WO2024058056A1 - Frequency selective surface - Google Patents

Abstract

In a first region (R1) of a substrate (2), adjacent first cells (7, 7) are in a conducting state to each other. The whole size of a first conductor pattern (6) is smaller than the wavelength of an electromagnetic wave that enters a frequency selective surface (1) and is a size at which reflection of said wavelength is possible. In a second region (R2) of the substrate (2), second conductive wires (11, 11) that form adjacent second cells (10, 10) are in a non-conducting state to each other. A second conductor pattern (9) is configured such that the size of a single one of the second cells (10) is smaller than the whole size of the first conductor pattern (6) and is a size at which transmission of said wavelength of the electromagnetic wave is possible.

Description

frequency selection board

The present disclosure relates to a frequency selection plate.

Conventionally, as a frequency selection plate used for the purpose of controlling a radio wave environment and an electromagnetic environment, those shown in, for example, Patent Document 1 and Patent Document 2 are known.

Patent Document 1 discloses a frequency selection board that includes a dielectric substrate and a plurality of first conductive patterns formed on one surface of the dielectric substrate. Each of the plurality of first conductive patterns is configured as a unit cell. The unit cells are spaced apart from each other on the surface of the dielectric substrate. A unit cell has at least one conductive wire section.

Patent Document 2 discloses a frequency selection plate (electromagnetic shielding member) that includes a transparent substrate having insulation properties and a conductive layer member disposed on the substrate. The conductive layer member has a first conductive layer that can selectively reflect electromagnetic waves. The first conductive layer is made of thin metal wires having a predetermined line width, and is made of a metal mesh having a plurality of square openings. Further, the conductive layer member has a non-conductive portion that can selectively transmit electromagnetic waves (see FIG. 7 of Patent Document 2). The non-conductive portion is located inside the first conductive layer and is a cross-shaped cutout of the metal mesh.

WO2021/009893 publication WO2021/131962 publication

In the frequency selection board of Patent Document 1, on one surface of the dielectric substrate, there are a region where a plurality of first conductive patterns are arranged and a region where a plurality of first conductive patterns are not arranged. Also in the frequency selection board of Patent Document 2, there are regions on the substrate where the first conductive layer is arranged and regions where the first conductive layer is not arranged (i.e., regions where the non-conductive part is arranged). ing. That is, in the frequency selection boards of each of the above-mentioned documents, the distribution state of the conductive pattern on the substrate was non-uniform.

For this reason, for example, when the frequency selection board disclosed in each of the above-mentioned documents is attached to a window of a building (flat or curved window surface), when the window is viewed from inside or outside of the building, there is no conductivity. It becomes easy to distinguish between a region where a pattern is arranged and a region where a conductive pattern is not arranged. That is, when looking at the window from inside or outside the building, only the conductive wire portion (corresponding to the thin metal wire in Patent Document 2) forming the conductive pattern, for example, becomes conspicuous. As described above, there is a problem in that depending on the usage condition, the appearance of the frequency selection board becomes poor and the visibility of the frequency selection board is reduced.

Furthermore, Patent Document 2 also discloses a structure in which the non-conductive portion is formed by oxidizing the metal mesh into a cross shape instead of the metal mesh cut out in a cross shape. However, in such a configuration, the oxidized metal mesh becomes difficult to visually recognize, and as a result, only the first conductive layer becomes conspicuous. Therefore, even with the configuration in which the metal mesh is oxidized into a cross shape, there is a problem in that the visibility of the frequency selection plate is reduced depending on the usage condition, similar to the configuration in which the metal mesh is cut out in the cross shape.

The present disclosure has been made in view of these points, and its purpose is to obtain a frequency selection plate that has improved visibility while ensuring a function for appropriately controlling electromagnetic waves.

To achieve the above object, one embodiment of the present disclosure is a frequency selection board, the frequency selection board includes a substrate provided with a first region and a second region, and a substrate disposed in the first region of the substrate. , at least one first conductor pattern having a plurality of first cells constituted by a plurality of first conductive lines; and a plurality of second conductor patterns arranged in a second region of the substrate and constituted by a plurality of second conductive lines. at least one second conductor pattern having two cells. The plurality of first cells are configured such that adjacent first cells are electrically connected to each other. The first conductor pattern is configured such that the overall size of the first conductor pattern is smaller than the wavelength of electromagnetic waves incident on the frequency selection plate and is large enough to reflect the wavelength of the electromagnetic waves. The plurality of second cells are configured such that second conductive lines constituting each of the second cells adjacent to each other are not electrically connected to each other. The second conductor pattern is configured such that the size of one second cell is smaller than the entire size of the first conductor pattern and is large enough to transmit the wavelength of electromagnetic waves.

According to the present disclosure, it is possible to obtain a frequency selection plate that ensures the function of appropriately controlling electromagnetic waves and has improved visibility.

