Circuit board and electronic substrate

Abstract

To provide a circuit board having adaptability to twisting and capable of reducing the number of components and man-hours for manufacturing in mounting an electronic component, and provide an electronic board in which the electronic component is mounted on the circuit board.SOLUTION: A circuit board 10 includes: base cloth 3 having heat resistance and flexibility; and an electric circuit diagram 5 configured to be electrically conducted to a surface on a side of the base cloth 3 to which a conductive thread is sewn by sewing the conductive thread to the base cloth 3. The electrical circuit diagram 5 includes a connecting part 7 configured to be sewn with a metal foil thread 4 so that an electronic component 8 can be disposed. The circuit board 10 is configured to be capable of electrically connecting the electric circuit diagram 5 and the electronic component 8 via the connection part 7. Since the base cloth 3 has flexibility, the strength of the circuit board 10 against bending and twisting can be improved. In addition, since the electronic component 8 can be directly disposed on the base cloth 3 which is a substrate, the number of components and the man-hours for manufacturing in mounting the electronic component 8 can be reduced.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a circuit board and an electronic board. [Background technology]

[0002] Conventionally, circuit boards that are strong against bending have been known, which are formed by forming wiring circuits for mounting electronic components on a flexible substrate. For example, Patent Document 1 discloses a substrate in which plastic films are arranged at predetermined intervals on a flexible base substrate, and electronic components are mounted on the plastic. In this substrate, the electronic components are connected to each other by conductive threads via electrodes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-175993 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the substrate described in Patent Document 1 has a configuration in which electronic components are mounted on a base substrate via a plastic film, which tends to increase the number of components and manufacturing steps. Also, in recent years, the range of applications for flexible circuit boards has expanded, and there has been a demand for circuit boards that are not only adaptable to bending but also adaptable to twisting.

[0005] The present invention has been devised in light of these points, and the problem that the present invention aims to solve is to provide a circuit board that is adaptable to twisting and that can reduce the number of parts and manufacturing steps required to mount electronic parts, and an electronic board on which electronic parts are mounted. [Means for solving the problem]

[0006] One feature of the circuit board that solves the above problem is that it comprises a base fabric that is heat-resistant and flexible, and an electrical circuit diagram that is configured so that conductive thread is sewn onto the base fabric, thereby providing electrical conductivity to the surface of the base fabric on which the conductive thread is sewn, and the electrical circuit diagram has connection parts that are configured so that electronic components can be arranged by sewing metal foil thread, and the electrical circuit diagram and the electronic components can be electrically connected via the connection parts.

[0007] One feature and advantage of the above configuration is that the circuit board has a base fabric and an electrical circuit diagram formed by sewing conductive thread to the base fabric. The electrical circuit diagram is configured to be electrically conductive on the side of the base fabric where the conductive thread is sewn. The electrical circuit diagram has connection parts formed by sewing metal foil thread. Electronic components can be arranged on the connection parts, and the electrical circuit diagram and the electronic components can be electrically connected via the connection parts. The flexibility of the base fabric improves the strength of the circuit board against bending and twisting. Furthermore, the heat resistance of the base fabric and the use of metal foil thread in the connection parts allow electronic components to be soldered to the connection parts on the electrical circuit diagram. In other words, since electronic components can be arranged directly on the base fabric, which is the substrate, the number of components and manufacturing labor required for mounting the electronic components can be reduced.

[0008] The circuit board may be configured such that the electrical circuit diagram is sewn onto the base fabric with either an upper thread or a lower thread sewn thereon using the conductive thread.

[0009] One feature and advantage of the above configuration is that when an electrical circuit diagram is to be formed on only one side of the base fabric, by using a conductive thread for either the upper or lower thread, the conductive thread can be sewn so that it is exposed on one side. In other words, the electrical circuit diagram can be formed on the side where the conductive thread is sewn. Furthermore, by using a non-conductive ordinary thread for the other thread, the amount of conductive thread used can be reduced, thereby reducing material costs.

