JPH11297388A - Connection structure between film circuit and flat cable or electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film circuit suitable for a seating sensor mounted on an automobile seat, which can be manufactured at low cost because it is thin, excellent in waterproofness, and easy to automate the manufacturing process. To provide a connection structure between the cable and a flat cable or an electric wire. SOLUTION: A region including a superposed portion G of connection terminals 5 and 5 of a film circuit B and conductor terminals 9 and 9 of a flat cable F is covered with insulating films 10 and 10, and the region and the insulating films 10 and 10 are covered. 10 is thermally fused to form an integrated structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure between a film circuit and a flat cable or between a film circuit and an electric wire, and more particularly, to a film circuit and a flat cable which are effective when applied to, for example, a seating sensor mounted on an automobile seat. The present invention relates to a connection structure between a cable or a film circuit and an electric wire.

[0002]

^2. Description of the Related Art A seating sensor mounted on a vehicle seat is composed of a flat film circuit and a signal wire having a conductor cross section of 0.3 to 0.5 cm ² , and a connection terminal of the film circuit and a connection terminal of the signal wire. Are electrically connected. Here, a general method of manufacturing a film circuit will be described. First, a circuit pattern having a plurality of circular switch portions and one drawer circuit line extending to a connection terminal of the film circuit by connecting a plurality of circular switch portions to each other using Ag paste is printed on one surface of a predetermined insulating film, Further, a carbon coating is applied thereon to prevent migration of the Ag to form one conductive circuit.

On the other hand, a circuit pattern of an Ag paste is similarly printed on one surface of another insulating film, and then a carbon coating is applied thereto to form another conductive circuit.
Then, the two films are aligned with the conductor circuits facing each other and an electrically insulating film spacer is interposed therebetween, and the whole is adhered with an adhesive.
The spacer used at this time has a smaller circular gap than the circular switch portion in each conductor circuit, and a portion corresponding to the lead portion of the conductor circuit is shorter than the lead portion.

Therefore, in the switch section of the manufactured film circuit, as shown in FIG. 20, a conductor circuit 2 composed of an Ag paste layer 2a and a carbon layer 2b formed on one surface of each of the insulating films 1 and 1 is formed. Has a cross-sectional structure sandwiched by an adhesive 4 via a film spacer 3 having a circular space 3a. When the pressing force is not applied to the switch portion, the conductor circuits 2 of the film circuits manufactured in this manner are not in contact with each other due to the action of the spacer 3 and are in an off state, but the pressing force is applied. And the conductor circuits 2 contact each other at the circular gap 3a of the spacer 3 to be turned on.

On the other hand, the connection terminal of the film circuit is shown in FIG.
As shown in the figure, a pair of tongue pieces 5 and 5 in which a conductor circuit (drawer circuit) 2 having a laminated structure of an Ag paste layer 2a and a carbon layer 2b is formed on one surface of the insulating film 1 are provided. The tongues 5, 5 are flexible and project from the end of the film circuit in a stepwise manner. In addition, as an insulating film of the above-described film circuit, a polyethylene naphthalate (PEN) or polyethylene terephthalate (PET) film or the like has been widely used, but polyethylene (PE), polypropylene (PP), and polyamide (PA) have been conventionally used. ), Polyimide (PI),
Polyetherimide (PEI) and polyetherketone (PEEK) films have also been used.

A conventional seat sensor is manufactured by connecting the connection terminals 5 and 5 of the film circuit and the conductor terminals of the electric wire. In this case, since the surface of the connection terminal of the film circuit is coated with carbon, and the melting temperature of the insulating film is about 250 to 300 ° C., connection using solder cannot be performed. Therefore, normally, a pair of connection terminals of the film circuit and the conductor terminals of the corresponding electric wires are respectively connected using two terminal connection jigs A manufactured by AMP having a structure as shown in FIG. 23, for example.

