JP2016184479A - Wire harness connecting flexible flat cable, wire harness, and method for manufacturing wire harness connecting flexible flat cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire harness connecting flexible flat cable capable of promoting cost reduction.SOLUTION: A wire harness connecting flexible flat cable of the present invention, comprises a plurality of conductors which are arranged in a stripe shape and expose one surface side at least in one end area, and electrically connects a terminal of a wire harness consisting of a plurality of extra fine coaxial wires. An area along the width direction excluding at least one conductor in the plurality of conductors in the one end area is ruptured. The wire harness connecting flexible flat cable comprises: a plurality of first conductive paste portions which are laminated so as to be arranged along the width direction on the one surface side in the plurality of conductors and closer to the one end side than the ruptured area; and a plurality of second conductive paste portions which are laminated so as to be arranged along the width direction on the one surface side in the ruptured conductors in the plurality of conductors and closer to the other end side than the ruptured area.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flexible flat cable for connecting a wire harness, a wire harness, and a method for manufacturing a flexible flat cable for connecting a wire harness.

  Conventionally, a plurality of coaxial wires may be used when electrically connecting wires of a small electronic device or the like. Generally, a wire harness in which a plurality of coaxial lines are bundled is used for such a coaxial line connection structure. When using a wire harness, the central conductor exposed at the tip region of a plurality of coaxial wires is electrically connected to a terminal or the like, and the external conductor layer exposed at the rear end side from the central conductor is connected to the ground terminal. As a result, an electrical connection structure is formed.

  In recent years, with the further miniaturization of electronic devices, a small-diameter ultra-fine coaxial wire has been used for the wire harness, and the wiring pitch of the coaxial wire has also been reduced. In addition, from such a viewpoint, a space saving of the connecting portion of the wire harness is also demanded.

  Based on such a request, a flexible printed wiring board is sometimes used as a connection terminal of a wire harness today. As a wire harness having such a flexible printed wiring board as a connection terminal, for example, a “cable harness” (see Japanese Patent Application Laid-Open No. 2007-287541) has been proposed.

JP 2007-287541 A

  The cable harness described in the above publication uses a flexible printed wiring board as a connection terminal. For this reason, the cable harness described in the above publication has a base wiring pattern comprising a central conductor connection pattern for connecting a central conductor of a coaxial line and a shield connection pad for connecting an outer conductor layer of the coaxial line. It must be formed on the surface of the film. However, in order to form such a pattern for connecting the central conductor and a pad for connecting the shield, it is necessary to go through many processes, and it is necessary to perform etching and the like in these processes. The time spent on manufacturing also increases.

  The present invention has been made based on the above-described circumstances, and provides a wire harness connecting flexible flat cable, a wire harness, and a method for manufacturing a wire harness connecting flexible flat cable that can promote cost reduction. With the goal.

  A flexible flat cable for connecting a wire harness according to an aspect of the present invention, which has been made to solve the above problems, includes a plurality of conductors that are arranged in a stripe shape and at least one surface side of one end region is exposed. A flexible flat cable for electrically connecting the ends of a wire harness composed of a very fine coaxial line, wherein a region along the width direction except for at least one of the plurality of conductors in the one end region is torn. A plurality of first conductive paste portions stacked so as to be arranged along the width direction on one surface side of the plurality of conductors and on one end side from the tearing region; A plurality of second conductive pastes stacked so as to be arranged along the width direction on one surface side of the conductor and on the other end side from the tear region Provided with a door.

  A wire harness according to another aspect of the present invention, which has been made to solve the above-described problems, is a wire harness that includes a plurality of fine coaxial wires, and includes a connection terminal at an end portion of these fine coaxial wires, The wire harness connecting flexible flat cable is used as a connection terminal, and the plurality of micro coaxial cables are aligned in a single plane and stripe, and the center conductor is exposed in the tip region along the width direction. The outer conductor layer is exposed in the intermediate region on the rear end side from the region, and the central conductors of the plurality of micro coaxial cables are connected to the plurality of second conductive paste portions of the flexible flat cable in a one-to-one relationship, A plurality of first conductive paste portions of the flexible flat cable are interposed through a single ground bar in which the outer conductor layers of the plurality of fine coaxial wires are disposed in the width direction. It is connected.

  A method for manufacturing a flexible flat cable for connecting a wire harness according to another aspect of the present invention, which has been made to solve the above problems, is arranged in a stripe shape, and a plurality of at least one surface side in one end side region is exposed. And a flexible flat cable manufacturing method for electrically connecting the ends of a wire harness composed of a plurality of micro-coaxial wires, the width excluding at least one of the plurality of conductors in the one end side region. A step of tearing a region along the direction, a step of laminating a plurality of first conductive paste portions so as to be arranged along the width direction on one surface side of the plurality of conductors and on one end side from the tear region, Among the plurality of conductors, a plurality of conductors are arranged along the width direction on one surface side of the conductor being torn and on the other end side from the torn region. And a step of laminating a second conductive paste portions.

  The flexible flat cable for wire harness connection and the wire harness of the present invention can promote cost reduction. Moreover, the manufacturing method of the flexible flat cable for wire harness connection of this invention can manufacture the said flexible flat cable for wire harness connection which can accelerate | stimulate cost reduction easily and reliably.

It is a typical perspective view showing the flexible flat cable for wire harness connection concerning one embodiment of the present invention. It is a typical perspective view which shows the state which connected the wire harness to the flexible flat cable for wire harness connection of FIG. It is a typical perspective view which shows the connection structure of the wire harness of FIG. FIG. 4 is a partial cross-sectional view taken along line AA of the connection structure of FIG. It is a typical top view explaining the manufacturing method of the flexible flat cable for wire harness connection of FIG. FIG. 5B is a schematic plan view for explaining the next step of FIG. 5A of the method for manufacturing the flexible flat cable for connecting the wire harness of FIG. 1. It is a typical top view explaining the next process of Drawing 5B of the manufacturing method of the flexible flat cable for wire harness connection of Drawing 1. It is a typical top view explaining the process following FIG. 5C of the manufacturing method of the flexible flat cable for wire harness connection of FIG. It is a typical top view explaining the manufacturing method of the wire harness of FIG. It is a typical top view explaining the next process of Drawing 6A of the manufacturing method of the wire harness of Drawing 2. FIG. 6 is a schematic plan view for explaining the next step of FIG. 6B of the method for manufacturing the wire harness of FIG. 2.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described.

  A flexible flat cable for connecting a wire harness according to one aspect of the present invention includes a plurality of conductors that are arranged in a stripe shape and that are exposed at least on one surface side in one end region, and are composed of a plurality of micro coaxial wires. A flexible flat cable for electrically connecting ends, wherein a region along the width direction except for at least one conductor among a plurality of conductors in the one end side region is torn, and one of the plurality of conductors A plurality of first conductive paste portions stacked so as to be arranged along the width direction on one side of the surface side and the torn region, and one surface side of the torn conductor among the plurality of conductors and the above A plurality of second conductive paste portions stacked so as to be arranged along the width direction are provided on the other end side from the tearing region.

  The flexible flat cable for connecting a wire harness includes a plurality of conductors that are arranged in a stripe shape and at least one surface side of one end region is exposed. Such a configuration is formed, for example, by laminating a plurality of conductors in a stripe shape on one surface of an insulating sheet mainly composed of synthetic resin or the like. Therefore, the flexible flat cable for connecting the wire harness does not require etching like a flexible printed wiring board, and can facilitate the manufacturing process and promote cost reduction. The flexible flat cable for connecting the wire harness has a first conductive paste portion and a second conductive paste portion in which one surface side of the plurality of conductors is exposed in at least one end region, and the exposed region is sandwiched by the tear region. Is arranged. Therefore, while maintaining the electrical insulation between the first conductive paste portion and the second conductive paste portion, the outer conductive layer of the micro coaxial cable is connected to the first conductive paste portion, and the second conductive paste A central conductor can be connected to the portion. Furthermore, since the flexible flat cable for connecting the wire harness is not torn at least one conductor in the one end region, this conductor can be used as a ground conductor. That is, for example, by holding the outer conductor layer of a plurality of fine coaxial lines by the ground bar, and connecting the ground bar to the unbroken conductor, the conductor can be used as the ground conductor. Therefore, the flexible flat cable for connecting the wire harness can be used as a connection terminal of the wire harness that can promote cost reduction.

