JPH0445601A - Manufacture of waveguide using fiber reinforced plastic as main material - Google Patents

Abstract

PURPOSE:To easily manufacture the waveguide without limitation of a curing temperature of a fiber reinforced plastic by employing a male die core member made of copper, forming a forming layer made of a fiber reinforced plastic on a metallic layer and melting and removing the male die core member. CONSTITUTION:A gold plating layer 1 is formed to a part on an outer face of a male die core member 5 made of copper except the part not coated with a plating mask 6, a nickel plating layer 2 and a copper plating layer 3 are sequentially formed. The plating layers are formed on the surface of the male die core member 5, a fiber reinforced plastic(FRP) layer is laminated on the plating layer, the FRP is cured by heating to form an FRP forming layer 4. Then the male die core member 5 is molten and removed entirely by using water solution of ferric chloride. Thus, the waveguide is realized in which the inner face and a flange face 7 for the connection to another waveguide are formed by the gold plating layer 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing waveguides used in microwave bands, etc., and in particular, to a method for manufacturing waveguides whose main constituent material is fiber-reinforced plastic. Regarding the method.

[Conventional technology]

To reduce weight, FRP (fiber reinforced plastic) or CFRP, a type of FRP, is used as the main component material.
Conventional methods for manufacturing waveguides using (carbon fiber reinforced plastic) include the first to third methods described below.

In the following explanation, the above-mentioned CFRP will be referred to as FRP.The first method uses a low-melting point alloy as a male core material, processes this male core material into a predetermined external shape, and then attaches it to the processed outer periphery. A predetermined metal plating layer is formed, and then F is applied to the outside of the above-mentioned plating layer.
This is a method in which RP layers are laminated, the FRP layer is hardened, and then a core material made of a low melting point alloy is heated, melted, and removed.

The second method uses an aluminum alloy as a male core material instead of the low melting point alloy used in the first method, and forms a metal plating layer using a metal other than aluminum on the surface of this core material. Next, an FRP layer is laminated on this metal plating layer, the FRP layer is cured, and then the male core material is dissolved in an aqueous solution of caustic soda and removed.

The third method is to laminate an FRP layer around the outer periphery of a male core material processed into the desired external shape, excluding both ends, and then heat the FRP layer.
The P layer is cured, and the above-mentioned male mold is mechanically pulled out from the FRP layer to form a tubular intermediate product.

Next, a flange portion separately prepared from an FRP layer or the like is attached to the end of the intermediate product using an adhesive or the like to form a flanged waveguide.

Next, a metal layer is formed by bonding metal foil to the inner surface of the flanged waveguide and the flange surface with an adhesive, or by plating metal on the inner surface of the FRP.

Note that the above-mentioned metal layer is normally used to reduce the amount of attenuation to radio waves propagating within the waveguide.

[Problem to be solved by the invention]

In the first conventional method described above, the melting point of the available low melting point alloy is about 120 to 130 degrees Celsius, whereas FRP, which can be used at high temperatures and has high reliability such as in artificial satellites, When using such FRP as the main constituent material, which often has a high curing temperature of about 130 to 180 degrees Celsius, it is necessary to heat-harden such FRP using a low melting point alloy such as the one mentioned above. It was impossible to do so.

In the second method, when the male aluminum alloy core material is dissolved and removed using an aqueous solution of caustic soda,
There was a drawback that the outside of the FRP layer was also chemically changed by this caustic soda.

In the third method, it is difficult to mechanically pull out the male core material from the FRP and then apply the metal foil to the inner surface of the FRP well over the entire surface, especially when the tube axis is not a straight line but a curved line. In this case, it is extremely difficult to mechanically pull out the male core material from the FRP and to adhere the metal foil to the entire surface of the inner surface of the FRP.

The object of the present invention is to be able to generate a metal layer that is in close contact with the FRP even if the waveguide has a curved tube axis, without being restricted by the curing temperature of the FRP used. It is an object of the present invention to provide a method for manufacturing a waveguide that does not cause unnecessary chemical changes to FRP.

[Means to solve the problem]

The method of manufacturing a waveguide mainly made of carbon fiber reinforced plastic according to the present invention uses copper whose internal shape and the external shape of the connection surface of the waveguide to other electrical parts correspond to the desired internal shape of the waveguide. A male core material is used as the material, excluding the part of the surface of the core material that faces the inside of the waveguide and the part that faces the part where the waveguide is connected to other electrical components. a plating prevention layer is applied to the exposed portion, a metal layer using a metal other than copper is formed by plating on the surface of the male core material on which the plating prevention layer is not provided, and the metal layer other than copper is formed by plating. After forming a molding layer made of thermosetting fiber-reinforced plastic on the metal layer and curing it, the plating prevention layer is removed and a chloride layer is formed. The method is characterized in that the male core material is dissolved and removed using an aqueous solution of ferric iron.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a partial side sectional view of a male core material used in the manufacturing method of the present invention.