FIG. 1 is a plan view showing the entire frequency selection board according to an embodiment of the present disclosure. FIG. 2 is a partially enlarged plan view showing part II of FIG. 1 on an enlarged scale. FIG. 3 is a partially enlarged plan view showing part III of FIG. 2 on an enlarged scale. FIG. 4 is a sectional view taken along the line IV--IV in FIG. 2. FIG. 5 is a graph schematically showing the measurement results of the reference example based on the perspective of how the relationship between the frequency of electromagnetic waves and the transmission loss appears depending on the presence or absence of the second region. FIG. 6 is a diagram corresponding to FIG. 2 showing the first and second conductor patterns in Modification 1 of the embodiment. FIG. 7 is a diagram corresponding to FIG. 2 showing the first and second conductor patterns in Modification 2 of the embodiment. FIG. 8 is a diagram corresponding to FIG. 2 showing the first and second conductor patterns in Modification 3 of the embodiment. FIG. 9 is a diagram corresponding to FIG. 2 showing the first and second conductor patterns in Modification 4 of the embodiment. FIG. 10 is a diagram corresponding to FIG. 2 showing the first and second conductor patterns in Modification 5 of the embodiment. FIG. 11 is a diagram corresponding to FIG. 2 showing a first conductor pattern, a second conductor pattern, and a third conductor pattern in modification example 6 of the embodiment. FIG. 12 is a diagram corresponding to FIG. 2 showing a first conductor pattern, a second conductor pattern, and a third conductor pattern in Modification 7 of the embodiment.

Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. The following description of the embodiments is merely illustrative in nature and is not intended to limit the present disclosure, its applications, or its uses.

FIG. 1 shows the overall configuration of a frequency selective surface (FSS) 1 according to an embodiment of the present disclosure. The frequency selection board 1 is used for the purpose of controlling the radio wave environment and the electromagnetic environment. Specifically, the frequency selection board 1 can be attached to a window of a building, for example, for the purpose of controlling electromagnetic waves entering the building from the outside to the inside.

Here, the above-mentioned "control" refers to selectively reflecting and/or transmitting electromagnetic waves having a predetermined frequency that propagate in space. Furthermore, in the following description, the electromagnetic waves incident on the frequency selection plate 1 will be simply referred to as "electromagnetic waves."

In this embodiment, for convenience of explanation, the direction from the left side to the right side of the paper in FIG. 1 is defined as the first direction X, while the direction from the bottom to the top of the paper in FIG. shall be established as follows.

(substrate)
As shown in FIG. 1, the frequency selection board 1 includes a substrate 2. As shown in FIG. The substrate 2 is formed into a substantially square shape when viewed from above. The substrate 2 is formed into a film shape.

The substrate 2 is provided with a plurality of (nine in the illustrated example) first regions R1 and one second region R2.

Each of the plurality of first regions R1 is set as a region that can selectively reflect the electromagnetic waves. Specifically, in each first region R1, electromagnetic waves that have been incident toward the frequency selection plate 1 from the front side of the page in FIG. 1 (or the back side of the page in FIG. It is possible to reflect the light toward the back of the paper. The plurality of first regions R1 are arranged at intervals on the substrate 2. The plurality of first regions R1 are aligned along each of the first direction X and the second direction Y. Each first region R1 has a substantially square shape. In addition, in FIG. 1, in order to clearly indicate each first region R1, each first region R1 is given dark dot hatching.

The second region R2 is set as a region that can selectively transmit the electromagnetic waves. Specifically, in the second region R2, the electromagnetic waves that have entered toward the frequency selection plate 1 from the front side of the paper in FIG. 1 (or the back side of the paper in FIG. It is possible to transmit the image toward the front side of the paper. The second region R2 is located on the substrate 2 in a region other than the plurality of first regions R1. In addition, in FIG. 1, in order to distinguish each first region R1 and second region R2, dot hatching that is thinner than the dot hatching that is attached to each first region R1 is attached.

As shown in FIG. 4, the substrate 2 has a film base material 3. The film base material 3 is made of a transparent resin material. Examples of this resin material include resin materials such as PET (polyethylene terephthalate), polycarbonate, COP (cycloolefin polymer), and COC (cycloolefin copolymer).

As shown in FIG. 4, the substrate 2 has a groove forming layer 4. The groove forming layer 4 is a layer for forming a groove portion 5, which will be described later. The groove forming layer 4 is made of a resin material having insulation and transparency. The groove forming layer 4 is arranged in a laminated manner on one surface of the film base material 3. The thickness of the groove forming layer 4 is, for example, 1.0 μm to 7.0 μm.

As shown in FIG. 4, the substrate 2 is provided with a plurality of grooves 5. The plurality of groove portions 5 linearly extend on one surface of the substrate 2 so as to form a predetermined pattern to be described later.

The groove portion 5 is formed in a bottomed shape recessed in the thickness direction of the substrate 2 (direction from the groove forming layer 4 toward the film base material 3). The groove depth of the concave groove portion 5 is set to, for example, 0.3 μm or more and 5.0 μm or less. The groove portion 5 is configured to have a groove width of 10 μm or less.

