function that allows a user to operate the display without directly touching it), a fingerprint authentication function, and a noise cut (electromagnetic wave shield) function. Here, in this specification, the "gesture sensing function" means a function of detecting the relative position (distance, angle, etc.) of an object with respect to a mesh wiring layer 20 of the wiring board 10 described later, or a function of detecting the moving speed of an object. In this case, for example, the mesh wiring layer 20 of the wiring board 10 may perform the gesture sensing function by detecting millimeter waves.

[0042] The wiring board 10 includes a transparent substrate 11 and a mesh wiring layer 20 disposed on the substrate 11. A power supply unit 40 is electrically connected to the mesh wiring layer 20.

[0043] The shape of the substrate 11 is a substantially rectangular shape in plan view (a rectangle with rounded corners (see FIG. 2)). In the illustrated example, the longitudinal direction is parallel to the X direction, and the lateral direction is parallel to the Y direction. The substrate 11 is transparent and substantially flat, and has a substantially uniform thickness overall. The shape of the substrate 11 can be appropriately selected to match the shape of a first base material 96 of a display device 95 to be attached to a frame 91.

[0044] The material of the substrate 11 may be any material that has transparency in the visible light region and electrical insulation. For example, organic insulating materials such as polyester resin, acrylic resin, polycarbonate resin, polyimide resin, polyolefin resin, cellulose resin, or fluororesin material are preferably used as the material of the substrate 11. The polyester resin may be polyethylene terephthalate or the like. The acrylic resin may be polymethyl methacrylate or the like. The polyolefin resin may be cycloolefin polymer or the like. The cellulose resin may be triacetyl cellulose or the like. The fluororesin material may be PTFE or PFA or the like. For example, organic insulating materials such as cycloolefin polymer (for example, ZF-16 manufactured by Nippon Zeon Co., Ltd.) or polynorbornene polymer (manufactured by Sumitomo Bakelite Co., Ltd.) may be used as the material of the substrate 11. In addition, glass, ceramics, or the like may be appropriately selected as the material of the substrate 11 depending on the application. Although the substrate 11 is illustrated as being made up of a single layer, the present invention is not limited thereto and may be made up of a laminate of multiple base materials or layers. The substrate 11 may be a film-like member or a plate-like member.

[0045] In addition, the substrate 11 has transparency. In this specification, "having transparency" means that the transmittance of visible light (light having a wavelength of 400 nm or more and 700 nm or less) is 85% or more. The transmittance of the substrate 11 for visible light (light having a wavelength of 400 nm or more and 700 nm or less) may be 85% or more, and is preferably 90% or more. There is no particular upper limit to the transmittance of visible light of the substrate 11, but it may be, for example, 100% or less. By setting the transmittance of visible light of the substrate 11 within the above range, it is possible to suppress the visibility of the outside world from being hindered when the wiring substrate 10 is incorporated into the HDM 90. The transmittance of visible light of 85% or more means that when the absorbance of the substrate 11 is measured using a known spectrophotometer (spectroscope: V-670 manufactured by JASCO Corporation), the transmittance is 85% or more in the entire wavelength range of 400 nm to 700 nm.

[0046] The tensile modulus of the substrate 11 is preferably 0.5 GPa or more and 4.5 GPa or less. When the tensile modulus of the substrate 11 is 0.5 GPa or more, the rigidity of the substrate 11 can be maintained, and the substrate 11 can be prevented from being deformed. When the tensile modulus of the substrate 11 is 4.5 GPa or less, the substrate 11 can be prevented from becoming too hard. This prevents the substrate 11 from being damaged even when the substrate 11 is bent. This prevents the antenna performance from being deteriorated due to the deformation of the wiring substrate 10. The tensile modulus of the substrate 11 can be measured in accordance with ASTM-D-882. Specifically, the elongation of the test piece is measured using a tensile tester, and the maximum elasticity immediately before plastic deformation (a linear equation of the tangent to the maximum slope of the stress-strain curve) can be obtained.

[0047] The dielectric loss tangent of the substrate 11 may be 0.002 or less, and preferably 0.001 or less. The dielectric loss tangent of the substrate 11 has no particular lower limit, but may be greater than 0. When the dielectric loss tangent of the substrate 11 is in the above range, the gain loss (i.e., the decrease in sensitivity) associated with the transmission and reception of electromagnetic waves can be reduced, particularly when the electromagnetic waves (e.g., millimeter waves) transmitted and received by the mesh wiring layer 20 are high frequency waves.

[0048] The relative dielectric constant of the substrate 11 is preferably 2 or more and 10 or less. When the relative dielectric constant of the substrate 11 is 2 or more, the options for the material of the substrate 11 can be increased. Furthermore, when the relative dielectric constant of the substrate 11 is 2 or more, an inexpensive material can be selected, and the manufacturing cost can be reduced. Furthermore, when the relative dielectric constant of the substrate 11 is 2 or more, a material suitable for the manufacturing process can be selected, and the manufacturing yield can be improved and the manufacturing cost can be reduced. Furthermore, when the relative dielectric constant of the substrate 11 is 10 or less, the loss of gain (sensitivity) associated with the transmission and reception of electromagnetic waves can be reduced. That is, when the relative dielectric constant of the substrate 11 is large, the influence of the thickness of the substrate 11 on the propagation of electromagnetic waves becomes large. Furthermore, when there is an adverse effect on the propagation of electromagnetic waves, the dielectric loss tangent of the substrate 11 becomes large, and the loss of gain associated with the transmission and reception of electromagnetic waves can become large. On the other hand, when the relative dielectric constant of the substrate 11 is 10 or less, the influence of the thickness of the substrate 11 on the propagation of electromagnetic waves can be reduced. Therefore, the loss of gain associated with the transmission and reception of electromagnetic waves can be reduced. In particular, when the electromagnetic waves (for example, millimeter waves) transmitted and received by the mesh wiring layer 20 are high frequency, the loss of gain associated with the transmission and reception of the electromagnetic waves can be reduced.

[0049] The dielectric loss tangent and the relative dielectric constant of the substrate 11 can be measured in accordance with IEC 62562. Specifically, first, a test piece is prepared by cutting out a portion of the substrate 11 where the mesh wiring layer 20 is not formed. The dimensions of the test piece are a width of 10 mm to 20 mm, and a length of 50 mm to 100 mm. Next, the dielectric loss tangent or the relative dielectric constant is measured in accordance with IEC 62562.

[0050] In this embodiment, the mesh wiring layer 20 is configured as a transmitting / receiving section of electromagnetic waves. In other words, the mesh wiring layer 20 is made of an antenna pattern that functions as an antenna. This mesh wiring layer 20 may be configured as an array antenna including two or more antenna elements (radiating elements (tip side portion 20b described later)). In this way, when the mesh wiring layer 20 is configured as an array antenna, it is possible to improve the millimeter wave antenna performance for transmitting and receiving highly linear millimeter waves. Note that an array antenna is an antenna in which multiple antenna elements are regularly arranged, and the amplitude and phase of the excitation of the elements can be independently controlled.

[0051] As shown in FIG. 4, a plurality of mesh wiring layers 20 are formed on the substrate 11. It is preferable that four or more mesh wiring layers 20 are provided. In this case, four or more antenna elements (tip side portions 20b described later) are provided on the wiring substrate 10. In the illustrated example, four mesh wiring layers 20 are formed on the substrate 11 (see FIG. 2). Also, as shown in FIG. 4, the mesh wiring layer 20 may not be present on the entire surface of the substrate 11, but may be present only in a partial region on the substrate 11. Each mesh wiring layer 20 may have the same shape as each other. In this case, each mesh wiring layer 20 has a length (length in the Y direction) L of the tip side portion 20b described later. a Error and width (length in X direction) W a It is preferable that the error of each is within 10%, which can effectively improve the performance of the millimeter wave antenna.