  The first conductive paste portion and the second conductive paste portion may be formed from a solder paste. As described above, the first conductive paste portion and the second conductive paste portion are formed of the solder paste, so that the first conductive paste portion and the second conductive paste portion allow the central conductor and the outside of the fine coaxial line to be The conductor layers can be connected easily and reliably.

  In the first conductive paste portion formation region and the second conductive paste portion formation region in the width direction, the other surface side of the plurality of conductors may be exposed. For example, when another layer such as an adhesive layer is laminated on the other surface side of the plurality of conductors, the first conductive paste part and the second conductive paste part, the center conductor of the micro coaxial line, and the outer conductor layer The other layers melt and flow during thermocompression bonding, and may collide with the first conductive paste portion and the second conductive paste portion. Moreover, by this, there exists a possibility that the 1st conductive paste part and the 2nd conductive paste part may be washed away, and adhesive force may fall, or the short circuit between adjacent conductors may arise. On the other hand, the other surface side of the plurality of conductors is also exposed in the first conductive paste portion forming region and the second conductive paste portion forming region in the width direction, so that the first layer is melted by melting of the other layers. It is possible to prevent the first conductive paste portion and the second conductive paste portion from being washed away.

  The conductor that is not torn among the plurality of conductors may be one conductor on one side in the width direction. As described above, the unbroken conductor of the plurality of conductors is a single conductor on one side in the width direction, thereby facilitating manufacture and promoting cost reduction. Is easy to use as a ground conductor.

  The wire harness which concerns on 1 aspect of this invention is a wire harness provided with the connection terminal in the edge part of these fine coaxial lines provided with the some fine coaxial line, Comprising: The said flexible flat cable for wire harness connection as said connection terminal The plurality of micro coaxial lines are aligned in a flat and striped manner, the central conductor is exposed in the tip region along the width direction, and the outer conductor is in the intermediate region on the rear end side from the tip region. A plurality of first conductive pastes of the flexible flat cable, wherein the layers are exposed, and the center conductors of the plurality of fine coaxial wires are connected to the plurality of second conductive paste portions of the flexible flat cable in a one-to-one relationship. The outer conductor layers of the plurality of fine coaxial wires are connected to the portion via a single ground bar disposed in the width direction.

  Since the said wire harness uses the said flexible flat cable for wire harness connection as a connection terminal, cost reduction can be accelerated | stimulated as already stated.

  It is good to further provide a reinforcing plate laminated at least in the connection region of the flexible flat cable. In this way, by further including at least a reinforcing plate laminated in the connection region of the flexible flat cable, the strength of the connection region is increased, and a decrease in strength due to the presence of the tear region is easily and reliably prevented. be able to.

  It is good to further provide a protective film laminated at least on the side opposite to the reinforcing plate in the connection region of the flexible flat cable. Thus, by further providing a protective film laminated on the side opposite to the reinforcing plate in at least the connection area of the flexible flat cable, the connection area is protected from both sides by the protective film and the reinforcing plate. The structure can be held stably.

  A method for manufacturing a flexible flat cable for connecting a wire harness according to an aspect of the present invention includes a plurality of conductors arranged in a stripe shape and exposed at least on one surface side in one end side region. A method of manufacturing a flexible flat cable for electrically connecting the ends of the wire harness, wherein the region along the width direction excluding at least one conductor among the plurality of conductors in the one end side region; A step of laminating a plurality of first conductive paste portions so as to be arranged along the width direction on one surface side of the plurality of conductors and on one end side from the tearing region, and a conductor that is torn among the plurality of conductors Laminating a plurality of second conductive paste portions so as to be arranged along the width direction on one surface side and the other end side of the tear region, Provided.

  The manufacturing method of the said flexible flat cable for wire harness connection can manufacture the said flexible flat cable for wire harness connection which can accelerate | stimulate cost reduction easily and reliably.

  In the present invention, “striped” means a state of being substantially parallel in the same plane, and “substantially parallel” means that the angle formed by the central axis is within ± 10 °. . “A plurality of micro coaxial lines are aligned in a single plane” means that the central axes of the plurality of micro coaxial lines are arranged in a plane. Further, the “extra-fine coaxial line” means a coaxial line having an outer diameter dimension of 1 mm or less, and preferably means a coaxial line having an outer diameter dimension of 0.5 mm or less. In addition, the lower limit of the outer diameter of the ultrafine coaxial line is not particularly limited, and may be 0.05 mm, for example.

[Details of the embodiment of the present invention]
Hereinafter, the manufacturing method of the flexible flat cable for wire harness connection, the wire harness, and the flexible flat cable for wire harness connection which concerns on embodiment of this invention is demonstrated, referring drawings suitably.

[First embodiment]
<Flexible flat cable for wire harness connection>
The flexible flat cable 1 for connecting a wire harness in FIG. 1 (hereinafter also simply referred to as “flexible flat cable 1”) electrically connects the ends of a wire harness composed of a plurality of micro coaxial cables. The flexible flat cable 1 has flexibility. The flexible flat cable 1 includes a plurality of conductors 2 arranged in stripes, an adhesive layer 3 directly laminated on the other surface of the plurality of conductors 2, and the other surface side of the adhesive layer 3. And an insulating layer 4 to be laminated. The flexible flat cable 1 includes a plurality of first conductive paste portions 5 and a plurality of second conductive paste layer portions 6 that are stacked so as to be arranged along the width direction of the plurality of conductors 2.

(conductor)
The plurality of conductors 2 are formed in a long and flat shape. One surface side of the plurality of conductors 2 is exposed. Specifically, one surface side of the plurality of conductors 2 is exposed over the entire surface. The conductor 2 is formed of a conductive material. An example of the main component of the conductor 2 is copper. The “main component” refers to a component having the highest content, for example, a component having a content of 50% by mass or more.

  The plurality of conductors 2 are plated on the surface, and a plating layer (not shown) is laminated on the surface by the plating treatment. Examples of the plating treatment include gold plating, silver plating, and tin plating. It is possible to prevent the exposed portions of the plurality of conductors 2 from being damaged by the plating process.

  As a minimum of average thickness (a plating layer is included) of conductor 2, 10 micrometers is preferred and 25 micrometers is more preferred. On the other hand, the upper limit of the average thickness of the conductor 2 is preferably 100 μm, and more preferably 80 μm. If the average thickness of the conductor 2 is less than the lower limit, the electrical conductivity may be insufficient. On the contrary, if the average thickness of the conductor 2 exceeds the upper limit, the flexible flat cable 1 may be unnecessarily thick.

  The lower limit of the average width (including the plating layer) of the conductor 2 is preferably 0.1 mm, and more preferably 0.2 mm. On the other hand, the upper limit of the average width of the conductor 2 is preferably 1 mm, and more preferably 0.4 mm. If the average width of the conductor 2 is less than the above lower limit, the conductivity may be insufficient. On the contrary, if the average width of the conductor 2 exceeds the upper limit, the width of the flexible flat cable 1 may become unnecessarily large.

  As a minimum of average pitch of conductor 2, 0.2 mm is preferred and 0.3 mm is more preferred. On the other hand, the upper limit of the average pitch of the conductor 2 is preferably 1.5 mm, and more preferably 1.2 mm. If the average pitch of the conductors 2 is less than the lower limit, adjacent conductors 2 may be in contact with each other. Conversely, if the average pitch of the conductors 2 exceeds the upper limit, the width of the flexible flat cable 1 may become unnecessarily large.

  The number of conductors 2 can be increased or decreased as necessary and is not particularly limited, but may be, for example, 10 or more and 60 or less.

