Patent Application
20230318203
An embodiment of the present disclosure relates to a wiring board and a method of manufacturing the wiring board.
These days, portable terminal devices such as smartphones and tablets are becoming more and more sophisticated in functionality, smaller in size, thinner in profile, and lighter in weight. These portable terminal devices use a plurality of communication bands, and therefore require a plurality of antennas corresponding to the communication bands. For example, a portable terminal device is equipped with a plurality of antennas such as a phone antenna, a wireless fidelity (Wi-Fi) antenna, a third generation (3G) antenna, a fourth generation (4G) antenna, a long term evolution (LTE) antenna, a Bluetooth (®) antenna, and a near field communication (NFC) antenna. However, as portable terminal devices are becoming smaller, it imposes a limitation on an antenna mounting space and reduces antenna design flexibility. Moreover, since the antennas are provided in a limited space, radio sensitivity is not always satisfactory.
To address this issue, film antennas mountable in a display region of a portable terminal device have been developed. A film antenna has a structure in which, in a transparent antenna including a transparent base substrate on which an antenna pattern is formed, the antenna pattern is formed of a conductor mesh layer having a mesh structure including a conductor portion where an opaque conductor layer is formed and a plurality of openings where no such conductor is formed.
[Patent Literature 1]: Japanese Unexamined Patent Application Publication No. 2011-66610
[Patent Literature 2]: Specification of Japanese Patent No. 5636735
[Patent Literature 3]: Specification of Japanese Patent No. 5695947
By the way, for example, in a film antenna according to related art, a single mesh antenna, or a plurality of mesh antennas, is mounted on a transparent base substrate, and there exist both an area where an antenna pattern is formed on the transparent base substrate and an area where no antenna pattern is formed on the transparent base substrate. In this case, the presence of the area where no antenna pattern is formed makes it easier for the area where the antenna pattern is formed to be visually noticed. Therefore, a solution for making it harder for a wiring pattern such as an antenna pattern to be visually noticed is demanded.
One of objects of the present embodiment is to provide a wiring board that makes it harder for a wiring pattern area to be visually noticed, and a method of manufacturing the wiring board.
A wiring board according to an embodiment of the present disclosure is a wiring board that includes: a substrate; a wiring pattern area arranged on the substrate and including pieces of wiring; and a plurality of dummy pattern areas arranged around the wiring pattern area and electrically independent of the wiring, wherein the substrate has transparency, among the plurality of dummy pattern areas, an aperture ratio of a first dummy pattern area, which is located next to the wiring pattern area, is not lower than an aperture ratio of the wiring pattern area, and among the plurality of dummy pattern areas, an aperture ratio of a second dummy pattern area, which is located next to the first dummy pattern area and farther from the wiring pattern area than the first dummy pattern area is, is higher than the aperture ratio of the first dummy pattern area.
In the wiring board according to an embodiment of the present disclosure, each as the wiring pattern area, a plurality of wiring pattern areas may exist, and at least one of the plurality of dummy pattern areas may be provided in such a way as to surround the plurality of wiring pattern areas.
In the wiring board according to an embodiment of the present disclosure, the aperture ratio of the wiring pattern area and aperture ratios of the plurality of dummy pattern areas may increase stepwise from the wiring pattern area toward the dummy pattern areas located farther from the wiring pattern area, a difference between the aperture ratio of the first dummy pattern area and the aperture ratio of the wiring pattern area may be within a range from 0% inclusive to 2% inclusive, and a difference between the aperture ratios of the dummy pattern areas located next to each other may be each within a range from 0.02% inclusive to 2% inclusive.
The wiring board according to an embodiment of the present disclosure may further include a peripheral area located around the dummy pattern area that is farthest from the wiring pattern area, wherein the peripheral area may have an aperture ratio of 100%.
In the wiring board according to an embodiment of the present disclosure, the aperture ratio of the wiring pattern area and aperture ratios of the plurality of dummy pattern areas may increase stepwise from the wiring pattern area toward the dummy pattern areas located farther from the wiring pattern area, a difference between the aperture ratio of the first dummy pattern area and the aperture ratio of the wiring pattern area may be within a range from 0% inclusive to 2% inclusive, and each of a difference between the aperture ratios of the dummy pattern areas located next to each other and a difference between the aperture ratio of the peripheral area and the dummy pattern area located next to the peripheral area may be within a range from 0.02% inclusive to 2% inclusive
In the wiring board according to an embodiment of the present disclosure, an outline of the wiring pattern area may include a first side and a second side that intersect with each other in a plan view, a vertex where the first side and the second side intersect with each other is defined as a first vertex, an extension line, of the first side, extending from the first vertex is defined as a first virtual line, an extension line, of the second side, extending from the first vertex is defined as a second virtual line, and given above definition, in an area located between the first virtual line and the second virtual line, an outline of the first dummy pattern area may have a shape of an arc having a center at the first vertex.
In the wiring board according to an embodiment of the present disclosure, in the area located between the first virtual line and the second virtual line, an outline of the second dummy pattern area may have a shape of an arc having a center at the first vertex.
A wiring board according to an embodiment of the present disclosure is a wiring board that includes: a substrate; a wiring pattern area arranged on the substrate and including pieces of wiring; and a plurality of dummy pattern areas arranged around the wiring pattern area and electrically independent of the wiring, wherein the substrate has transparency, an aperture ratio of a first dummy pattern area, which is located next to the wiring pattern area, among the plurality of dummy pattern areas is lower than an aperture ratio of a second dummy pattern area, which is located next to the first dummy pattern area and farther from the wiring pattern area than the first dummy pattern area is, among the plurality of dummy pattern areas, an outline of the first dummy pattern area includes a third side and a fourth side that intersect with each other in a plan view, a vertex where the third side and the fourth side intersect with each other is defined as a second vertex, an extension line, of the third side, extending from the second vertex is defined as a third virtual line, an extension line, of the fourth side, extending from the second vertex is defined as a fourth virtual line, and given above definition, in an area located between the third virtual line and the fourth virtual line, an outline of the second dummy pattern area has a shape of an arc having a center at the second vertex.
In the wiring board according to an embodiment of the present disclosure, each of the plurality of dummy pattern areas may include pieces of dummy wiring that are electrically independent of the wiring, each of the pieces of dummy wiring may include a first dummy wiring portion and a second dummy wiring portion, the first dummy wiring portions of the dummy pattern areas located next to each other may be arranged in parallel with each other, and the second dummy wiring portions of the dummy pattern areas located next to each other may be arranged in parallel with each other.