Note that a fillet is formed at the corner between the side surface and the bottom surface of the groove portion 5. Note that fillets may not be formed at the corner portions. Further, the side surfaces of the groove portion 5 may be inclined so as to gradually widen from the bottom surface of the groove portion 5 toward the opening.

(first conductor pattern)
As shown in FIGS. 1 and 2, the frequency selection board 1 includes a plurality of first conductor patterns 6. As shown in FIGS. Each first conductor pattern 6 is arranged in each first region R1 of the substrate 2. The plurality of first conductor patterns 6 are arranged at intervals on the substrate 2. Each first conductor pattern 6 has a substantially square shape in plan view. Each first conductor pattern 6 has a network structure in which a plurality of first cells 7, which will be described later, are regularly arranged (see FIG. 2). In addition, in FIG. 1, illustration of the detailed structure of the first conductor pattern 6 is omitted for convenience of illustration.

As shown in FIG. 2, each first conductor pattern 6 has a plurality of first cells 7. The plurality of first cells 7 are constituted by the plurality of first conductive lines 8.

Each first conductive wire 8 extends in a direction along the first direction X or the second direction Y. The plurality of first conductive wires 8 are arranged at predetermined intervals (equally spaced in the illustrated example) in the first direction X or the second direction Y. The line width of each first conductive line 8 is set to, for example, 10 μm or less.

Each first cell 7 is formed in a closed shape. Each first cell 7 in this embodiment has a substantially square shape. The plurality of first cells 7 are configured such that adjacent first cells 7 are electrically connected to each other.

The first conductor pattern 6 is configured such that the overall size of the first conductor pattern 6 is smaller than the wavelength of the electromagnetic wave incident on the frequency selection plate 1 and is large enough to reflect the wavelength of the electromagnetic wave. There is.

Here, the length of one side of the square forming each first conductor pattern 6 is set as the dimension P1 shown in FIG. 2. This dimension P1 corresponds to the length of the first conductive wire 8. This dimension P1 is set, for example, to be 1/10 of the wavelength of the electromagnetic wave.

As a specific example of the dimension P1, when the frequency of the electromagnetic wave is, for example, 28 GHz (that is, the wavelength of the electromagnetic wave is about 1 cm), the dimension P1 is set to 1 mm, which is equivalent to 1/10 of the wavelength of the electromagnetic wave. . If such a dimension P1 (that is, the overall size of each first conductive pattern 6 having a square shape with one side length of dimension P1) is set, the conductor resistance of each first conductive wire 8 will be relatively becomes smaller. This increases the reflection effect of each first conductive wire 8 on the electromagnetic waves. That is, it becomes possible to enhance the reflection effect of the first conductor pattern 6 on the electromagnetic waves.

(Second conductor pattern)
As shown in FIGS. 1 and 2, the frequency selection plate 1 includes one second conductor pattern 9. As shown in FIGS. The second conductor pattern 9 is arranged in the second region R2 of the substrate 2. The second conductor pattern 9 is formed to surround each first conductor pattern 6 (see FIG. 1). The second conductor pattern 9 has a mesh structure in which a plurality of second cells 10 (described later) are regularly arranged (see FIG. 2). In addition, in FIG. 1, illustration of the detailed structure of the second conductor pattern 9 is omitted for convenience of illustration.

As shown in FIG. 2, the second conductor pattern 9 has a plurality of second cells 10. In this embodiment, each second cell 10 is formed in a non-occluded shape by a slit 12, which will be described later. Each second cell 10 has, for example, a substantially square shape.

Each second cell 10 is composed of a plurality of second conductive wires 11. Each second cell 10 is mainly composed of four mutually independent second conductive lines 11. Each second conductive wire 11 extends in a direction along the first direction X or the second direction Y. The plurality of second conductive wires 11 are arranged at predetermined intervals (equally spaced in the illustrated example) in the first direction X or the second direction Y.

Note that near the outer periphery of the first conductor pattern 6, each second cell 10 is constituted by a part of one first conductive wire 8 and three second conductive wires 11. Each second cell 10 located near the outer periphery of the first conductive pattern 6 and each first cell 7 located on the outer periphery side of the first conductive pattern 6 are in a non-conducting state with each other due to a slit 12 to be described later. .

As shown in FIGS. 2 and 3, a slit 12 is formed between the second conductive wires 11, 11 that are adjacent to each other. This slit 12 is formed between the second conductive wires 11, 11 adjacent to each other in each of the first direction X and the second direction Y. In this embodiment, the slits 12 are arranged at positions corresponding to substantially square corners forming each second cell 10. Thereby, in the second cells 10, 10 adjacent to each other, the ends of the second conductive wires 11, 11 are arranged with a predetermined interval between them. The length of the slit 12 (dimension S shown in FIG. 3) is set to be larger than the line width of the second conductive wire 11 (dimension W shown in FIG. 3). In addition, in FIG. 3, the slit 12 is virtually illustrated using a two-dot chain line.

