JP5568450B2 - Wiring body connection element - Google Patents

Description

  The present invention relates to a wiring body connection element in which a flexible element including a pair of flexible flexible wiring bodies and another wiring body that can be connected to a connector of a circuit board are electrically connected.

  Development of flexible sensors, actuators, etc. using elastomers is ongoing. For example, electrodes and wirings are formed on the surface of a pair of elastomer substrates. And a capacitance type sensor can be constituted by arranging the pair of substrates so that the electrodes face each other. When a load is applied to the capacitive sensor, the base material bends and the distance between the electrodes changes. At this time, it is desirable that the electrode can be expanded and contracted according to the deformation of the base material so as not to prevent the deformation of the base material. Similarly, it is desirable that the wiring connected to the electrode can be expanded and contracted following the deformation of the base material and the electrode. Therefore, attempts have been made to form electrodes and wirings from conductive materials in which conductive carbon or metal powder is blended with elastomer (see, for example, Patent Documents 1 and 2).

  In the flexible sensor or the like, one end of the wiring is connected to an electrode, and the other end is connected to an electric circuit such as a control device. However, a method that can stably connect a flexible wiring that expands and contracts and an electric circuit has not yet been established. On the other hand, as means for electrically connecting terminals of an existing circuit board such as a flexible printed wiring board (FPC), an anisotropic conductive adhesive or the like is used (for example, see Patent Document 3). . Patent Document 4 discloses a connection structure in which terminals between an FPC and a flexible flat cable (FFC) are joined by soldering and a connection portion is covered with an insulating film to be reinforced.

JP 2010-43880 A JP 2007-173226 A Japanese Patent Laid-Open No. 5-25446 JP 2010-27762 A

  When a flexible wiring body is formed by forming a wiring made of the above-described conductive material on the surface of an elastomer base material and the wiring body is to be connected to an electric circuit, the wiring body and the circuit board are provided. A method of directly connecting an existing connector can be considered. According to the existing connector, the electrode of the connector is bitten into the wiring body, and the wiring body and the electric circuit are electrically connected. However, as described above, the wiring expands and contracts following the deformation of the connected electrode and base material. Repeated expansion and contraction causes sag in the wiring due to the compression set of the elastomer. In this case, in the connection by mechanical engagement between the wiring body and the connector, the connection portion cannot follow the sag of the wiring. As a result, there is a risk of poor contact between the wiring body and the connector. Moreover, the base material which comprises a wiring body consists of elastomers. The wiring also uses an elastomer as a base material. For this reason, the mechanical strength of the wiring body is relatively small. Therefore, there is a possibility that cracks may occur in the wiring or the like due to the biting of the connector. Thus, when a flexible wiring body using an elastomer is connected to an existing connector, there is a problem in the reliability of the connection portion. Therefore, it is difficult to connect a flexible wiring body directly to an existing connector.

  Also, connect the flexible wiring body to one end of an existing wiring body such as a flexible flat cable (FFC) or flexible printed wiring board (FPC), and connect the other end of the FFC or the like to the connector of the circuit board. Thus, a method of connecting the flexible wiring body to the connector of the circuit board indirectly can be considered. In this method, a flexible wiring body and FFC are bonded with a conductive adhesive or the like.

  As described above, in the flexible wiring body, the wiring expands and contracts together with the base material. On the other hand, wiring bodies such as FFC do not expand and contract. Further, the rigidity of the flexible wiring body is extremely small compared to the rigidity of FFC or the like. For this reason, when the flexible wiring body expands and contracts, stress concentrates on the tip of the FFC or the like in the bonded portion. As a result, while the flexible wiring body repeatedly expands and contracts, the wiring of the flexible wiring body may be cut in the vicinity of the boundary with the tip of the FFC or the like.

  The present invention has been made in view of such a situation, and can connect a flexible element having a pair of flexible wiring bodies and an electric circuit with high reliability and low cost, and also provide a flexible element. It is an object of the present invention to provide a wiring body connection element in which wiring is difficult to be cut even if it repeatedly expands and contracts.

  (1) In order to solve the above-mentioned problems, each of the wiring body connecting elements of the present invention has an elastomeric flexible base material, and a flexible wiring arranged on the flexible base material and containing an elastomer and a conductive material, A wiring body connecting element including a flexible element including a pair of flexible wiring bodies disposed opposite to each other and a plurality of wiring bodies connected to the flexible element, each of the pair of flexible wiring bodies, A connecting portion connected to an end portion of the wiring body, and a cover portion formed of a part of the flexible base material, the connecting portion of one flexible wiring body, and the other flexible wiring body The cover portion is disposed to face each other, the cover portion of one of the flexible wiring bodies and the connection portion of the other flexible wiring body are arranged to face each other, and the connection portion and the Provided with a conductive adhesive layer that adheres to the end of the wiring body while ensuring conductivity, the end of the wiring body is The pair of flexible wiring bodies are sandwiched between the connection portion and the cover portion, the end portion and the connection portion are bonded via the conductive adhesive layer, and the end portion and the cover portion are It is characterized by being bonded in an insulating state.

  According to the wiring body connecting element of the present invention, the wiring body and the flexible element are connected by interposing one end of the wiring body between the pair of flexible wiring bodies. Therefore, by connecting the other end of the wiring body to the connector of the circuit board, the flexible element that can be expanded and contracted can be indirectly connected to the connector of the circuit board. As the wiring body, for example, an existing wiring body such as FFC or FPC can be used. An existing wiring body such as FFC can be connected to an existing connector such as a ZIF (Zero Insertion Force) connector. As described above, according to the wiring body connection element of the present invention, it is possible to connect the flexible element that can be expanded and contracted to the connector of the circuit board at low cost by utilizing the existing highly reliable connection technology. Therefore, the utility of the wiring body connection element of the present invention is high.

  Further, the wiring body is bonded to one of the flexible wiring bodies constituting the flexible element through the conductive adhesive layer. For this reason, it is hard to produce a contact failure compared with the mechanical connection by biting. The conductive adhesive layer has both conductivity and adhesiveness. Therefore, compared with the case where it connects with another member, it is easy to make a connection area | region small and thin.

  As described above, the difference in rigidity between the existing wiring body and the flexible wiring body using the elastomer is large. Therefore, for example, when an existing wiring body is simply bonded to one flexible wiring body, the rigidity at the boundary between the end portion of the wiring body and the laminated section of the flexible wiring body and the section composed of the flexible wiring body connected thereto Changes significantly. For this reason, when the flexible wiring body expands and contracts, stress tends to concentrate on the tip of the end of the wiring body arranged at the boundary between both sections.