[0010] In the circuit board, the electrical circuit diagram may be configured such that both the upper thread and the lower thread are sewn onto the base fabric using the conductive thread.

[0011] One feature and advantage of the above configuration is that by sewing both the upper and lower threads with conductive thread, electrical circuit patterns can be formed on both sides of the base fabric, allowing electronic components to be arranged on both sides of the base fabric, thereby increasing the flexibility of the circuit board's uses.

[0012] One feature of an electronic board that solves the above problem is that it comprises a base fabric that is heat-resistant and flexible, an electrical circuit diagram that is configured so that conductive thread is sewn onto the base fabric to electrically connect the surface of the base fabric on which the conductive thread is sewn, and electronic components arranged on the electrical circuit diagram, wherein the electrical circuit diagram has connection parts that are configured by sewing metal foil thread, and the electronic components arranged on the connection parts by soldering are electrically connected to the electrical circuit diagram via the connection parts.

[0013] One feature and advantage of the above configuration is that the electronic board has a base fabric and an electrical circuit diagram formed by sewing conductive thread to the base fabric. The electrical circuit diagram has connection parts formed by sewing metal foil thread. The electronic board has electronic components arranged by soldering to the connection parts of the electrical circuit diagram. Solder mounting allows the electronic components to be firmly mounted. Furthermore, by arranging the electronic components directly on the base fabric, which is the substrate, the number of parts and manufacturing labor required for mounting the electronic components can be reduced. Furthermore, the flexibility of the base fabric can improve the strength of the electronic board against bending and twisting. [Effects of the Invention]

[0014] By adopting the above-described configuration, the present invention can provide a circuit board that is adaptable to twisting and that can reduce the number of components and manufacturing steps required to mount electronic components, and an electronic board on which electronic components are mounted. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a plan view schematically illustrating an example of a circuit board according to an embodiment. [Figure 2] FIG. 2 is a side view schematically showing the electronic substrate according to the embodiment. [Figure 3] FIG. 1 is a side view schematically illustrating an example of an electronic board in which electronic components are disposed on both sides of a base fabric. [Figure 4] FIG. 10 is a diagram showing an example of a state in which the electronic substrate is twisted. [Figure 5] FIG. 10 is a plan view schematically showing another example of an electronic substrate. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A circuit board 10 according to this embodiment is a flexible circuit board having an electric circuit diagram 5 on which electronic components 8 can be mounted, and can be used for a variety of purposes.

[0017] As shown in FIG. 1, the circuit board 10 has a base fabric 3 and an electric circuit diagram 5 configured such that conductive thread is sewn into the base fabric 3, thereby electrically conducting the surface of the base fabric 3 on which the conductive thread is sewn. The conductive thread is a thread that has conductivity. In this embodiment, metal foil thread 4 is selected as the conductive thread. The electric circuit diagram 5 is configured on one of the front surface 3a and the back surface 3b of the base fabric 3. A connection portion 7 on which an electronic component 8 can be arranged is provided on the electric circuit diagram 5.

[0018] The base fabric 3 is a sheet-like fabric that is heat-resistant and flexible, and functions as the substrate of the circuit board 10. For example, glass cloth is selected as the base fabric 3. Examples of fabrics that can be used for the base fabric 3 include plain weave, twill weave, and satin weave. Materials that can be used for the base fabric 3 include glass fiber, natural fibers such as cotton and linen, and synthetic fibers such as aramid. The width, length, shape, etc. of the base fabric 3 are appropriately set depending on the application of the circuit board 10. In this embodiment, a circuit board 10 in which an electrical circuit diagram 5 is formed on a substantially rectangular base fabric 3 will be described as an example.

[0019] The metal foil thread 4 is composed of a central thread, which is a thread-like fiber material, and a metal foil wrapped around the central thread. The central thread can be made of various natural or chemical fibers, such as cotton, aramid, or polyester. The metal foil is made by rolling a metal plating or alloy into a rectangular wire, and is used to ensure the conductivity of the metal foil thread 4. In this embodiment, copper foil is selected, for example. The metal foil is wrapped around the central thread so that the electrical circuit diagram 5 is conductive. The metal foil thread 4 may be configured so that the metal foil is partially exposed. Alternatively, the metal foil may be wrapped around the central thread to cover the entire length of the central thread.

