JP6788827B2 - Radio wave transmission / reception board and its manufacturing method - Google Patents

Description

The present embodiment relates to a radio wave transmission / reception substrate used for a radio wave transmission / reception antenna or the like and a method for manufacturing the same.

Conventionally, a flat plate antenna such as a radial line slot array antenna has been used as an antenna for transmitting and receiving radio waves.

Such a radio wave transmission / reception antenna is configured to include a laminated substrate as a radio wave transmission / reception substrate having a glass substrate and a metal layer including a pattern provided on the glass substrate.

Such a laminated substrate is generally obtained by subjecting a glass substrate to sputtering, vapor deposition, electrolysis, or electroless plating to form a metal layer, and then etching the metal layer.

However, the process of performing sputtering, vapor deposition or electrolysis, or electroless plating on a glass substrate is costly, and the production time is long, resulting in poor productivity.

Japanese Unexamined Patent Publication No. 2007-295044

The present embodiment has been made in consideration of the above points, and an object of the present invention is to provide a radio wave transmission / reception substrate and a method for manufacturing the same, which can reduce costs.

One embodiment of the present disclosure is a radio wave transmission / reception substrate comprising a substrate and a metal foil including a pattern adhered to the substrate via an adhesive layer.

In the radio wave transmission / reception substrate, the adhesive layer may be a coating film applied on the substrate.

In the radio wave transmission / reception substrate, the maximum height Rmax of the surface of the metal foil may be 100 nm or less.

In the radio wave transmission / reception substrate, the metal foil may be gold, silver, copper, nickel, or titanium.

Further, one embodiment of the present disclosure includes a step of providing an adhesive layer on the substrate in a method of manufacturing a radio wave transmission / reception substrate having a substrate and a radio wave transmission / reception layer including a pattern provided on the substrate. A pattern is formed on the metal foil by a step of adhering the metal foil to the substrate via the adhesive layer and a desired portion of the metal foil on the substrate is removed, and the metal foil containing the pattern is formed. This is a method for manufacturing a substrate for transmitting and receiving radio waves, which comprises a step of forming the radio wave transmitting and receiving layer.

In the method for manufacturing a radio wave transmission / reception substrate, the adhesive layer may be a coating film applied on the substrate.

In the method for manufacturing a radio wave transmission / reception substrate, the adhesive layer may be applied by a spin coater or a die coater.

In the method for manufacturing a radio wave transmission / reception substrate, the adhesive layer may be coated so that the maximum height Rmax of the surface thereof is 100 nm or less.

In the method for manufacturing a radio wave transmission / reception substrate, the maximum height Rmax of the surface of the metal foil may be 100 nm or less.

In the method for manufacturing a radio wave transmission / reception substrate, the metal foil may be gold, silver, copper, nickel, or titanium.

According to this embodiment, it is possible to reduce the cost of the radio wave transmission / reception substrate.

FIG. 1 is a side sectional view showing an antenna board including a board for transmitting and receiving radio waves. FIG. 2 is a plan view showing an antenna board including a board for transmitting and receiving radio waves. 3 (a) to 3 (g) are diagrams showing a method of manufacturing a radio wave transmission / reception substrate according to an embodiment.

Hereinafter, one embodiment will be described with reference to the drawings.
1 to 3 are views showing an embodiment, of which FIG. 1 is a side sectional view showing an antenna board including a radio wave transmission / reception board, and FIG. 2 is a plan view showing an antenna board including a radio wave transmission / reception board. 3 (a) to 3 (g) are process diagrams showing a method of manufacturing a radio wave transmission / reception substrate.

As shown in FIGS. 1 and 2, the antenna board 10 includes a radio wave transmission / reception board 20 for transmitting / receiving radio waves, so that a flat antenna such as a radial line slot array antenna used as a radio wave transmission / reception antenna can be provided. Configure.

Such an antenna substrate 10 is refracted by a glass substrate 11, a metal foil 13 including a pattern 13P bonded to the surface of the glass substrate 11 via an adhesive layer 12, and a refracting layer 14 provided on the metal foil 13. It includes a glass substrate 15 provided on the layer 14. Further, a waveguide layer 16 is provided on the back surface of the glass substrate 11. Of these, the radio wave transmission / reception substrate 20 includes a glass substrate 11, an adhesive layer 12, and a metal foil 13.

The antenna substrate 10 having the above configuration is used as an antenna for transmitting and receiving radio waves, for example, an antenna for broadcasting reception and an antenna for satellite communication.