  In this regard, according to the wiring body connection element of the present invention, the end portion of the wiring body is sandwiched between the connection portion and the cover portion of the pair of flexible wiring bodies. A cover part is a part of flexible base material which comprises a flexible wiring body. That is, the flexible base material of the other flexible wiring body is disposed from the stacking section of the end of the wiring body and one flexible wiring body to the section continuous in the flexible wiring body direction. By sandwiching the end of the wiring body between the one flexible wiring body and the flexible base material of the other flexible wiring body, the stress acting on the end of the wiring body can be dispersed. In addition, since the flexible base material is continuously disposed in the laminated section of the end portion of the wiring body and the one flexible wiring body and the section adjacent thereto, the difference in rigidity between both sections is reduced. That is, the change in rigidity in the direction of the flexible wiring body from the tip of the end of the wiring body is alleviated. This makes it difficult for stress to concentrate on the tip of the end of the wiring body. As a result, disconnection of the flexible wiring near the boundary with the tip of the end of the wiring body is suppressed. Thus, according to the wiring body connection element of the present invention, even if the flexible element repeatedly expands and contracts, the flexible wiring is not easily cut. That is, the wiring body connection element of the present invention is excellent in durability.

  Moreover, according to the wiring body connection element of the present invention, a part of the flexible base material in one flexible wiring body is used as the cover portion. For this reason, it is not necessary to arrange a separate cover member. Therefore, a highly durable wiring body connection element can be realized easily and at low cost.

  (2) Preferably, in the configuration of (1), at least the connection portion of the flexible wiring body, the conductive adhesive layer, the end portion of the wiring body, and the other flexible wiring in the thickness direction. A laminated portion in which the cover portion of the body is laminated, and includes one flexible wiring body connected to the laminated portion and the flexible base material continuous from the cover portion of the other flexible wiring body. In a section, it is better to set it as the structure by which the member laminated | stacked on the thickness direction is stuck.

  For example, when the laminated portion where the connection portion of one flexible wiring body, the conductive adhesive layer, the end portion of the wiring body, and the cover portion (flexible base material) of the other flexible wiring body are laminated is partitioned, When the flexible wiring body is extended, the thickness of one flexible wiring body and the flexible base material of the other flexible wiring body is reduced in the laminated portion and the section adjacent thereto. In this case, if one flexible wiring body and the flexible base material of the other flexible wiring body are not attached in a section adjacent to the laminated portion, one flexible wiring is formed in the vicinity of the boundary between the section and the laminated portion. The end of the body and the wiring body, and the other flexible base material and the end of the wiring body are easily peeled off. Moreover, there exists a possibility that stress may be added to the front-end | tip of the edge part of a wiring body by being pulled by one flexible wiring body and the other flexible base material.

  In this regard, according to the present configuration, in the section adjacent to the laminated portion, the members laminated in the thickness direction, that is, at least one flexible wiring body and the flexible base material of the other flexible wiring body are attached. The Therefore, even when the pair of flexible wiring bodies are extended, the end portions of the wiring bodies are hardly peeled in the vicinity of the boundary between the laminated portion and the adjacent section. Moreover, when it expand | extends with the same force, the displacement of the front-end | tip vicinity of the edge part of a wiring body becomes small compared with the aspect which is not stuck. For this reason, the stress added to the front-end | tip of the edge part of a wiring body becomes small. Therefore, according to this configuration, the effect of suppressing the disconnection of the flexible wiring is further improved.

  (3) Preferably, in the configuration of (1) or (2) above, an intermediate interposed between the tip of the end of the wiring body and the connection portion of one of the flexible wiring bodies It is better to have a configuration including a mounting member.

  The flexible wiring is exposed at the connection portion of the flexible wiring body. Therefore, in this configuration, the interposition member is interposed between the tip of the end of the wiring body and the flexible wiring. For this reason, even if the flexible wiring body expands and contracts and a stress is generated at the end of the end of the wiring body, the stress is not easily applied to the flexible wiring because the interposed member becomes a cushioning material. Therefore, disconnection of the flexible wiring is suppressed. That is, according to this configuration, even if the flexible wiring body repeatedly expands and contracts, the flexible wiring is not easily cut.

  Further, in the manufacturing process of the wiring body connection element of the present invention, when bonding the connection portion of the flexible wiring body and the end portion of the wiring body, sandwiching a conductive adhesive between the connection portion and the end portion, Crimp. At this time, the tip end corner portion of the end portion may contact the connecting portion via the conductive adhesive, and the flexible wiring may be cut. In this regard, according to the present configuration, the tip corner portion of the end portion comes into contact with the interposed member via the conductive adhesive layer. The stress on the flexible wiring is reduced by using the interposition member as a cushioning material. Therefore, at the time of manufacturing the wiring body connection element of the present invention, the possibility that the flexible wiring is cut is small.

  (4) Preferably, in any one of the configurations (1) to (3), the flexible wiring body includes a plurality of flexible wirings, the wiring body includes a plurality of wirings, and the conductive The adhesive layer is preferably made of an anisotropic conductive adhesive that electrically connects the flexible wiring and the wiring facing each other in the thickness direction.

  An anisotropic conductive adhesive is obtained by dispersing conductive particles in an insulating resin or insulating rubber (base material) having adhesiveness. As anisotropic conductive adhesives, there are thermosetting anisotropic conductive adhesives, thermoplastic anisotropic conductive adhesives, ultraviolet curable anisotropic conductive adhesives, elastomeric anisotropic conductive adhesives, etc., depending on the type of base material. Can be mentioned. When pressure is applied to the anisotropic conductive adhesive, the conductive particles in the base material make point contact in one direction between the connecting members to form a conduction path. By solidifying or curing in this state, conductivity is exhibited. In the present specification, a reversible state change without a chemical reaction is referred to as “solidification”, and an irreversible state change with a chemical reaction such as a crosslinking reaction is referred to as “curing”.

  An anisotropic conductive adhesive has a property (anisotropic conductivity) having high conductivity in one direction. For this reason, when the anisotropic conductive adhesive is interposed between the flexible wiring and the wiring of the wiring body facing in the thickness direction, the wirings can be bonded together, and the anisotropic conductive adhesive is in the thickness direction. In addition, the wirings can be made conductive. In this case, the conductivity in the surface direction of the anisotropic conductive adhesive is low. Therefore, in each of the flexible wiring and the wiring of the wiring body, there is no possibility that adjacent wirings are electrically connected.

  According to the wiring body connection element of the present invention, an elastic flexible element using an elastomer can be connected to a connector on a circuit board through an existing wiring body at low cost and high reliability. Moreover, according to the wiring body connection element of the present invention, the flexible wiring is not easily cut even if the flexible element repeatedly expands and contracts.

It is a front view of the wiring body connection element of 1st embodiment. It is a disassembled perspective view of the 1st connection area | region of the same wiring body connection element. It is III-III sectional drawing of FIG. It is IV-IV sectional drawing of FIG. It is a fragmentary sectional view of the wiring body connection element of a second embodiment. It is a fragmentary sectional view of the wiring body connection element of a third embodiment.

  Hereinafter, embodiments of the wiring body connection element of the present invention will be described.

<First embodiment>
[Constitution]
First, the configuration of the wiring body connection element of the present embodiment will be described. In FIG. 1, the front view of the wiring body connection element of this embodiment is shown. FIG. 2 is an exploded perspective view of the first connection region of the wiring body connection element. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is a sectional view taken along the line IV-IV in FIG. In addition, in FIG. 1, the member laminated | stacked on the front and back direction (thickness direction) is permeate | transmitted and shown. Further, the detection units A0101 to A0606 are hatched. Among the symbols “AOOΔΔ” of the detector, the upper two digits “OO” correspond to the back electrodes 01X to 06X. The last two digits “ΔΔ” correspond to the front electrodes 01Y to 06Y.