[0020] The electrical circuit diagram 5 is a circuit formed by sewing metal foil thread 4 (conductive thread) onto the base fabric 3. In this embodiment, it is embroidered on the base fabric 3 using metal foil thread 4 as the upper thread and non-conductive thread as the lower thread. As a result, the metal foil thread 4 is exposed on the surface of the base fabric 3 facing the upper thread (e.g., surface 3a), thereby forming the electrical circuit diagram 5. For example, an embroidery machine or an embroidery sewing machine is used to embroider the base fabric 3. The pattern of the electrical circuit diagram 5 is appropriately set depending on the application of the circuit board 10. The electrical circuit diagram 5 is formed on one surface of the base fabric 3 by sewing either the upper thread or the lower thread onto the base fabric 3 with metal foil thread 4. In other words, it may be configured to be embroidered on the base fabric 3 using non-conductive thread as the upper thread and metal foil thread 4 (conductive thread) as the lower thread. In this case, the electrical circuit diagram 5 is formed on the surface facing the lower thread.

[0021] As shown in FIG. 1 , the electrical circuit diagram 5 according to this embodiment has a wiring section 6 arranged on a base fabric 3 as an electrical pathway, and multiple connection sections 7 arranged at predetermined intervals on the wiring section 6. The wiring section 6 is a section where metal foil thread 4 is embroidered in a linear pattern using a running stitch. The length of the stitches is set appropriately. The connection section 7 has two pad sections 7a, 7b embroidered in a substantially rectangular shape so that the metal foil thread 4 is concentrated. An electronic component 8 can be arranged across these pad sections 7a, 7b. In other words, the connection sections 7 function as electrodes that electrically connect the electronic component 8 arranged on the electrical circuit diagram 5 to the electrical circuit diagram 5. The metal foil thread 4 is sewn at the connection sections 7 using an embroidery method such as a satin stitch, which sews the ends of the connection sections 7, or a tatami stitch, which embroiders with stitches finer than a satin stitch.

[0022] Depending on the application, connection terminals (not shown) are provided on the circuit board 10. The connection terminals electrically connect the wiring portion 6 to a power source.

[0023] As shown in FIG. 2, the electronic board 13 according to this embodiment includes the circuit board 10 described above and an electronic component 8 disposed at a connection portion 7 on the electronic circuit diagram 5. Examples of the electronic component 8 include resistors such as chip resistors and light-emitting elements such as LEDs. In the electronic board 13, electrodes of the electronic component 8 are soldered to the pads 7a and 7b at the connection portion 7. The electrical circuit diagram 5 and the electronic component 8 are electrically connected via the connection portion 7. Examples of solder materials include those containing lead and tin. For example, wire solder is used as the soldering method, and the temperature is set to approximately 180 to 270°C.

[0024] As shown in Fig. 3, the circuit board 10 may be configured such that both the upper and lower threads are sewn onto the base fabric 3 with metal foil thread 4. This allows for the formation of an electrical circuit diagram 5 on which electronic components 8 can be arranged on both sides (front surface 3a and back surface 3b) of the base fabric 3. By arranging electronic components 8 on both surfaces 3a and 3b of the base fabric 3, the degree of freedom in the use of the electronic board 13 can be improved. In the electrical circuit diagram 5, electronic components 8 may be arranged alternately at the connection portions 7 on the front surface 3a and the connection portions 7 on the back surface 3b.

[0025] The size of the circuit board 10 can be made smaller by making the stitches in the electrical circuit diagram 5 finer. This allows the electronic board 13, on which the electronic components 8 are mounted, to be placed in a small, narrow space. Furthermore, the circuit board 10 has strength against bending and twisting because the base fabric 3 is flexible. This allows the electronic board 13 to be used even when it is bent or twisted. For example, as shown in FIG. 4, one end edge 3c and the other end edge 3d in the longitudinal direction of the base fabric 3 rotate in opposite directions around the longitudinal axis. The number of rotations (twists) can be set as desired.