In the wiring board according to an embodiment of the present disclosure, the wiring pattern area may further include pieces of interconnection wiring interconnecting the pieces of wiring, each of the plurality of dummy pattern areas may include pieces of dummy wiring that are electrically independent of the wiring and the interconnection wiring, each of the pieces of dummy wiring may include a first dummy wiring portion and a second dummy wiring portion, the wiring and the first dummy wiring portion of each of the dummy pattern areas may be arranged in parallel with each other, and the interconnection wiring and the second dummy wiring portion of each of the dummy pattern areas may be arranged in parallel with each other.
A wiring board according to an embodiment of the present disclosure is a wiring board that includes: a substrate; a wiring pattern area arranged on the substrate and including pieces of wiring; and a dummy pattern area arranged around the wiring pattern area and electrically independent of the wiring, wherein the substrate has transparency, an outline of the wiring pattern area includes a first side and a second side that intersect with each other in a plan view, a vertex where the first side and the second side intersect with each other is defined as a first vertex, an extension line, of the first side, extending from the first vertex is defined as a first virtual line, an extension line, of the second side, extending from the first vertex is defined as a second virtual line, and given above definition, in an area located between the first virtual line and the second virtual line, an outline of the first dummy pattern area has a shape of an arc having a center at the first vertex.
The wiring board according to an embodiment of the present disclosure may have a radio-wave transmitting-and-receiving function.
An image display device according to an embodiment of the present disclosure is an image display device that includes: the wiring board according to an embodiment, and a display device underlying the wiring board, wherein the wiring pattern area is provided at a corner portion of the display device.
A method of manufacturing a wiring board according to an embodiment of the present disclosure is a method of manufacturing a wiring board that includes: preparing a substrate; and forming, on the substrate, a wiring pattern area including pieces of wiring, and a plurality of dummy pattern areas arranged around the wiring pattern area and electrically independent of the wiring, wherein the substrate has transparency, among the plurality of dummy pattern areas, an aperture ratio of a first dummy pattern area, which is located next to the wiring pattern area, is not lower than an aperture ratio of the wiring pattern area, and among the plurality of dummy pattern areas, an aperture ratio of a second dummy pattern area, which is located next to the first dummy pattern area and farther from the wiring pattern area than the first dummy pattern area is, is higher than the aperture ratio of the first dummy pattern area.
A method of manufacturing a wiring board according to an embodiment of the present disclosure is a method of manufacturing a wiring board that includes: preparing a substrate; and forming, on the substrate, a wiring pattern area including pieces of wiring, and a dummy pattern area arranged around the wiring pattern area and electrically independent of the wiring, wherein the substrate has transparency, an outline of the wiring pattern area includes a first side and a second side that intersect with each other in a plan view, a vertex where the first side and the second side intersect with each other is defined as a first vertex, an extension line, of the first side, extending from the first vertex is defined as a first virtual line, an extension line, of the second side, extending from the first vertex is defined as a second virtual line, and given above definition, in an area located between the first virtual line and the second virtual line, an outline of the first dummy pattern area has a shape of an arc having a center at the first vertex.
A method of manufacturing a wiring board according to an embodiment of the present disclosure is a method of manufacturing a wiring board that includes: preparing a substrate; and forming, on the substrate, a wiring pattern area including pieces of wiring, and a plurality of dummy pattern areas arranged around the wiring pattern area and electrically independent of the wiring, wherein the substrate has transparency, an aperture ratio of a first dummy pattern area, which is located next to the wiring pattern area, among the plurality of dummy pattern areas is lower than an aperture ratio of a second dummy pattern area, which is located next to the first dummy pattern area and farther from the wiring pattern area than the first dummy pattern area is, among the plurality of dummy pattern areas, an outline of the first dummy pattern area includes a third side and a fourth side that intersect with each other in a plan view, a vertex where the third side and the fourth side intersect with each other is defined as a second vertex, an extension line, of the third side, extending from the second vertex is defined as a third virtual line, an extension line, of the fourth side, extending from the second vertex is defined as a fourth virtual line, and given above definition, in an area located between the third virtual line and the fourth virtual line, an outline of the second dummy pattern area has a shape of an arc having a center at the second vertex.
With the embodiment of the present disclosure, it is possible to make it harder for a wiring pattern area to be visually noticed.
First, with reference to
The drawings mentioned below are schematic. Therefore, the illustration will be exaggerated where appropriate in order to facilitate understanding of sizes/shapes of portions.
Modifications can be made as appropriate within a range of not departing from the technical idea. In the drawings mentioned below, the same reference signs will be assigned to the same portions, and detailed description may be partially omitted. Numerical values such as dimensions of members described in this specification, and material names thereof, are mere examples in the embodiment, and selection can be made as appropriate without any limitation to them. In this specification, terms that specify shapes and geometric conditions, for example, “parallel”, “orthogonal”, “perpendicular”, and the like, shall be construed not only in a strict sense but also in a sense of being deemed to be substantially the same as their exact definitions.
In the present embodiment, the term “X direction” means a direction perpendicular to a longer-side direction of a wiring pattern area and perpendicular to a direction of a length corresponding to a frequency band of antenna wiring. The term “Y direction” means a direction perpendicular to the X direction and parallel to the longer-side direction of the wiring pattern area and parallel to the direction of the length corresponding to the frequency band of the antenna wiring. The term “Z direction” means a direction perpendicular to both the X direction and the Y direction and parallel to a thickness direction of a wiring board. The term “front surface” means a surface which is on a positive side in the Z direction and on which, with respect to the substrate, antenna wiring is provided. The term “back surface” means a surface which is on a negative side in the Z direction and is the opposite of the surface on which, with respect to the substrate, the antenna wiring is provided. In the present embodiment, a description will be given while taking, as an example, a case where a wiring pattern area 20 is an antenna pattern area 20 having a radio-wave transmitting-and-receiving function (a function to serve as an antenna). However, the wiring pattern area 20 does not necessarily have to have the radio-wave transmitting-and-receiving function (the function to serve as an antenna).
[Configuration of Wiring Board]
With reference to
As illustrated in
The substrate 11 has a substantially rectangular shape in a plan view. Its longer-side direction is parallel to the Y direction. Its shorter-side direction is parallel to the X direction. The substrate 11 has transparency and is substantially flat. Its thickness is substantially uniform as a whole. The length L1 of the substrate 11 in its longer-side direction (Y direction) can be selected within a range from, for example, 100 mm inclusive to 200 mm inclusive. The length L2 of the substrate 11 in its shorter-side direction (X direction) can be selected within a range from, for example, 50 mm inclusive to 100 mm inclusive.