  As shown in FIGS. 1 to 4, the wiring body connection element 1 includes a flexible element 10, flexible flat cables (FFC) 20 a and 20 b, and a conductive adhesive layer 30. The wiring body connection element 1 includes a first connection region 1a to which the flexible element 10 and the FFC 20a are connected, and a second connection region 1b to which the flexible element 10 and the FFC 20b are connected. The first connection region 1 a is disposed near the center of the left end of the flexible element 10. The second connection region 1b is disposed near the center of the rear end of the flexible element 10.

  The flexible element 10 includes a back side wiring body 11, a front side wiring body 12, and a dielectric film 13. The back side wiring body 11 and the front side wiring body 12 are included in a pair of flexible wiring bodies in the present invention. The back side wiring body 11 has a back side base material 14, back side electrodes 01X to 06X, and back side wirings 01x to 06x. The back-side base material 14 is made of silicone rubber and has a sheet shape. The thickness of the back side base material 14 is about 0.5 mm, and the Young's modulus is 4 MPa. The back side base material 14 is included in the flexible base material in the present invention.

  A total of six back-side electrodes 01X to 06X are arranged on the surface (upper surface) of the back-side base material 14. The back side electrodes 01X to 06X are each formed by screen-printing an electrode paint containing acrylic rubber and conductive carbon black on the surface of the back side base material 14. Each of the back side electrodes 01X to 06X has a strip shape. The back-side electrodes 01X to 06X each extend in the left-right direction. The back-side electrodes 01X to 06X are arranged in the front-rear direction so as to be substantially parallel to each other at a predetermined interval.

  A total of six backside wirings 01x to 06x are arranged on the surface of the backside base material 14. The back side wirings 01x to 06x are each formed by screen-printing a wiring paint containing acrylic rubber and silver powder on the surface of the back side base material 14. The thicknesses of the back side wirings 01x to 06x are all about 20 μm, and the Young's modulus is all 10 MPa. The tensile strengths of the back side wirings 01x to 06x are all 0.3 MPa. The back side wirings 01x to 06x each have a linear shape. The back side wirings 01x to 06x connect the left ends of the back side electrodes 01X to 06X and the FFC 20a, respectively. The back side wirings 01x to 06x are included in the flexible wiring in the present invention.

  As shown in FIGS. 2 and 3, the back side wiring body 11 has a back side connection part 16 in the first connection region 1 a. On the surface of the back-side base material 14 in the back-side connection portion 16, the back-side wirings 01x to 06x are exposed. As shown in FIG. 4, the back side wiring body 11 has a back side cover portion 17 in the second connection region 1 b. The back side cover part 17 consists of the back side base material 14 which protruded back. The back side cover part 17 is arrange | positioned so that the front side connection part 18 of the front side wiring body 12 mentioned later may be opposed.

  The front side wiring body 12 includes a front side base material 15, front side electrodes 01Y to 06Y, and front side wirings 01y to 06y. The configuration of the front wiring body 12 is the same as that of the back wiring body 11. That is, the front-side base material 15 is made of silicone rubber and has a sheet shape. The front side base material 15 is included in the flexible base material in the present invention.

  A total of six front side electrodes 01Y to 06Y are arranged on the back surface (lower surface) of the front side base material 15. Each of the front side electrodes 01Y to 06Y is formed by screen-printing an electrode paint containing acrylic rubber and conductive carbon black on the back surface of the front side base material 15. The front side electrodes 01Y to 06Y each have a strip shape. Each of the front side electrodes 01Y to 06Y extends in the front-rear direction. The front-side electrodes 01Y to 06Y are arranged in the left-right direction so as to be substantially parallel to each other with a predetermined interval.

  A total of six front side wirings 01y to 06y are arranged on the back surface of the front side base material 15. Each of the front side wirings 01y to 06y is formed by screen-printing a wiring paint containing acrylic rubber and silver powder on the back surface of the front side base material 15. Each of the front-side wirings 01y to 06y has a linear shape. The front wirings 01y to 06y connect the rear ends of the front electrodes 01Y to 06Y and the FFC 20b, respectively. The front side wirings 01y to 06y are included in the flexible wiring in the present invention.

  As shown in FIG. 4, in the second connection region 1 b, the front side wiring body 12 has a front side connection portion 18. Front-side wirings 01y to 06y are exposed on the back surface of the front-side base material 15 in the front-side connection portion 18. As shown in FIGS. 2 and 3, the front-side wiring body 12 has a front-side cover portion 19 in the first connection region 1 a. The front side cover part 19 consists of the front side base material 15 protruded to the left. The front side cover part 19 is arrange | positioned so that the back side connection part 16 of the back side wiring body 11 mentioned above may be opposed.

  The dielectric film 13 is made of urethane rubber and has a substantially square sheet shape. The dielectric film 13 is interposed between the back side wiring body 11 and the front side wiring body 12. The dielectric film 13 is disposed in a region where the opposing back-side electrodes 01X to 06X and front-side electrodes 01Y to 06Y are formed. The surface of the dielectric film 13 is in contact with the front electrodes 01Y to 06Y. The back surface of the dielectric film 13 is in contact with the back-side electrodes 01X to 06X. Along the four sides of the dielectric film 13, the peripheral portions of the back side wiring body 11 and the front side wiring body 12 are bonded.

  As shown by hatching in FIG. 1, the detectors A0101 to A0606 are arranged at portions (overlapping portions) where the front side electrodes 01Y to 06Y and the back side electrodes 01X to 06X intersect when viewed from the front and back directions. . Each of the detection units A0101 to A0606 includes a part of the front side electrodes 01Y to 06Y, a part of the back side electrodes 01X to 06X, and a part of the dielectric film 13. The detectors A0101 to A0606 are arranged at substantially equal intervals over substantially the entire surface of the dielectric film 13. The detection units A0101 to A0606 are sequentially applied with voltages in a scanning manner. Then, the capacitance is detected for each of the detection units A0101 to A0606.

  The FFC 20a is connected to the flexible element 10 in the first connection region 1a. The FFC 20b is connected to the flexible element 10 in the second connection region 1b. The configuration of the two FFCs 20a and 20b is the same. Therefore, the configuration of the FFC 20a will be described on behalf of the FFCs 20a and 20b.

  The FFC 20 a includes an insulating base material 21 and wirings 22. The insulating base material 21 has a strip shape extending in the left-right direction. The insulating base material 21 is made of two polyester films laminated in the front and back direction with the wiring 22 interposed therebetween. The thickness of each polyester film is about 0.1 mm. The Young's modulus of each polyester film is 4 GPa.

  A total of six wires 22 are embedded in the insulating base material 21. The wiring 22 is a tin-plated copper foil. The thickness of the wiring 22 is about 0.1 mm, and the Young's modulus is about 100 GPa. Each of the wirings 22 has a linear shape. Each of the wirings 22 extends in the left-right direction. The six wires 22 are arranged in the front-rear direction so as to be substantially parallel to each other with a predetermined interval.