[0052] The mesh wiring layer 20 has a base end portion (transmission portion) 20a on the power supply unit 40 side, and a tip end portion (transmission / reception portion) 20b connected to the base end portion 20a. The base end portion 20a is connected to the power supply unit 40. In this case, the base end portion (transmission portion) 20a may be configured as a microstrip line or a coplanar line. The base end portion 20a and the tip end portion 20b each have a substantially rectangular shape in a plan view. In this case, the width (X-direction distance) of the tip end portion 20b is wider than the width (X-direction distance) of the base end portion 20a.

[0053] The tip portion 20b of the mesh wiring layer 20 corresponds to a predetermined frequency band. a The length L of the tip portion 20b corresponds to a specific frequency band. a The length of the mesh wiring layer 20 becomes longer. In addition to the millimeter wave antenna, the mesh wiring layer 20 may correspond to any of a telephone antenna, a WiFi antenna, a 3G antenna, a 4G antenna, a 5G antenna, an LTE antenna, an Bluetooth (registered trademark) antenna, an NFC antenna, etc. The lengths of the multiple tip side portions 20b may be different from each other and each may correspond to a different frequency band. Alternatively, each mesh wiring layer 20 may perform a function such as a hovering function, a fingerprint authentication, a heater, a noise cut (electromagnetic wave shield), etc.

[0054] In the illustrated example, the tip portion 20b has a longitudinal direction parallel to the X direction and a lateral direction parallel to the Y direction. The tip portion 20b may have a longitudinal direction parallel to the Y direction and a lateral direction parallel to the X direction. The length L of the tip portion 20b in the Y direction is a The width W of the tip portion 20b in the X direction can be selected, for example, in the range of 1 mm to 100 mm. a In particular, when the mesh wiring layer 20 is a millimeter wave antenna, the length L of the tip portion 20b can be selected within a range of, for example, 1 mm or more and 100 mm or less. a When the mesh wiring layer 20 is a millimeter wave antenna, the length L of the tip portion 20b can be selected in the range of 1 mm or more, more preferably 1.5 mm or more. a can be selected in the range of 10 mm or less, more preferably 5 mm or less.

[0055] The distance between the mesh wiring layers 20 can be appropriately set according to the corresponding frequency, but is preferably 1 mm or more and 30 mm or less. 20b(See FIG. 4) is preferably 1 mm or more and 30 mm or less. By setting an appropriate distance, it is possible to obtain the desired antenna directivity and gain improvement.

[0056] 4, the mesh wiring layer 20 has a pattern shape in which metal wires are arranged in a mesh shape. This pattern shape is repeatedly arranged in the X direction and the Y direction. That is, the mesh wiring layer 20 has a pattern shape composed of a portion (first direction wiring 21 described later) extending in a first direction (e.g., Y direction) and a portion (second direction wiring 22 described later) extending in a second direction (e.g., X direction).

[0057] As shown in FIG. 5, the mesh wiring layer 20 has wiring. Specifically, the mesh wiring layer 20 has a plurality of first-directional wirings (wirings) 21 and a plurality of second-directional wirings (wirings) 22 connecting the plurality of first-directional wirings 21. The plurality of first-directional wirings 21 and the plurality of second-directional wirings 22 are integrated as a whole to form a mesh-like shape. Each of the first-directional wirings 21 extends in the longitudinal direction (Y direction) of the mesh wiring layer 20. Each of the second-directional wirings extends in the width direction (X direction) of the mesh wiring layer 20. The first-directional wirings 21 and the second-directional wirings 22 may extend in a direction that is not parallel to either the X direction or the Y direction.

[0058] The planar shape of the first directional wiring 21 and the second directional wiring 22 is a shape in which a plurality of curves are connected. In this case, the curves are circular arcs or elliptical arcs. In the illustrated example, the planar shape of the first directional wiring 21 and the second directional wiring 22 is a shape in which a plurality of arcs are connected. Here, the diffraction image caused by the linear structure extends in a direction perpendicular to the longitudinal direction of the structure and becomes a light beam (a streak of light observed to have a tail). On the other hand, when the planar shape of the first directional wiring 21 and the second directional wiring 22 is a shape in which a plurality of arcs are connected, the generated light beam extends in various directions. When the generated light beams extend in various directions, the light beams overlap each other, making it difficult to distinguish each light beam. This reduces the effect of the light beams on visibility. In addition, when the curves are elliptical arcs, the length of the major axis of the ellipse formed by the elliptical arcs may be more than 1 time and 1.1 times or less than the length of the minor axis.

[0059] In the mesh wiring layer 20, an opening 23 is formed by being surrounded by the first directional wires 21 and the second directional wires 22. Specifically, in the mesh wiring layer 20, a plurality of openings 23 are formed by being surrounded by the first directional wires 21 adjacent to each other and the second directional wires 22 adjacent to each other. From each opening 23, the substrate 11 having transparency is exposed. This can increase the transparency of the wiring substrate 10 as a whole.

[0060] In the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23, the shape of the ends of the chords of a plurality of arcs (curves) connected together is a polygon. In this case, one side of the polygon may be composed of 2N (N is a natural number equal to or greater than 1) chords. In this embodiment, one side of the polygon is composed of two (N=1) chords. In addition, in this embodiment, the shape of the ends of the chords of a plurality of arcs (curves) connected together in the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23 is a square. That is, the straight line L1 connecting the ends of the chords of the first directional wiring 21 and the straight line L2 connecting the ends of the chords of the second directional wiring 22 are arranged at equal intervals. The straight lines L1 connecting the ends of the chords of the first directional wiring 21 are arranged at equal intervals, and the pitch P1 can be, for example, in the range of 0.01 mm to 1 mm. In addition, the straight lines L2 connecting the ends of the chords of the second direction wiring 22 are arranged at equal intervals, and the pitch P2 can be, for example, in the range of 0.01 mm to 1 mm. This eliminates variation in the size of the openings 23 in the mesh wiring layer 20, making the mesh wiring layer 20 difficult to see with the naked eye. Note that the straight lines L1 and L2 are mutually orthogonal, but are not limited to this, and may intersect at an acute angle or an obtuse angle. In addition, the shape of the openings 23 is preferably the same shape and size over the entire surface, but may be changed depending on the location and may not be uniform over the entire surface. Furthermore, although not shown, one side of the polygon may be composed of four or more (N≧2) chords, or may be composed of an odd number of chords.

[0061] Here, the first directional wiring 21 and the second directional wiring 22 may have a shape in which a plurality of arcs cut at a central angle of 160° to 200° are connected. In this case, the diameter of the circle from which the arcs are cut may be 0.4 to 0.6 times the length of one side of the square S1 formed by the straight lines L1 and L2. In this specification, the square S1 formed by the straight lines L1 and L2 refers to the square with the smallest area (see the shaded area in FIG. 5) among the regions (squares) surrounded by the straight lines L1 and L2.