The material of the substrate 11 may be any material as long as it has transparency in the spectrum of visible light and has electric insulation property. In the present embodiment, the material of the substrate 11 is polyethylene terephthalate, but is not limited thereto. As the material of the substrate 11, it is preferable to use an organic insulating material, for example, a polyester-based resin such as polyethylene terephthalate, an acryl-based resin such as polymethyl methacrylate, a polycarbonate-based resin, a polyimide-based resin, a polyolefin-based resin such as a cycloolefin polymer, a cellulose-based resin material such as triacetyl cellulose, or the like. Alternatively, an organic insulating material such as a cycloolefin polymer (for example, ZF-16 manufactured by Zeon Corporation), a polynorbornene polymer (manufactured by Sumitomo Bakelite Co., Ltd.), or the like may be used as the material of the substrate 11. Glass, ceramics, or the like can be selected as the material of the substrate 11, depending on the intended use. In the illustrated example, the substrate 11 has a single-layer structure, but is not limited thereto; it may have a structure made up of a plurality of bases or a multilayer structure. The substrate 11 may be like a film or like a plate. Therefore, the thickness of the substrate 11 is not specifically limited, and selection can be made as appropriate, depending on the intended use. As one example, the substrate 11 can have a thickness T1 (a length in the Z direction, see
The substrate 11 may have a dielectric loss tangent of 0.002 or less, or preferably, 0.001 or less. The lower limit of the dielectric loss tangent of the substrate 11, though not specifically limited, may be zero exclusive. Setting the dielectric loss tangent of the substrate 11 to the above range makes it possible to make a gain (sensitivity) loss in transmission and reception of an electromagnetic wave smaller, especially when the electromagnetic wave (for example, a millimeter wave) transmitted and received by the antenna pattern area 20 has a high frequency. The lower limit of the dielectric loss tangent of the substrate 11 is not specifically limited. The substrate 11 may have a relative permittivity of, though not specifically limited, 2.0 or more and 10.0 or less.
The dielectric loss tangent of the substrate 11 can be measured in conformity with IEC 62562. Specifically, first, a piece of test sample is prepared by cutting out of the substrate 11 a portion where the antenna pattern area 20 is not formed. Alternatively, a portion where the antenna pattern area 20 is formed may be cut out of the substrate 11, and the antenna pattern area 20 may be removed by etching or the like. The piece of test sample has a width of 10 mm to 20 mm and a length of 50 mm to 100 mm. Next, the dielectric loss tangent is measured in conformity with IEC 62562. The relative permittivity and dielectric loss tangent of the substrate 11 may be measured in conformity with ASTM D150.
The substrate 11 has transparency. In this specification, the meaning of “has transparency” is that the transmittance of visible light (light whose wavelengths are within a range from 400 nm inclusive to 700 nm inclusive) is 85% or greater. The substrate 11 may be transparent to an extent that the transmittance of visible light (light whose wavelengths are within a range from 400 nm inclusive to 700 nm inclusive) is 85% or greater, or preferably, 90% or greater. Though there is no specific upper limit in the transmittance of visible light through the substrate 11, for example, the limit may be 100% or less. Setting the transmittance of visible light through the substrate 11 to the above range makes it possible to enhance the transparency of the wiring board 10 and makes it easier to view a display 91 of an image display device 90 (to be described later). The visible light means light whose wavelengths are within a range from 400 nm inclusive to 700 nm inclusive. The meaning of “the transmittance of visible light is 85% or greater” is that the transmittance is 85% or greater throughout the entire spectrum within the range from 400 nm inclusive to 700 nm inclusive when light absorbance measurement is performed for the substrate 11 using a known spectrophotometer (for example, a spectroscope V-670 manufactured by JASCO corporation).
In
Each antenna pattern area 20 has a quadrangular shape in a plan view. In the present embodiment, each antenna pattern area 20 has a substantially rectangular shape in a plan view. The longer-side direction of each antenna pattern area 20 is parallel to the Y direction, and the shorter-side direction thereof is parallel to the X direction. The length La of each antenna pattern area 20 in its longer-side direction (Y direction) can be selected within a range from, for example, 3 mm inclusive to 100 mm inclusive. The width Wa of each antenna pattern area 20 in its shorter-side direction (X direction) can be selected within a range from, for example, 1 mm inclusive to 10 mm inclusive. The antenna pattern area 20 may function as a millimeter-wave antenna, among others. In a case where the antenna pattern area 20 is a millimeter-wave antenna, the length La of the antenna pattern area 20 can be selected within a range from 1 mm inclusive to 10 mm inclusive, or more preferably, 1.5 mm inclusive to 5 mm inclusive.
Each antenna pattern area 20 has a grid shape or a mesh shape formed of metal wiring and has a uniform iterative pattern in the X direction and the Y direction. That is, as illustrated in
As illustrated in
In each antenna pattern area 20, a plurality of openings 23 is formed by being surrounded by the pieces of antenna wiring 21 arranged adjacent to one another and by the pieces of antenna interconnection wiring 22 arranged adjacent to one another. The pieces of antenna wiring 21 and the pieces of antenna interconnection wiring 22 are arranged at equal intervals with respect to one another. That is, the pieces of antenna wiring 21 are arranged at equal intervals with respect to one another, and the pitch P1 (see
As illustrated in
In the present embodiment, the line width W1 (the length in the X direction, see
The material of the antenna wiring 21 and the antenna interconnection wiring 22 may be any metal material having conductivity. In the present embodiment, the material of the antenna wiring 21 and the antenna interconnection wiring 22 is copper but is not limited thereto. For example, a metal material (including alloy) such as gold, silver, copper, platinum, tin, aluminum, iron, nickel, or the like can be used as the material of the antenna wiring 21 and the antenna interconnection wiring 22.
By the way, as described above, the wiring board 10 includes a plurality of dummy pattern areas 30. Referring back to
In the illustrated example, the wiring board 10 includes three dummy pattern areas 30. That is, the wiring board 10 includes first dummy pattern areas 301 located next to the antenna pattern areas 20, second dummy pattern areas 302 located next to the first dummy pattern areas 301, and a third dummy pattern area 303 located next to the second dummy pattern areas 302. Among them, the second dummy pattern area 302 is located at a position farther from the antenna pattern area 20 than the first dummy pattern area 301 is, and surrounds the first dummy pattern area 301. The third dummy pattern area 303 is located at a position farther from the antenna pattern area 20 than the second dummy pattern area 302 is, and surrounds the second dummy pattern area 302. The number of the dummy pattern areas 30 included in the wiring board 10 may be any number, for example, two or more and fifty or less or so, or two or more and ten or less or so.
The first dummy pattern area 301 includes a pair of first portions 301A extending in the Y direction and a second portion 301B extending between the first portions 301A in the X direction. The width Wa1 of the first portion 301A in its shorter-side direction (X direction) can be selected within a range from, for example, 0.1 mm inclusive to 50 mm inclusive, or preferably, within a range from 0.2 mm inclusive to 10 mm inclusive. The width Wa2 of the second portion 301B in its shorter-side direction (Y direction) can be selected within a range from, for example, 0.1 mm inclusive to 50 mm inclusive, or preferably, within a range from 0.2 mm inclusive to 10 mm inclusive.
