JP7561306B2 - A conductive circuit board formed by plating on a substrate consisting of only parallel-arranged fiber threads - Google Patents

Description

The present invention relates to a conductive circuit board in which plating is formed on a base material in which fiber threads of various materials and shapes are arranged in parallel at equal or irregular intervals.

Conventionally, there exists a glass cloth for printed wiring boards made by sewing warp threads and weft threads, in which the weft thread is a glass yarn made by bundling glass fibers having a single fiber diameter equal to or smaller than that of the warp thread and having a diameter of 4.5 μm or less (see, for example, Patent Document 1).
However, the current situation is that the conventional woven fabric or nonwoven fabric substrates made of fibers have drawbacks even when conductive circuits are formed by plating. For example, in recent years, with the miniaturization and precision of electronic devices, there is a demand for conductive circuit boards that are as thin, inexpensive, and have as few irregularities as possible, and that have a large contact area with line contact rather than point contact at the intersections of the woven fabric, as in the case of woven fabric. However, such boards do not currently exist.
In response to this demand, we have been able to obtain a thin conductive circuit board with few irregularities by forming it integrally by plating multiple fibers that are simply arranged in parallel , without weaving them. In this way, conductive circuits are formed on a substrate that is lighter, thinner, softer, flatter, and cheaper to provide, making it possible to address the shortcomings.
Therefore, the present invention has invented something that could not be achieved with conventional woven and nonwoven fabrics , in which a conductive circuit is formed using a base material made of parallel -arranged fiber threads that is integrally formed by plating the base material.

JP 2001-73249 A (see claims, detailed description of the invention, and Figs. 1 and 2)

In conventional glass cloth woven with fiber yarns, strength can be obtained by adopting stronger fiber yarns, but in reality, in order to obtain various shapes and functions, and to be adopted in precision equipment, compactness is aimed for, and in order to achieve this, the thickness of the substrate must be made thinner, which means that if the substrate is woven or nonwoven fabric, the thickness of the substrate must be at least twice as thick. In addition, conductive circuit substrates must have fewer projections and recesses, because electronic components are becoming increasingly miniaturized, and if the substrate is woven or nonwoven fabric, there are projections and recesses, and when electronic components are placed on the substrate, there are gaps, and the phenomenon of the electronic components falling into the gaps (stumbling) is often observed.
In order to solve these problems, the present invention aims to provide a better conductive circuit board that is integrally formed by plating a base material made of parallel-arranged fibers that can accommodate the flatness and thinness of the plane of the conductive circuit board.

The first invention of the present invention, which can achieve the above object, is a conductive circuit board formed by plating on a base material consisting only of fiber threads arranged in parallel as described in claim 1, and is as follows.
In a conductive circuit board whose base material is only fiber threads arranged in parallel , the fiber threads are chemical fibers, vegetable fibers, paper fibers, or metal fibers, either of the same type or of multiple types , and the entire conductive circuit formed integrally by plating the fiber threads arranged in parallel is covered with a reinforcing resin.

The second invention of the present invention, which can achieve the above object, is a conductive circuit board formed by plating on a base material consisting only of fiber threads arranged in parallel as described in claim 2, and is as follows.
In the present invention, both the shape and the pitch of the fiber yarn that is the base material in claim 1 are changed.

The third invention of the present invention, which can achieve the above object, is a conductive circuit board formed by plating on a base material consisting only of fiber threads arranged in parallel as described in claim 3, and is as follows.
In addition to the invention described in claim 1 or claim 2, a configuration is provided in which in addition to the reinforcing resin covering the entire portion of the conductive circuit formed by plating, the base material is supported and reinforced by a plurality of strips of reinforcing resin.

The fourth invention of the present invention, which can achieve the above object, is a conductive circuit board formed by plating on a base material consisting only of fiber threads arranged in parallel as described in claim 4, and is as follows.
In addition to the invention described in any one of claims 1 to 3, the conductive circuit board is configured to have multiple layers and have circuits in each layer electrically conductive.

The fifth invention of the present invention, which can achieve the above object, is a conductive circuit board formed by plating on a base material consisting only of fiber threads arranged in parallel as described in claim 5, and is as follows.
In addition to the invention described above, the tip portion is provided with a connection portion to which a contact or other component can be connected.

The sixth invention of the present invention, which can achieve the above object, is a conductive circuit board formed by plating on a base material consisting only of fiber threads arranged in parallel as described in claim 6, and is as follows.
In the conductive circuit board according to any one of claims 1, 2 and 5, a conductive circuit is formed by plating only on fiber yarns arranged in parallel on a substrate , and another conductive circuit is formed by stacking similarly formed conductive circuits, and the two conductive circuits are pressed together with an adhesive through gaps and gaps between them to conductively bond the conductive circuits .