In this embodiment, by providing the above-mentioned slit 12, each of the plurality of second conductive wires 11 becomes independent from each other. As a result, the second cells 10, 10 adjacent to each other are brought into a non-conducting state. That is, the second conductor pattern 9 is configured as a so-called dummy pattern. Further, since the second conductor pattern 9 is provided with the above-mentioned slits 12, the electromagnetic wave transmission effect is superior to that of the first conductor pattern 6.

Further, a slit is also provided between each first conductive wire 8 located on the outer periphery of the first conductive pattern 6 and each second conductive wire 11 of each second cell 10 located near the outer periphery of the first conductive pattern 6. 12 are formed. Thereby, each first conductive wire 8 and each second conductive wire 11 are in a non-conducting state with each other. That is, the first conductor pattern 6 and the second conductor pattern 9 are in a non-conducting state with each other.

The second conductor pattern 9 is configured such that the size of one second cell 10 is smaller than the entire size of the first conductor pattern 6 and is large enough to transmit the wavelength of the electromagnetic wave. .

The length of one side of the substantially square shape forming each second cell 10 is set as the dimension P2 shown in FIG. 2. This dimension P2 corresponds to the interval between the second conductive wires 11, 11 facing each other in the first direction X or the second direction Y. Further, the length of each second conductive wire 11 (dimension L shown in FIG. 3) is formed to be shorter than the length of one side (dimension P2) of the substantially square shape forming each second cell 10. ing. Specifically, each second conductive wire 11 is configured such that its length (dimension L) is 1/50 or less of the wavelength of the electromagnetic wave. More preferably, the length (dimension L) of each second conductive wire 11 is set to 1/100 or less of the wavelength of the electromagnetic wave.

As a specific example of the length of each second conductive wire 11, when the frequency of the electromagnetic wave is 28Ghz (that is, the wavelength of the electromagnetic wave is approximately 1 cm), the length (dimension L) of each second conductive wire 11 is , is set to 100 μm, which corresponds to 1/100 of the wavelength of the electromagnetic wave. If the length of each second conductive wire 11 is set to such a length (that is, the size of the second cell 10 constituted by a plurality of second conductive wires 11), the conductor resistance of each second conductive wire 11 becomes relative. become larger. This increases the ability of each second conductive wire 11 to transmit the electromagnetic waves. As a result, the transmission effect of the second conductor pattern 9 on the electromagnetic waves is improved.

Note that when the conductor resistance is relatively small and the volume of the conductor is relatively large, the number of free electrons in the conductor becomes relatively large, and the effect on the electromagnetic waves becomes large. In other words, the reflection effect on the electromagnetic waves increases. On the other hand, when the conductor resistance is relatively large and the volume of the conductor is relatively small, the number of free electrons in the conductor becomes relatively small, and the effect on the electromagnetic waves becomes small. That is, the permeation effect on the electromagnetic waves is enhanced.

By the way, as shown in FIG. 3, in the first direction X, the end of the second conductive wire 11 extending along the first direction It is preferable that the interval (that is, the dimension A shown in FIG. 3) is set to 1 μm or more. Similarly, in the second direction Y, the distance between the end of the second conductive wire 11 extending along the second direction Y and the second conductive wire 11 extending along the first direction , is preferably set to 1 μm or more. In this way, if the shortest distance between the second conductive lines 11, 11 that are perpendicular to each other is set to 1 μm or more, the higher the frequency of the electromagnetic waves, the higher the transmittance of the electromagnetic waves in the second conductor pattern 9. It is possible to increase it.

In order to ensure transparency, each of the first conductor pattern 6 and the second conductor pattern 9 is configured to have a total light transmittance of 70% or more. Further, each second conductive wire 11 is configured to have a line width (dimension W shown in FIG. 3) of 10 μm or less. The line width of the second conductive line 11 may be the same as the line width of the first conductive line 8. Note that the above-mentioned "total light" may be visible light.

(Cross-sectional structure of the first and second conductive wires)
As shown in FIG. 4, the first conductive wire 8 includes an adhesive layer 21, a conductive layer 22, and a blackened layer 25. Although not shown, the second conductive wire 11 also includes an adhesion layer 21, a conductive layer 22, and a blackened layer 25, similarly to the first conductive wire 8. In this embodiment, the main component of the conductive material that makes up the conductive layer 22 of the first conductive wire 8 and the main component of the conductive material that makes up the conductive layer 22 of the second conductive wire 11 are the same.

The adhesion layer 21 is an element for ensuring the adhesion of the conductive layer 22 to the groove portion 5. The adhesive layer 21 is, for example, a metal nitride or metal oxide containing at least one metal selected from the group consisting of Ti, Al, V, W, Ta, Si, Cr, Ag, Mo, Cu, and Zn. This is a metal layer composed of The adhesive layer 21 may be a single layer or a laminate of a plurality of layers having different compositions. The adhesive layer 21 is laminated in the form of a thin film on the groove portion 5 by, for example, vapor deposition or sputtering.