The second dummy pattern area 302 includes a pair of first portions 302A extending in the Y direction and a second portion 302B extending between the first portions 302A in the X direction. The width Wa3 of the first portion 302A in its shorter-side direction (X direction) can be selected within a range from, for example, 0.1 mm inclusive to 50 mm inclusive, or preferably, within a range from 0.2 mm inclusive to 10 mm inclusive. The width Wa4 of the second portion 302B in its shorter-side direction (Y direction) can be selected within a range from, for example, 0.1 mm inclusive to 50 mm inclusive, or preferably, within a range from 0.2 mm inclusive to 10 mm inclusive.
The width Wa3 of the first portion 302A of the second dummy pattern area 302 may be greater than the width Wa1 of the first portion 301A of the first dummy pattern area 301. As will be described later, in the present embodiment, the aperture ratio A22 of the second dummy pattern area 302 is higher than the aperture ratio A21 of the first dummy pattern area 301. Therefore, the width Wa3 of the first portion 302A of the second dummy pattern area 302 is greater than the width Wa1 of the first portion 301A of the first dummy pattern area 301, and this makes it possible to increase the aperture ratio of the wiring board 10 as a whole and enhance the transparency of the wiring board 10. Similarly, the width Wa4 of the second portion 302B may be greater than the width Wa2 of the second portion 301B of the first dummy pattern area 301. This makes it possible to increase the aperture ratio of the wiring board 10 as a whole and enhance the transparency of the wiring board 10.
The third dummy pattern area 303 is provided in such a way as to surround the plurality of antenna pattern areas 20. In the illustrated example, the third dummy pattern area 303 is provided in such a way as to surround all of the antenna pattern areas 20. This makes it harder for the plurality of antenna pattern areas 20 to be visually noticed effectively. The third dummy pattern area 303 is arranged on the substrate 11 at substantially the entire area, except for the antenna pattern areas 20, the first dummy pattern areas 301, the second dummy pattern areas 302, and the power feeding portion 40.
As illustrated in
The pieces of dummy wiring 301a are arranged regularly throughout the entire first dummy pattern area 301. The pieces of dummy wiring 302a are arranged regularly throughout the entire second dummy pattern area 302. The pieces of dummy wiring 303a are arranged regularly throughout the entire third dummy pattern area 303. The pieces of dummy wiring 301a, 302a, 303a are separated from one another in a plane direction and are arranged like islands on the substrate 11 by protruding therefrom. That is, each of the pieces of dummy wiring 301a, 302a, 303a is electrically independent of the antenna pattern area 20, the power feeding portion 40, and the others of the pieces of dummy wiring.
Each of the pieces of dummy wiring 301a, 302a, 303a includes a first dummy wiring portion 311, 312, 313 and a second dummy wiring portion 321, 322, 323. In addition, as illustrated in
Furthermore, as illustrated in
Moreover, as illustrated in
Furthermore, as illustrated in
Next, the dummy wiring 301a, 302a, and 303a will now be described in more detail. First, the dummy wiring 301a of the first dummy pattern area 301 will be described here.
As illustrated in
Moreover, in the first dummy pattern area 301, there is a clearance portion 331a (a halftone-dotted portion in
In the present embodiment, the dummy wiring 301a has a shape of partial missing of the unit pattern shape 20a of the antenna pattern area 20 described earlier. That is, the shape of the dummy wiring 301a is a shape obtained by removing the clearance portion 331a, 331b described above from the unit pattern shape 20a, which is like a letter L, of the antenna pattern area 20. That is, a shape obtained by combining the pieces of dummy wiring 301a of the first dummy pattern area 301 and a plurality of clearance portions 331a, 331b thereof together is equivalent to the grid shape or the mesh shape of the antenna pattern area 20. Since the dummy wiring 301a of the first dummy pattern area 301 has a shape of partial missing of the unit pattern shape 20a of the antenna pattern area 20, it is possible to make it harder for the difference between the antenna pattern area 20 and the first dummy pattern area 301 to be visually perceived and thus make the antenna pattern area 20 formed on the substrate 11 more invisible.
In
Moreover, in
As illustrated in
In the present embodiment, the line width W3 (the length in the X direction, see
Next, the dummy wiring 302a of the second dummy pattern area 302 will now be described.
As illustrated in
Moreover, in the second dummy pattern area 302, there is a clearance portion 332a (a halftone-dotted portion in
In the present embodiment, the dummy wiring 302a has a shape of partial missing of the dummy wiring 301a described above. That is, the dummy wiring 302a has a shape of partial missing of the unit pattern shape 20a of the antenna pattern area 20. In this case, the shape of the dummy wiring 302a is a shape obtained by removing the clearance portion 332a, 332b described above from the unit pattern shape 20a, which is like a letter L, of the antenna pattern area 20. That is, a shape obtained by combining the pieces of dummy wiring 302a of the second dummy pattern area 302 and a plurality of clearance portions 332a, 332b thereof together is equivalent to the grid shape or the mesh shape of the antenna pattern area 20. Since the dummy wiring 302a of the second dummy pattern area 302 has a shape of partial missing of the dummy wiring 301a of the first dummy pattern area 301, it is possible to make it harder for the difference between the first dummy pattern area 301 and the second dummy pattern area 302 to be visually perceived and thus make the first dummy pattern area 301 and the second dummy pattern area 302 that are arranged on the substrate 11 more invisible.
In
In addition, in
In the present embodiment, the shape in terms of other parameters (cross-sectional shape in X-directional cross section, line width, and height) of the first dummy wiring portion 312 of the second dummy pattern area 302 is substantially the same as the shape of the first dummy wiring portion 311 of the first dummy pattern area 301; therefore, a detailed explanation is not given here. In addition, the shape in terms of other parameters (cross-sectional shape in Y-directional cross section, line width, and height) of the second dummy wiring portion 322 of the second dummy pattern area 302 is substantially the same as the shape of the second dummy wiring portion 321 of the first dummy pattern area 301; therefore, a detailed explanation is not given here.
Next, the dummy wiring 303a of the third dummy pattern area 303 will now be described.
As illustrated in
Moreover, in the third dummy pattern area 303, there is a clearance portion 333a (a halftone-dotted portion in
In the present embodiment, the dummy wiring 303a has a shape of partial missing of the dummy wiring 302a described above. That is, the dummy wiring 303a has a shape of partial missing of the unit pattern shape 20a of the antenna pattern area 20. In this case, the shape of the dummy wiring 303a is a shape obtained by removing the clearance portion 333a, 333b described above from the unit pattern shape 20a, which is like a letter L, of the antenna pattern area 20. That is, a shape obtained by combining the pieces of dummy wiring 303a of the third dummy pattern area 303 and a plurality of clearance portions 333a, 333b thereof together is equivalent to the grid shape or the mesh shape of the antenna pattern area 20. Since the dummy wiring 303a of the third dummy pattern area 303 has a shape of partial missing of the dummy wiring 302a of the second dummy pattern area 302, it is possible to make it harder for the difference between the second dummy pattern area 302 and the third dummy pattern area 303 to be visually perceived and thus make the second dummy pattern area 302 and the third dummy pattern area 303 that are arranged on the substrate 11 more invisible.