The conductive circuit board according to the present invention, which is formed by plating a substrate consisting of only parallel-arranged fiber threads, has the structure described above and therefore provides the effects described below.
(1) Since the base material is made of fiber threads arranged in parallel , it is possible to mount very small components.
(2) Since the substrate is not woven, it is possible to use stiff and extremely fine fiber yarns.
(3) When compared with woven or nonwoven fabric substrates, the thickness of the substrate can be at least half that of the substrate when made to the same size and using the same materials.
(4) Since there are fewer projections and recesses compared to woven fabric and nonwoven fabric, even very small components can be mounted horizontally without falling onto the projections and recesses.
(5) Conductive circuits made from woven or nonwoven fabric substrates have uneven surfaces and are difficult to use for high-frequency substrates. However, the conductive circuit of the present invention has fewer uneven surfaces and is therefore suitable for use on high-frequency substrates.
(6) In conductive circuits made from a woven or nonwoven fabric substrate, intersections are unavoidable, so that attachment of electronic components requires point contact. However, since the substrate of the present invention is a conductive circuit formed by plating a substrate made of fiber threads arranged in parallel , attachment of electronic components requires line contact rather than point contact at the very least, and the contact area can be increased.
(7) The base material is made of fiber yarns arranged in parallel . Compared to conventional woven fabrics and nonwoven fabrics, therefore, stiffer fiber yarns or fiber yarns with finer diameters can be used. Since there is no need to weave or press the material like nonwoven fabrics, costs can be reduced.
(8) When stacking conductive circuits, the strength of the conductive circuits can be increased by, for example, arranging the first layer horizontally and the second layer vertically so as to cross each other.
(9) Since the conductive circuit uses fiber threads arranged in parallel as the base material, the gaps between the fiber threads and the conductive circuit can be utilized to press an adhesive or to pour in a conductive adhesive or solder to conductively bond the conductive circuit, making the work extremely simple.

FIG. 1 is a schematic enlarged perspective view of a first embodiment of a conductive circuit board formed by plating on a substrate made of only parallel-arranged fiber threads according to the present invention. This is a schematic enlarged oblique view showing a substrate made only of parallel-arranged fiber threads according to the present invention, in which an appropriate number of strip-shaped reinforcing resins are provided in areas without conductive circuits, in addition to the reinforcing resin covering the conductive circuits formed by plating on the substrate. FIG. 5 is a schematic enlarged plan view showing a second embodiment of the present invention. This is a schematic enlarged cross-sectional view showing an embodiment in which a lower layer conductive circuit formed by plating only fiber threads arranged in parallel is conductively connected to an upper layer conductive circuit formed in a similar manner, by pouring solder or conductive adhesive into the gaps between the fiber threads and the conductive circuits. FIG. 13 is a schematic enlarged cross-sectional view showing a specific embodiment in which a lower layer conductive circuit formed by plating only fiber threads arranged in parallel and an upper layer conductive circuit formed in a similar manner are pressure-bonded via an adhesive so as to be conductively bonded.

This conductive circuit board has a base material consisting only of fiber threads arranged in parallel , and the fiber threads are chemical fibers, vegetable fibers, paper fibers, or metal fibers, either of the same type or a combination of types , and the conductive circuit is formed integrally by plating the fiber threads arranged in parallel, and the entire conductive circuit is covered with a reinforcing resin.

Hereinafter, a conductive circuit board according to one embodiment of the present invention will be described with reference to the drawings. The conductive circuit board is formed by plating on a base material consisting of fiber threads arranged in parallel .
A first embodiment of the present invention will be described with reference to FIG.
The base material 1 is made of only fiber threads 3 arranged in parallel , and the base material 1 is entangled with plating 2 to form an integrally plated conductive circuit 4, which is then covered with reinforcing resin 5 to obtain a thin, flexible, and durable plated conductive circuit board A.
Needless to say, the reinforcing resin 5 has an insulating function in addition to the function of protecting and supporting the conductive circuit.
The material of the fiber threads 3 of the base material 1 may be chemical fiber, vegetable fiber, paper fiber, or metal fiber, and may be the same type or a combination of multiple types.
Furthermore, the cross-sectional shape of the fiber thread 3 may be circular, elliptical, rectangular, or squashed, and it goes without saying that one or more of these cross-sectional shapes may be used in combination.

A modification of the first embodiment of the present invention will be described with reference to FIG.
This is a modified example for stabilizing the shape of a substrate 1 consisting only of fiber threads 3 arranged in parallel , and in addition to the reinforcing resin 5 covering the plated conductive circuits 4, an appropriate number of strip-shaped reinforcing resin 10 are provided in the areas where there are no conductive circuits 4.