(Adhesive layer)
Although it does not specifically limit as an adhesive agent which comprises the adhesive bond layer 3, What was excellent in the softness | flexibility and heat resistance is preferable, for example, an epoxy resin, a polyimide, polyester, a phenol resin, a polyurethane, an acrylic resin, a melamine Various resin-based adhesives such as resins and polyamideimides can be used. Among them, a thermoplastic resin that can be firmly bonded to the protective film 15 to be described later by remelting is preferable, and among these thermoplastic resins, a polyester excellent in moldability, insulation, and the like is preferable.

  The lower limit of the average thickness of the adhesive layer 3 (the average distance between the conductor 2 and the insulating layer 4) is preferably 5 μm, and more preferably 10 μm. On the other hand, the upper limit of the average thickness is preferably 100 μm, and more preferably 50 μm. If the average thickness is less than the lower limit, the adhesive strength between the plurality of conductors 2 and the insulating layer 4 may be insufficient. Conversely, if the average thickness exceeds the upper limit, the flexible flat cable 1 may be unnecessarily thick.

  As a minimum of the softening temperature of the polymer which comprises the adhesive bond layer 3, 70 degreeC is preferable and 75 degreeC is more preferable. If the softening temperature of the polymer constituting the adhesive layer 3 is less than the lower limit, a first conductive paste portion 5 and a second conductive paste portion 6 described later for connecting the plurality of conductors 2 and the micro coaxial line are used. When heat is applied to the adhesive layer 3, the adhesive layer 3 may melt and flow. Further, this may cause the fluidized adhesive layer 3 to collide with the first conductive paste portion 5 and the second conductive paste portion 6. As a result, the first conductive paste portion 5 and the second conductive paste portion 6 may be swept away and a short circuit may occur between the adjacent conductors 2. On the other hand, the upper limit of the softening temperature of the polymer constituting the adhesive layer 3 is not particularly limited, and can be, for example, 200 ° C.

  As a minimum of the glass transition temperature of the polymer which constitutes adhesive layer 3, 50 ° C is preferred, 60 ° C is more preferred, and 70 ° C is still more preferred. If the glass transition temperature of the polymer constituting the adhesive layer 3 is less than the lower limit, the strength of the adhesive layer 3 may be insufficient. On the other hand, the upper limit of the glass transition temperature of the polymer constituting the adhesive layer 3 is not particularly limited, and can be, for example, 200 ° C.

(Insulating layer)
The insulating layer 4 is composed of a sheet-like member having flexibility and electrical insulation. Specifically, a resin film can be employed as the insulating layer 4. As the main component of this resin film, for example, polyimide, polyethylene terephthalate or the like is preferably used.

  As a minimum of average thickness of insulating layer 4, 5 micrometers is preferred and 10 micrometers is more preferred. On the other hand, the upper limit of the average thickness of the insulating layer 4 is preferably 40 μm, and more preferably 20 μm. If the average thickness of the insulating layer 4 is less than the lower limit, the strength of the insulating layer 4 may be insufficient. Conversely, if the average thickness of the insulating layer 4 exceeds the upper limit, the flexible flat cable 1 may be unnecessarily thick.

(Rupture area)
In the flexible flat cable 1, a region along the width direction is torn except for at least one conductor 2 a (hereinafter, also referred to as “ground conductor 2 a”) among the plurality of conductors 2 (hereinafter, this torn-off). The region thus formed is also referred to as “rupture region A”). Specifically, a conductor 2b (hereinafter, also referred to as “wiring conductor 2b”) excluding one conductor 2a on one side in the width direction among the plurality of conductors 2 is torn along the width direction. Since the conductor 2 that is not torn among the plurality of conductors 2 is one conductor 2a on one side in the width direction, manufacturing can be facilitated and cost reduction can be promoted. Easy to use as a ground conductor.

  In the tear region A, the adhesive layer 3 and the insulating layer 4 laminated on the other surface of the plurality of wiring conductors 2b are torn together with the plurality of wiring conductors 2b. That is, the tear region A is a cut that penetrates in the front-back direction from the other side in the width direction of the flexible flat cable 1 (the other side in the width direction of the plurality of conductors 2, that is, the side opposite to the ground conductor 2a) to one side. It is provided by forming a notch. Further, the tear region A is formed in a substantially rectangular shape in plan view with the width direction of the plurality of conductors 2 as the longitudinal direction. The “substantially rectangular shape” means that an angle formed by two opposing sides is ± 10 ° or less, preferably ± 5 ° or less.

  As a minimum of the average length of the transversal direction of tearing field A, 0.2 mm is preferred and 0.4 mm is more preferred. On the other hand, the upper limit of the average length of the tear region A in the short direction is preferably 2 mm, and more preferably 1 mm. If the average length in the short direction of the fracture region A is less than the lower limit, it may not be possible to accurately ensure the insulation between the conductors 2 divided by the fracture region A, and the formation of the fracture region A becomes difficult. There is a risk. On the contrary, if the average length in the short direction of the torn region A exceeds the above upper limit, the torn region A becomes unnecessarily large, which is contrary to the demand for downsizing of the flexible flat cable 1 and the strength may be lowered. .

(First conductive paste part)
The plurality of first conductive paste portions 5 are stacked on one surface side of the plurality of conductors 2 and on one end side with respect to the tearing region A. The plurality of first conductive paste portions 5 are directly laminated on one surface of the plurality of conductors 2. The plurality of first conductive paste portions 5 are arranged along the width direction of the plurality of conductors 2. The plurality of first conductive paste portions 5 are laminated on one surface side of all the conductors 2.

  The material of the plurality of first conductive paste portions 5 is not particularly limited as long as it has conductivity, but a low melting point electrical connection paste that can be freely changed in shape by room temperature or slight heating is preferably used. it can. By using such an electrical connection paste, the conductive paste portion 5 can be reliably laminated on one surface side of the plurality of conductors 2 at a low cost by, for example, a printing technique. If an electrically connecting paste having a relatively low melting point is used as the material of the conductive paste portion 5, only the first conductive paste portion 5 is melted when connecting the plurality of conductors 2 and the plurality of micro coaxial cables 12. Thus, the plurality of conductors 2 and the plurality of micro coaxial wires 12 can be electrically connected without being deformed or damaged.

  As the electrical connection paste for forming the first conductive paste portion 5, a conductive adhesive in which conductive particles such as metal particles are dispersed in an adhesive, a solder paste in which low melting point metal powder is kneaded with a flux, or the like is used. it can. Among these, a solder paste having a relatively low melting temperature and capable of easily and reliably electrically connecting the fine coaxial wire and the conductor 2 is preferable.

  Examples of the metal particles of the conductive adhesive include silver, platinum, gold, copper, nickel, palladium, indium, tin, and solder. These can be used alone or in combination of two or more. Among these, silver powder, silver-coated copper powder, solder powder and the like exhibiting excellent conductivity are preferable. As the adhesive of the conductive adhesive, an adhesive that can easily spread on one surface of the conductor 2, a thermoplastic resin having a low melting point, and the like are preferable.

  The metal powder (solder) contained in the solder paste is preferably one having a low melting point, for example, a tin-bismuth alloy having a melting point of 139 ° C. The particle size of the metal powder of the solder paste is preferably 20 μm or more and 40 μm or less. When the solder is melted, it spreads to the bonding portion between the conductor 2 and the center conductor of the fine coaxial line due to wettability, thereby improving the reliability of electrical connection between the conductor 2 and the fine coaxial line. The solder paste flux is preferably one that can contribute to the wettability of the solder, and a resin-based, organic acid-based or inorganic acid-based one can be used.

  Examples of the solvent used in the flux include organic solvents such as ester, ether, ketone, ether ester, alcohol, hydrocarbon, and amine, and one or two of these can be used. The above can be used. Of these, carbitol acetate, butyl carbitol acetate, and the like having a high boiling point and excellent printability are preferable. Moreover, as a boiling point of such a high boiling point solvent, 200 degreeC or more is preferable.