More specifically, a conductor end of an electric wire is inserted into one end A2 of the jig A, crimped and electrically connected, and then the flat end of the film circuit is connected from the other end A1 of the jig A. Is inserted into the holding portion A3 of the spring structure located at the center, and then crimping is performed to mechanically connect and fix the terminal. Next, as shown in FIG. 22, the connection part D formed by connecting the connection terminal of the film circuit B and the conductor terminal of the electric wire C with the jig A is fixed using the terminal fixing plate D1, and the lid 7a is fixed. The container 7b is arranged and fixed on the gel 6 of the storage box 7 in which the electrically insulating gel 6 is provided. Then, the lid 7a is closed, and the lid 7a and the container 7b are locked by the pair of lock mechanisms 8a and 8b, so that the connection portion D is sealed in the storage box 7, and the entire connection structure is assembled. The connecting portion A is made of a soft gel-like material 6.
In this state, the insulation is ensured, and even if an external force is applied, the gel-like material 6 absorbs the external force, and the connection state of the two terminals at the connection portion D is maintained. It will also provide a great waterproof effect.

[0008]

Although it is true that the connection structure shown in FIG. 22 has the above advantages, it also has the following problems. First, although the thickness of the ordinary film circuit B is about 0.3 to 0.5 mm and the conductor cross section of the electric wire C is about 0.3 to 0.5 cm ² , The thickness of the storage box 7 for storing
That is, it is quite thick, about 10 mm. Therefore, when this is mounted on a seat, it is necessary to cut off the seat portion where the storage box 7 is arranged and to place the storage box 7 there in order to remove the discomfort of the passenger. come.

When assembling the connection structure shown in FIG. 22, an operation of providing an appropriate amount of the gel-like material 6 in the lid 7a or the container 7b, or an operation of arranging the connection portion D and then closing the lid 7a to assemble the connection structure. And so on, and there is a problem that automation of these operations is considerably difficult. for that reason,
The productivity associated with assembling the connection structure is reduced, and as a result, it is difficult to reduce the manufacturing cost.

Furthermore, the terminal fixing plate D1, the gel-like material 6, the storage box 7 and the like are relatively expensive, and this also inevitably increases the manufacturing cost of the connection structure.
On the other hand, the connection portion D is wrapped in the gel-like material 6 and thus has an appropriate waterproof effect. However, under severe conditions (for example, in hot water or in a high-temperature and high-humidity atmosphere), the waterproof effect is limited, and There is a possibility that the insulating property in the portion D is reduced.

When the bending stress is repeatedly applied to the periphery of the storage box 7, the bending stress concentrates on a connection portion between the storage box 7 and the electric wire C, and the electric wire C may be disconnected therefrom. Furthermore, since the connection terminal of the film circuit B is soft, the crimping of the terminal jig A cannot be made too strong, and when a tensile stress is applied between the film circuit B and the electric wire, the film circuit B May come off from the jig A.

The present invention can solve all of the above-mentioned problems of the connection structure in the seating sensor shown in FIG. 22, and the overall thickness is extremely thin as compared with the conventional one, and the reliability regarding waterproofness is extremely high. It has high connection strength (tensile properties) and excellent flexibility in connection (durability against repeated bending), and can be manufactured inexpensively under high productivity because the manufacturing process can be automated. It is an object of the present invention to provide a connection structure between a film circuit and a flat cable or an electric wire, and a connection structure between film circuits or flat cables.

[0013]

In order to achieve the above object, according to the present invention, an area including an overlapping portion of a connection terminal of a film circuit and a conductor terminal of a flat cable is formed of an insulating film. Wherein the region and the insulating film are heat-sealed to form an integrated structure.

According to a second aspect of the present invention, in the overlapping portion, a conductive film is interposed between a connection terminal of the film circuit and a conductor terminal of the flat cable. A cable connection structure is provided. According to a third aspect of the present invention, there is provided a connection structure between a film circuit and a flat cable, wherein the conductive film is interposed in an area of 4/5 to 1/5 of an area of the overlapping portion. Is done.

According to a fourth aspect of the present invention, there is provided a connection structure between a film circuit and a flat cable, wherein a narrow groove is formed in a longitudinal direction of a connection terminal and / or a conductor terminal. According to a fifth aspect of the present invention, there is provided a connection structure between a film circuit and a flat cable, wherein a region including an overlapping portion is covered with a self-fusing tape.