[0062] Also, on one side of a square (polygon) S1, among the division points obtained by dividing the side into 2N equal parts, the Mth division point (M is a natural number between 1 and (2N-1)) counting from one end E1 of the ends E1 and E2 of the side is defined as the Mth division point. Also, among the connection points between chords on one side, the Mth connection point counting from one end E1 of the side is defined as the Mth connection point. In this case, the distance from the Mth division point to the Mth connection point may be 0.1 / N times or less the length of the side.

[0063] In this embodiment, as described above, one side of a polygon is composed of two chords, and N=1. Therefore, the only division point on one side that divides the side into 2N is the first division point DiP1 (M=1), which is the first division point (M=1) counting from one end E1 of the side. In this embodiment, this first division point DiP1 is the midpoint of the side. Also, on one side, the only connection point between the chords is the first connection point CP1, which is the first connection point (M=1) counting from one end E1 of the side.

[0064] In this way, when N=1 and M=1, as shown by the imaginary line (two-dot chain line) in FIG. 5, the shortest distance D p1 may be 0.1 times (N=1) or less the length of one side. When the first directional wiring 21 and the second directional wiring 22 have a shape in which arcs that satisfy the above relationship are connected, a nearly perfect circle can be formed by connecting the first directional wiring 21 and the second directional wiring 22 that surround the opening 23. Note that the virtual line in Fig. 5 is a curved line connecting two arcs, and is a curved line when the first connection point CP1 is not the midpoint of one side (first division point DiP1).

[0065] In this embodiment, as shown in FIG. 5, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ1 of 180° are connected. In this case, the diameter of the circle C1 from which the arcs are cut is 0.5 times the length of one side of the square S1 formed by the straight lines L1 and L2. In addition, on one side of the square S1 formed by the straight lines L1 and L2, the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side). In addition, the second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ2 of 180° are connected. In this case, the diameter of the circle C2 from which the arcs are cut is 0.5 times the length of one side of the square S1 formed by the straight lines L1 and L2. In addition, on one side of the square S1 formed by the straight lines L1 and L2, the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side). In this case, a complete circle can be formed by connecting, for example, the second directional wirings 22, 22a that form the upper straight line L1 among the first directional wiring 21 and the second directional wiring 22 that surround the opening 23 (see the shaded portion in FIG. 5). Here, a complete circle means a circle that is formed without overlapping arcs when curves are connected. Also, in this case, a plurality of complete circles can be formed by connecting the first directional wiring 21 and the second directional wiring 22 that surround the opening 23 (see the shaded portion in FIG. 5). In this specification, the opening 23 means the area that is the smallest among the areas surrounded by the first directional wiring 21 and the second directional wiring 22 (see the shaded portion in FIG. 5).

[0066] As described above, the diffraction image caused by the linear structure extends in a direction perpendicular to the longitudinal direction of the structure and becomes a light beam (a streak of light observed to have a trailing tail). On the other hand, when the generated light beam extends in all directions (360°), each light beam becomes difficult to distinguish. That is, the influence of the light beam on visibility can be reduced by overlapping a large number of light beams in a circular shape. Therefore, in order for the light beams to extend in all directions and, as a result, for the large number of light beams to overlap each other and be visually recognized as a circle, it is only necessary that the normals perpendicular to the longitudinal direction of the first directional wiring 21 and the second directional wiring 22 surrounding one opening 23 are distributed in all directions.

[0067] In contrast, in this embodiment, the first directional wiring 21 and the second directional wiring 22 may have a shape in which a plurality of arcs cut at a central angle of 160° or more and 200° or less are connected. p1 can be 0.1 times or less the length of one side. As a result, the normals perpendicular to the longitudinal direction of the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23 (see the shaded portion in FIG. 5) can be distributed in almost all directions. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed. In particular, when the first directional wiring 21 and the second directional wiring 22 have a shape in which a plurality of arcs are connected, which are obtained by cutting the circles C1 and C2, each having a diameter 0.5 times the length of one side of the square S1 formed by the straight lines L1 and L2, at the central angles θ1 and θ2 of 180°, and the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side), the above-mentioned normals are distributed in all directions. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed.

[0068] As shown in FIG. 6, each of the first direction wirings 21 has a shape in which a cross section perpendicular to its longitudinal direction is substantially rectangular or substantially square. In this case, the cross-sectional shape of the first direction wirings 21 is substantially uniform along the longitudinal direction of the first direction wirings 21. As shown in FIG. 7, each of the second direction wirings 22 has a cross-sectional shape perpendicular to its longitudinal direction that is substantially rectangular or substantially square, and has a shape substantially identical to the cross-sectional shape of the first direction wirings 21 described above. In this case, the cross-sectional shape of the second direction wirings 22 is substantially uniform along the longitudinal direction of the second direction wirings 22. The cross-sectional shapes of the first direction wirings 21 and the second direction wirings 22 do not necessarily have to be substantially rectangular or substantially square. For example, the cross-sectional shapes of the first direction wirings 21 and the second direction wirings 22 may be substantially trapezoids in which the front side (positive side in the Z direction) is narrower than the back side (negative side in the Z direction), or may have curved sides located on both sides in the width direction.

[0069] In this embodiment, the line width W1 of the first direction wiring 21 (see FIG. 6) and the line width W2 of the second direction wiring 22 (see FIG. 7) are not particularly limited and can be appropriately selected depending on the application. Here, the line width W1 of the first direction wiring 21 is the width in a cross section perpendicular to its longitudinal direction, and the line width W2 of the second direction wiring 22 is the width in a cross section perpendicular to its longitudinal direction. For example, the line width W1 of the first direction wiring 21 can be selected in the range of 0.1 μm to 5.0 μm, and may be 0.2 μm to 2.0 μm. Moreover, the line width W2 of the second direction wiring 22 can be selected in the range of 0.1 μm to 5.0 μm, and may be 0.2 μm to 2.0 μm.

[0070] The height H1 of the first directional wiring 21 (see FIG. 6) and the height H2 of the second directional wiring 22 (see FIG. 7) are not particularly limited and can be appropriately selected depending on the application. Here, the height H1 of the first directional wiring 21 and the height H2 of the second directional wiring 22 are lengths in the Z direction. The height H1 of the first directional wiring 21 and the height H2 of the second directional wiring 22 can each be selected within a range of 0.1 μm or more, for example, and may be 0.2 μm or more. The height H1 of the first directional wiring 21 and the height H2 of the second directional wiring 22 can each be selected within a range of 5.0 μm or less, for example, and may be 2.0 μm or less.

[0071] The material of the first directional wiring 21 and the second directional wiring 22 may be any metal material having electrical conductivity. In the present embodiment, the material of the first directional wiring 21 and the second directional wiring 22 is copper, but is not limited thereto. The material of the first directional wiring 21 and the second directional wiring 22 may be, for example, a metal material such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or an alloy containing these metals. The first directional wiring 21 and the second directional wiring 22 may be a plating layer formed by an electrolytic plating method.

[0072] The overall aperture ratio At of the mesh wiring layer 20 may be, for example, in the range of 87% or more and less than 100%. By setting the overall aperture ratio At of the mesh wiring layer 20 in this range, the conductivity and transparency of the wiring board 10 can be ensured. The overall aperture ratio At of the mesh wiring layer 20 is preferably 94% or more and less than 100%. This allows the transparency of the wiring board 10 to be increased while ensuring the conductivity of the wiring board 10. The aperture ratio refers to the ratio (%) of the area of ​​the opening region to the unit area of ​​a predetermined region (for example, the entire region of the mesh wiring layer 20). The opening region refers to a region where no metal parts such as the first directional wiring 21 and the second directional wiring 22 exist and the substrate 11 is exposed.