  The first conductive paste portion 5 is formed in a substantially rectangular shape in plan view with the axial direction of the conductor 2 as the longitudinal direction. As a minimum of the average length of the longitudinal direction of the 1st conductive paste part 5, 0.3 mm is preferred and 0.5 mm is more preferred. On the other hand, the upper limit of the average length in the longitudinal direction of the first conductive paste portion 5 is preferably 1.5 mm, and more preferably 1.2 mm. If the average length in the longitudinal direction of the first conductive paste portion 5 is less than the lower limit, the conductor 2 and the micro coaxial line 12 may not be firmly bonded. Conversely, if the average length in the longitudinal direction of the first conductive paste portion 5 exceeds the upper limit, the first conductive paste portion 5 may become unnecessarily large.

  The average length of the first conductive paste portion 5 in the short direction is smaller than the average width of the conductor 2. Further, both ends of the first conductive paste portion 5 in the short direction are disposed inside both ends of the conductor 2 in the width direction. That is, the first conductive paste portion 5 is included in the conductor 2 in plan view. As described above, when the first conductive paste portion 5 has an average length in the short direction smaller than the average width of the conductor 2, the first conductive paste portion 5 is bonded to the conductor 2 and the fine coaxial line. 5 is easily held in one surface of the conductor 2. Thereby, even if the 1st electroconductive paste part 5 flows a little when adhere | attaching the conductor 2 and a micro coaxial line, it can prevent that a short circuit arises between several conductors 2. FIG.

  As a minimum of the average length of the transverse direction of the 1st conductive paste part 5, 0.15 mm is preferred and 0.2 mm is more preferred. On the other hand, the upper limit of the average length in the short direction of the first conductive paste portion 5 is preferably 0.5 mm, and more preferably 0.4 mm. If the average length of the first conductive paste portion 5 in the short direction is less than the lower limit, the conductor 2 and the micro coaxial line may not be firmly bonded. Conversely, if the average length in the short direction of the first conductive paste portion 5 exceeds the upper limit, it may be difficult to hold the first conductive paste portion 5 in one surface of the conductor 2.

  The lower limit of the difference between the average width of the conductor 2 and the average length in the short direction of the first conductive paste portion 5 is preferably 0.02 mm, and more preferably 0.04 mm. On the other hand, the upper limit of the difference between the average width of the conductor 2 and the average length in the short direction of the first conductive paste portion 5 is preferably 0.3 mm, and more preferably 0.1 mm. By making the difference in length within the above range, it is possible to easily and surely prevent a short circuit between the plurality of conductors 2 and improve the electrical connectivity between the conductors 2 and the fine coaxial line.

  As a minimum of average thickness of the 1st conductive paste part 5, 0.05 mm is preferred and 0.07 mm is more preferred. On the other hand, the upper limit of the average thickness of the first conductive paste portion 5 is preferably 0.2 mm, and more preferably 0.15 mm. If the average thickness of the first conductive paste portion 5 is less than the above lower limit, the conductor 2 and the micro coaxial line may not be firmly bonded. Conversely, if the average thickness of the first conductive paste portion 5 exceeds the upper limit, the first conductive paste portion 5 may be unnecessarily thick. In addition, when the first conductive paste portion 5 is melted when connecting the conductor 2 and the micro coaxial cable 12, the first conductive paste portion 5 flows to cause a short circuit with another conductor 2. There is a fear.

  In the band-like region (first conductive paste portion forming region B) extending in the width direction of the flexible flat cable 1 and including the plurality of first conductive paste portions 5 in plan view, the other surface side of the plurality of conductors 2 is Exposed. In the present embodiment, the adhesive layer 3 and the insulating layer 4 are removed in the first conductive paste portion forming region B. The first conductive paste portion forming region B is formed in a substantially rectangular shape in plan view from one end to the other end in the width direction of the flexible flat cable 1. When the adhesive layer 3 is not removed in the first conductive paste portion forming region B, the adhesive layer 3 is melted at the time of thermocompression bonding between the plurality of conductors 2 and the outer conductor layer 18 of the micro coaxial cable 12, and the first There is a possibility of colliding with the conductive paste portion 5. Moreover, by this, the 1st conductive paste part 5 may be washed away and adhesive force may fall, or there exists a possibility that the short circuit between the adjacent conductors 2 may arise. On the other hand, the other surface side of the plurality of conductors 2 is exposed in the first conductive paste portion forming region B, thereby preventing the first conductive paste portion 5 from being washed away by melting of the adhesive layer 3. can do. As a result, the plurality of conductors 2 and the outer conductor layer 18 of the micro coaxial cable 12 can be accurately connected, and a short circuit between the adjacent conductors 2 can be prevented. Furthermore, by removing both the adhesive layer 3 and the insulating layer 4 in the first conductive paste portion forming region B, the other surface side of the plurality of conductors 2 can be easily and reliably exposed.

  The lower limit of the average length of the first conductive paste portion forming region B in the short direction (the axial direction of the plurality of conductors 2) is preferably 0.6 mm, and more preferably 0.8 mm. On the other hand, the upper limit of the average length in the short direction of the first conductive paste portion forming region B is preferably 2 mm, and more preferably 1.2 mm. If the average length is less than the lower limit, the molten adhesive layer 3 may collide with the first conductive paste portion 5. On the other hand, if the average length exceeds the upper limit, the first conductive paste portion forming region B becomes unnecessarily large, which is contrary to the demand for downsizing of the flexible flat cable 1 and the strength may be lowered.

  The lower limit of the difference between the average length in the short direction of the first conductive paste portion forming region B and the average length in the longitudinal direction of the first conductive paste portion 5 is preferably 0.1 mm, and more preferably 0.15 mm. . On the other hand, the upper limit of the average length difference is preferably 1 mm, and more preferably 0.5 mm. If the difference in the average length is less than the lower limit, the molten adhesive layer 3 may collide with the first conductive paste portion 5. On the contrary, if the difference in the average length exceeds the upper limit, the first conductive paste portion forming region B becomes unnecessarily large, which is contrary to the demand for downsizing of the flexible flat cable 1 and the strength may be lowered. is there.

  The average length from one end of the first conductive paste portion forming region B of the plurality of conductors 2 to one end of the flexible flat cable 1 is not particularly limited, and is, for example, about 0.2 mm to 2 mm. It can be. Further, the average length from one end of the tear region A to the other end of the first conductive paste portion forming region B is not particularly limited, and can be, for example, about 0.2 mm or more and 2 mm or less.

(Second conductive paste part)
The plurality of second conductive paste portions 6 are stacked on the one surface side of the conductor 2 b that is torn among the plurality of conductors 2 and on the other end side from the torn region A. The second conductive paste portion 6 is not laminated on one surface side of the ground conductor 2a. On the other hand, the plurality of second conductive paste portions 6 are directly laminated on one surface of the plurality of wiring conductors 2b. The plurality of second conductive paste portions 6 are disposed along the width direction of the plurality of wiring conductors 2b.

  The material of the plurality of second conductive paste portions 6 can be the same as the material of the plurality of first conductive paste portions 5.

  The second conductive paste portion 6 is formed in a substantially rectangular shape in plan view with the axial direction of the wiring conductor 2b as the longitudinal direction. The average length in the longitudinal direction, the average length in the short direction, and the average thickness of the second conductive paste portion 6 are the average length in the longitudinal direction of the first conductive paste portion 5 and the average length in the short direction. And the average thickness. The difference between the average width of the wiring conductor 2b and the average length of the second conductive paste portion 6 in the short direction is the average width of the conductor 2 and the average length of the first conductive paste portion 5 in the short direction. The same can be said.