The conductive layer 22 is an element for ensuring the conductivity of each of the first conductive wire 8 and the second conductive wire 11. The conductive layer 22 is buried in the groove portion 5 . The conductive layer 22 is composed of a seed layer 23 and a main body layer 24. Both the seed layer 23 and the main body layer 24 are made of a conductive material. A conductive metal such as copper (Cu) or silver (Ag) is suitable as this conductive material. Note that instead of the conductive metal, for example, a transparent conductive material having light transmittance such as a conductive resin material, indium tin oxide, or tin oxide may be used.

The seed layer 23 has a function of increasing the adhesion between the adhesive layer 21 and the main body layer 24. Specifically, the seed layer 23 functions as a cathode for depositing a plating solution such as copper (Cu) on the adhesive layer 21 during electroplating processing for forming the main body layer 24, for example. The seed layer 23 is laminated in the form of a thin film on the adhesive layer 21 by, for example, vapor deposition or sputtering. Note that if the main body layer 24 is formed by a method different from electroplating, the seed layer 23 may not be provided.

The main body layer 24 is formed by, for example, vapor deposition, sputtering, electroless plating, or electroplating. This embodiment shows a configuration in which the main body layer 24 is stacked on the seed layer 23 by electroplating. Note that after the electroplating process, the seed layer 23 and the main body layer 24 are integrally formed, and the interface between the seed layer 23 and the main body layer 24 cannot be distinguished.

The blackening layer 25 is laminated on the conductive layer 22 on the opening side of the groove portion 5 . The thickness of the blackening layer 25 is, for example, 7 nm to 10 nm. The blackening layer 25 has a function of making the first and second conductive wires 8 and the second conductive wires 11 less visible when the frequency selection plate 1 is viewed from the outside.

In the blackened layer 25, copper crystal grains located at boundaries between copper crystal grains (so-called "grain boundaries") located on the surface of the conductive layer 22 (main body layer 24) are replaced with palladium (blackened layer 25). formed by processing). Specifically, in the blackening treatment, intergranular corrosion progresses along the boundaries (crystal grain boundaries) between copper crystal grains located on the surface of the main body layer 24, and the copper constituting the surface of the main body layer 24 crystal grains are replaced with palladium. As a result, the blackening layer 25 is laminated on the surface of the main body layer 24.

[Operations and effects of embodiment]
As described above, the plurality of first cells 7 are configured such that adjacent first cells 7, 7 are electrically connected to each other. The first conductor pattern 6 is configured such that the overall size of the first conductor pattern 6 is smaller than the wavelength of the electromagnetic wave incident on the frequency selection plate 1 and is large enough to reflect the wavelength. Thereby, each first region R1 in which each first conductor pattern 6 is arranged can be configured as a region capable of selectively reflecting electromagnetic waves incident on the frequency selection plate 1.

Further, the plurality of second cells 10 are configured such that the second conductive lines 11, 11 forming each of the second cells 10, 10 adjacent to each other are not electrically connected to each other. The second conductor pattern 9 is configured such that the size of one second cell 10 is smaller than the entire size of the first conductor pattern 6 and is large enough to transmit the wavelength of the electromagnetic wave. Thereby, the second region R2 in which the second conductor pattern 9 is arranged can be configured as a region through which electromagnetic waves incident on the frequency selection plate 1 can selectively pass.

Furthermore, in the frequency selection board 1, each first conductor pattern 6 is configured such that the first cells 7, 7 are in a conductive state, and the second cells 10, 10 are configured so as to be in a non-conductive state. A second conductor pattern 9 (so-called dummy pattern) coexists on the substrate 2 as a first region R1 and a second region R2. This makes it easier to uniformize the distribution of the conductor patterns on the substrate 2. As a result, when the frequency selection board 1 is attached to a window of a building, for example, when the window is viewed from inside or outside of the building, each of the first conductor patterns 6 and the second conductor pattern 9 (dummy pattern) becomes difficult to distinguish. That is, a phenomenon in which, for example, only each first conductor pattern 6 (the plurality of first conductive lines 8) stands out when looking at the window from inside or outside the building is less likely to occur. This makes it possible to improve the appearance of the frequency selection plate 1 in appropriate usage conditions.

Therefore, in the embodiment of the present disclosure, it is possible to obtain the frequency selection plate 1 that ensures the function for appropriately controlling the electromagnetic waves and has improved visibility.