  As shown in FIGS. 2 and 3, the right end portion 23 of the FFC 20 a is interposed between the back side wiring body 11 and the front side wiring body 12. On the back side of the right end portion 23 of the FFC 20a, the insulating base material 21 is peeled off so that the wiring 22 is exposed on the back surface (lower surface) of the insulating base material 21. That is, the wiring 22 is exposed on the back surface of the right end portion 23. The left end of the FFC 20a is connected to a connector (not shown). The connector is installed on an electric circuit board (not shown).

  Further, as shown in FIG. 4, the front end portion 24 of the FFC 20 b is interposed between the back side wiring body 11 and the front side wiring body 12. On the front side of the front end portion 24 of the FFC 20b, the insulating base material 21 is peeled off so that the wiring 22 is exposed on the surface (upper surface) of the insulating base material 21. That is, the wiring 22 is exposed on the surface of the front end portion 24. The rear end portion of the FFC 20b is connected to a connector (not shown). The connector is installed on an electric circuit board (not shown).

  The conductive adhesive layer 30 is made of an anisotropic conductive adhesive in which nickel particles are dispersed in an epoxy resin. The conductive adhesive layer 30 has a sheet shape. The thickness of the conductive adhesive layer 30 is about 5 μm, and the Young's modulus is 4 GPa.

  As shown in FIGS. 2 and 3, the conductive adhesive layer 30 is interposed between the back side connection portion 16 of the back side wiring body 11 and the right end portion 23 of the FFC 20 a. Thereby, the surface of the back side connection part 16 and the back surface of the right end part 23 are bonded via the conductive adhesive layer 30. The width and interval of the back-side wirings 01x to 06x on the surface of the back-side connection portion 16 are the same as the width and interval of the wiring 22 on the back surface of the right end portion 23. That is, the back-side wirings 01x to 06x and the wiring 22 are electrically connected through the conductive adhesive layer 30, respectively. On the other hand, the surface of the right end 23 of the FFC 20a is bonded to the front cover 19 of the front wiring body 12 in an insulated state.

  As shown in FIG. 4, the conductive adhesive layer 30 is interposed between the front side connection portion 18 of the front side wiring body 12 and the front end portion 24 of the FFC 20b. Thereby, the back surface of the front side connection part 18 and the surface of the front end part 24 are bonded via the conductive adhesive layer 30. The width and interval of the front-side wirings 01y to 06y on the back surface of the front-side connecting portion 18 are the same as the width and interval of the wiring 22 on the surface of the front end portion 24. That is, the front-side wirings 01y to 06y and the wiring 22 are electrically connected through the conductive adhesive layer 30, respectively. On the other hand, the back surface of the front end portion 24 of the FFC 20b is bonded to the back side cover portion 17 of the back side wiring body 11 in an insulated state.

  In the first connection region 1a of the wiring body connection element 1, the back side connection portion 16, the conductive adhesive layer 30, the right end portion 23 of the FFC 20a, and the front side cover portion 19 of the front side wiring body 12 are arranged in the front and back direction. The laminated portions 31 that are laminated are partitioned. In the section 32 that continues to the stacked portion 31, the front side base material 15 that continues from the front side cover portion 19 and the back side wiring body 11 are bonded.

  Similarly, in the second connection region 1b, the front side connection part 18, the conductive adhesive layer 30, the front end part 24 of the FFC 20b, and the back side cover part 17 of the back side wiring body 11 are laminated in the front and back direction. The stacked unit 31 is partitioned. In the section 32 that continues to the laminated portion 31, the back-side base material 14 that continues from the back-side cover portion 17 and the front-side wiring body 12 are bonded.

[Production method]
Next, the manufacturing method of the wiring body connection element 1 is demonstrated. The manufacturing method of the wiring body connection element 1 includes a wiring body placement step, a crimping step, and a flexible base material bonding step. The connection method between the FFC 20a and the flexible element 10 and the connection method between the FFC 20b and the flexible element 10 are the same. Therefore, here, a method of connecting the FFC 20a to the flexible element 10 will be described.

  In the wiring body arranging step, the back side connection part 16 of the back side wiring body 11, the anisotropic conductive adhesive, and the right end part 23 of the FFC 20a are laminated and arranged. Specifically, first, a paste-like anisotropic conductive adhesive before curing is applied to the surface of the back side connection portion 16. Next, the right end portion 23 of the FFC 20a is disposed so as to overlap the anisotropic conductive adhesive. At this time, the back side connection part 16 and the right end part 23 are arranged so that the back side wirings 01x to 06x exposed on the surface of the back side connection part 16 and the wiring 22 exposed on the back side of the right end part 23 face each other. .

  In the crimping step, the opposite back side wirings 01x to 06x and the wirings 22 are bonded so as to be conductive in the front and back direction by curing the anisotropic conductive adhesive. Specifically, a portion (corresponding to the laminated portion 31 in FIG. 3) where the back side connecting portion 16, the anisotropic conductive adhesive, and the right end portion 23 are laminated is heated from the FFC 20a side and pressurized in the front and back directions. Thereby, the anisotropic conductive adhesive is cured and the conductive adhesive layer 30 is formed. As a result, the back side connection portion 16 and the right end portion 23 are bonded.

  In the flexible base material bonding step, the front side base material 15 including the front side cover portion 19 of the front side wiring body 12 is attached to the surface of the right end portion 23 and the surface of the back side wiring body 11 around the laminated portion 31 including the section 32. Adhere with an adhesive. In this way, the FFC 20a is connected to the flexible element 10. Similarly, the wiring body connection element 1 is manufactured by connecting the FFC 20 b to the flexible element 10.

[Function and effect]
Next, the effect of the wiring body connection element 1 will be described. According to the wiring body connection element 1, the right end portion 23 of the FFC 20a is connected to the back side wiring body 11, and the left end portion is connected to a connector installed on the electric circuit board. Similarly, the front end 24 of the FFC 20b is connected to the front-side wiring body 12, and the rear end is connected to a connector installed on the electric circuit board. Thus, according to the wiring body connection element 1, the extendable flexible element 10 can be connected to the electric circuit board with low cost and high reliability through the existing FFCs 20a and 20b.