Further, as shown in FIGS. 1 and 2, the metal foil 13 of the radio wave transmission / reception substrate 20 is formed with a pattern 13P forming a slot-shaped opening for propagating radio waves. Since the pattern 13P formed on the metal foil 13 does not form an island-shaped isolated region with respect to the metal foil 13, when the carrier layer 23 is peeled from the metal foil 13 as described later (FIG. 3 (f). ), The carrier layer 23 can be easily and easily peeled off.

Here, "the pattern 13P forms an island-shaped isolated region" means that the pattern formed on the metal foil 13 forms an island-shaped closed region, and the isolated region surrounded by the pattern is another. It means that it is not continuous with the area of.

Further, as shown in FIG. 1, an interface 13a between the carrier layer 23 and the metal foil 13 that is peeled off from the metal foil 13 remains on the upper surface of the metal foil 13.

Furthermore, an antioxidant film 18 such as ITO (Indium Tin Oxide) is provided on the interface 13a of the metal foil 13. Further, the refraction layer 14 is provided on the antioxidant film 18 as described above. The refracting layer 14 includes a dielectric or a variable inductive dielectric, for example, refracting a radio wave received from the glass substrate 15 side and directing the radio wave in an appropriate direction to pass through the metal foil 13 or a metal foil. The radio wave transmitted from the 13 side is refracted and transmitted from the glass substrate 15 side.

Next, each component will be described in more detail. As the glass substrates 11 and 15, quartz glass, non-alkali glass, soda glass, and tempered glass having a thickness of 1.1 mm or less can be used. Of these, it is preferable to use quartz glass having a low non-dielectric constant.

Further, as the shapes of the glass substrates 11 and 15, G4, G5 size (730 mm × 920 mm) or G8 size (2500 mm × 2200 mm) can be used, and a multi-imposed glass substrate can also be used. ..

Further, as the adhesive layer 12, an epoxy adhesive, an acrylic adhesive, a rubber adhesive, a silicone rubber adhesive, or a plastic adhesive can be used. In this case, either a liquid adhesive or a sheet-like adhesive can be used. Here, the liquid adhesive means a curable adhesive or the like that is cured by heat, light, or the like, and the sheet-like adhesive means a pressure-sensitive adhesive, a so-called pressure-sensitive adhesive or the like.

When a liquid adhesive is used, the adhesive can be uniformly applied using a coater machine such as a spin coater, a die coater, a spray coater, or a dip coater, and the thickness of the adhesive can be adjusted. Here, in the present embodiment, the adhesive layer 12 is a coating film formed by applying a liquid adhesive. In this case, it is preferable to use a spin coater or a die coater in order to make the surface of the coating film precisely uniform.

On the other hand, when the sheet-shaped adhesive is used, the sheet-shaped adhesive may be bonded on the glass substrate 11, so that the adhesive layer 12 can be easily formed. The sheet-like adhesive may be attached to the glass substrate 11 by a roll laminator, a vacuum pressure laminator, an autoclave, a pressure press, or the like.

When transmitting and receiving radio waves in the high frequency band, the adhesive layer 12 having an appropriate low relative permittivity and an appropriate dielectric loss tangent is used.

Generally, dielectric polarization occurs when an electric field is applied to an insulator (dielectric), and the degree to which dielectric polarization occurs and the electric field changes in the insulator is called "relative permittivity".

The dielectric loss tangent is a numerical value indicating the degree of electrical energy loss in an insulator (dielectric).

Next, as the metal foil 13, a metal such as gold, silver, copper, nickel (Ni), and titanium (Ti) can be used, but in consideration of cost and resistance value, copper (Cu) is preferably used. .. As such a metal foil 13, for example, a copper electrolytic plating layer having a thickness of 1.5 to 10 μm formed by electroplating on a carrier layer 23 having a thickness of 18 μm made of copper foil, which will be described later, is formed. Can be used. Further, the metal foil 13 may be rolled copper or the like.

By forming the metal foil 13 made of the electrolytic plating layer on the carrier layer 23 made of copper foil in this way, when the radio wave transmission / reception substrate 20 is manufactured as described later, the metal foil 13 swells, swells, and wrinkles. The substrate 10 can be manufactured with high accuracy without generating the above.

Further, a two-layer multilayer metal foil 13A (see FIG. 3) can be formed from the carrier layer 23 and the metal foil 13 described above.

In this case, there is an interface 13a that separates the carrier layer 23 and the metal foil 13 between the carrier layer 23 and the metal foil 13. In the present embodiment, when the radio wave transmission / reception substrate 20 is manufactured as described later, the carrier layer 23 is peeled off from the metal foil 13, but the carrier layer 23 is easily peeled off from the carrier layer 23. A release layer may be interposed between the metal foil 13 and the metal foil 13.