Here, FIG. 5 shows the so-called "free space method" based on the viewpoint of how the relationship between the frequency of electromagnetic waves and the transmission loss appears depending on the presence or absence of the second region R2 (the presence or absence of the second conductor pattern 9). This figure shows the results of a reference example measured by (hereinafter referred to as "measurement results of a reference example"). The measurement example indicated by "Sp1" in FIG. 5 (hereinafter referred to as "measurement example Sp1") has a configuration in which the first region R1 and the second region R2 are provided on the substrate 2 (i.e., the frequency according to the embodiment of the present disclosure). This is a measurement example regarding a configuration corresponding to the selection board 1). The measurement example indicated by "Sp2" in FIG. 5 (hereinafter referred to as "measurement example Sp2") is a measurement example regarding a configuration in which only the first region R1 is provided on the substrate 2 (a configuration different from the frequency selection plate 1, not shown). It is. In addition, in FIG. 5, in both measurement examples Sp1 and Sp2, the length of the first conductive wire 6 and/or the length of the second conductive wire 11 is set to the length of the electromagnetic wave when the transmission effect on the electromagnetic wave is the lowest. frequency ("28Ghz" mentioned above).

According to FIG. 5, in both measurement examples Sp1 and Sp2, there was no significant difference in transmission loss (corresponding to the vertical axis in FIG. 5) when the electromagnetic wave frequency was around 28 GHz. That is, measurement examples Sp1 and Sp2 both had substantially the same transmission effect when the frequency of electromagnetic waves was around 28 GHz. From this, in the structure in which the first region R1 and the second region R2 are provided on the substrate 2, it is possible to obtain the same appearance as in the structure in which only the first region R1 is provided in the substrate 2. In this way, the measurement results of the reference example shown in FIG. 5 also confirm that the visibility of the frequency selection plate 1 is improved.

Further, each of the first conductive pattern 6 and the second conductive pattern 9 is configured to have a total light transmittance of 70% or more, and each of the second conductive lines 11 is configured to have a line width of 10 μm or less and a long length. The wavelength of the electromagnetic wave is 1/50 or less of the wavelength of the electromagnetic wave. According to this configuration, the electromagnetic waves can be appropriately transmitted through the second region R2 while ensuring transparency.

Further, in the first direction X, the distance (dimension A) between the end of the second conductive wire 11 extending along the first direction , is set to 1 μm or more. According to this setting, the higher the frequency of the electromagnetic waves is, the higher the transmittance of the electromagnetic waves in the second conductor pattern 9 can be.

Further, the substrate 2 is formed into a film shape. This makes it easy to attach the frequency selection board 1 to, for example, a window of a building.

Furthermore, each of the first conductive wire 8 and the second conductive wire 11 includes a conductive layer 22 embedded in the groove portion 5. This conductive layer 22 can ensure the conductivity of each of the first conductive wire 8 and the second conductive wire 11.

Further, the main component of the conductive material that makes up the conductive layer 22 of the first conductive wire 8 and the main component of the conductive material that makes up the conductive layer 22 of the second conductive wire 11 are the same. Thereby, the manufacturing cost of the frequency selection plate 1 can be suppressed.

Each of the first conductive wire 8 and the second conductive wire 11 further includes a blackened layer 25 stacked on the conductive layer 22 on the opening side of the groove portion 5 . This blackened layer 25 makes it difficult for the first conductive wire 8 and the second conductive wire 11 to be visually recognized when the frequency selection plate 1 is viewed from the outside.

[Modification 1 of embodiment]
In the embodiment described above, the slits 12 are arranged at positions corresponding to the substantially square corners forming each second cell 10, but the present invention is not limited to this embodiment. For example, as in Modification 1 shown in FIG. 6, the slits 12 may be arranged in the middle of each side of the substantially square shape that constitutes the second cell 10. That is, in this modification, the second conductive wire 11 extending along the first direction X and the second conductive wire 11 extending along the second direction Y cross each other (so-called cross shape). ing.

Even in the form in which the slits 12 are arranged in this way, each of the plurality of second conductive wires 11 is in a mutually independent state, similarly to the above embodiment. That is, the second conductive wires 11, 11 constituting each of the second cells 10, 10 adjacent to each other are in a non-conducting state with each other. Thereby, the second conductor pattern 9 can be configured as a dummy pattern. Further, even in the second conductor pattern 9 of this modification, the electromagnetic wave transmission effect is superior due to each slit 12 in comparison with the first conductor pattern 6.

[Modification 2 of embodiment]
In addition, as in the second modification shown in FIG. 7, the slits 12 are placed at both positions corresponding to the corner portions of the approximately square shape forming the second cell 10 and midway portions of each side of the approximately square shape. It may be placed in Even in this modification, the second conductor pattern 9 can be configured as a dummy pattern, similarly to the above embodiment and the first modification. Further, even in the second conductor pattern 9 of this modification, the electromagnetic wave transmission effect is superior due to each slit 12 in comparison with the first conductor pattern 6.

[Modification 3 of embodiment]
In the embodiment described above, each of the first cell 7 and the second cell 10 has a substantially square shape, but the present invention is not limited to this shape. For example, as in Modification 3 shown in FIG. 8, each of the first cell 7 and the second cell 10 may have a substantially circular shape.

In this modification, the first cells 7, 7 adjacent to each other are arranged such that their substantially circular outer edges touch each other. That is, the first cells 7, 7 that are adjacent to each other are electrically connected to each other. Thereby, similarly to the embodiment described above, each first region R1 in which each first conductor pattern 6 is arranged can be made into a region capable of selectively reflecting the electromagnetic waves.