Next, a second embodiment of the present invention will be described with reference to FIG.
The second embodiment is an embodiment in which the same plated conductive circuits 4 as in the first embodiment are stacked, and shows an upper/lower conductive connection portion 8 connected to the intersection of a lower conductive circuit board B stacked horizontally and an upper conductive circuit board C stacked vertically; however, it goes without saying that the lower conductive circuit board B and the upper conductive circuit board C may be stacked in the same direction or may be made to intersect at an angle.

Next, a third embodiment of the present invention will be briefly described.
This is a conductive circuit board in which plating is formed on a base material consisting only of fiber threads arranged in parallel, and a connection portion (which may be a conventionally known existing connection portion) is provided at the tip of the conductive circuit board A formed in the same manner as in the first embodiment described above, to which contacts or other components can be connected.

Also, the fact that the plated conductive circuit 4 can be more easily manufactured will be described.
As shown in FIG. 4 , the plated conductive circuit 4 of the lower layer conductive circuit board B and the plated conductive circuit 4 of the upper layer conductive circuit board C are formed by plating only the fiber threads 3 arranged in parallel , and the conductive connection can be made simply by pouring and dropping solder 9 or conductive adhesive 7.
Furthermore, as shown in Figure 5 , in order to conductively connect the plated conductive circuit 4 of the lower layer conductive circuit board B, which is formed by plating only the fiber threads 3 arranged in parallel, to the plated conductive circuit 4 of the upper layer conductive circuit board C, which is formed by plating only the fiber threads 3 arranged in parallel in the same manner, the plated conductive circuits 4 of the upper and lower layer conductive circuit boards to be conductively bonded are directly pressure-welded together with adhesive 6 to form a conductive circuit.
Furthermore, other adhesive connection methods such as ultrasonic conductive connection and wire bonding conductive connection can be performed extremely well by utilizing the present invention.

As described above, specific examples have been disclosed. To disclose more detailed points, the material of the fiber yarn 3 serving as the substrate 1 can be selected from chemical fibers, vegetable fibers, paper fibers, metal fibers, glass fibers, carbon fibers, ceramic fibers, and various other fibers that can be used in place of fibers, and a suitable substrate can be used by selecting and combining these fibers.
It goes without saying that the reinforcing resin 5 and the strip-shaped reinforcing resin 10 can be made of various resins such as acrylic resin, silicon resin, and glass resin.

The cross-sectional shape of the fiber thread 3 may be circular, elliptical, square, or rectangular with different thicknesses, and may be a compressed calendered fiber or a twisted fiber.
Moreover, various resins can be formed by an inkjet printer or screen printing, and it goes without saying that a photosensitive resin may also be used.

The present invention can employ a variety of combinations of the above-mentioned materials and shapes. Moreover, it is possible to use not just one type of fiber thread 3, but a mixture of multiple types to suit the application.

When using the conductive circuit board of the present invention for testing purposes, using a frame to support the periphery will make it extremely easy to use.

It can also be used for motor windings, wiring boards for curved parts of robots, fine wiring boards for smartphones, wiring boards for high-current electric vehicles, and wiring boards for drones.

LIST OF SYMBOLS 1. Substrate 2. Circuit formed by plating 3. Fiber thread 4. Plated conductive circuit 5. Reinforcing resin 6. Adhesive 7. Conductive adhesive 8. Upper and lower conductive connection parts 9. Solder 10. Strip-shaped reinforcing resin A. Conductive circuit board B. Lower conductive circuit board C. Upper conductive circuit board

Claims (6)

A conductive circuit board whose base material is only fiber threads arranged in parallel , the fiber threads being of the same or multiple types selected from chemical fibers, vegetable fibers, paper fibers, and metal fibers, the conductive circuit being integrally formed by plating the fiber threads arranged in parallel, and the entire conductive circuit being covered with a reinforcing resin. The conductive circuit board according to claim 1, characterized in that it is formed by changing both the shape and pitch interval of the fiber thread that is the base material. A conductive circuit board according to claim 1 or 2, characterized in that in addition to the reinforcing resin covering the entire conductive circuit formed by plating, the substrate is supported and reinforced by multiple strips of reinforcing resin. A conductive circuit board comprising multiple layers of the conductive circuit board according to any one of claims 1 to 3, with the circuits of each layer being electrically conductive. A conductive circuit board according to any one of claims 1 to 4, characterized in that a connection part is provided at the tip to which a contact or other component can be connected. 6. The conductive circuit board according to claim 1, 2 or 5, wherein the conductive circuit is formed by plating only the fiber yarns arranged in parallel on the base material , and the conductive circuit is formed by stacking another conductive circuit formed in the same manner, and the two conductive circuits are pressure-welded with an adhesive through a gap or space between the two conductive circuits to conductively bond the conductive circuits.

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