  Further, the right end portion 23 of the FFC 20 a is interposed between the back side connection portion 16 of the back side wiring body 11 and the front side cover portion 19 of the front side wiring body 12. Similarly, the front end portion 24 of the FFC 20 b is interposed between the front side connection portion 18 of the front side wiring body 12 and the back side cover portion 17 of the back side wiring body 11. Thereby, the stress which acts on the right end part 23 of FFC20a and the front end part 24 of FFC20b can be disperse | distributed. In addition, the back side connecting portion 16, the conductive adhesive layer 30, the right end portion 23 of the FFC 20 a, and the front side cover portion 19 are laminated in the front and back directions, and the section 32 that continues to the laminated portion 31 includes the front side base material 15. Is arranged. Similarly, the back-side base material 18 is provided in the laminated portion 31 in which the front-side connecting portion 18, the conductive adhesive layer 30, the front end portion 24 of the FFC 20 b, and the back-side cover portion 17 are laminated in the front-and-back direction, and in the section 32 that continues to the laminated portion 31. 14 is arranged. Thereby, the difference in rigidity in both sections 31 and 32 becomes small. That is, the change in rigidity in the direction from the front end 230 of the right end portion 23 of the FFC 20a to the back side wiring body 11 is alleviated. Therefore, it becomes difficult for stress to concentrate on the tip 230 of the right end 23 of the FFC 20a. As a result, disconnection of the backside wirings 01x to 06x in the vicinity of the boundary with the tip 230 of the FFC 20a is suppressed. Similarly, the change in rigidity in the direction from the front end 240 of the front end portion 24 of the FFC 20b to the front side wiring body 12 is alleviated. Therefore, it becomes difficult for stress to concentrate on the front end 240 of the front end 24 of the FFC 20b. As a result, disconnection of the front-side wirings 01y to 06y near the boundary with the tip 240 of the FFC 20b is suppressed.

  Thus, according to the wiring body connection element 1, even if the flexible element 10 repeatedly expands and contracts, the back-side wirings 01x to 06x and the front-side wirings 01y to 06y are not easily cut. Therefore, the wiring body connection element 1 is excellent in durability. Further, according to the wiring body connecting element 1, the back side cover portion 17 is a part of the back side base material 14. Similarly, the front side cover part 19 is a part of the front side base material 15. For this reason, it is not necessary to arrange a separate cover member.

  Further, in the section 32 of the first connection region 1a, the front side base material 15 continuous from the front side cover portion 19 and the back side wiring body 11 are bonded. Therefore, even if the back side wiring body 11 and the front side wiring body 12 extend, the right end portion 23 of the FFC 20a is hardly peeled in the vicinity of the boundary between the laminated portion 31 and the section 32. Moreover, when extended | stretched with the same force, the displacement of the front end 230 vicinity of the right end part 23 of FFC20a is small compared with the aspect in which the front side base material 15 and the back side wiring body 11 are not adhere | attached. Therefore, the stress applied to the tip 230 of the FFC 20a is reduced. Similarly, in the section 32 of the second connection region 1b, the back side base material 14 continuous from the back side cover part 17 and the front side wiring body 12 are bonded. Therefore, even if the back side wiring body 11 and the front side wiring body 12 extend, the front end portion 24 of the FFC 20b is unlikely to peel off in the vicinity of the boundary between the stacked portion 31 and the section 32. Moreover, when extended | stretched with the same force, the displacement of the front-end | tip part 240 vicinity of FFC20b vicinity is small compared with the aspect in which the front side wiring body 12 and the back side base material 14 are not adhere | attached. Therefore, the stress applied to the tip 240 of the FFC 20b is reduced.

  The back side wiring body 11 and the FFC 20 a are bonded by the conductive adhesive layer 30. Similarly, the front wiring body 12 and the FFC 20b are bonded by the conductive adhesive layer 30. For this reason, it is hard to produce a contact failure compared with the mechanical connection by biting. Moreover, the conductive adhesive layer 30 has both conductivity and adhesiveness. Therefore, compared with the case where it connects with another member, it is easy to make the wiring body connection element 1 small and thin.

  The conductive adhesive layer 30 is made of an anisotropic conductive adhesive. As a result, the opposing back-side wirings 01x to 06x and the wiring 22, and the front-side wirings 01y to 06y and the wirings 22 can be bonded and can be made conductive in the front-back direction. On the other hand, the conductivity in the surface direction of the conductive adhesive layer 30 is low. For this reason, in the 1st connection area | region 1a, back side wiring 01x-06x adjacent to the front-back direction and wiring 22 do not have a possibility of electrical conduction. Similarly, in the second connection region 1b, there is no possibility that the front side wirings 01y to 06y adjacent to each other in the left-right direction and the wirings 22 are electrically connected. Thus, according to the conductive adhesive layer 30, a plurality of opposing wirings can be bonded and conducted together.

  Further, as the anisotropic conductive adhesive, a thermosetting adhesive mainly composed of an epoxy resin is used. Curing of the anisotropic conductive adhesive is completed at a low temperature of about 150 ° C. and in a short time of about 10 to 15 seconds. For this reason, the silicone rubber and acrylic rubber constituting the back side wiring body 11 and the front side wiring body 12 are unlikely to thermally expand. Therefore, there is little possibility that the width and position of the previously formed back-side wirings 01x to 06x and front-side wirings 01y to 06y will change due to heating during curing. Moreover, in the crimping | compression-bonding process which manufactures the wiring body connection element 1, it heats from the FFC20a, 20b side which is hard to thermally expand. Thereby, the thermal expansion of the elastomer which comprises the back side wiring body 11 and the front side wiring body 12 can be suppressed. As a result, misalignment between the back-side wirings 01x to 06x and the front-side wirings 01y to 06y is suppressed, and the opposing wirings can be reliably brought into conduction.

<Second embodiment>
The difference between the wiring body connection element of the present embodiment and the wiring body connection element of the first embodiment is that a member (specifically, the first connection) is laminated in the front and back direction in the section 32 connected to the lamination portion 31. The back side wiring body 11 and the front side base material 15 in the region 1a, and the front side wiring body 12 and the back side base material 14) in the second connection region 1b are not bonded. The configuration of the first connection region 1a and the configuration of the second connection region 1b are the same. Therefore, the difference in the 1st connection area | region 1a is demonstrated on behalf of both.

  First, the configuration of the first connection region 1a of the wiring body connection element of the present embodiment will be described. FIG. 5 shows a partial cross-sectional view (corresponding to the III-III cross-sectional view of FIG. 1) of the wiring body connection element of the present embodiment. 5, parts corresponding to those in FIG. 3 are denoted by the same reference numerals.

  As shown in FIG. 5, the right end 23 of the FFC 20 a is interposed between the back side wiring body 11 and the front side wiring body 12 in the first connection region 1 a. The conductive adhesive layer 30 is interposed between the back side connection portion 16 of the back side wiring body 11 and the right end portion 23 of the FFC 20a. Thereby, the surface of the back side connection part 16 and the back surface of the right end part 23 are bonded via the conductive adhesive layer 30. Further, the surface of the right end portion 23 of the FFC 20a is bonded to the front cover portion 19 of the front wiring body 12 in an insulated state.

  In the first connection region 1a, there is a laminated part 31 in which the back side connecting part 16, the conductive adhesive layer 30, the right end part 23 of the FFC 20a, and the front side cover part 19 of the front side wiring body 12 are laminated in the front and back direction. Is partitioned. In the section 32 that continues to the stacked portion 31, the front-side base material 15 that continues from the front-side cover portion 19 and the back-side wiring body 11 are not bonded.

  Next, the manufacturing method of the wiring body connection element of this embodiment is demonstrated. The manufacturing method of the wiring body connection element of this embodiment has a wiring body arrangement | positioning process, a crimping | compression-bonding process, and a cover part adhesion | attachment process. The previous two steps are the same as in the first embodiment. In the subsequent cover portion bonding step, the front side base material 15 including the front side cover portion 19 of the front side wiring body 12 is bonded to the surface of the right end portion 23 and the back side base material 14 disposed in the front-rear direction of the laminated portion 31. Glue with the agent. In this way, the FFC 20a is connected to the flexible element 10.