Further, in the above embodiment, each second cell 10 is formed in a non-occluded form by the slit 12, but the present invention is not limited to this form. For example, as in Modification 3, each second cell 10 may be formed in a closed shape. Specifically, in Modification 3, the slits 12 are not provided, and a plurality of second cells 10 each having a closed shape are arranged at intervals from each other. Even in such a form, each of the plurality of second conductive wires 11 is in a mutually independent state, similarly to the above embodiment. That is, the second cells 10, 10 adjacent to each other are in a non-conducting state with each other. Thereby, the second conductor pattern 9 can be configured as a dummy pattern. Furthermore, in the second conductor pattern 9 of this modification, since the second cells 10, 10 are arranged with a distance from each other, the electromagnetic wave transmission effect is superior in comparison with the first conductor pattern 6. Become.

[Modifications 4 and 5 of the embodiment]
Further, as in Modification 4 shown in FIG. 9, only the second conductor pattern 9 shown in the above embodiment may be replaced with the second conductor pattern 9 shown in Modification 3. Furthermore, as in Modification 5 shown in FIG. 10, only the first conductor pattern 6 shown in the above embodiment may be replaced with the first conductor pattern 6 shown in Modification 3 above.

[Variation 6 of embodiment]
Further, although the frequency selection board 1 according to the above embodiment has the first conductor pattern 6 and the second conductor pattern 9, the present invention is not limited to this embodiment. For example, as in Modification 6 shown in FIG. 11, the frequency selection board 1 may further include a third conductor pattern 30.

The third conductor pattern 30 is configured to have a lower reflectance of the electromagnetic waves than the first conductor pattern 6. The third conductor pattern 30 is arranged in the second region R2 of the substrate 2. The third conductor pattern 30 is in electrical continuity with the first conductor pattern 6.

The third conductor pattern 30 has a plurality of third cells. The plurality of third cells are constituted by the plurality of third conductive lines 31. Note that the main configuration of the third conductive wire 31 is the same as the configuration of the first conductive wire 8, so detailed description thereof will be omitted. Further, in FIG. 11, the reference numeral of the third cell is omitted to simplify the illustration.

Each third cell is formed in a closed shape. Each third cell has a substantially square shape. The size of each third cell corresponds to the same size as the four first cells 7 combined in a substantially square shape. That is, the size of each third cell is larger than the first cell 7. The plurality of third cells are configured such that adjacent third cells are electrically connected to each other.

In this modification, the second conductor pattern 9 and the third conductor pattern 30 are arranged so as to overlap each other in the second region R2. Specifically, in this modification, the four second cells 10 are configured to be located inside a substantially square shape forming one third cell.

In the frequency selection plate 1 of this modification, the first conductor pattern 6 is located in the first region R1, while the second conductor pattern 9 and the third conductor pattern 30 are located in the second region R2 in a mixed state. There is. This makes it possible to make the reflectance of the electromagnetic waves different between the first region R1 and the second region R2. Furthermore, since the second conductor pattern 9 and the third conductor pattern 30 coexist in the second region R2, the distribution state of the conductor patterns on the substrate 2 is made uniform. That is, the first conductor pattern 6 having a relatively high wiring density of conductive lines becomes less noticeable in comparison with the third conductor pattern 30 having a relatively low wiring density of conductive lines. As a result, when the frequency selection board 1 is attached to a window of a building, for example, when the window is viewed from inside or outside of the building, each of the first conductor pattern 6, the second conductor pattern 9, and the third conductor pattern It becomes difficult to distinguish between 30 and 30. Therefore, also in this modification, the visibility of the frequency selection board 1 can be improved.

[Modification 7 of embodiment]
In the above embodiment, the first conductor patterns 6, 6 arranged at a predetermined interval are brought into a non-conducting state by the second conductor pattern 9, but the present invention is not limited to this embodiment. For example, as in Modified Example 7 shown in FIG. A connecting element 41 may also be provided. The connection element 41 is made of, for example, a variable capacitance diode.

In this modification, the connecting element 41 is provided between the first conductor patterns 6, 6 in the second direction Y. That is, the first conductor patterns 6, 6 facing each other in the second direction Y are electrically connected to each other by the connecting element 41. Further, a connecting element 41 is also provided between the first conductor pattern 6 and the external control circuit 40 located on the lower side of the paper in FIG. As a result, the three first conductor patterns 6 aligned along the second direction Y and the external control circuit 40 are electrically connected. With this configuration, the reflection performance of the electromagnetic waves in the first conductor pattern 6 can be adjusted as appropriate.

[Other embodiments]
Although the frequency selection board 1 according to the embodiment described above includes the substrate 2 having one film base material 3, the present invention is not limited to this embodiment. For example, the substrate 2 may be a laminate (not shown) in which a plurality of film base materials 3 are bonded together.