  In the band-like region (second conductive paste portion forming region C) extending in the width direction of the flexible flat cable 1 and including the plurality of second conductive paste portions 6 in plan view, the other surface of the plurality of wiring conductors 2b The side is exposed. In the present embodiment, the adhesive layer 3 and the insulating layer 4 are removed in the second conductive paste portion forming region C. The second conductive paste portion forming region C is formed in a substantially rectangular shape in plan view from one end to the other end in the width direction of the flexible flat cable 1. In the flexible flat cable 1, the second conductive paste portion 6 is washed away by melting of the adhesive layer 3 because the other surface side of the plurality of wiring conductors 2 b is exposed in the second conductive paste portion forming region C. Can be suppressed. As a result, the plurality of wiring conductors 2b and the central conductor 16 of the micro coaxial cable 12 can be accurately connected, and a short circuit between the adjacent wiring conductors 2b can be prevented. Furthermore, by removing both the adhesive layer 3 and the insulating layer 4 in the second conductive paste portion forming region C, the other surface side of the plurality of wiring conductors 2b can be easily and reliably exposed. .

  The average length of the second conductive paste portion forming region C in the short direction (the axial direction of the plurality of wiring conductors 2b) is the same as the average length of the first conductive paste portion forming region B in the short direction. be able to. The difference between the average length in the short direction of the second conductive paste portion forming region C and the average length in the long direction of the second conductive paste portion 6 is the short length of the first conductive paste portion forming region B. The average length in the direction and the average length in the longitudinal direction of the first conductive paste portion 5 can be the same.

  In addition, the other end side of the 2nd conductive paste part formation area C of the said flexible flat cable 1 is comprised as a connection part connected to a dedicated connector etc. FIG. The average length from the other end of the second conductive paste portion forming region C of the plurality of conductors 2 to the other end of the flexible flat cable 1 is not particularly limited and is, for example, about 2 mm to 10 mm. be able to. When the average length is within the above range, the plurality of conductors 2 and the dedicated connectors can be appropriately electrically connected while preventing the flexible flat cable 1 from becoming unnecessarily large.

<Advantages>
The flexible flat cable 1 includes a plurality of conductors 2 arranged in a stripe shape and exposed at least on one surface side in one end region. Such a configuration is formed by laminating a plurality of conductors 2 in a stripe shape on one surface of an insulating sheet having an insulating layer 4 and an adhesive layer 3 laminated on one surface side of the insulating layer 4. The Therefore, the flexible flat cable 1 does not require etching unlike a flexible printed wiring board, and can facilitate the manufacturing process and promote cost reduction. The flexible flat cable 1 has at least one end region in which one surface side of the plurality of conductors 2 is exposed, and the exposed conductive region is sandwiched between the first conductive paste portion 5 and the second conductive paste portion. 2 is disposed. Therefore, while maintaining electrical insulation between the first conductive paste portion 5 and the second conductive paste portion 6, the first conductive paste portion 5 is connected to the outer conductor layer 18 of the micro coaxial cable 12, and the first conductive paste portion 5 and the second conductive paste portion 6 are electrically connected. The central conductor 16 can be connected to the two conductive paste portions 6. Furthermore, since the flexible flat cable 1 is not torn about at least one conductor 2a in one end region, the conductor 2a can be used as the ground conductor 2a. That is, for example, the outer conductor layer 18 of the plurality of micro coaxial cables 12 is held by the ground bar, and the conductor 2a can be used as the ground conductor 2a by connecting the ground bar to the unbroken conductor 2a. it can. Therefore, the said flexible flat cable 1 can be used as a connection terminal of the wire harness which can promote cost reduction.

<Wire harness>
The wire harness 11 shown in FIGS. 2 and 3 includes a plurality of fine coaxial lines 12, and includes connection terminals 13 at the ends of these fine coaxial lines 12. Further, the flexible flat cable 1 shown in FIG. 1 is used as the connection terminal 13. Further, the wire harness 11 includes at least a reinforcing plate 14 laminated on the connection region D of the flexible flat cable 1 and a protective film laminated on the opposite side of the reinforcing plate 14 at least in the connection region D of the flexible flat cable 1. 15. The “connection region D” refers to a region in which the plurality of micro coaxial cables 12 and the flexible flat cable 1 are connected to each other when the plurality of micro coaxial cables 12 overlap with the flexible flat cable in a plan view.

(Ultra fine coaxial line)
In the plurality of micro coaxial wires 12, an insulating layer 17, an outer conductor layer 18, and a jacket 19 are sequentially laminated on the outer periphery of the center conductor 16 in a coaxial manner. Further, the plurality of micro coaxial wires 12 are arranged in a single flat shape and a stripe shape, and the central conductor 16 is exposed in a tip region (a connection side region with the flexible flat cable 1) along the width direction. The outer conductor layer 18 is exposed in an intermediate region on the rear end side from the region.

  The average pitch of the micro coaxial cable 12 is preferably the same as the average pitch of the conductor 2. Further, the number of cores of the plurality of micro coaxial wires 12 is one less than the number of the plurality of conductors 2. That is, the number of cores of the plurality of micro coaxial wires 12 is equal to the number of wiring conductors 2b among the plurality of conductors 2.

  The center conductor 16 is not particularly limited, and for example, a metal wire such as copper, copper alloy, aluminum, or aluminum alloy can be used. Further, such a metal wire may be a single wire or a stranded wire. Although the number of strands in the case of a stranded wire is not specifically limited, For example, they are 3 or more and 30 or less.

  The cross-sectional shape of the metal wire forming the central conductor 16 is not particularly limited, and various shapes such as a circular shape, a rectangular shape, and a rectangular shape can be adopted. In the wire harness 11, a round wire having a circular cross-sectional shape is preferable. Used for.

  The lower limit of the average diameter of the center conductor 16 is preferably 20 μm and more preferably 25 μm. On the other hand, the upper limit of the average diameter of the center conductor 16 is preferably 500 μm, and more preferably 200 μm. If the average diameter of the central conductor 16 is less than the lower limit, the central conductor 16 may be easily broken. Moreover, when the average diameter of the center conductor 16 exceeds the said upper limit, there exists a possibility that the connection structure of the said wire harness 11 may become large unnecessarily.

  The average exposed length of the central conductor 16 from the insulating layer 17 can be, for example, 0.2 mm or more and 1.5 mm or less.

  The insulating layer 17 is laminated on the outer peripheral surface of the center conductor 16 so as to cover the center conductor 16. The insulating layer 17 may be a single layer or a multilayer structure including two or more layers.

  The material of the insulating layer 17 is not particularly limited as long as it has insulating properties and flexibility. For example, ethylene resin such as polyethylene, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene resin, etc. Resins blended with polyolefin such as polypropylene, ethylene propylene rubber, styrene elastomer, polyimide, polyamideimide, polyesterimide, silane crosslinkable resin composition, and the like can be used.

  The insulating layer 17 is formed by, for example, a method in which a molten resin is extruded onto the outer peripheral surface of the central conductor 16 and cured, or a method in which a resin in which the resin is dissolved in an organic solvent is applied and baked on the outer peripheral surface of the central conductor 16. Can be coated.

  The average thickness (thickness) of the insulating layer 17 can be, for example, 10 μm or more and 1 mm or less.

  The insulating layer 17 may have a primer layer in contact with the central conductor 16. As this primer layer, what hardened | cured crosslinkable resin, such as ethylene which does not contain a metal hydroxide, can be used conveniently. By providing such a primer layer, it is possible to prevent deterioration of the peelability between the insulating layer 17 and the central conductor 16 with time.

  The outer conductor layer 18 is laminated on the outer peripheral surface of the insulating layer 14. The outer conductor layer 18 can be formed, for example, by braiding or transverse winding of a plurality of thin wire rods made of conductive metal. The external conductor layer 7 can also be formed by winding a metal tape around the outer peripheral surface of the insulating layer 14.

  When the outer conductor layer 18 is formed of a conductive metal thin wire, for example, a tin-plated copper alloy, tin-plated copper, silver-plated copper, or coarse copper can be used as the conductive metal. Moreover, as an average diameter of the said thin wire, it can be set as about 20 micrometers or more and 100 micrometers or less, for example.