  The wiring body connection element of this embodiment has the same effects as those of the first embodiment with respect to the parts common to the wiring body connection element of the first embodiment. Moreover, according to this embodiment, the front side base material 15 and the back side wiring body 11 which continue from the front side cover part 19 are not adhere | attached in the area 32 of the 1st connection area | region 1a. Further, in the section 32 of the second connection region 1b, the back-side base material 14 continuous from the back-side cover part 17 and the front-side wiring body 12 are not bonded. Therefore, it can be manufactured more easily than the first embodiment.

<Third embodiment>
The difference between the wiring body connection element of the present embodiment and the wiring body connection element of the first embodiment is that a cover film is formed on a part of the front surface of the back wiring body 11 and a part of the back surface of the front wiring body 12. Is the point where is placed. Specifically, a cover film is disposed so as to cover the backside wirings 01x to 06x exposed on the surface of the backside wiring body 11. Similarly, the cover film is arrange | positioned so that the front side wiring 01y-06y exposed on the back surface of the front side wiring body 12 may be covered. The cover film is interposed between the front end of the right end portion 23 of the FFC 20a and the back side connection portion 16 of the back side wiring body 11 in the first connection region 1a. Further, in the second connection region 1b, the FFC 20b is interposed between the front end portion 24 of the FFC 20b and the front side connection portion 18 of the front side wiring body 12. The configuration of the first connection region 1a and the configuration of the second connection region 1b are the same. For this reason, the difference in the 1st connection area | region 1a is demonstrated on behalf of both.

  First, the configuration of the first connection region 1a of the wiring body connection element of the present embodiment will be described. FIG. 6 shows a partial cross-sectional view (corresponding to the III-III cross-sectional view of FIG. 1) of the wiring body connecting element of the present embodiment. In FIG. 6, the parts corresponding to those in FIG.

  As shown in FIG. 6, the right end 23 of the FFC 20 a is interposed between the back side wiring body 11 and the front side wiring body 12 in the first connection region 1 a. The backside wiring body 11 includes a backside base material 14, backside wirings 01x to 06x, and a cover film 40. The cover film 40 is made of silicone rubber and has a sheet shape. The cover film 40 is formed by screen-printing a cover film paint so as to cover the back side wirings 01x to 06x exposed on the surface of the back side wiring body 11. The cover film 40 has a thickness of about 20 μm. The cover film 40 has a Young's modulus of 4 MPa and a tensile strength of 2.5 MPa. The cover film 40 is included in the interposed member in the present invention.

  On the surface of the back side connection portion 16 of the back side wiring body 11, a first exposed region 16a and a first covering region 16b are arranged. The first exposed region 16 a is disposed on the left side of the front surface of the back side connecting portion 16. The first exposed region 16 a is not covered with the cover film 40. That is, the back side wirings 01x to 06x are exposed in the first exposed region 16a. Moreover, the 1st coating area | region 16b is continuously arrange | positioned on the right side of the 1st exposure area | region 16a. The first covering region 16 b is covered with the cover film 40. That is, in the first covering region 16b, the surface of the back side base material 14 and the back side wirings 01x to 06x are covered with the cover film 40.

  Similarly, a second exposed region 23a and a second covered region 23b are disposed on the back surface of the right end portion 23 of the FFC 20a. The second covering region 23 b is disposed on the right side of the back surface of the right end portion 23. The second covering region 23b is arranged to face the first covering region 16b with the cover film 40 interposed therebetween. The second covering region 23b includes the tip 230 of the right end 23. The second exposed region 23a is continuously arranged on the left side of the second covered region 23b. The second exposed region 23a is disposed to face the first exposed region 16a.

  The conductive adhesive layer 30 is interposed between the back side connection portion 16 and the right end portion 23. That is, the first exposed region 16 a and the second exposed region 23 a are bonded via the conductive adhesive layer 30. Further, the first covering region 16 b and the second covering region 23 b are bonded via the cover film 40 and the conductive adhesive layer 30. The back side wirings 01x to 06x of the first exposed region 16a and the wiring 22 of the second exposed region 23a are electrically connected via the conductive adhesive layer 30.

  Next, the manufacturing method of the wiring body connection element of this embodiment is demonstrated. The manufacturing method of a wiring body connection element has a wiring body arrangement | positioning process, a crimping | compression-bonding process, and a flexible base material adhesion process similarly to 1st embodiment.

  In the wiring body arranging step, the back side connection part 16 of the back side wiring body 11, the anisotropic conductive adhesive, and the right end part 23 of the FFC 20a are laminated and arranged. Specifically, first, a paste-like anisotropic conductive adhesive before curing is applied to the surface of the back side connection portion 16. Next, the right end portion 23 of the FFC 20a is disposed so as to overlap the anisotropic conductive adhesive. At this time, the back side connection portion 16 and the right end portion 23 are arranged so that the back side wirings 01x to 06x of the first exposed region 16a and the wiring 22 of the second exposed region 23a face each other.

  In the crimping step, the opposite back side wirings 01x to 06x and the wirings 22 are bonded so as to be conductive in the front and back direction by curing the anisotropic conductive adhesive. Specifically, a portion (corresponding to the laminated portion 31 in FIG. 3) where the back side connecting portion 16, the anisotropic conductive adhesive, and the right end portion 23 are laminated is heated from the FFC 20a side and pressurized in the front and back directions. Thereby, the anisotropic conductive adhesive is cured and the conductive adhesive layer 30 is formed. As a result, the first exposed region 16a and the second exposed region 23a are bonded. Moreover, the 2nd coating area | region 23b and the cover film 40 which covers the 1st coating area | region 16b are adhere | attached.

  In the flexible base material bonding step, the front-side base material 15 including the front-side cover portion 19 of the front-side wiring body 12 is connected to the back-side wiring body 11 and the cover film 40 around the surface of the right end portion 23 and the laminated portion 31 including the section 32. It adheres to the surface of this with an adhesive. In this way, the FFC 20a is connected to the flexible element 10.

  The wiring body connection element of this embodiment has the same effects as those of the first embodiment with respect to the parts common to the wiring body connection element of the first embodiment. Further, according to the wiring body connecting element of the present embodiment, the first covering region 16 b and the second covering region 23 b are bonded via the cover film 40. That is, the cover film 40 is interposed between the tip 230 of the right end portion 23 included in the second covering region 23b and the back side wirings 01x to 06x of the first covering region 16b. For this reason, even if the back side wiring body 11 expands and contracts and a stress is generated at the tip 230 of the right end 23, the stress is not easily applied to the back side wirings 01x to 06x because the cover film 40 becomes a cushioning material. Moreover, the tensile strength of the cover film 40 is larger than the tensile strength of the back side wirings 01x to 06x. For this reason, even if stress is applied from the front end 230 of the right end portion 23, the cover film 40 is not easily broken. Therefore, according to the wiring body connection element of the present embodiment, disconnection of the back-side wirings 01x to 06x during use can be more effectively suppressed.