In
In addition, in
In the present embodiment, the shape in terms of other parameters (cross-sectional shape in X-directional cross section, line width, and height) of the first dummy wiring portion 313 of the third dummy pattern area 303 is substantially the same as the shape of the first dummy wiring portion 311 of the first dummy pattern area 301; therefore, a detailed explanation is not given here. In addition, the shape in terms of other parameters (cross-sectional shape in Y-directional cross section, line width, and height) of the second dummy wiring portion 323 of the third dummy pattern area 303 is substantially the same as the shape of the second dummy wiring portion 321 of the first dummy pattern area 301; therefore, a detailed explanation is not given here.
The same metal material as the material of the antenna wiring 21 and the material of the antenna interconnection wiring 22 can be used as the material of the dummy wiring 301a, 302a, and 303a described above.
By the way, in the present embodiment, the antenna pattern area 20, the first dummy pattern area 301, the second dummy pattern area 302, and the third dummy pattern area 303 have predetermined aperture ratios A1, A21, A22, and A23 respectively. In this case, the aperture ratio A21 of the first dummy pattern area 301 is not lower than the aperture ratio A1 of the antenna pattern area 20, and the aperture ratio A22 of the second dummy pattern area 302 is higher than the aperture ratio A21 of the first dummy pattern area 301. As described here, in the present embodiment, the aperture ratios A1, A21, A22, and A23 of the antenna pattern area 20 and the plurality of dummy pattern areas 30 increase stepwise from the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20. That is, the aperture ratio A21 of the first dummy pattern area 301 is not lower than the aperture ratio A1 of the antenna pattern area 20, the aperture ratio A22 of the second dummy pattern area 302 is higher than the aperture ratio A21 of the first dummy pattern area 301, and the aperture ratio A23 of the third dummy pattern area 303 is higher than the aperture ratio A22 of the second dummy pattern area 302 (A23>A22>A21≥A1). This ensures sufficient transparency of the wiring board 10.
The difference between the aperture ratio A21 of the first dummy pattern area 301, which is located next to the antenna pattern area 20, and the aperture ratio A1 of the antenna pattern area 20 should preferably be within a range from 0% inclusive to 2% inclusive, more preferably, from 0.02% inclusive to 1% inclusive, still more preferably, from 0.08% inclusive to 0.5% inclusive. Setting the difference between the aperture ratio A21 and the aperture ratio A1 to 0% or greater makes it possible to enhance the transparency of the wiring board 10. Setting the difference between the aperture ratio A21 and the aperture ratio A1 to 2% or less makes it possible to make the difference between the aperture ratio A21 and the aperture ratio A1 small and thus make the boundary between the antenna pattern area 20 and the first dummy pattern area 301 more invisible. This makes it harder for the presence of the antenna pattern area 20 to be noticed with the naked eye. The difference from the aperture ratio A1 of the antenna pattern area 20 may be within a range from 0.1% inclusive to 3% inclusive.
Furthermore, the difference between the aperture ratios A21, A22, and A23 of the dummy pattern areas 30 located next to each other (for example, the difference between the aperture ratio A21 and the aperture ratio A22) should preferably be within a range from 0.02% inclusive to 2% inclusive, more preferably, from 0.04% inclusive to 1% inclusive, still more preferably, from 0.08% inclusive to 0.5% inclusive. Setting the difference between the aperture ratios A21, A22, and A23 to 0.02% or greater makes it possible to enhance the transparency of the wiring board 10. Setting the difference between the aperture ratios A21, A22, and A23 to 2% or less makes it possible to make the difference between, for example, the aperture ratio A21 and the aperture ratio A22 small and thus make the boundary between the first dummy pattern area 301 and the second dummy pattern area 302 more invisible. As described above, it is possible to make each boundary between the dummy pattern areas 30 more invisible and therefore make it harder for the presence of each dummy pattern area 30 to be noticed with the naked eye. The difference between the aperture ratios A21, A22, and A23 of the dummy pattern areas 30 located next to each other may be within a range from 0.1% inclusive to 3% inclusive.
The aperture ratio A1 of the antenna pattern area 20 described above can be selected within a range from, for example, 85% inclusive to 99.9% inclusive. The aperture ratio A21 of the first dummy pattern area 301 can be selected within a range from, for example, 85% inclusive to 100% exclusive. The aperture ratio A22 of the second dummy pattern area 302 can be selected within a range from, for example, 86% inclusive to 100% exclusive. The aperture ratio A23 of the third dummy pattern area 303 can be selected within a range from, for example, 86.5% inclusive to 100% exclusive.
An aperture ratio A3 of a combination area made up of the antenna pattern area 20 and the respective dummy pattern areas 30 (namely, the aperture ratio of the wiring board 10 as a whole) can be selected within a range from, for example, 87% inclusive to 100% exclusive. Selecting the aperture ratio A3 within this range ensures sufficient conductivity and transparency of the wiring board 10.
The term “aperture ratio” means an area-size ratio (%) of an open area (an area where no metal portion such as the antenna wiring 21, the antenna interconnection wiring 22, the dummy wiring 301a, 302a, and 303a exists and therefore the substrate 11 is exposed) to unit area of a predetermined area (the antenna pattern area 20, the dummy pattern area 30, or the antenna pattern area 20 and the dummy pattern area 30).
Referring back to
Next, with reference to
First, as illustrated in
Next, an antenna pattern area 20 that includes pieces of antenna wiring 21 and a plurality of dummy pattern areas 30 arranged around the antenna pattern area 20 and electrically independent of the antenna wiring 21 are formed on the substrate 11. In this process, first, a conductive layer 51 is formed at substantially the entire area on the front surface of the substrate 11. In the present embodiment, the conductive layer 51 has a thickness of 200 nm. However, the thickness of the conductive layer 51, without being limited to the above, can be selected as appropriate within a range from 10 nm inclusive to 1,000 nm inclusive. In the present embodiment, the conductive layer 51 is formed by sputtering using copper. A plasma CVD method may be used for forming the conductive layer 51.
Next, as illustrated in
Then, as illustrated in
The trenches 54a can be formed using an imprint method, without being limited to the above, in the surface of the insulating layer 54. In this case, a transparent imprinting mold that has convex portions corresponding to the trenches 54a is prepared, the mold is brought close to the substrate 11, and the photo-curable insulating resist 52 is spread between the mold and the substrate 11. Next, light is applied from the mold side to cure the photo-curable insulating resist 52, thereby forming the insulating layer 54. As a result, the trenches 54a having a convex-pattern-transferred shape are formed. The insulating layer 54 having a cross-sectional structure illustrated in
Next, as illustrated in
Next, as illustrated in
After that, as illustrated in
Next, the operational effects of a wiring board having the configuration described above will now be explained.