[0073] Although not shown, a protective layer may be formed on the first surface 11a of the substrate 11 so as to cover the mesh wiring layer 20. The protective layer protects the mesh wiring layer 20 and is formed so as to cover at least the mesh wiring layer 20 of the substrate 11. As a material for the protective layer, colorless and transparent insulating resins such as acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate, modified resins thereof, and copolymers thereof, polyester, polyvinyl alcohol, polyvinyl acetate, polyvinyl acetal, polyvinyl butyral, and copolymers thereof, polyurethane, epoxy resin, polyamide, and chlorinated polyolefin can be used.

[0074] Furthermore, when a bending resistance test is performed on wiring board 10, the increase in the resistance value of mesh wiring layer 20 may be 10% or less, or may be 5% or less. The bending resistance test is a test in which wiring board 10 is bent 180° around a cylinder with a diameter of 1 mm and then straightened 100 times using a cylindrical mandrel bending tester.

[0075] Specifically, the test is performed as follows. First, the electrical resistance between both ends in the longitudinal direction of the mesh wiring layer 20 is measured. The resistance value at this time is defined as R0 (Ω). Next, the wiring board 10 is wound around the cylinder of a cylindrical mandrel bending tester so that both ends in the longitudinal direction of the wiring board 10 face in opposite directions at 180°. After that, the wiring board 10 is removed from the cylinder and flattened out. This operation is repeated 100 times. Then, the electrical resistance between both ends in the longitudinal direction of the mesh wiring layer 20 is measured again. The resistance value at this time is defined as R1 (Ω). The value calculated by ((R1-R0) / R0)×100(%) is defined as the increase in the resistance value. When the increase in the resistance value is 10% or less, the durability of the wiring board 10 can be improved when the wiring board 10 is used while being curved or bent.

[0076] 4 again, the power supply section 40 is electrically connected to the mesh wiring layer 20. The power supply section 40 is made of a substantially rectangular conductive thin plate member.

[0077] Moreover, power supply unit 40 is disposed at a longitudinal end (negative end in the Y direction) of substrate 11. The material of power supply unit 40 may be, for example, a metal material such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or an alloy containing these metals.

[0078] When the wiring board 10 is incorporated into the HDM 90 (see FIG. 2), the power supply unit 40 is electrically connected to a wireless communication circuit 94a provided on a frame 91 of the HMD 90. The power supply unit 40 is preferably provided at a position overlapping a rim 92 of the frame 91 in a front view of the HMD 90. This makes it easier to connect the mesh wiring layer 20 and the wireless communication circuit 94a, and prevents the visibility of the outside world from being hindered. The power supply unit 40 is provided on the first surface 11a of the substrate 11, but is not limited thereto, and a part or the whole of the power supply unit 40 may be located outside the periphery of the substrate 11.

[0079] [Method of manufacturing wiring board] Next, a method for manufacturing wiring board 10 according to the present embodiment will be described with reference to FIGS. 8A to 8F.

[0080] First, as shown in Fig. 8A, a substrate 11 is prepared, which includes a first surface 11a and a second surface 11b located on the opposite side to the first surface 11a. The substrate 11 is transparent.

[0081] Next, on the first surface 11a of the substrate 11, the mesh wiring layer 20 and the power supply section 40 electrically connected to the mesh wiring layer 20 are formed.

[0082] 8B, first, metal foil 51 is laminated over substantially the entire first surface 11a of substrate 11. In this embodiment, metal foil 51 may have a thickness of 0.1 μm or more and 5.0 μm or less. In this embodiment, metal foil 51 may contain copper.

[0083] 8C, a photocurable insulating resist 52 is applied to substantially the entire surface of the metal foil 51. As the photocurable insulating resist 52, for example, an organic resin such as an acrylic resin or an epoxy resin can be used.

[0084] 8D, the insulating layer 54 is formed by photolithography. In this case, the photo-curable insulating resist 52 is patterned by photolithography to form the insulating layer 54 (resist pattern). At this time, the insulating layer 54 is formed so that the metal foil 51 corresponding to the first directional wiring 21 and the second directional wiring 22 is exposed.

[0085] 8E, metal foil 51 located on a portion of first surface 11a of substrate 11 that is not covered with insulating layer 54 is removed. At this time, metal foil 51 is etched so that first surface 11a of substrate 11 is exposed by performing a wet treatment using ferric chloride, cupric chloride, a strong acid such as sulfuric acid or hydrochloric acid, a persulfate, hydrogen peroxide, or an aqueous solution of these, or a combination of these, or the like.

[0086] 8F, 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, N-methyl-2-pyrrolidone, an acid or alkaline solution, or a dry treatment using oxygen plasma.

[0087] In this manner, a wiring board 10 is obtained, which includes the substrate 11 and the mesh wiring layer 20 provided on the first surface 11a of the substrate 11. In this case, the mesh wiring layer 20 includes first directional wiring 21 and second directional wiring 22. At this time, the power supply unit 40 may be formed by a part of the metal foil. Alternatively, a flat-plate-shaped power supply unit 40 may be separately prepared and electrically connected to the mesh wiring layer 20.

[0088] 1 is obtained by attaching the wiring board 10 to the first base material 96 that is fitted into the rim 92 of the frame 91. Note that the wiring board 10 may be attached to the first base material 96 before the first base material 96 is fitted into the rim 92 of the frame 91.

[0089] [Operation of this embodiment] Next, the operation of this embodiment having the above configuration will be described.

[0090] 2, the wiring board 10 is incorporated into the HMD 90 as a component of the display device 95. The mesh wiring layer 20 of the wiring board 10 is electrically connected to a wireless communication circuit 94a of the HMD 90 via the power supply unit 40. In this way, radio waves of a predetermined frequency can be transmitted and received via the mesh wiring layer 20, and communication can be performed using the HMD 90.

[0091] According to this embodiment, the planar shape of the first directional wiring 21 and the second directional wiring 22 is a shape in which a plurality of arcs are connected. As a result, the generated light beams extend in various directions. Therefore, the light beams overlap each other, making it difficult to distinguish each light beam. As a result, the decrease in visibility due to the light beams can be suppressed. In addition, in this case, the decrease in visibility due to the light beams can be suppressed without increasing the variation in the pitch of the first directional wiring 21 and the second directional wiring 22 and the variation in the pitch of the second directional wiring 22. Therefore, flicker caused by the reflection of visible light by the mesh wiring layer 20 can be suppressed. Furthermore, since the planar shape of the first directional wiring 21 and the second directional wiring 22 is a shape in which a plurality of arcs are connected, the reflection of electromagnetic waves in the first directional wiring 21 and the second directional wiring 22 can be reduced. Therefore, the transmission efficiency in the wiring board 10 can be improved.

[0092] Furthermore, according to this embodiment, in the HMD 90, the wiring board 10 includes a transparent board 11 and a mesh wiring layer 20 disposed on the board 11. The mesh wiring layer 20 has an aperture ratio of 94% or more. This ensures the transparency of the wiring board 10. As a result, when the wiring board 10 is incorporated into the HMD 90, the outside world can be viewed through the openings 23 of the mesh wiring layer 20, and visibility of the outside world is not impeded.

[0093] Next, modified examples of the wiring board will be described.