According to a sixth aspect of the present invention, the outside of the insulating film is covered with a self-sealing tape, and the insulating film and the self-sealing tape are fused and integrated. And a flat cable connection structure are provided. According to the present invention, a through-hole is formed in the surface of the film circuit or / and the flat cable excluding the connection terminal and the conductor terminal in the area covered with the insulating film or the self-fusing tape. And a connection structure between the film circuit and the flat cable.

In the present invention according to claim 8, in the connection structure according to any one of claims 1 to 7, instead of connecting the connection terminal of the film circuit to the conductor terminal of the flat cable, the connection structure of the film circuit is replaced with the connection terminal. A connection structure between a film circuit and a film circuit, or a flat cable and a flat cable, wherein connection terminals are connected to each other or conductor terminals of a flat cable are connected to each other.

According to the ninth aspect of the present invention, a connection portion is formed by connecting a connection end of the film circuit and a conductor end of the electric wire with a terminal jig, and a region including the connection portion is covered with an insulating film; Further, there is provided a connection structure between a film circuit and an electric wire, wherein the region and the insulating film are heat-sealed to form an integrated structure. According to a tenth aspect of the present invention, there is provided a connection structure between a film circuit and an electric wire, wherein a region including the connection portion is covered with a self-fusing tape.

According to the eleventh aspect of the present invention, the outside of the insulating film is covered with a self-sealing tape, and the insulating film and the self-sealing tape are fused and integrated. And an electric wire connection structure are provided.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The connection structure of the present invention will be described below in detail with reference to the drawings. First, FIG. 1 is a partially cutaway perspective view showing a basic structure E of the connection structure of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II of FIG. In FIGS. 1 and 2, a pair of tongue-shaped connection terminals as shown in FIG. 21 having a laminated structure of an Ag paste layer 2a and a carbon layer 2b on the surface of an insulating film 1 are provided at the end of a film circuit B. 5, 5 are formed. And these connection terminals 5,
The surface on the carbon coating side of No. 5 is in contact with the surfaces of the pair of conductor terminals 9 and 9 exposed from the ends of the flat cable F, thereby forming a superimposed portion G indicated by a broken line in FIG. Has been taken.

A region including the overlapping portion G,
Specifically, insulating films 10 and 10 are disposed on the upper and lower surfaces of a region including the surface portion of the film circuit B and the flat cable F over the overlapping portion G, and cover the region in a liquid-tight state. I have. Examples of the insulating film 10 used at this time include a PET film, a PE film, a PP film, a PA film, a PEI film, a PI film, a PEEK film, a PAI film, and a polyphenylene sulfide (PPS) film. Particularly, a PET film is preferable.

In this connection structure E, after the overlap portion G shown in the figure is formed by the connection terminal 5 of the film circuit B and the conductor terminal 9 of the flat cable F, the width including the overlap portion G on the upper surface and the lower surface is formed. For example, an insulating film having an adhesive layer on one side is arranged, and then the insulating film is adhered. As the adhesive layer, for example, a polyolefin-based, polyester-based, or polyamide-based hot melt adhesive may be used. Particularly, from the viewpoint of heat resistance, a polyester-based adhesive is preferable. Further, a known flame retardant may be added to the above-mentioned adhesive for imparting flame retardancy, or an adhesive containing a concealing agent (titanium oxide or the like) for imparting a concealing effect may be used.

As described above, the insulating films may be adhered to each other using an insulating film in which an adhesive layer is formed on one surface in advance, but the present invention is not limited to this. The insulating films may be adhered to each other by interposing a film having an adhesive layer on both surfaces between the insulating films. In any case, when the insulating film of the present invention is arranged so as to face the connection structure, it is necessary that the adhesive layer is interposed between the insulating films.

At the time of sticking, for example, at a temperature of 10
0 to 300 ° C, preferably 120 to 150 ° C, pressure 1 to 3
0 kgf / cm ^2, preferably at 8~12kgf / cm ² 5~180
Seconds, preferably 5 to 20 seconds hot pressing, the contact state between the connection end of the film circuit and the conductor end face of the flat cable becomes good, and the conduction is stabilized, and when the insulating film 10 is a PET film, it is different from that. Since the insulating film 1 or the PET film 10 of the film circuit B and the insulating coating of the flat cable F are integrated by heat fusion, the waterproof property and the connection strength are improved, which is preferable.