As illustrated in
According to the present embodiment, the wiring board 10 includes the substrate 11 that has transparency and the antenna pattern area 20 arranged on the substrate 11 and including pieces of antenna wiring 21; therefore, sufficient transparency of the wiring board 10 is ensured. Therefore, the display 91 is viewable through the openings 23 of the antenna pattern area 20 when the wiring board 10 is disposed on the display 91; consequently, viewability of the display 91 is not impaired.
The plural dummy pattern areas 30 that are electrically independent of the antenna wiring 21 are arranged around the antenna pattern area 20. The aperture ratio A21 of the first dummy pattern area 301, which is located next to the antenna pattern area 20, is not lower than the aperture ratio A1 of the antenna pattern area 20. In addition, the aperture ratio A22 of the second dummy pattern area 302, which is located next to the first dummy pattern area 301 and farther from the wiring pattern area 20 than the first dummy pattern area 301 is, is higher than the aperture ratio A21 of the first dummy pattern area 301. This makes it possible to make each boundary between the antenna pattern area 20, the first dummy pattern area 301, and the second dummy pattern area 302 obscure. Therefore, it is possible to make the antenna pattern area 20, the first dummy pattern area 301, and the second dummy pattern area 302 more invisible on the surface of the display 91 and make it harder for the user of the image display device 90 to notice the antenna pattern area 20, the first dummy pattern area 301, and the second dummy pattern area 302 with the naked eye. Moreover, even when each boundary between the antenna pattern area 20, the first dummy pattern area 301, and the second dummy pattern area 302 is made obscure, it is possible to obtain a high aperture ratio A3 of the wiring board 10 as a whole because the aperture ratio A21 of the first dummy pattern area 301 is not lower than the aperture ratio A1 of the antenna pattern area 20 and because the aperture ratio A22 of the second dummy pattern area 302 is higher than the aperture ratio A21 of the first dummy pattern area 301. Therefore, it is possible to ensure sufficient conductivity and transparency of the wiring board 10.
In order to improve antenna performance, high conductivity of the antenna wiring 21 is required; however, for example, if the line width W1 of the antenna wiring 21 is increased for the purpose of making the conductivity of the antenna wiring 21 higher, the aperture ratio A1 of the antenna pattern area 20 will decrease. In this case, it is conceivable to provide a dummy pattern area around the antenna pattern area 20 for the purpose of making the antenna pattern area 20 more invisible. In a case where a single dummy pattern area is provided around the antenna pattern area 20 (for example, if a single dummy pattern area is provided on the substrate 11 at substantially the entire area, except for the antenna pattern area 20), the decrease in the aperture ratio A1 of the antenna pattern area 20 necessitates that the aperture ratio of the dummy pattern area should also be decreased in order to make the boundary between the antenna pattern area 20 and the dummy pattern area obscure. Decreasing the aperture ratio of the dummy pattern area results in a decrease in the aperture ratio A3 of the wiring board 10 as a whole and, therefore, there is a possibility that the wiring board 10 will look dark as a whole. By contrast, according to the present embodiment, the wiring board 10 includes a plurality of dummy pattern areas 30, the aperture ratio A21 of the first dummy pattern area 301 is not lower than the aperture ratio A1 of the antenna pattern area 20, and the aperture ratio A22 of the second dummy pattern area 302 is higher than the aperture ratio A21 of the first dummy pattern area 301. Therefore, even in a case where the aperture ratio A1 of the antenna pattern area 20 is decreased, it is possible to obtain a high aperture ratio A3 of the wiring board 10 as a whole while making each boundary between the antenna pattern area 20, the first dummy pattern area 301, and the second dummy pattern area 302 obscure. Therefore, it is possible to ensure sufficient conductivity and transparency of the wiring board 10.
Moreover, according to the present embodiment, the third dummy pattern area 303 is provided in such a way as to surround a plurality of antenna pattern areas 20. This makes it harder for the plurality of antenna pattern areas 20 to be visually noticed effectively.
Moreover, according to the present embodiment, each of the plurality of dummy pattern areas 301, 302, 303 includes pieces of dummy wiring 301a, 302a, 303a that are electrically independent of the antenna wiring 21. Moreover, each of the pieces of dummy wiring 301a, 302a, 303a includes a first dummy wiring portion 311, 312, 313 and a second dummy wiring portion 321, 322, 323. In addition, the first dummy wiring portions 311, 312, and 313 of the dummy pattern areas 301, 302, and 303 located next to each other are arranged in parallel with each other. This makes it possible to make each boundary between the dummy pattern areas 301, 302, and 303 located next to each other obscure in the Y direction and make it harder for the dummy pattern areas 301, 302, and 303 to be noticed with the naked eye on the surface of the display 91.
Moreover, the second dummy wiring portions 321, 322, and 323 of the dummy pattern areas 301, 302, and 303 located next to each other are arranged in parallel with each other. This makes it possible to make each boundary between the dummy pattern areas 301, 302, and 303 located next to each other obscure in the X direction and make it harder for the dummy pattern areas 301, 302, and 303 to be noticed with the naked eye on the surface of the display 91.
Moreover, according to the present embodiment, the antenna pattern area 20 further includes pieces of antenna interconnection wiring 22 interconnecting the pieces of antenna wiring 21. Moreover, each of the plurality of dummy pattern areas 301, 302, 303 includes pieces of dummy wiring 301a, 302a, 303a that are electrically independent of the antenna wiring 21 and the antenna interconnection wiring 22. Moreover, each of the pieces of dummy wiring 301a, 302a, 303a includes a first dummy wiring portion 311, 312, 313 and a second dummy wiring portion 321, 322, 323. In addition, the antenna wiring 21 of the antenna pattern area 20 and the first dummy wiring portions 311, 312, and 313 of the respective dummy pattern areas 301, 302, and 303 are arranged in parallel with each other. This makes it possible to make the boundary of the antenna pattern area 20 and each dummy pattern area 301, 302, 303 obscure in the Y direction and make it harder for the antenna pattern area 20 and the dummy pattern areas 301, 302, and 303 to be noticed with the naked eye on the surface of the display 91.
Furthermore, as illustrated in
Next, with reference to
Though not illustrated, the first dummy pattern area 301 may be provided in such a way as to surround the plurality of antenna pattern areas 20. In this case, the first dummy pattern area 301 may be provided in such a way as to surround all of the antenna pattern areas 20.