[0094] Fig. 9 shows a first modified example of the wiring board 10. The modified example shown in Fig. 9 is different in that the first directional wiring 21 and the second directional wiring 22 have a shape in which a plurality of arcs cut at a central angle of 80° or more and 100° or less are connected, and other configurations are substantially the same as the embodiment shown in Figs. 1 to 8F described above. In Fig. 9, the same parts as those in the embodiment shown in Figs. 1 to 8F are given the same reference numerals and detailed description will be omitted.

[0095] In the wiring board 10 shown in FIG. 9, the first directional wiring 21 and the second directional wiring 22 have a shape in which a plurality of circular arcs cut at a central angle of 80° or more and 100° or less are connected. In this case, the diameter of the circle from which the circular arcs are cut may be (1 / √2)×0.8 times or more and (1 / √2)×1.2 times or less than the length of one side of the square S1 formed by the straight lines L1 and L2. Also in this modification, the shortest distance D from the first division point DiP1 to the first connection point CP1 on one side of the square S1 formed by the straight lines L1 and L2 is p1 (See FIG. 5) may be 0.1 times or less the length of one side. Even when the first directional wiring 21 and the second directional wiring 22 have a shape formed by connecting arcs that satisfy the above relationship, a nearly perfect circle can be formed by connecting the first directional wiring 21 and the second directional wiring 22 that surround the opening 23.

[0096] In this modification, as shown in FIG. 9, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ3 of 90° are connected. In this case, the diameter of the circle C3 from which the arcs are cut is 1 / √2 times the length of one side of the square S1 formed by the straight lines L1 and L2. In addition, on one side of the square S1 formed by the straight lines L1 and L2, the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side). In addition, the second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ4 of 90° are connected. In this case, the diameter of the circle C4 from which the arcs are cut is 1 / √2 times the length of one side of the square S1 formed by the straight lines L1 and L2. In addition, on one side of the square S1 formed by the straight lines L1 and L2, the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side). Even in this case, multiple complete circles can be formed by connecting the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23. Even in this case, the influence of the light beams on visibility can be reduced by overlapping the light beams in a circular shape. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed.

[0097] In this modification, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ3 of 80° to 100° are connected, and the second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ4 of 80° to 100° are connected. In this case, in the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23, the difference between the line length of the shape (polygon) in which the ends of the chords of a plurality of curves are connected to each other and the total line length of the first directional wiring 21 and the second directional wiring 22 can be made small. In other words, compared to the case in which the central angle θ3 and the central angle θ4 are, for example, 180°, the central angle θ3 and the central angle θ4 are 80° to 100°, so that the increase rate of the total line length of the first directional wiring 21 and the second directional wiring 22 with respect to the above-mentioned polygon can be reduced. This makes it possible to suppress an increase in the resistance value of the mesh wiring layer 20.

[0098] In addition, since the rate of increase in the line length can be reduced, the decrease in the aperture ratio of the mesh wiring layer 20 can be suppressed. In addition, since the rate of increase in the line length can be reduced, the line length of the first direction wiring 21 and the line length of the second direction wiring 22 can be suppressed from becoming too long. Therefore, the risk of disconnection of the first direction wiring 21 and the second direction wiring 22 can also be reduced. Furthermore, since the line length of the first direction wiring 21, etc. and the line length of the second direction wiring 22 can be suppressed from becoming too long, the patterning accuracy when manufacturing the first direction wiring 21 and the second direction wiring 22 and the dimensional stability of the first direction wiring 21 and the second direction wiring 22 can be improved. Therefore, the productivity of the wiring board 10 can be improved.

[0099] Fig. 10A shows a second modified example of the wiring board 10. The modified example shown in Fig. 10A differs in that the shape of the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23, where the ends of the chords of a plurality of curves are connected to each other, is a rhombus, and the other configurations are substantially the same as those shown in Figs. 1 to 9 described above. In Fig. 10A, the same parts as those shown in Figs. 1 to 9 are given the same reference numerals, and detailed description thereof will be omitted.

[0100] In the wiring board 10 shown in FIG. 10A, the shape of the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23, in which the ends of the chords of the multiple curves are connected to each other, is a rhombus. In other words, the above-mentioned polygon is a rhombus. In this case, the first directional wiring 21 and the second directional wiring 22 extend in a direction non-parallel to both the X direction and the Y direction, respectively. This makes it possible to reduce the resistance in the Y direction in which the current flows. This makes it possible to improve the antenna characteristics.

[0101] Moreover, the first directional wiring 21 and the second directional wiring 22 have a shape in which a plurality of circular arcs cut at a central angle of 160° or more and 200° or less are connected. In this case, the diameter of the circle from which the circular arcs are cut may be 0.4 times or more and 0.6 times or less the length of one side of the rhombus S2 formed by the straight lines L1 and L2. Also, as shown by the imaginary line (two-dot chain line) in FIG. 10A, the shortest distance D from the first division point DiP1 to the first connection point CP1 on one side of the rhombus S2 formed by the straight lines L1 and L2 is 0.4 times or more and 0.6 times or less. p2 may be 0.1 times or less the length of one side. Even when the first directional wiring 21 and the second directional wiring 22 have a shape formed by connecting arcs that satisfy the above relationship, a nearly perfect circle can be formed by connecting the first directional wiring 21 and the second directional wiring 22 that surround the opening 23. Note that the virtual line in Fig. 10A is a curved line connecting two arcs, and is a curved line when the first connection point CP1 is not the midpoint of one side (first division point DiP1).

[0102] In this modification, as shown in FIG. 10A, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ5 of 180° are connected. In this case, the diameter of the circle C5 from which the arcs are cut is 0.5 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. In addition, on one side of the rhombus S2 formed by the straight lines L1 and L2, the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side). In addition, the second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ6 of 180° are connected. In this case, the diameter of the circle C6 from which the arcs are cut is 0.5 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. In addition, on one side of the rhombus S2 formed by the straight lines L1 and L2, the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side). Even in this case, multiple complete circles can be formed by connecting the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23. Even in this case, the influence of the light beams on visibility can be reduced by overlapping the light beams in a circular shape. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed.

[0103] In the wiring board 10 shown in FIG. 10A, the first directional wiring 21 and the second directional wiring 22 have a shape in which a plurality of arcs cut at a central angle of 160° to 200° are connected, but the present invention is not limited to this. For example, the first directional wiring 21 and the second directional wiring 22 may have a shape in which a plurality of arcs cut at a central angle of 80° to 100° are connected. Even in this case, the diameter of the circle from which the arcs are cut may be 0.4 to 0.6 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. Also, as shown by the virtual line (two-dot chain line) in FIG. 10B, the shortest distance D from the first division point DiP1 to the first connection point CP1 on one side of the rhombus S2 formed by the straight lines L1 and L2 may be 0.4 to 0.6 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. p2 may be 0.1 times or less the length of one side. Note that the virtual line in Fig. 10B is a curve that connects two circular arcs, and is a curve when the first connection point CP1 is not the midpoint of one side (the first division point DiP1).

[0104] In this modification, as shown in FIG. 10B, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ5 of 90° are connected. In this case, too, the diameter of the circle C5 from which the arcs are cut is 0.5 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. In addition, on one side of the rhombus S2 formed by the straight lines L1 and L2, the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side). In addition, the second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ6 of 90° are connected. In this case, too, the diameter of the circle C6 from which the arcs are cut is 0.5 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. In addition, on one side of the rhombus S2 formed by the straight lines L1 and L2, the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side).