A case is shown in which a flange is attached to the waveguide shown in the following example.

The male core material 5 is made of copper and has an outer shape equal to the inner shape of the desired waveguide.The male core material 5 is processed into a hollow shape in a subsequent step to a thickness that provides sufficient mechanical strength.

The shape of the cross section perpendicular to the tube axis of the waveguide is usually rectangular or has a circular hollow part, and the waveguide back surface corresponding part 9 of the male core material 5 is formed on the inner surface of the waveguide to be manufactured. It has the corresponding shape and dimensions.

The flange surface corresponding portion 8 is a portion corresponding to the flange surface of the waveguide to be manufactured, that is, the connection surface with another electrical component to which this waveguide is connected, for example, a waveguide of the same type. .

A plating mask 6 is applied to portions of the male core material 5 that do not require plating.

As the plating mask 6, a silicone-based or rubber-based coating material is used.

By using this plating mask 6, plating on the surface of the male core portion covered with the plating mask 6 can be prevented.

FIGS. 2 to 3 are partial side sectional views illustrating an embodiment of the present invention in the order of manufacturing steps.

As shown in FIG. 2, gold plating is performed on the outer surface of the male core material 5 on the part where the plating mask 6 is not applied to form the gold plating layer 1 as the first plating layer. Plating and copper plating are performed to form a nickel plating layer 2 and a copper plating layer 3 as second and third metal plating layers, respectively.

Gold, which has low electrical resistance and is chemically stable, is used as the first plating layer as described above.

Further, as the second plating layer, the copper of the copper plating layer 3 used as the third plating layer passes through the pinholes of the gold plating layer 1 and is deposited on this gold plating layer. Nickel is used to prevent exposure to

Copper, which has good adhesion to FRP, is used as the third plating layer.

As described above, after forming a plating layer on the surface of the male core material 5, FRP is laminated on the above-mentioned plating layer, and then heated to a predetermined temperature to harden the FRP to form an FRP molded layer. Form 4.

However, when using FRP that hardens at room temperature, heating is omitted and the FRP is hardened at room temperature.

After the above-mentioned steps are completed, the plating mask 6 is removed, leaving the state as shown in the partial side sectional view shown in FIG.

When a rubber-based coating material is used as the plating mask 6, the plating mask 6 can be removed by dissolving it with chlorocene, for example.

Next, all of the male core material 5 is dissolved and removed using an aqueous solution of ferric chloride.

Since the ferric chloride aqueous solution selectively dissolves only copper and does not chemically change other metals or FRP, only the male core material 5 can be removed.

By the process explained above, a waveguide whose inner surface and flange surface for connecting to another waveguide are gold-plated layer 1 as shown in the partial cross-sectional side view of FIG. 4 can be obtained. I can do it.

After performing the above processing, mechanical finishing of the outer peripheral portion of the FRP and holes for mounting the waveguide on the flange surface 7 can be performed.

In the explanation so far, a waveguide with a flange surface was used as an example, but it is clear that the same manufacturing method can be applied to a waveguide without a flange surface.

〔Effect of the invention〕

As explained above, according to the present invention, even in a waveguide whose tube axis is not a straight line but a curved tube axis, the FR can be achieved as described above.
A waveguide made of P as the main material and having a metal layer on the inner surface can be easily manufactured without being restricted by the curing temperature of FRP.

[Brief explanation of the drawing]

FIG. 1 is a partial side cross-sectional view of a male core material used in the manufacturing method of the present invention, FIGS. 2 to 3 are partial side cross-sectional views explaining the manufacturing process of the present invention, and FIG. FIG. 3 is a partial side sectional view showing a waveguide manufactured by the manufacturing method. 1... Gold plating layer, 2... Nickel plating layer, 3...
...Copper plating layer, 4...FRP molding layer, 5...Male core material, 6...Plating mask, 7...Flange surface.

Claims (2)

[Claims] 1. A male core material made of copper is used, and the external shape corresponds to the desired internal shape of the waveguide and the shape of the connection surface of the waveguide to other electrical components, and the surface of the male core material is An anti-plating layer is applied to the surface of the male core material, excluding the portion facing the inside of the waveguide and the portion facing the portion where the waveguide is connected to other electrical components. A metal layer using a metal other than copper is formed by plating on the surface without the plating prevention layer, a single or plural dissimilar metal layers including the metal layer other than copper are formed by plating, and the metal layer is formed by plating. After forming and curing a molded layer made of thermosetting fiber-reinforced plastic on the layer, removing the plating prevention layer,
A method for manufacturing a waveguide mainly made of fiber-reinforced plastic, comprising dissolving and removing the male core material using an aqueous solution of ferric chloride. 2. Gold is used as the metal other than copper, a metal layer using nickel is formed on the metal layer using gold, and a metal layer using copper is further formed on the metal layer using nickel. 2. A method for manufacturing a waveguide made of fiber-reinforced plastic as a main material according to claim 1, wherein the dissimilar metal layer is made of a fiber-reinforced plastic.