In this case, each of the difference between the aperture ratios of the dummy pattern areas 30 located next to each other and the difference between the aperture ratios of the peripheral area 50 and the dummy pattern area 30 located next to the peripheral area 50 may be within a range from 0.02% inclusive to 2% inclusive. Setting the above-mentioned difference to 0.02% or greater makes it possible to enhance the transparency of the wiring board 10. Setting the above-mentioned difference to 2% or less makes it possible to make the boundary between the dummy pattern area 30 and the peripheral area 50 more invisible. This makes it harder for the presence of the antenna pattern area 20 to be noticed with the naked eye.
As described above, the wiring board 10B further includes the peripheral area 50 located around the dummy pattern area 30 that is farthest from the antenna pattern area 20, and the peripheral area 50 has an aperture ratio of 100%; therefore, it is possible to obtain a high aperture ratio A3 of the wiring board 10B as a whole. For this reason, it is possible to enhance the transparency of the wiring board 10B.
Moreover, each of the first dummy wiring portion 311 of the first dummy pattern area 301, the first dummy wiring portion 312 of the second dummy pattern area 302, and the first dummy wiring portion 313 of the third dummy pattern area 303 extends in parallel with the antenna wiring 21. Similarly, each of the second dummy wiring portion 321 of the first dummy pattern area 301, the second dummy wiring portion 322 of the second dummy pattern area 302, and the second dummy wiring portion 323 of the third dummy pattern area 303 extends in parallel with the antenna interconnection wiring 22.
This modification example also makes it possible to make the boundary of the antenna pattern area 20 and each dummy pattern area 30 obscure. Therefore, it is possible to make the antenna pattern area 20 and each dummy pattern area 30 more invisible on the surface of the display 91 and make it harder for the user of the image display device 90 to notice the antenna pattern area 20 and each dummy pattern area 30 with the naked eye. Moreover, it is possible to ensure sufficient conductivity and transparency of the wiring board 10C.
Configuring the line widths of the antenna wiring 21 and the first dummy wiring portions 311, 312, and 313 in such a way as to decrease stepwise from the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20 as described above makes it possible to increase the aperture ratios A1, A21, A22, and A23 of the antenna pattern area 20 and the plurality of dummy pattern areas 30 stepwise from the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20.
Moreover, in
Configuring the line widths of the antenna interconnection wiring 22 and the second dummy wiring portions 321, 322, and 323 in such a way as to decrease stepwise from the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20 as described above makes it possible to increase the aperture ratios A1, A21, A22, and A23 of the antenna pattern area 20 and the plurality of dummy pattern areas 30 stepwise from the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20.
In the illustrated example, each of the pitches of the first dummy wiring portions 311, 312, and 313 is an integral multiple of the pitch of the antenna wiring 21. Specifically, the pitch of the first dummy wiring portion 311 is twice as great as the pitch of the antenna wiring 21, the pitch of the first dummy wiring portion 312 is three times as great as the pitch of the antenna wiring 21, and the pitch of the first dummy wiring portion 313 is four times as great as the pitch of the antenna wiring 21. Each of the pitches of the first dummy wiring portions 311, 312, and 313 does not necessarily have to be an integral multiple of the pitch of the antenna wiring 21.
Configuring the pitches of the antenna wiring 21 and the first dummy wiring portions 311, 312, and 313 in such a way as to increase stepwise from the antenna pattern area 20 toward the area 20 as described above makes it possible to increase the aperture ratios A1, A21, A22, and A23 of the antenna pattern area 20 and the plurality of dummy pattern areas 30 stepwise from the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20.
Moreover, in
In the illustrated example, each of the pitches of the second dummy wiring portions 321, 322, and 323 is an integral multiple of the pitch of the antenna interconnection wiring 22. Specifically, the pitch of the second dummy wiring portion 321 is twice as great as the pitch of the antenna interconnection wiring 22, the pitch of the second dummy wiring portion 322 is three times as great as the pitch of the antenna interconnection wiring 22, and the pitch of the second dummy wiring portion 323 is four times as great as the pitch of the antenna interconnection wiring 22. Each of the pitches of the second dummy wiring portions 321, 322, and 323 does not necessarily have to be an integral multiple of the pitch of the antenna interconnection wiring 22.
Configuring the pitches of the antenna interconnection wiring 22 and the second dummy wiring portions 321, 322, and 323 in such a way as to increase stepwise from the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20 as described above makes it possible to increase the aperture ratios A1, A21, A22, and A23 of the antenna pattern area 20 and the plurality of dummy pattern areas 30 stepwise from the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20.
As described above, the first dummy wiring portions 311, 312, and 313 are formed to have a broken-line pattern, and breaks in the first dummy wiring portions 311, 312, and 313 formed to have the broken-line pattern increase in length stepwise from the dummy pattern area 30 located next to the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20; this makes it possible to increase the aperture ratios A1, A21, A22, and A23 of the antenna pattern area 20 and the plurality of dummy pattern areas 30 stepwise from the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20.
In
As described above, the second dummy wiring portions 321, 322, and 323 are formed to have a broken-line pattern, and breaks in the second dummy wiring portions 321, 322, and 323 formed to have the broken-line pattern increase in length stepwise from the dummy pattern area 30 located next to the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20; this makes it possible to increase the aperture ratios A1, A21, A22, and A23 of the antenna pattern area 20 and the plurality of dummy pattern areas 30 stepwise from the antenna pattern area 20 toward the dummy pattern areas 30 located farther from the antenna pattern area 20.
In this modification example, it is possible to make the boundary of the antenna pattern area 20 and each dummy pattern area 30 more obscure. Therefore, it is possible to make the antenna pattern area 20 and each dummy pattern area 30 more invisible on the surface of the display 91 and make it harder for the user of the image display device 90 to notice the antenna pattern area 20 and each dummy pattern area 30 with the naked eye.
This modification example also makes it possible to make the boundary of the antenna pattern area 20 and each dummy pattern area 30 more obscure. Therefore, it is possible to make the antenna pattern area 20 and each dummy pattern area 30 more invisible on the surface of the display 91 and make it harder for the user of the image display device 90 to notice the antenna pattern area 20 and each dummy pattern area 30 with the naked eye.
As described earlier, the antenna pattern area 20 has a quadrangular shape in a plan view. In this case, in a plan view, the outline of the antenna pattern area 20 has a pair of first sides 201 extending in its longer-side direction (Y direction) and a pair of second sides 202 extending in its width direction (X direction). The first side 201 and the second side 202 intersect with each other. It may be configured such that, on the first side 201 of the outline of the antenna pattern area 20, the antenna wiring 21 or the antenna interconnection wiring 22 does not overlap in parallel with the first side 201. Similarly, it may be configured such that, on the second side 202 of the outline of the antenna pattern area 20, the antenna wiring 21 or the antenna interconnection wiring 22 does not overlap in parallel with the second side 202. That is, the first side 201 and the second side 202 of the outline of the antenna pattern area 20 are sides on which the outermost portion (the side that is away from the antenna pattern area 20) of the antenna wiring 21 or the antenna interconnection wiring 22 is located.