[0105] In the example shown in FIG. 10B, the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23 are connected to form a plurality of complete circles. In this case, the influence of the light beams on visibility can be reduced by overlapping a large number of light beams in a circular shape. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed. Also, in the example shown in FIG. 10B, the increase rate of the total line length of the first directional wiring 21 and the second directional wiring 22 with respect to the polygon described above can be reduced, and the increase in the resistance value of the mesh wiring layer 20 can be suppressed. In addition, since the increase rate of the line length can be reduced, the decrease in the aperture ratio of the mesh wiring layer 20 can be suppressed. Also, in the example shown in FIG. 10B, the line length of the first directional wiring 21 and the line length of the second directional wiring 22 can be suppressed from becoming too long, and the risk of disconnection of the first directional wiring 21 and the second directional wiring 22 can be reduced. Furthermore, it is possible to improve the patterning accuracy when producing the first directional wires 21 and the second directional wires 22, and the dimensional stability of the first directional wires 21 and the second directional wires 22. As a result, the productivity of the wiring board 10 can be improved.

[0106] Fig. 11 shows a third modified example of the wiring board 10. The modified example shown in Fig. 11 differs in that one side of the rhombus S2 is composed of four (N=2) chords, and the other configurations are substantially the same as those shown in Figs. 1 to 10B described above. In Fig. 11, the same parts as those shown in Figs. 1 to 10B are given the same reference numerals and detailed description is omitted.

[0107] In the wiring board 10 shown in Fig. 11, one side of the diamond S2 is composed of four chords (N = 2). Therefore, on one side, there are three division points that divide the side into four (N = 2): a first division point DiP1, a second division point DiP2, and a third division point DiP3. Of these, the second division point DiP2 is the midpoint of the side. In addition, on one side, there are three connection points between the chords: a first connection point CP1, a second connection point CP2, and a third connection point CP3.

[0108] In this modification, as shown by the imaginary line (two-dot chain line) in FIG. 11, the shortest distance D from the first division point DiP1 to the first connection point CP1 on one side of the rhombus S2 is p3 may be 0.05 times the length of one side (N=2) or less. Also, on one side of the rhombus S2, the shortest distance D from the second division point DiP2 to the second connection point CP2 is p4 may be 0.05 times the length of one side (N=2) or less. Furthermore, on one side of the rhombus S2, the shortest distance D from the third division point DiP3 to the third connection point CP3 is p5 may be 0.05 times (N=2) or less the length of one side. Even when the first directional wiring 21 and the second directional wiring 22 have a shape formed by connecting arcs that satisfy the above relationship, a nearly perfect circle can be formed by connecting the first directional wiring 21 and the second directional wiring 22 that surround the opening 23. The virtual line in Fig. 11 is a curved line connecting four arcs, and is a curved line when the first connection point CP1 is not the first division point DiP1, the second connection point CP2 is not the second division point DiP2, and the third connection point CP3 is not the third division point DiP3.

[0109] 11, the diameter of the circles C5 and C6 from which the arcs are cut is 0.25 times the length of one side of the rhombus S2. Also, on one side of the rhombus S2 formed by the straight lines L1 and L2, the first connection point CP1 is located on the first division point DiP1, the second connection point CP2 is located on the second division point DiP2 (the midpoint of the side), and the third connection point CP3 is located on the third division point DiP3.

[0110] In this modification, as shown in FIG. 11, the shortest distance D from the first division point DiP1 to the first connection point CP1 on one side of the rhombus S2 is p3 is less than 0.05 times the length of one side (N=2). Also, on one side of the rhombus S2, the shortest distance D from the second division point DiP2 to the second connection point CP2 is p4 is less than 0.05 times the length of one side (N=2). Furthermore, on one side of the rhombus S2, the shortest distance D from the third division point DiP3 to the third connection point CP3 is p5 is 0.05 times (N=2) or less of the length of one side. Even in this case, by connecting the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23, a plurality of complete circles can be formed. Even in this case, the influence of the light beams on visibility can be reduced by overlapping the light beams in a circular shape. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed.

[0111] Fig. 12A shows a fourth modified example of the wiring board 10. The modified example shown in Fig. 12A differs in that the shape of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 surrounding the opening 23, in which the ends of the chords of a plurality of curves are connected to each other, is a regular hexagon, and the other configurations are substantially the same as those shown in Figs. 1 to 11 described above. In Fig. 12A, the same parts as those in the embodiments shown in Figs. 1 to 11 are given the same reference numerals, and detailed description thereof will be omitted.

[0112] In the wiring board 10 shown in FIG. 12A, the shape of the first directional wiring 21, the second directional wiring 22, and the third directional wiring (wiring) 24 surrounding the opening 23, in which the ends of the chords of the multiple curves are connected to each other, is a regular hexagon. In other words, the above-mentioned polygon is a regular hexagon. In this case, the first directional wiring 21 and the second directional wiring 22 extend in a direction non-parallel to both the X direction and the Y direction, respectively. On the other hand, the third directional wiring 24 extends in the X direction. This makes it possible to reduce the resistance in the Y direction in which the current flows. This improves the antenna characteristics. In addition, since the third directional wiring 24 connects the first directional wiring 21 and the second directional wiring 22, it is possible to effectively suppress breakage of the mesh wiring layer 20. It is to be noted that the third directional wiring 24 may extend in a direction non-parallel to both the X direction and the Y direction. The line width and height of the third directional wiring 24 and the material constituting the third directional wiring 24 may be the same as those of the first directional wiring 21.

[0113] Moreover, the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 each have a shape in which a plurality of circular arcs cut at a central angle of 160° or more and 200° or less are connected. In this case, the diameter of the circle from which the circular arcs are cut may be 0.4 times or more and 0.6 times or less the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. Also, as shown by the imaginary line (two-dot chain line) in FIG. 12A, the shortest distance D from the first division point DiP1 to the first connection point CP1 on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3 is 0.4 times or more and 0.6 times or less. p6 may be 0.1 times (N=1) or less the length of one side. Even when the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 have a shape in which arcs that satisfy the above relationship are connected, a nearly perfect circle can be formed by connecting the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 that surround the opening 23. Note that the virtual line in Fig. 12A is a curve that connects two arcs, and is a curve when the first connection point CP1 is not the midpoint of one side (first division point DiP1).

[0114] In this modification, as shown in FIG. 12A, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ7 of 180° are connected. In this case, the diameter of the circle C7 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. In addition, on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3, the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side). In addition, the second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ8 of 180° are connected. In this case, the diameter of the circle C8 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. Moreover, on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3, the first connection point CP1 is located on the first division point DiP1 (midpoint of one side). Furthermore, the third directional wiring 24 has a shape in which a plurality of arcs cut at a central angle θ9 of 180° are connected. In this case, the diameter of the circle C9 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. Furthermore, on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3, the first connection point CP1 is located on the first division point DiP1 (midpoint of one side). Even in this case, by connecting the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 surrounding the opening 23, a plurality of complete circles can be formed. Even in this case, the influence of the light beams on visibility can be reduced by overlapping a large number of light beams in a circular shape. This makes it possible to more effectively prevent the deterioration of visibility due to the rays of light.

[0115] In this modification, the shape (polygon) of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 surrounding the opening 23, in which the ends of the chords of a plurality of curves are connected to each other, is a regular hexagon. In this case, the number of wirings (the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24) connected to the vertices of the polygon is a maximum of three. In addition, the angle formed by the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 at the vertices of the polygon is 120°, which is larger than when the polygon is a square. Therefore, in the vicinity of the vertices of the polygon, the patterning accuracy when the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 are manufactured, and the dimensional stability of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 can be improved. Therefore, the productivity of the wiring board 10 can be improved.