  On the other hand, when the external conductor layer 18 is formed of a metal tape, as the metal tape, for example, a synthetic resin tape with a metal foil pasted can be used. In addition, the average thickness of the metal tape can be, for example, about 10 μm or more and 100 μm or less.

  The average exposed length of the outer conductor layer 18 from the outer jacket 19 can be, for example, 1.5 mm or more and 3 mm or less.

  The jacket 19 is laminated on the outer peripheral surface of the outer conductor layer 18. The jacket 19 can be formed using the same material as the insulating layer 17. In addition, the average thickness (wall thickness) of the jacket 19 can be the same as the average thickness of the insulating layer 17.

  The outer conductor layers 18 of the plurality of micro coaxial cables 12 are sandwiched from one side and the other side by a pair of ground bars 20a and 20b. Specifically, the ground bar 20a on one side is in contact with one side of the outer conductor layer 18 of the plurality of micro coaxial cables 12, and the ground bar 21b on the other side is the other side of the outer conductor layer 18 of the plurality of micro coaxial cables 12. It is in contact with the side. Each of the pair of ground bars 20a and 20b is a plate-like body having a rectangular shape in plan view, and sandwiches the outer conductor layers 18 of all the fine coaxial wires 12 between the opposed inner surfaces. One end of each of the pair of ground bars 20a and 20b protrudes to one side (the ground conductor 2a side) in the parallel direction of the plurality of fine coaxial wires 12. Examples of the material of the pair of ground bars 20a and 20b include conductive metals such as copper or copper alloys.

(Reinforcement plate)
The reinforcing plate 14 includes a reinforcing sheet 21 and an adhesive layer 22 laminated on one surface side of the reinforcing sheet 21. The reinforcing plate 14 is laminated at least on the connection region D of the flexible flat cable 1 to increase the strength of the connection region D, and torn the region A, the first conductive paste portion formation region B, and the second conductive paste portion. A decrease in strength due to the presence of the formation region C and the like can be easily and reliably prevented.

  The reinforcing plate 14 has one surface of the adhesive layer 22 laminated on the other surface of the insulating layer 4 of the flexible flat cable 1. The reinforcing plate 14 is laminated on the entire other surface of the flexible flat cable 1.

(Reinforcement sheet)
The reinforcing sheet 21 is composed of a sheet-like member having flexibility and electrical insulation. Specifically, a resin film can be used as the reinforcing sheet 21. As the main component of this resin film, for example, polyimide, polyethylene terephthalate or the like is preferably used.

  As a minimum of average thickness of reinforcing sheet 21, 100 micrometers is preferred, 150 micrometers is more preferred, and 200 micrometers is still more preferred. On the other hand, the upper limit of the average thickness of the reinforcing sheet 21 is preferably 400 μm, more preferably 300 μm, and even more preferably 250 μm. If the average thickness of the reinforcing sheet 21 is less than the lower limit, the strength of the connection region D may not be sufficiently increased. Conversely, if the average thickness of the reinforcing sheet 21 exceeds the above upper limit, the connecting portion of the wire harness 11 may be unnecessarily thick.

(Adhesive layer)
Although it does not specifically limit as an adhesive agent which comprises the adhesive bond layer 22, What was excellent in the softness | flexibility and heat resistance is preferable, for example, an epoxy resin, a polyimide, polyester, a phenol resin, a polyurethane, an acrylic resin, a melamine Various resin-based adhesives such as resins and polyamideimides can be used.

  As a minimum of average thickness of adhesive layer agent 22, 5 micrometers is preferred and 15 micrometers is more preferred. On the other hand, the upper limit of the average thickness of the adhesive layer 22 is preferably 50 μm, and more preferably 40 μm. If the average thickness of the adhesive layer 22 is less than the above lower limit, the adhesive strength may be insufficient. Conversely, if the average thickness of the adhesive layer 22 exceeds the above upper limit, the connecting portion of the wire harness may become unnecessarily thick.

(Protective film)
The protective film 15 includes a cover film 23 and an adhesive layer 24 laminated on the other surface side of the cover film 23. The protective film 15 is laminated at least on the side opposite to the reinforcing plate 14 of the connection region D of the flexible flat cable 1, thereby protecting the connection region D from both sides together with the reinforcing plate 14, thereby stabilizing the connection structure. Can be held.

  The protective film 15 covers one surface side of the connection region D of the flexible flat cable 1. Specifically, the reinforcing film 15 is laminated from one end of the flexible flat cable 1 to a region including the other end of the connection region D. In addition, the protective film 15 is not laminated | stacked on the other end side of the said flexible flat cable 1, The one surface of the some conductor 2 is exposed. The wire harness 11 is configured to be connectable to a dedicated connector or the like by the exposed portions of the plurality of conductors 2.

  The cover film 23 can have the same configuration as the insulating layer 4 laminated on the other surface side of the plurality of conductors 2 of the flexible flat cable 1, for example. Further, the adhesive layer 24 can have the same configuration as the adhesive layer 3 laminated on the other surface of the plurality of conductors 2 of the flexible flat cable 1.

(Connection structure)
Next, with reference to FIG.3 and FIG.4, the connection structure of the said wire harness 11 is demonstrated.

  Center conductors 16 of a plurality of fine coaxial wires 12 are connected to the plurality of second conductive paste portions 6 of the flexible flat cable 1 in a one-to-one relationship. Further, on the other surface side of the plurality of conductors 2 in the connection portion, a strip-like region from which the adhesive layer 3 and the insulating layer 4 are removed extends in the width direction of the plurality of conductors 2.

  The plurality of first conductive paste portions 5 of the flexible flat cable 1 are connected to the outer conductor layers 18 of the plurality of fine coaxial wires 12 via ground bars 20a and 20b arranged in the width direction. Specifically, the outer conductor layer 18 of the plurality of micro coaxial wires 12 is sandwiched between a pair of ground bars 20a and 20b, and the plurality of conductors 2 side (the other side) of the pair of ground bars 20a and 20b. The ground bar 20b is connected to the plurality of first conductive paste portions 5 on the other surface. Here, one end of the other ground bar 20b is connected to the ground conductor 2a. Further, on the other surface side of the plurality of conductors 2 in the connection portion, a strip-like region from which the adhesive layer 3 and the insulating layer 4 are removed extends in the width direction of the plurality of conductors 2.

  The wire harness 11 can electrically connect the outer conductor layer 18 of the plurality of micro coaxial cables 12 to the ground conductor 2a via the pair of ground bars 20a and 20b, and can connect the ground via the ground conductor 2a. can do.

  Further, in the wire harness 11, since the plurality of wiring conductors 2 b are torn by the tearing region A, the insulation state between the center conductor 16 of the plurality of ultrafine coaxial wires 12 and the ground conductor 2 a can be easily maintained. These central conductors 16 can be electrically connected to a dedicated connector or the like via the plurality of wiring conductors 2b.

<Advantages>
Since the flexible flat cable 1 is used as the connection terminal 13 in the wire harness 1, cost reduction can be promoted as described above.

<Method for manufacturing flexible flat cable>
Then, with reference to FIG. 5A-FIG. 5D, the manufacturing method of the said flexible flat cable 1 of FIG. 1 is demonstrated. The method for manufacturing the flexible flat cable includes a step of exposing the other surface side of the plurality of conductors 2 in the first conductive paste portion forming region B and the second conductive paste portion forming region C, and a plurality of the one end region. A step of tearing a region along the width direction excluding at least one conductor 2a out of the conductors 2 and a plurality of conductors 2 arranged along the width direction on one surface side of the plurality of conductors 2 and at one end side from the tear region. The first conductive paste portion 5 of the plurality of conductors, and a plurality of conductors arranged so as to be arranged along the width direction on one surface side of the conductor 2b that is torn and on the other end side from the torn region. A step of laminating the second conductive paste portion 6.