  Further, in the manufacturing process of the wiring body connecting element of the present embodiment, when the laminated section of the back side connecting portion 16, the anisotropic conductive adhesive, and the right end portion 23 is pressurized, the corner portion of the tip 230 of the right end portion 23 is It contacts the cover film 40 via a conductive adhesive. By the cover film 40 being a cushioning material, stress on the backside wirings 01x to 06x is reduced. Therefore, the back side wirings 01x to 06x are not easily cut at the time of pressure bonding.

  In the wiring body connection element of the present embodiment, the back side wirings 01x to 06x exposed on the surface of the back side wiring body 11 and the front side wirings 01y to 06y exposed on the back surface of the front side wiring body 12 40. As a result, it is possible to ensure the waterproofness of the back-side wirings 01x to 06x and the front-side wirings 01y to 06y, and to suppress oxidation. Moreover, the cover film 40 is extended to the 1st coating area | region 16b, and the disconnection inhibitory effect of the back side wiring 01x-06x mentioned above is acquired. Therefore, in order to protect the back side wirings 01x to 06x, it is not necessary to separately prepare an interposition member interposed between the tip 230 of the right end portion 23 and the back side wirings 01x to 06x.

<Others>
The embodiment of the wiring body connection element of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  In the said embodiment, the 1st connection area | region was arrange | positioned in the left end center vicinity of the flexible element, and the 2nd connection area | region was each arrange | positioned near the rear end center. However, the number and arrangement of the connection portions between the flexible element and the wiring body are not limited to the above embodiment. For example, you may connect a some wiring body symmetrically on both sides of a flexible element. Further, a plurality of wiring bodies may be connected to one end of the flexible element.

  Moreover, the flexible element was comprised from a pair of flexible wiring body and the dielectric film interposed between them. However, the configuration of the flexible element is not limited to the above embodiment. For example, a pair of flexible wiring bodies may be opposed to each other without disposing a dielectric. Further, the configuration of the flexible wiring body is not limited to the above embodiment. That is, the material, shape and thickness of the flexible substrate, the material and number of the electrodes, the arrangement, the material, number and arrangement of the flexible wiring are not particularly limited.

  For example, as the elastomer constituting the flexible substrate, in addition to the silicone rubber of the above embodiment, ethylene-propylene copolymer rubber, natural rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber, epichloro Hydrine rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, fluorine rubber, chloroprene rubber, isobutylene isoprene rubber, various thermoplastic elastomers, and the like can be used.

  Further, the number of flexible wirings may be any number. For example, one piece may be arranged for each flexible wiring body. One electrode may be formed on each flexible wiring body.

  The flexible wiring includes an elastomer and a conductive material. The elastomer may be the same as or different from the elastomer of the flexible substrate. In addition to the acrylic rubber of the above embodiment, for example, silicone rubber, ethylene-propylene copolymer rubber, natural rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, urethane rubber, epichlorohydrin rubber, chlorosulfonated polyethylene Chlorinated polyethylene and the like are preferable. The kind of conductive material is not particularly limited. For example, metal powders such as silver, gold, copper, and nickel, and conductive carbon powders are suitable. In order to express desired conductivity, it is desirable that the filling rate of the conductive material in the elastomer is 20 vol% or more when the volume of the flexible wiring is 100 vol%. On the other hand, when the filling rate of the conductive material exceeds 65 vol%, mixing with the elastomer becomes difficult, and molding processability is deteriorated. In addition, the flexibility of the flexible wiring is reduced. For this reason, the filling rate of the conductive material is desirably 50 vol% or less.

  The method for forming the flexible wiring is not particularly limited. For example, first, an unvulcanized thin-film wiring is produced from a wiring paint containing a flexible wiring forming component. Next, the wiring may be disposed on the surface of the flexible base material and pressed under predetermined conditions to be vulcanized and bonded. Alternatively, the wiring paint may be printed on the surface of the flexible substrate and then dried by heating to volatilize the solvent in the paint. According to the printing method, the crosslinking reaction for the elastomer can be allowed to proceed simultaneously with drying during heating. Examples of the printing method include screen printing of the above embodiment, inkjet printing, flexographic printing, gravure printing, pad printing, lithography, and the like. Of these, a high-viscosity paint can also be used, and the screen printing method is preferable because it is easy to adjust the coating thickness. The wiring paint may be prepared by mixing a flexible wiring forming component (elastomer, conductive material, additive, etc.) with a solvent. In this case, the solid content concentration may be adjusted so as to obtain a desired viscosity.

  In the said embodiment, FFC was used as a wiring body. However, the wiring body is not limited to FFC. For example, a flexible printed wiring board (FPC) may be used as the wiring body. According to FPC, a desired wiring pattern can be easily formed by etching. For this reason, it is easy to change the interval between adjacent wirings or to join and aggregate the wirings. Moreover, the kind of connector which connects a wiring body is not specifically limited. For example, an existing connector (such as a ZIF connector) that can be connected to an FPC, FFC, or the like may be used.

  In the said 3rd embodiment, the cover film arrange | positioned at the back side wiring body and the front side wiring body was used as an intervention member. For example, as in the first and second embodiments, when a cover film is not disposed, between the front end of the right end portion of the FFC and the back side wiring body, and between the front end portion of the FFC and the front side wiring body. Separately, an interposition member can be disposed. Further, even when a cover film is disposed, an interposed member may be disposed separately.

  When arranging the interposed member, it is desirable that the mechanical strength of the interposed member is larger than the mechanical strength of the flexible wiring. For example, the tensile strength of the interposed member may be 1 MPa or more and 10 MPa or less. The tensile strength may be measured according to JIS K 6251 (2004). The value of the tensile strength in this specification is a value measured using dumbbell-shaped No. 3 as a test piece. Further, when the cover film is used as an interposed member as in the third embodiment, the Young's modulus of the interposed member (cover film) is set to 0. 0 in consideration of the flexibility necessary for the cover film. It is good to set it as 1 MPa or more and 10 MPa or less.

  From the viewpoint of improving the effect of suppressing the disconnection of the flexible wiring, it is desirable that the thickness of the interposed member is thicker. For example, it is desirable that the thickness of the interposed member is the same as that of the flexible wiring or thicker than that of the flexible wiring. However, when the cover film is used as an interposed member as in the third embodiment, it is necessary to ensure the flexibility of the cover film. Therefore, it is desirable that the thickness of the interposed member (cover film) is the same as that of the flexible base material or thinner than that of the flexible base material.

  In the flexible wiring body, when a plurality of flexible wirings are arranged, it is necessary to prevent conduction between adjacent flexible wirings. In this case, the interposed member may be made of an insulating material. In addition to the silicone rubber of the above embodiment, the material of the interposing member is, for example, ethylene-propylene copolymer rubber, natural rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber, epichlorohydrin rubber. Chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, fluororubber, chloroprene rubber, isobutylene isoprene rubber, various thermoplastic elastomers, and the like are suitable. These materials are also suitable as the material for the cover film.