[0116] In the wiring board 10 shown in FIG. 12A, the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 have a shape in which a plurality of arcs cut at a central angle of 160° to 200° are connected, but the present invention is not limited to this. For example, the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 may have a shape in which a plurality of arcs cut at a central angle of 80° to 100° are connected. Even in this case, the diameter of the circle from which the arcs are cut may be 0.4 to 0.6 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. Also, as shown by the virtual line (two-dot chain line) in FIG. 12B, the shortest distance D from the first division point DiP1 to the first connection point CP1 on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3 may be 0.4 to 0.6 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. p6 may be 0.1 times the length of one side (N=1) or less. Note that the virtual line in Fig. 12B is a curve that connects two circular arcs, and is a curve when the first connection point CP1 is not the midpoint of one side (the first division point DiP1).

[0117] In this modification, as shown in FIG. 12B, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ7 of 90° are connected. In this case, too, the diameter of the circle C7 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. In addition, on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3, the first connection point CP1 is located on the first division point DiP1 (the midpoint of one side). In addition, the second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ8 of 90° are connected. In this case, too, the diameter of the circle C8 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. Moreover, on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3, the first connection point CP1 is located on the first division point DiP1 (midpoint of one side). Furthermore, the third directional wiring 24 has a shape in which a plurality of arcs cut at a central angle θ9 of 90° are connected. In this case as well, the diameter of the circle C9 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. Furthermore, on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3, the first connection point CP1 is located on the first division point DiP1 (midpoint of one side).

[0118] In the example shown in FIG. 12B, the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 surrounding the opening 23 are connected to form a plurality of complete circles. In this case, the influence of the light beams on visibility can be reduced by overlapping a large number of light beams in a circular shape. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed. In addition, in the example shown in FIG. 12B, the increase rate of the total line length of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 with respect to the polygon described above can be reduced, and the increase in the resistance value of the mesh wiring layer 20 can be suppressed. In addition, since the increase rate of the line length can be reduced, the decrease in the aperture ratio of the mesh wiring layer 20 can be suppressed. In addition, in the example shown in FIG. 12B, the line length of the first directional wiring 21, the line length of the second directional wiring 22, and the line length of the third directional wiring 24 can be suppressed from becoming too long, and the risk of disconnection of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 can be reduced. Furthermore, it is possible to improve the patterning accuracy when fabricating the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24, and the dimensional stability of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24. As a result, the productivity of the wiring board 10 can be improved.

[0119] Fig. 13 shows a fifth modified example of the wiring board. The modified example shown in Fig. 13 is different in that the corners of the polygon are irregularly arranged, and other configurations are substantially the same as the embodiment shown in Figs. 1 to 12B described above. In Fig. 13, the same parts as those shown in Figs. 1 to 12B are given the same reference numerals and detailed description is omitted.

[0120] In the wiring board 10 shown in FIG. 13, the corners of the polygon S4 formed by the straight lines L1 and L2 are irregularly arranged. That is, the straight line L1 connecting the ends of the chords of the first directional wiring 21 and the straight line L2 connecting the ends of the chords of the second directional wiring 22 are irregularly arranged. Specifically, the straight lines L1 are arranged parallel to each other, and the pitch P1 is irregular. Similarly, the straight lines L2 are arranged parallel to each other, and the pitch P2 is irregular. In this way, the pitch P1 of the straight lines L1 and the pitch P2 of the straight lines L2 are irregular, so that the decrease in visibility due to the light beams can be suppressed. Also in this case, multiple complete circles can be formed by connecting the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23. Also in this case, the influence of the light beams on visibility can be reduced by overlapping a large number of light beams in a circular shape. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed.

[0121] As shown in FIG. 14, the polygon S5 formed by the straight lines L1 and L2 may be a quadrangle in which the opposing sides are not parallel. In this case, the chords of the curves may extend in a bent linear shape. In other words, the chords connected to each other may extend in directions that are not parallel to each other. As shown in FIG. 15, in the mesh wiring (wiring) 200 surrounding the opening 23, the shape in which the ends of the chords of a plurality of arcs (curves) are connected to each other may be a polygon S6, and the planar structure formed by the polygon S6 may be a Voronoi pattern. The line width and height of the mesh wiring 200, and the material constituting the mesh wiring 200 may be the same as those of the first direction wiring 21.

[0122] Figures 16 and 17 show a sixth modified example of the wiring board. The modified example shown in Figures 16 and 17 is different in that a dummy wiring layer 30 is provided around the mesh wiring layer 20, and other configurations are substantially the same as the embodiment shown in Figures 1 to 15 described above. In Figures 16 and 17, the same parts as those in the embodiment shown in Figures 1 to 15 are given the same reference numerals and detailed description will be omitted.

[0123] 16, a dummy wiring layer 30 is provided along the periphery of the mesh wiring layer 20. Unlike the mesh wiring layer 20, this dummy wiring layer 30 does not substantially function as an antenna.

[0124] As shown in Fig. 17, the dummy wiring layer 30 is composed of repeated dummy wirings 30a having a predetermined pattern shape. That is, the dummy wiring layer 30 includes a plurality of dummy wirings 30a, and each dummy wiring 30a is electrically independent from the mesh wiring layer 20 (the first directional wiring 21 and the second directional wiring 22). The plurality of dummy wirings 30a are regularly arranged over 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 arranged to protrude above the substrate 11. That is, each dummy wiring 30a is electrically independent from the mesh wiring layer 20, the power supply section 40, and the other dummy wirings 30a.

[0125] In this case, the dummy wiring 30a has a shape in which a part of the pattern shape of the mesh wiring layer 20 described above is missing. This makes it difficult to visually recognize the difference between the mesh wiring layer 20 and the dummy wiring layer 30, and makes the mesh wiring layer 20 arranged on the substrate 11 less visible. As shown in FIG. 17, the dummy wiring 30a includes a first part 31a in which a part of the first directional wiring 21 is cut out, and a second part 32a in which a part of the second directional wiring 22 is cut out. In this way, the dummy wiring 30a is composed of a part of the first directional wiring 21 or the second directional wiring 22 cut out, so that the mesh wiring layer 20 arranged on the substrate 11 can be made even less visible. The aperture ratio of the dummy wiring layer 30 may be the same as or different from the aperture ratio of the mesh wiring layer 20, but is preferably close to the aperture ratio of the mesh wiring layer 20. Therefore, in the region of the dummy wiring layer 30, copper wiring having the same shape as the missing part may be arranged at any position so that the dummy wirings 30a are not connected to each other. In this case, within the region of the dummy wiring layer 30, copper wiring having the same area as the missing portion in a plan view may be disposed at any position so that the dummy wirings 30a are not connected to each other.

[0126] As in this modified example, the dummy wiring layer 30 that is electrically independent from the mesh wiring layer 20 is provided around the mesh wiring layer 20, making it possible to make the outer edge of the mesh wiring layer 20 unclear. This makes it possible to make the mesh wiring layer 20 less visible on the surface of the HMD 90, and makes it difficult for a user of the HMD 90 to recognize the mesh wiring layer 20 with the naked eye.

[0127] Figures 18 and 19 show a seventh modified example of the wiring board. The modified example shown in Figures 18 and 19 is different in that a plurality of dummy wiring layers 30A, 30B having different aperture ratios are provided around the mesh wiring layer 20, and other configurations are substantially the same as the embodiment shown in Figures 1 to 17 described above. In Figures 18 and 19, the same parts as those in the embodiment shown in Figures 1 to 17 are given the same reference numerals and detailed description will be omitted.