As described above, the carrier layer 23 and the metal foil 13 constituting the multilayer metal foil 13A are preferably made of the same metal, for example, the same copper, in order to perform the etching step described later with high accuracy.

Further, regarding the surface roughness of the metal foil 13, it is preferable that the maximum height Rmax of the surface is 100 nm or less in order to exert the function as an antenna. The maximum height Rmax conforms to JIS B0601: 1982.

On the other hand, the carrier layer 23 of the multilayer metal foil 13A is made of copper foil as described above, and examples of such copper foil include copper foil manufactured by Mitsui Metal Co., Ltd., copper foil manufactured by JX Nippon Mining & Metal Co., Ltd., or Copper foil manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. can be used.

Next, a method of manufacturing the radio wave transmission / reception substrate will be described with reference to FIGS. 3A to 3G.
First, the glass substrate 11 is prepared (FIG. 3 (a)), and the adhesive layer 12 is provided on the glass substrate 11 (FIG. 3 (b)).

In this case, the adhesive layer 12 is formed by applying a liquid adhesive onto the glass substrate 11 with a coater machine or by adhering a sheet-like adhesive onto the glass substrate 11. In this example, the adhesive layer 12 is a coating film formed by applying a liquid adhesive with a spin coater, and the adhesive layer 12 is formed so that the maximum height Rmax of the surface of the adhesive layer 12 is 100 nm or less. Provided.

Next, as shown in FIG. 3C, a multilayer metal foil 13A having a carrier layer 23 and a metal foil 13 provided on the carrier layer 23 is prepared. In this example, the carrier layer 23 has heat resistance.

Here, the heat-resistant carrier layer 23 has a property that the carrier layer 23 does not easily melt or soften when the adhesive layer 12 is cured by heat-treating the radio wave transmission / reception substrate as described later. For example, the carrier layer 23 is preferably made of a material having a melting temperature of 300 ° C. or higher, for example, copper foil.

Next, the multilayer metal foil 13A having such a structure is adhered onto the glass substrate 11 via the adhesive layer 12. As a result, a laminated substrate 10A including the glass substrate 11 and the multilayer metal foil 13A bonded to the glass substrate 11 via the adhesive layer 12 can be obtained. In this case, the metal foil 13 of the multilayer metal foil 13A is on the glass substrate 11 side, and the carrier layer 23 is on the opposite side of the glass substrate 11.

Next, in order to form a pattern on the carrier layer 23, a resist 24 having a desired pattern is provided (FIG. 3 (d)).

Next, as shown in FIG. 3E, the multilayer metal foil 13A of the laminated substrate 10A is subjected to an etching treatment to remove the desired portion 25 of the multilayer metal foil 13A. The desired portion 25 is a portion that becomes the pattern 13P of the metal foil 13 as described later.

Wet etching can be used as the etching treatment for the multilayer metal foil 13A, and in this case, a ferric chloride solution having a high etching rate can be used as the etching solution.

Then, the laminated substrate 10A is heat-treated. This heat treatment comprises a curing step of curing the adhesive layer 12 provided on the glass substrate 11, and is a process of processing the laminated substrate 10A above the glass transition temperature of the adhesive layer 12.

When the laminated substrate 10A is heat-treated, it is conceivable that the metal foil 13 is pressed by the gas generated from the adhesive layer 12 to swell, swell, and wrinkle the metal foil 13.

However, in the present embodiment, for example, the metal foil 13 having a thickness of 3 μm is held by the carrier layer 23 having a thickness of 18 μm to reinforce its strength, so that gas is generated from the adhesive layer 12 and the metal foil 13 is generated. Even if the metal foil 13 is pressurized, the metal foil 13 does not swell, swell, wrinkle, or the like.

Next, as shown in FIG. 3 (f), the resist 24 and the carrier layer 23 are peeled from the metal foil 13 using a suction device 30 having a suction plate 31. In this case, the carrier layer 23 can be easily peeled off from the metal foil 13 via the interface 13a. Further, since the pattern 13P of the metal foil 13 does not form an island-shaped isolated region, the resist 24 and the carrier layer 23 can be peeled off from the metal foil 13 at one time. The pattern 13P of the metal foil 13 can be formed from the portion 25 removed by the etching process in this way.
At this time, the adhesive layer 12 is exposed on the pattern 13P portion of the metal foil 13. Further, in the present embodiment, the maximum height Rmax of the surface of the metal foil 13 is 100 nm or less. Here, in the present embodiment, the adhesive layer 12 is provided so that the maximum height Rmax of the surface of the adhesive layer 12 is 100 nm or less, so that the maximum height Rmax of the surface of the metal foil 13 provided on the surface thereof is Rmax. Can be easily set to 100 nm or less.