  In the said embodiment, the anisotropic conductive adhesive which uses an epoxy resin (thermosetting type adhesive) as a base material was used as a conductive adhesive layer. As the main component of the thermosetting adhesive, phenol resin, acrylic resin, polyurethane and the like can be used in addition to the epoxy resin. What is necessary is just to combine additives, such as a hardening | curing agent, suitably according to the kind of main ingredient. When the number of wirings in the flexible wiring body and the wiring body is one each, the conductive adhesive layer may not have anisotropy.

  Regardless of the presence or absence of anisotropy, the base material of the conductive adhesive constituting the conductive adhesive layer includes a thermosetting adhesive, a thermoplastic adhesive, an ultraviolet curable adhesive, an elastomer adhesive, and the like. Can be used.

  For example, a thermosetting adhesive has an advantage that a strong adhesive force can be obtained in a wide temperature range. Further, since a glass transition temperature (Tg) of 100 ° C. or higher can be easily realized, there is an advantage that a usable temperature range is wide as compared with a thermoplastic adhesive. In general, a thermosetting adhesive has a higher glass transition temperature than a thermoplastic adhesive. When glass transition occurs within the operating temperature range, it is in a glass state below the glass transition temperature and has a high elastic modulus. On the other hand, when the glass transition temperature is exceeded, a rubber state is formed, and a rapid decrease in elastic modulus and a rapid increase in thermal expansion coefficient occur. In this way, if the physical properties of the conductive adhesive change greatly with the glass transition temperature as a boundary, a change in adhesive strength accompanying a change in elastic modulus, a dimensional change due to a change in thermal expansion coefficient, or a change in conductive performance may be induced. There is. Therefore, according to the thermosetting adhesive having a high glass transition temperature, it is possible to set a wide temperature range in which reliability can be ensured.

  From the viewpoint of suppressing the thermal expansion of the elastomer of the flexible wiring body, the thermosetting adhesive is desirably cured at a low temperature in a short time. Specifically, a curing temperature of 130 ° C. or higher and 180 ° C. or lower is desirable. Further, it is desirable that the curing time is 60 seconds or less, and further 20 seconds or less. When a thermosetting adhesive is used as a base material, it is preferable to cure the conductive adhesive in a state in which a heat dissipating means is disposed on the flexible wiring body side from the viewpoint of suppressing thermal expansion of the elastomer. Examples of the heat radiating means include a heat radiating plate and a heat exchange device using a refrigerant. Moreover, the thing with the high glass transition temperature (Tg) as much as possible is desirable from a viewpoint of suppressing the physical property change of a conductive adhesive and ensuring the reliability of a connection part. For example, those having a Tg of 130 ° C. or more are suitable. Examples of suitable anisotropic conductive adhesive using a thermosetting adhesive as a base material include anisotropic conductive connection materials “TAP0402F” and “TAP0401C” manufactured by Kyocera Chemical Co., Ltd.

  As the main component of the ultraviolet curable adhesive, an epoxy resin, an acrylic resin, or the like can be used as in the case of the thermosetting adhesive. What is necessary is just to combine additives, such as a hardening | curing agent, suitably according to the kind of main ingredient.

  Examples of the thermoplastic resin used for the thermoplastic adhesive include polyester resin and polyurethane. As a suitable anisotropic conductive adhesive using a thermoplastic adhesive as a base material, there is an anisotropic conductive adhesive “NIR-30E” manufactured by Sanyu Rec Co., Ltd.

  Examples of the elastomer used for the elastomeric adhesive include chloroprene rubber and acrylic rubber. Examples of suitable anisotropic conductive adhesives using an elastomeric adhesive as a base material include anisotropic conductive adhesives “NIR-11” manufactured by Sanyu Rec Co., Ltd., “TB3373C” manufactured by ThreeBond Co., Ltd., and the like.

  The kind of conductive particles filled in the base material is not particularly limited. Metal particles such as nickel, or particles obtained by plating the surface of resin particles with metal can be used. The method, conditions, etc. of the conductive adhesive may be appropriately determined according to the type of the base material used. Further, it is desirable to solidify or cure the conductive adhesive while pressurizing the thick section. For example, the pressure may be about 9.8 to 490 kPa.

  The wiring body connecting element of the present invention is useful when connecting a flexible element such as a sensor or an actuator using an elastomer to an electric circuit.

1: Wiring body connection element 1a: First connection area 1b: Second connection area 10: Flexible element 11: Back side wiring body (flexible wiring body) 12: Front side wiring body (flexible wiring body)
13: Dielectric film 14: Back side base material (flexible base material) 15: Front side base material (flexible base material)
16: Back side connection part 16a: First exposed area 16b: First covering area 17: Back side cover part 18: Front side connection part 19: Front side cover part 20a, 20b: FFC (wiring body) 21: Insulating substrate 22: Wiring 23 : Right end portion 24: front end portion 230, 240: tip 23a: second exposed region 23b: second covering region 30: conductive adhesive layer 31: laminated portion 32: section 40: cover film (intervening member)
01X to 06X: Back side electrode 01Y to 06Y: Front side electrode 01x to 06x: Back side wiring (flexible wiring) 01y to 06y: Front side wiring (flexible wiring)

Claims (4)

A flexible element comprising a pair of flexible wiring bodies, each having a flexible substrate made of an elastomer, and a flexible wiring disposed on the flexible substrate and including an elastomer and a conductive material;
A plurality of wiring bodies connected to the flexible element;
A wiring body connecting element comprising:
Each of the pair of flexible wiring bodies includes a connection portion connected to an end portion of the wiring body and a cover portion formed of a part of the flexible base material, and the connection of one of the flexible wiring bodies And the cover part of the other flexible wiring body are arranged to face each other, and the cover part of one flexible wiring body and the connection part of the other flexible wiring body face each other. Arranged,
Furthermore, a conductive adhesive layer that bonds the connecting portion and the end of the wiring body while ensuring conductivity is provided,
An end portion of the wiring body is sandwiched between the connection portion and the cover portion of a pair of the flexible wiring bodies, and the end portion and the connection portion are bonded via the conductive adhesive layer, The wiring body connection element, wherein the end portion and the cover portion are bonded in an insulated state. In the thickness direction, at least the connection portion of one of the flexible wiring bodies, the conductive adhesive layer, the end portion of the wiring body, and the stacked portion where the cover portion of the other flexible wiring body is stacked are defined. ,
In a section that is connected to the laminated portion and includes one flexible wiring body and the flexible base material continuous from the cover portion of the other flexible wiring body, a member laminated in the thickness direction is attached. The wiring body connection element according to claim 1.   Furthermore, the wiring body connection element of Claim 1 or Claim 2 provided with the interposed member interposed between the front-end | tip of the edge part of the said wiring body, and the said connection part of one said flexible wiring body. . The flexible wiring body has a plurality of the flexible wirings,
The wiring body has a plurality of wirings,
4. The wiring body connection element according to claim 1, wherein the conductive adhesive layer is made of an anisotropic conductive adhesive that electrically connects the flexible wiring and the wiring that face each other in the thickness direction. 5.

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