In the frequency selection plate 1 according to the above embodiment, the groove forming layer 4 is provided on one surface of the film base material 3, but the present invention is not limited to this embodiment. That is, the groove forming layer 4 may also be provided on the other surface of the film base material 3.

Although the frequency selection board 1 according to the above embodiment shows a form in which the first conductor pattern 6 and the second conductor pattern 9 are formed on one surface of the substrate 2, the present invention is not limited to this form. That is, the first conductor pattern 6 may be formed on one surface of the substrate 2, and the second conductor pattern 9 may be formed on the other surface of the substrate 2.

Although the frequency selection board 1 according to the above embodiment has a configuration including a plurality of first conductor patterns 6, the present invention is not limited to this configuration. That is, the frequency selection board 1 only needs to include at least one first conductor pattern 6.

Although the frequency selection board 1 according to the embodiment described above has a form including one second conductor pattern 9, the present invention is not limited to this form. That is, the frequency selection board 1 may include a plurality of second conductor patterns 9.

In the above embodiment, each first cell 7 has a substantially square shape, but the present invention is not limited to this shape. For example, each first cell 7 may have a substantially diamond shape. Each second cell 10 may also have a substantially rhombic shape instead of the substantially square shape shown in the above embodiment.

In the above embodiment, the first conductive wires 8, 8 are arranged at equal intervals in the first direction X or the second direction Y, but the first conductive wires 8, 8 are arranged at equal intervals. It does not have to be placed. The second conductive wires 11, 11 do not need to be arranged at equal intervals.

In the frequency selection plate 1 according to the above embodiment, the adhesive layer 21 is formed in the groove portion 5, but the present invention is not limited to this embodiment. That is, the conductive layer 22 may be formed directly on the groove portion 5 without providing the adhesive layer 21.

Further, although the frequency selection plate 1 according to the above embodiment has the blackening layer 25 provided, the blackening layer 25 may not be provided.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various changes can be made within the scope of the present disclosure.

The present disclosure can be used industrially as a frequency selection board.

1: Frequency selection plate 2: Substrate 3: Film base material 4: Groove forming layer 5: Concave groove portion 6: First conductor pattern 7: First cell 8: First conductive line 9: Second conductor pattern 10: Second cell 11: Second conductive wire 12: Slit 21: Adhesive layer 22: Conductive layer 23: Seed layer 24: Main body layer 25: Blackening layer 30: Third conductive pattern 31: Third conductive wire 40: External control circuit 41: Connection Element R1: First region R2: Second region

Claims (8)

A frequency selection board,
a substrate provided with a first region and a second region;
at least one first conductor pattern disposed in the first region of the substrate and having a plurality of first cells configured by a plurality of first conductive lines;
at least one second conductor pattern disposed in the second region of the substrate and having a plurality of second cells configured by a plurality of second conductive lines,
The plurality of first cells are configured such that the first cells adjacent to each other are electrically connected to each other,
The first conductor pattern is configured such that the overall size of the first conductor pattern is smaller than the wavelength of electromagnetic waves incident on the frequency selection plate and is large enough to reflect the wavelength of the electromagnetic waves. ,
The plurality of second cells are configured such that the second conductive lines constituting each of the second cells adjacent to each other are not electrically connected to each other,
The second conductor pattern is configured such that the size of one second cell is smaller than the entire size of the first conductor pattern and is large enough to transmit the wavelength of the electromagnetic wave. selection board. The frequency selection board according to claim 1,
Each of the first conductor pattern and the second conductor pattern is configured to have a total light transmittance of 70% or more,
Each of the plurality of second conductive lines is configured to have a line width of 10 μm or less and a length of 1/50 or less of the wavelength of the electromagnetic wave. The frequency selection board according to claim 1,
Each of the plurality of second conductive lines is configured to extend along each of a first direction and a second direction intersecting the first direction,
In the first direction, a distance between an end of the second conductive wire extending along the first direction and the second conductive wire extending along the second direction is set to 1 μm or more. Electromagnetic wave control board. The frequency selection board according to claim 1,
The substrate is a frequency selection plate formed in the form of a film. The frequency selection board according to claim 4,
At least one bottomed groove portion is provided on the outer surface of at least one of the substrates,
Each of the first conductive wire and the second conductive wire includes a conductive layer embedded in the groove portion. The frequency selection board according to claim 5,
An electromagnetic wave control board, wherein a main component of a conductive material forming the conductive layer of the first conductive wire is the same as a main component of a conductive material forming the conductive layer of the second conductive wire. The frequency selection board according to claim 7,
Each of the first conductive wire and the second conductive wire further includes a blackened layer laminated on the opening side of the groove portion of the conductive layer. The frequency selection board according to claim 1,
The substrate is provided with a plurality of the first conductor patterns,
The plurality of first conductor patterns are arranged at intervals from each other on the substrate,
A frequency selection board, wherein each of the plurality of first conductor patterns is provided with a connection element for electrically connecting each of the plurality of first conductor patterns and an external control circuit.