As illustrated in
Moreover, in the area R1 located between the first virtual line IL1 and the second virtual line IL2, the outline of the second dummy pattern area 302 has a shape of an arc having the center at the first vertex V1. That is, in the area R1, the borderline B2 between the second dummy pattern area 302 and the third dummy pattern area 303 has a shape of an arc having the center at the first vertex V1. As described earlier, the number of the dummy pattern areas 30 included in the wiring board 10 (the wiring board 10I) may be any number, for example, two or more and fifty or less or so, or two or more and ten or less or so. In this case, the outline of each dummy pattern area 30 may have a shape of an arc having the center at the first vertex V1.
In a case where the antenna pattern area 20 has a quadrangular shape in a plan view, it could happen that the boundary of the antenna pattern area 20 is less invisible in the neighborhood of a corner portion (for example, the first vertex V1) of the quadrangular shape. Moreover, in this case, there is a possibility that streaks of light propagating from the corner portion of the quadrangular shape outward (toward the side that is away from the antenna pattern area 20) not in parallel with the X direction nor in parallel with the Y direction are visible due to reflection of visible light or the like. By contrast, according to this modification example, in the area R1 located between the first virtual line IL1 and the second virtual line IL2, the outline of the first dummy pattern area 301 has a shape of an arc having the center at the first vertex V1. Therefore, even in a case where the antenna pattern area 20 has a quadrangular shape in a plan view, it is possible to make it harder for the antenna pattern area 20 and streaks of light to be visually noticed effectively.
Moreover, according to this modification example, in the area R1 located between the first virtual line IL1 and the second virtual line IL2, the outline of the second dummy pattern area 302 has a shape of an arc having the center at the first vertex V1. Therefore, it is possible to make it harder for the antenna pattern area 20 and streaks of light to be visually noticed effectively.
In this modification example, as illustrated in
Also in this modification example, in the area R1 located between the first virtual line IL1 and the second virtual line IL2, the outline of the first dummy pattern area 301 has a shape of an arc having the center at the first vertex V1; therefore, even in a case where the antenna pattern area 20 has a quadrangular shape in a plan view, it is possible to make it harder for the antenna pattern area 20 and streaks of light to be visually noticed effectively.
In this case, in a plan view, the outline of the first dummy pattern area 301 has a pair of third sides 3011 extending in its longer-side direction (Y direction) and a fourth side 3012 extending in its width direction (X direction). The third side 3011 and the fourth side 3012 intersect with each other. It may be configured such that, on the third side 3011 of the outline of the first dummy pattern area 301, the first dummy wiring portion 311 or the second dummy wiring portion 321 does not overlap in parallel with the third side 3011. Similarly, it may be configured such that, on the fourth side 3012 of the outline of the first dummy pattern area 301, the first dummy wiring portion 311 or the second dummy wiring portion 321 does not overlap in parallel with the fourth side 3012. That is, the third side 3011 and the fourth side 3012 of the outline of the first dummy pattern area 301 are sides on which the outermost portion (the side that is away from the antenna pattern area 20) of the first dummy wiring portion 311 or the second dummy wiring portion 321 is located.
As illustrated in
As described earlier, the aperture ratio A21 of the first dummy pattern area 301 is not lower than the aperture ratio A1 of the antenna pattern area 20. In a case where the aperture ratio A21 is equal to the aperture ratio A1, it is possible to prevent the boundary of the antenna pattern area 20 from being less invisible in the neighborhood of a corner portion (for example, the first vertex V1) of the antenna pattern area 20, or reduce the risk thereof. Therefore, even in a case where the outline of the first dummy pattern area 301 does not have a shape of an arc having the center at the first vertex V1 in the area R1 located between the first virtual line IL1 and the second virtual line IL2, it is possible to make it harder for the antenna pattern area 20 and streaks of light to be visually noticed.
On the other hand, in this case, the aperture ratio A21 of the first dummy pattern area 301 may be lower than the aperture ratio A22 of the second dummy pattern area 302. That is, the aperture ratio A22 of the second dummy pattern area 302 may be higher than the aperture ratio A21 of the first dummy pattern area 301 for the purpose of increasing the aperture ratio A3 of the wiring board 10L as a whole.
In a case where the outline of the first dummy pattern area 301 includes the third side 3011 and the fourth side 3012 intersecting with each other in a plan view, it could happen that the boundary of the first dummy pattern area 301 is less invisible in the neighborhood of the second vertex V2 where the third side 3011 and the fourth side 3012 intersect with each other. Moreover, in this case, there is a possibility that streaks of light propagating from the second vertex V2 outward not in parallel with the X direction nor in parallel with the Y direction are visible due to reflection of visible light or the like. By contrast, according to this modification example, in the area R2 located between the third virtual line IL3 and the fourth virtual line IL4, the outline of the second dummy pattern area 302 has a shape of an arc having the center at the second vertex V2. Therefore, it is possible to make it harder for the first dummy pattern area 301 and streaks of light to be visually noticed effectively.
Moreover, also in this modification example, in the area R2 located between the third virtual line IL3 and the fourth virtual line IL4, the outline of the second dummy pattern area 302 may have a shape of an arc having the center at the second vertex V2. This makes it harder for the first dummy pattern area 301 and streaks of light to be visually noticed effectively.
Also in this modification example, in a case where the aperture ratio A21 of the first dummy pattern area 301 is equal to the aperture ratio A1, it is possible to make it harder for the antenna pattern area 20 and streaks of light to be visually noticed.
Moreover, also in this modification example, in the area R2 located between the third virtual line IL3 and the fourth virtual line IL4, the outline of the second dummy pattern area 302 may have a shape of an arc having the center at the second vertex V2. This makes it harder for the first dummy pattern area 301 and streaks of light to be visually noticed effectively.
Also in this modification example, in a case where the aperture ratio A21 of the first dummy pattern area 301 is equal to the aperture ratio A1, it is possible to make it harder for the antenna pattern area 20 and streaks of light to be visually noticed.
Moreover, also in this modification example, in the area R2 located between the third virtual line IL3 and the fourth virtual line IL4, the outline of the second dummy pattern area 302 may have a shape of an arc having the center at the second vertex V2. This makes it harder for the first dummy pattern area 301 and streaks of light to be visually noticed effectively.
Plural elements disclosed in the foregoing embodiment and the modification examples can be combined as appropriate, where necessary. Alternatively, some elements may be deleted from among all of the elements disclosed in the foregoing embodiment and the modification examples.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-167992 | Oct 2020 | JP | national |
| 2021-163019 | Oct 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/036612 | 10/4/2021 | WO |