[0026] The electronic substrate 13 can be used for various purposes that require a thin, small, flexible circuit board, such as in communication electronic devices, automobiles, and robots. For example, it can be used in robot arms, lighting components, decorative components, communication boards, etc.

[0027] As shown in Fig. 5, the electronic board 13 may have a circuit board 10 with an electrical circuit diagram 5 formed on a strip-shaped base fabric 3. Furthermore, the electronic board 13 may be spirally wound and disposed inside a long, thin hollow tube. For example, by inserting the electronic board 13, in which a light-emitting element is disposed as an electronic component 8 at the connection portion 7 of the electrical circuit diagram 5, into a light-transmitting hollow tube, it can be used as a light source for a linear light-emitting element.

[0028] <Effects of the embodiment> The circuit board 10 according to the above embodiment has a base fabric 3 and an electric circuit diagram 5 formed by sewing metal foil threads 4 (conductive threads) to the base fabric 3. The electric circuit diagram 5 is configured so that it is electrically conductive on the surface of the base fabric 3 on which the metal foil threads 4 are sewn. The electric circuit diagram 5 has a connection portion 7 formed by sewing the metal foil threads 4. An electronic component 8 can be disposed in the connection portion, and the electric circuit diagram 5 and the electronic component 8 can be electrically connected via the connection portion 7. The flexibility of the base fabric 3 can improve the strength of the circuit board 10 against bending and twisting.

[0029] The circuit board 10 has a heat-resistant base fabric 3, and the connection portions 7 are formed by sewing metal foil threads 4 to the base fabric 3. Conventional conductive threads, such as those with a central thread sparsely coated with metal particles or conductive threads containing conductive fibers coated with an insulating film, have weak adhesion and may even come off when soldered. Therefore, using conventional conductive threads for connection portions has made it difficult to solder electronic components. In contrast, metal foil threads are suitable for soldering. Therefore, the circuit board 10 according to the above embodiment uses metal foil threads 4 for the connection portions 7, allowing electronic components 8 to be solder-mounted to the connection portions 7 on the electrical circuit diagram 5. In other words, the electronic components 8 can be directly mounted on the base fabric 3, which is the substrate, thereby reducing the number of components and manufacturing steps required to mount the electronic components 8.

[0030] When forming the electrical circuit diagram 5 on only one side of the base fabric 3 of the circuit board 10, metal foil thread 4 (conductive thread) can be used for either the upper or lower thread, and the metal foil thread 4 can be sewn so that it is exposed on one side. In other words, the electrical circuit diagram 5 can be formed on the side on which the metal foil thread 4 is sewn. Furthermore, by using a non-conductive ordinary thread for the other thread, the amount of metal foil thread 4 used can be reduced, thereby reducing material costs. Furthermore, sewing a non-conductive thread (e.g., embroidery thread) on the other side can enhance the design.

[0031] The circuit board 10 may be configured such that both the upper thread and the lower thread are sewn onto the base fabric 3 with the metal foil thread 4. By sewing both the upper thread and the lower thread with the metal foil thread 4, an electric circuit diagram 5 can be formed on both sides (the front surface 3a and the back surface 3b) of the base fabric 3. Therefore, electronic components 8 can be disposed at the connection portions 7 on both sides 3a and 3b of the base fabric 3, which can improve the flexibility of use.

[0032] The circuit board 10 has the ability to conform to the components on which it is placed due to the flexibility of the base fabric 3. In other words, the circuit board 10 and the electronic board 13 can be placed on components that undergo shape changes such as bending and twisting.