Next, the antioxidant film 18 is provided on the metal foil 13 and the adhesive layer 12 (FIG. 3 (g)). As a result, in the present embodiment, the radio wave transmission / reception substrate 20 is manufactured.

After that, the refraction layer 14 is provided on the antioxidant film 18, and the glass substrate 15 is provided on the refraction layer 14.

Next, the waveguide layer 16 is provided on the back surface of the glass substrate 11, and the antenna substrate 10 shown in FIG. 1 is obtained in this way.

As described above, the radio wave transmission / reception substrate 20 according to the present embodiment includes the glass substrate 11 and the metal foil 13 including the pattern 13P adhered to the glass substrate 11 via the adhesive layer 12. In the radio wave transmission / reception substrate 20, an adhesive layer 12 is provided on the glass substrate 11, the metal foil 13 is adhered to the glass substrate 11 via the adhesive layer 12, and a desired portion 25 of the metal foil 13 on the glass substrate 11 is attached. Is produced by forming a pattern 13P on the metal foil 13 and forming a radio wave transmission / reception layer for transmitting / receiving radio waves by the metal foil 13 including the pattern 13P. Since the metal foil 13 including the pattern 13P is adhered to the glass substrate 11 via the adhesive layer 12 in this way, the metal foil 13 is formed on the glass substrate 11 by sputtering, vapor deposition or electrolysis, or electroless plating. Compared with the case, the metal foil 13 can be easily provided on the glass substrate 11, and the time required for the installation process is also shortened. Therefore, the cost can be reduced.

Further, since the adhesive layer 12 is a coating film applied on the glass substrate 11, the surface thereof can be easily smoothed. As a result, the surface of the metal foil 13 can be easily smoothed, and stability when transmitting and receiving radio waves can be easily ensured. In particular, in the present embodiment, the adhesive layer 12 is coated by a spin coater, and the maximum height Rmax of the surface of the adhesive layer 12 is 100 nm or less. As a result, the maximum height Rmax of the surface of the metal foil 13 on the adhesive layer 12 can be easily set to 100 nm or less, and the stability when transmitting and receiving radio waves is sufficiently ensured.

Although the embodiment has been described above, various changes can be made to the present embodiment. For example, in the above-described embodiment, the multilayer metal foil 13A is etched to remove the desired portion 25, but the multilayer metal foil 13A may be punched to remove the desired portion 25. .. Further, the desired portion 25 of the multilayer metal foil 13A may be removed by performing laser processing on the multilayer metal foil 13A. Further, in the above-described embodiment, the multilayer metal foil 13A having the carrier layer 23 and the metal foil 13 is used, but only the metal foil 13 is laminated on the glass substrate 11, and the desired portion 25 in the metal foil 13 is used. The pattern 13P may be formed by removing the above.

10 ... Antenna substrate 10A ... Laminated substrate 11 ... Glass substrate 12 ... Adhesive layer 13 ... Metal foil 13a ... Interface 13A ... Multilayer metal foil 13P ... Pattern 14 ... Refractive layer 15 ... Glass substrate 16 ... waveguide layer 20 ... Radio wave transmission / reception substrate 23 ... Carrier layer 24 ... Resist 25 ... Desired part

Claims (4)

In a method for manufacturing a radio wave transmission / reception board having a substrate and a radio wave transmission / reception layer including a pattern provided on the substrate.
The process of providing an adhesive layer on the substrate and
The step of adhering the metal foil to the substrate via the adhesive layer and
A step of forming a pattern on the metal foil by removing a desired portion of the metal foil on the substrate and forming the radio wave transmission / reception layer with the metal foil containing the pattern is provided .
The adhesive layer is a coating film applied on the substrate.
A method for manufacturing a substrate for transmitting and receiving radio waves , wherein the adhesive layer is applied so that the maximum height Rmax of the surface thereof is 100 nm or less . The method for manufacturing a radio wave transmission / reception substrate according to claim 1 , wherein the adhesive layer is applied by a spin coater or a die coater. The method for manufacturing a radio wave transmission / reception substrate according to claim 1 , wherein the maximum height Rmax of the surface of the metal foil is 100 nm or less. The method for manufacturing a radio wave transmission / reception substrate according to any one of claims 1 to 3 , wherein the metal foil is gold, silver, copper, nickel, or titanium.

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