[0128] 18, a plurality of (two in this case) dummy wiring layers 30A, 30B (a first dummy wiring layer 30A and a second dummy wiring layer 30B) having different aperture ratios are provided along the periphery of the mesh wiring layer 20. Specifically, the first dummy wiring layer 30A is disposed along the periphery of the mesh wiring layer 20, and the second dummy wiring layer 30B is disposed along the periphery of the first dummy wiring layer 30A. Unlike the mesh wiring layer 20, these dummy wiring layers 30A, 30B do not substantially function as antennas.

[0129] As shown in FIG. 19, the first dummy wiring layer 30A is composed of repeated dummy wirings 30a1 having a predetermined pattern shape. The second dummy wiring layer 30B is composed of repeated dummy wirings 30a2 having a predetermined pattern shape. That is, the dummy wiring layers 30A and 30B each include a plurality of dummy wirings 30a1 and 30a2, and each of the dummy wirings 30a1 and 30a2 is electrically independent from the mesh wiring layer 20. The dummy wirings 30a1 and 30a2 are regularly arranged over the entire area of ​​the dummy wiring layers 30A and 30B, respectively. The dummy wirings 30a1 and 30a2 are spaced apart from each other in the planar direction and are arranged to protrude above the substrate 11. The dummy wirings 30a1 and 30a2 are electrically independent from the mesh wiring layer 20, the power supply section 40, and the other dummy wirings 30a1 and 30a2, respectively.

[0130] In this case, the dummy wirings 30a1 and 30a2 have a shape in which a part of the pattern shape of the mesh wiring layer 20 described above is missing. This makes it difficult to visually recognize the difference between the mesh wiring layer 20 and the first dummy wiring layer 30A, and the difference between the first dummy wiring layer 30A and the second dummy wiring layer 30B, and makes it difficult to see the mesh wiring layer 20 arranged on the substrate 11. As shown in FIG. 19, the dummy wiring 30a1 includes a first portion 31a1 having a shape in which a part of the first directional wiring 21 is cut out, and a second portion 32a1 having a shape in which a part of the second directional wiring 22 is cut out. The dummy wiring 30a2 includes a first portion 31a2 having a part of the first directional wiring 21 cut out, and a second portion 32a2 having a part of the second directional wiring 22 cut out.

[0131] The area of ​​each dummy wiring 30a1 in the first dummy wiring layer 30A is larger than the area of ​​each dummy wiring 30a2 in the second dummy wiring layer 30B. In this case, the line width of each dummy wiring 30a1 is the same as the line width of each dummy wiring 30a2, but this is not limited thereto, and the line width of each dummy wiring 30a1 may be larger than the line width of each dummy wiring 30a2.

[0132] In this modification, the aperture ratio of the mesh wiring layer 20 and the multiple dummy wiring layers 30A, 30B is preferably increased stepwise from the mesh wiring layer 20 toward the dummy wiring layers 30A, 30B far from the mesh wiring layer 20. In other words, the aperture ratio of each dummy wiring layer is preferably gradually increased from the one closer to the mesh wiring layer 20 toward the one farther away. In this case, the aperture ratio of the first dummy wiring layer 30A is preferably larger than the aperture ratio of the mesh wiring layer 20. The aperture ratio of the second dummy wiring layer 30B is preferably larger than the aperture ratio of the first dummy wiring layer 30A. This makes it possible to further obscure the outer edges of the mesh wiring layer 20 and the dummy wiring layers 30A, 30B. This makes it possible to further obscure the mesh wiring layer 20 on the surface of the HMD90.

[0133] In this way, by disposing the dummy wiring layers 30A and 30B electrically independent from the mesh wiring layer 20, the outer edge of the mesh wiring layer 20 can be made more unclear. This makes it possible to make the mesh wiring layer 20 less visible on the surface of the HMD 90, and makes it difficult for a user of the HMD 90 to recognize the mesh wiring layer 20 with the naked eye. Note that three or more dummy wiring layers having different aperture ratios may be provided around the mesh wiring layer 20.

[0134] It is also possible to combine the multiple components disclosed in the above embodiment and each modification as necessary, or to delete some of the components disclosed in the above embodiment and each modification.

Claims

1. A wiring board, A transparent substrate; a mesh wiring layer disposed on the substrate; The wiring board has an electromagnetic wave transmitting and receiving function, The mesh wiring layer is configured as a transmission / reception unit for electromagnetic waves, and has wiring. The planar shape of the wiring is a shape in which a plurality of curved lines are connected, the curve is a circular arc or an elliptical arc, the wiring includes first directional wiring extending in a first direction, second directional wiring extending in a second direction different from the first direction, and third directional wiring extending in a third direction non-parallel to both the first direction and the second direction; an opening is formed by being surrounded by the first directional wiring, the second directional wiring, and the third directional wiring; the wiring surrounding the opening has a shape formed by connecting ends of the chords of the plurality of curves to each other, the shape being a hexagon; Each side of the hexagon is composed of 2N chords (N is a natural number equal to or greater than 1), Among the division points obtained by dividing the side into 2N equal parts, an Mth division point (M is a natural number between 1 and (2N-1)) counting from one end of the side is designated as an Mth division point, Among the connection points between the strings on the one side, when the Mth connection point counting from the one end of the one side is defined as the Mth connection point, A wiring board, wherein a distance from the Mth division point to the Mth connection point is equal to or less than 0.1 / N times the length of the one side.

2. The wiring board according to claim 1 , wherein the mesh wiring layer has an aperture ratio of 94% or more.

3. 2. The wiring board according to claim 1, wherein the wiring has a shape in which a plurality of circular arcs cut at a central angle of 160 degrees or more and 200 degrees or less are connected.

4. A plurality of the openings are formed, The wiring board according to claim 3 , wherein the corners of the hexagon are irregularly arranged.

5. The wiring board described in claim 3, wherein the hexagon is a regular hexagon.

6. The wiring board described in claim 1, wherein the wiring has a shape formed by connecting multiple arcs cut at a central angle of 80° or more and 100° or less.

7. A plurality of the openings are formed, The wiring board according to claim 6 , wherein the corners of the hexagon are irregularly arranged.

8. The wiring board as described in claim 6, wherein the hexagon is a regular hexagon.

9. The wiring board according to claim 1 , wherein the curve is a circular arc cut at a central angle of 90° or 180°.

10. 2. The wiring board according to claim 1, wherein N is 1.

11. The wiring board according to claim 1 , wherein the wiring board has a function of transmitting and receiving radio waves at a frequency of 1 GHz or more.

12. The wiring board according to claim 1 , wherein the mesh wiring layer has an electromagnetic wave shielding function.

13. 2. The wiring board according to claim 1, wherein when the wiring board is bent 180 degrees around a cylinder having a diameter of 1 mm and then straightened 10 times, the increase in resistance value of the mesh wiring layer is 10% or less.

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

15. 15. The wiring board according to claim 14, wherein a plurality of the dummy wiring layers are provided, and the aperture ratios of the mesh wiring layer and the dummy wiring layer are gradually increased from the mesh wiring layer to the dummy wiring layer farther from the mesh wiring layer.

16. A frame, a transparent display attached to the frame; The display device includes: A first substrate; The wiring board according to claim 1 , which is provided on the first base material; a display unit provided between the first base material and the wiring board.

Images