[0033] The electronic substrate 13 has a base fabric 3 and an electrical circuit diagram 5 formed by sewing conductive thread to the base fabric 3. The electrical circuit diagram 5 has connection portions 7 formed by sewing metal foil thread 4. The electronic substrate 13 has electronic components 8 arranged by soldering to the connection portions 7 on the electrical circuit diagram 5. Solder mounting allows the electronic components 8 to be firmly mounted. Furthermore, by directly arranging the electronic components 8 on the base fabric 3, which is the substrate, the number of components and manufacturing steps required to mount the electronic components 8 can be reduced. Furthermore, the flexibility of the base fabric 3 allows the electronic substrate 13 to have improved strength against bending and twisting.

[0034] The electronic components 8 are soldered to the electronic board 13 on the electrical circuit diagram 5. This allows the electronic components 8 to be firmly mounted, and can prevent damage to the electronic board 13 due to the electronic components 8 coming off.

[0035] When the circuit board 10 is configured such that the metal foil thread 4 is wrapped around the entire central thread with metal foil, the central thread of the metal foil thread 4 is covered with metal foil at the connection portion 7 on the electrical circuit diagram 5, and an appropriate electrical circuit diagram 5 can be formed by soldering the electronic component 8.

[0036] The circuit board 10 can be manufactured through a simpler process by using an embroidery machine to sew the metal foil thread 4 onto the base fabric 3.

[0037] The circuit board and electronic board according to the present invention are not limited to the appearance and configuration described in the above embodiments, and can be embodied in various other forms by various modifications, additions, deletions, and combinations of configurations within the scope that does not change the gist of the present invention.

[0038] The electrical circuit diagram 5 may be configured such that at least a portion of the wiring section 6 uses a conductive thread other than the metal foil thread 4. In other words, the conductive thread that makes up the wiring section 6 is not limited to the metal foil thread 4, and various conductive threads can be used. For example, a conductive thread may be used in which a core material such as polyester or nylon is plated with a conductive material such as silver, copper, or nickel.

[0039] The electric circuit diagram 5 of the circuit board 10 may be arranged over the entire base fabric 3 or may be arranged in a partial area of ​​the base fabric 3.

[0040] The base fabric 3 of the circuit board 10 may be a single sheet-like fabric, or may be configured by stacking a plurality of sheet-like fabrics.

[0041] The circuit board 10 may have a configuration in which multiple electrical circuit diagrams 5 are formed on one side of a single base fabric 3. In other words, multiple circuits on which electronic components 8 are arranged may be formed on one side or on each side.

[0042] The electric circuit diagram 5 may be configured such that the metal foil thread 4 is sewn to the base fabric 3 by a straight stitch or a running stitch. [Explanation of symbols]

[0043] 3 Base fabric 3a surface 3b back side 4 Metal foil thread (conductive thread) 5 Electrical circuit diagram 6 Wiring section 7 Connection 7a Pad section 7b Pad section 8. Electronic Components 10 Circuit Board 13 Electronic board

Claims

1. A base fabric that is heat resistant and flexible, and an electrical circuit diagram configured so that the conductive thread is sewn into the base fabric, thereby electrically conducting the conductive thread on the surface of the base fabric on which the conductive thread is sewn; the electrical circuit diagram has a connection portion configured to allow electronic components to be arranged by sewing metal foil threads; A circuit board configured so that the electrical circuit diagram and the electronic component can be electrically connected via the connection portion.

2. 2. The circuit board according to claim 1, The electrical circuit diagram is a circuit board configured such that either an upper thread or a lower thread is sewn onto the base fabric using the conductive thread.

3. 2. The circuit board according to claim 1, The electrical circuit diagram is a circuit board configured such that both the upper thread and the lower thread are sewn onto the base fabric using the conductive thread.

4. A base fabric that is heat resistant and flexible, An electrical circuit diagram configured so that a conductive thread is sewn into the base fabric, thereby electrically conducting the surface of the base fabric on which the conductive thread is sewn; and electronic components arranged on the electrical circuit diagram, the electrical circuit diagram has a connection portion formed by sewing a metal foil thread; The electronic circuit board is electrically connected to the electronic components arranged on the connection portions by soldering and the electrical circuit diagram via the connection portions.

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