(Exposure process)
In the exposure step, as shown in FIG. 5A, the insulating sheet 25 (adhesive layer 3 and insulating layer 4 in FIG. 1) laminated on the other surface side of the plurality of conductors 2 is arranged in the width direction (the plurality of conductors 2 Two slits extending in the width direction of the plurality of conductors 2 in the stacked state are formed. Further, in the exposing step, the plurality of conductors 2 are arranged on one surface of the insulating sheet 25 so that the two slits correspond to the first conductive paste portion forming region B and the second conductive paste portion forming region C. Laminate on the side (one surface side of the adhesive layer 3). Thereby, the other surface side of the plurality of conductors 2 in the first conductive paste portion forming region B and the second conductive paste portion forming region C is exposed. The method of forming these two slits is not particularly limited, and can be performed by, for example, known laser processing.

(Rearing process)
In the tearing step, as shown in FIG. 5B, after laminating a plurality of conductors 2 on one surface side of the insulating sheet 25, the two slits and the two slits formed in the exposing step Form parallel notches. In the tearing step, a portion of the insulating sheet 25 that overlaps with a tearing portion of the plurality of wiring conductors 2b excluding the ground conductor 2a in plan view is also torn simultaneously with the plurality of wiring conductors 2b. The method of tearing the plurality of wiring conductors 2b and the insulating sheet 25 is not particularly limited, and can be performed by, for example, laser processing similar to the above exposure step.

(First conductive paste portion laminating step)
In the first conductive paste portion laminating step, as shown in FIG. 5C, the first conductive paste portion laminating step is performed on one surface of the plurality of conductors 2 and overlapping with the slit on one side formed in the exposing step in plan view. 1 Conductive paste portion 5 is laminated. The plurality of first conductive paste portions 5 can be formed by printing or coating. Examples of the printing method include screen printing, gravure printing, offset printing, flexographic printing, inkjet printing, dispenser printing, and the like. Examples of the coating method include knife coating, die coating, and roll coating.

(Second conductive paste portion laminating step)
In the second conductive paste portion laminating step, as shown in FIG. 5D, the other slit and the plane formed on the one side of the plurality of conductors 2b torn in the tearing step and formed in the exposing step. The second conductive paste portions 6 are laminated on the overlapping regions as viewed. The second conductive paste portion laminating step can be performed by the same printing method or coating method as the first conductive paste portion laminating step.

  Note that the tearing step, the first conductive paste portion laminating step, and the second conductive paste portion laminating step are not necessarily performed in this order. For example, a plurality of first conductive paste portions 5 and a second conductive paste portion 6 are laminated in advance on one surface of the plurality of conductors 2, and the plurality of conductors 2 are further connected to the plurality of first conductive paste portions. The insulating sheet 25 may be laminated on one surface so that 5 is included in the slit on one side in plan view and the plurality of second conductive paste portions 6 are included in the slit on the other side in plan view. .

<Advantages>
The manufacturing method of the flexible flat cable can easily and reliably manufacture the flexible flat cable for connecting the wire harness that can promote cost reduction.

<Method for manufacturing wire harness>
Next, with reference to FIG. 6A-FIG. 6C, the manufacturing method of the said wire harness 11 of FIG. 2 is demonstrated. The method for manufacturing the wire harness 11 includes a step of connecting the central conductors 16 of the plurality of fine coaxial wires 12 to the plurality of second conductive paste portions 6 and a pair of sandwiching the outer conductors 18 of the plurality of fine coaxial wires 12. A step of connecting the ground bars 20a, 20b to the plurality of first conductive paste portions 5, a step of laminating the reinforcing plate 14 on at least the connection region D of the flexible flat cable 1, and at least a connection region of the flexible flat cable 1. And a step of laminating a protective film 15 on the side opposite to the reinforcing plate 14 of D.

(Center conductor connection process)
In the center conductor connecting step, as shown in FIG. 6A, the center conductors 16 of the plurality of micro coaxial wires 12 are connected to the plurality of second conductive paste portions 6 in a one-to-one relationship. In the center conductor connecting step, first, the plurality of center conductors 16 and the plurality of second conductive paste portions 6 are opposed to each other in plan view. Thereafter, the plurality of second conductive paste portions 6 are melted by heating, for example, by pulse heat, and the center conductor 16 of the micro coaxial wire 12 is thermocompression bonded to each of the plurality of second conductive paste portions 6.

  The lower limit of the thermocompression bonding temperature in the central conductor connection step is preferably 120 ° C, more preferably 140 ° C. On the other hand, as an upper limit of the said thermocompression bonding temperature, 200 degreeC is preferable and 180 degreeC is more preferable. If the said thermocompression bonding temperature is less than the said minimum, there exists a possibility that the center conductor 16 and the 2nd conductive paste part 6 may not be connected correctly. On the contrary, when the said thermocompression bonding temperature exceeds the said upper limit, there exists a possibility that the adhesive bond layer 3 laminated | stacked on the other surface of the some conductor 2 may fuse | melt and may collide with the 2nd conductive paste part 6. FIG.

  The lower limit of the thermocompression bonding load in the center conductor connection step is preferably 5N, and more preferably 7N. On the other hand, the upper limit of the thermocompression bonding load is preferably 50N, and more preferably 20N. If the thermocompression bonding load is less than the lower limit, the center conductor 16 and the second conductive paste portion 6 may not be accurately connected. Conversely, if the thermocompression bonding load exceeds the upper limit, the adhesive layer 3 laminated on the other surface of the plurality of conductors 2 may melt and collide with the second conductive paste portion 6.

  The lower limit of the thermocompression bonding time in the center conductor connecting step is preferably 3 seconds, and more preferably 4 seconds. On the other hand, the upper limit of the thermocompression bonding time is preferably 8 seconds, and more preferably 7 seconds. If the said thermocompression bonding time is less than the said minimum, there exists a possibility that the center conductor 16 and the 2nd conductive paste part 6 may not be connected correctly. On the contrary, when the said thermocompression bonding time exceeds the said upper limit, there exists a possibility that the adhesive bond layer 3 laminated | stacked on the other surface of the some conductor 2 may fuse | melt and may collide with the 2nd conductive paste part 6. FIG.

(External conductor connection process)
In the external conductor connecting step, the outer surface of the other ground bar 20b of the pair of ground bars 20a and 20b is connected to the plurality of first conductive paste portions 5. In the external conductor connecting step, first, the longitudinal direction of the other ground bar 20b and the width direction of the plurality of conductors 2 are adjusted to be parallel, and then the outer surface of the ground bar 20b and the plurality of first conductive pastes. The part 5 is made to face in plan view. Thereafter, for example, the outer surface of the ground bar 20b and the plurality of first conductive paste portions 5 are thermocompression-bonded by the same method as in the central conductor connecting step. The thermocompression bonding temperature, thermocompression bonding load, and thermocompression bonding time in the external conductor connection step can be the same as the thermocompression bonding temperature, thermocompression bonding load, and thermocompression bonding time in the central conductor connection step.

(Reinforcement plate lamination process)
In the reinforcing plate laminating step, the adhesive layer 22 of the reinforcing plate 14 is laminated on the entire other surface of the flexible flat cable 1 as shown in FIG. 6B. In the reinforcing plate lamination step, the adhesive layer 22 of the reinforcing plate 14 and the other surface of the flexible flat cable 1 are thermocompression bonded.

  The thermocompression bonding temperature in the reinforcing plate lamination step can be, for example, 70 ° C. or higher and 100 ° C. or lower. The thermocompression bonding load in the reinforcing plate lamination step can be, for example, 50N or more and 100N or less. The thermocompression bonding time in the reinforcing plate lamination step can be, for example, 3 seconds or more and 10 seconds or less.

(Protective film lamination process)
In the protective film laminating step, as shown in FIG. 6C, the adhesive layer 24 of the protective film 15 is laminated from one end of the flexible flat cable 1 to an area including the other end of the connection area D. In the protective film lamination step, the adhesive layer 24 of the protective film 5 and one surface of the flexible flat cable are thermocompression bonded.

  As thermocompression-bonding temperature in the said protective film lamination process, it can be set as 70 to 100 degreeC, for example. As a thermocompression-bonding load in the said protective film lamination process, it can be set as 50 N or more and 100 N or less, for example. The thermocompression bonding time in the protective film laminating step can be, for example, 3 seconds or more and 10 seconds or less.

  Any of the reinforcing plate lamination step and the protective film lamination step may be performed first. Further, the reinforcing plate laminating step and the protective film laminating step can be simultaneously performed in one step. That is, after laminating the adhesive layer 22 of the reinforcing plate 14 on the other surface of the flexible flat cable 1 and laminating the adhesive layer 24 of the protective film 15 on one surface of the flexible flat cable 1, The flexible flat cable 1, the reinforcing plate 14, and the protective film 15 can be thermocompression bonded simultaneously. Further, the reinforcing plate laminating step may be performed before laminating the plurality of conductors 2 on one surface side of the insulating sheet 25.

<Advantages>
The wire harness manufacturing method can easily and reliably manufacture the wire harness capable of promoting cost reduction.

[Other Embodiments]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configuration of the embodiment described above, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  For example, the flexible flat cable only needs to expose one surface of the plurality of conductors at least on one end side, and does not need to expose the entire surface of one surface of the plurality of conductors. The flexible flat cable can be electrically connected to the plurality of fine coaxial cables as long as one surface side of the plurality of conductors is exposed in the connection region D connected to the plurality of fine coaxial cables.

  In the first conductive paste portion forming region and the second conductive paste forming region, the back surfaces of the plurality of conductors do not necessarily have to be exposed. The flexible flat cable electrically connects the plurality of conductors and the micro coaxial cable even when the back surfaces of the plurality of conductors are not exposed in the first conductive paste portion forming region and the second conductive paste portion forming region. It is laminated on the other surface of the plurality of conductors by adjusting the temperature and the amount of lamination of the first conductive paste portion and the second conductive paste portion laminated on one surface side of the plurality of conductors. It is possible to prevent the adhesive layer from colliding with the first conductive paste portion and the second conductive paste portion. Thereby, while shortly connecting a plurality of conductors and a micro coaxial line, a short circuit between a plurality of conductors can be prevented.

  Further, it is not necessary to remove the adhesive layer and the insulating layer laminated on the other surface of the conductor in the entire region of the first conductive paste portion forming region and the second conductive paste forming region. Only the region including the conductive paste portion and the second conductive paste portion in plan view may be removed. Furthermore, in the first conductive paste portion formation region and the second conductive paste portion formation region, only the adhesive layer is removed, and the insulating layer may not be removed.

  The first conductive paste portion and the second conductive paste portion are not necessarily formed in a substantially rectangular shape in plan view, and may be, for example, a polygonal shape or an elliptical shape.

  The flexible flat cable does not necessarily need to tear all the remaining conductors leaving only one conductor, and may be broken leaving two or more conductors as necessary. Moreover, the conductor which is not torn does not necessarily need to be one conductor of the width direction one side among several conductors. In the flexible flat cable, for example, the conductor at the center in the width direction among the plurality of conductors may not be torn, and the plurality of conductors disposed on both sides of the conductor may be torn.

  In the flexible flat cable, the adhesive layer and the insulating layer laminated on the other surface of the plurality of wiring conductors do not necessarily have to be torn in the torn region. That is, in the flexible flat cable, for example, only a plurality of wiring conductors may be torn in a tearing region, or only a plurality of wiring conductors and an adhesive layer may be torn. However, the tearing region can be easily formed by tearing the adhesive layer and the insulating layer together with the plurality of wiring conductors.

  The wire harness does not necessarily have a reinforcing plate and a protective film. Further, even if the wire harness has a reinforcing plate, the reinforcing plate does not need to be laminated on the other surface side of the flexible flat cable, and one of the flexible flat cables is covered so as to cover the connection region. It may be laminated on the surface side. Furthermore, the said protective film may be laminated | stacked on the other surface side of the said flexible flat cable.

  Moreover, as long as the said reinforcement board and protective film are laminated | stacked at least on the connection area | region D, it is not necessary to be laminated | stacked on parts other than the connection area | region D. FIG.

  As described above, the flexible flat cable of the present invention can promote cost reduction, and thus is suitable as a connection terminal for a wire harness. Moreover, the manufacturing method of the flexible flat cable of this invention is suitable as the said flexible flat cable manufacturing method suitable as a connection terminal.

1 Flexible flat cable for wiring harness connection (Flexible flat cable)
2, 2a, 2b Conductor 3 Adhesive layer 4 Insulating layer 5 First conductive paste part 6 Second conductive paste part 11 Wire harness 12 Micro coaxial cable 13 Connection terminal 14 Reinforcement plate 15 Protective film 16 Central conductor 17 Insulating layer 18 External conductor layer 19 Jacket 20a, 20b Ground bar 21 Reinforcing sheet 22 Adhesive layer 23 Cover film 24 Adhesive layer 25 Insulating sheet A Rupture region B First conductive paste portion formation region C Second conductive paste portion formation region D Connection area

Claims (8)

A flexible flat cable that is arranged in a stripe shape and includes a plurality of conductors exposed at least on one surface side in one end region, and electrically connects the ends of a wire harness composed of a plurality of micro coaxial wires,
A region along the width direction except for at least one conductor among the plurality of conductors in the one end side region is torn,
A plurality of first conductive paste portions laminated so as to be arranged along the width direction on one surface side of the plurality of conductors and on one end side from the tear region;
A wire harness comprising: a plurality of second conductive paste portions stacked so as to be arranged along the width direction on one surface side of the conductor that is torn among the plurality of conductors and on the other end side from the torn region. Flexible flat cable for connection.   The flexible flat cable for connecting a wire harness according to claim 1, wherein the first conductive paste portion and the second conductive paste portion are formed of a solder paste.   The wire harness connection according to claim 1 or 2, wherein the other surface side of the plurality of conductors is also exposed in the first conductive paste portion forming region and the second conductive paste portion forming region in the width direction. Flexible flat cable for use.   The flexible flat cable for connecting a wire harness according to claim 1, wherein the conductor that is not torn among the plurality of conductors is one conductor on one side in the width direction. A wire harness comprising a plurality of fine coaxial wires, and having a connection terminal at an end of these fine coaxial wires,
The flexible flat cable for connecting a wire harness according to any one of claims 1 to 4 is used as the connection terminal.
The plurality of ultrafine coaxial wires are aligned in a single plane and stripe shape, the central conductor is exposed in the tip region along the width direction, and the outer conductor layer is exposed in the intermediate region on the rear end side from the tip region. And
Center conductors of the plurality of fine coaxial wires are connected in a one-to-one relationship to the plurality of second conductive paste portions of the flexible flat cable,
A wire harness in which the plurality of first conductive paste portions of the flexible flat cable are connected to each other through a single ground bar in which the outer conductor layers of the plurality of fine coaxial wires are arranged in the width direction.   The wire harness according to claim 5, further comprising a reinforcing plate laminated at least in a connection region of the flexible flat cable.   The wire harness according to claim 6, further comprising a protective film laminated at least on the side opposite to the reinforcing plate in the connection region of the flexible flat cable. A method for producing a flexible flat cable, comprising a plurality of conductors arranged in a stripe shape and having at least one surface exposed in one end side region, and electrically connecting the ends of a wire harness composed of a plurality of fine coaxial wires. And
Cutting the region along the width direction excluding at least one conductor among the plurality of conductors in the one end side region;
Laminating a plurality of first conductive paste portions so as to be arranged along the width direction on one surface side of the plurality of conductors and on one end side from the tearing region;
Laminating a plurality of second conductive paste portions so as to be arranged along the width direction on one surface side of the conductor that is torn among the plurality of conductors and on the other end side from the torn region. Manufacturing method of flexible flat cable for harness connection.

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