FIG. 3 is a sectional view showing another connection structure H of the present invention. This connection structure H has the same structure as that of the connection structure E except that the conductive film 11 is interposed between the connection terminal 5 of the film circuit and the conductor terminal 9 of the flat cable in the overlapping portion G. It has the same structure. In the case of this connection structure H, since the conductive film 11 is interposed in pressure contact with both terminals, the contact resistance between both terminals is reduced, and the stabilization of conduction can be realized.

As the conductive film having such a function, for example, a thermocompression-bondable anisotropic conductive film ZAF (trade name) series commercially available from Sumitomo 3M Ltd. is suitable. Note that there is no inconvenience even when various conductive adhesives are applied between both terminals. When this connection structure H is manufactured, as shown in FIG. 4, a conductive film 11 having a predetermined size and shape is provided between the connection terminals 5 and 5 of the film circuit B and the conductor terminals 9 and 9 of the flat cable F. , 11 are arranged to form a superimposed portion G, and the insulating films 10, 10 having an adhesive layer on the upper and lower surfaces thereof are arranged.

Here, an epoxy-based thermosetting adhesive is used as a main material of the conductive film 11, and the conductive film 11 is cured by thermocompression bonding to establish an electrical connection between the connection terminal 5 and the conductor terminal 9. It is designed to be stable and reliable. However, in this case, the hard conductive film 11 is interposed between the flexible film circuit B and the flat cable F, and when the bending stress is repeatedly applied to the overlapping portion G,
Cracks and cracks may occur in the conductive film 11 and contact failure or conduction failure may occur in a short period of time.

Therefore, the area where the conductive film 11 is interposed is
It is better to make it as small as possible so that the above-mentioned cracks and cracks do not occur.
/ 5 is preferable. If the area where the conductive film 11 is interposed exceeds 4/5 of the area of the overlapping portion G, the cracks and cracks are likely to occur.
If it is less than the above, a conduction failure may occur between the film circuit B and the flat cable F. Note that the area of the overlapping portion G refers to the area of the overlapping portion of the connection terminal 5 and the conductor terminal 9.

FIG. 5 shows a connection structure M of the present invention in which the conductive film 11 is interposed in a part of the overlapping portion G. In this case, for example, when the width of the connection terminal 5 is 3.0 mm, the conductive film ZAF (trade name, tape width 2.5 mm) is changed to the length 3.
If cut to 0 mm and affixed to the connection terminal 5 (the interposed area becomes about 7.5 mm ² ), the cut length of the tape can be made to match the width of the connection terminal 5 and the tape width can be reduced. Since it can be used without processing, it is advantageous in terms of automation of the manufacturing process. Further, since the tape may be attached to a part of the overlapping portion G, the amount of the tape used can be reduced, which is advantageous in cost.

It is preferable that a narrow groove 15 is formed in the longitudinal direction of the connection terminal 5 or the conductor terminal 9. In general, the adhesive strength of the conductive film 11 is not sufficient. For example, a pre-process in which the conductive film 11 is interposed in the overlapping portion G of the connection terminal 5 and the conductor terminal 9 and an insulating film having an adhesive layer in the overlapping portion G When the post-process for covering the film 10 is divided, the conductive film 11 may be peeled off while the conductive film 11 bonded and thermo-compressed in the previous process is transported to the post-process. For this reason, it is necessary to perform the above pre-process and post-process in one process, and there is a possibility that the arrangement of manufacturing facilities is limited.

When the narrow groove 15 is formed in the connection terminal 5 or the conductor terminal 9, when the conductive film 11 is thermocompression-bonded,
Is melted and thermally cured after flowing into the narrow groove 15, so that the adhesive strength of the conductive film 11 is improved by the anchor effect.
Therefore, it is possible to divide the pre-process and the post-process, and it is possible to improve the production efficiency without being restricted by the manufacturing process and the like.

FIG. 6 shows a state in which the conductive film 11 is adhered to the connection terminal 5 in which the narrow groove 15 is formed, and FIG.
It shows a cross-sectional view along the line II. In order to form the narrow groove 15, the Ag paste layer 2a,
What is necessary is just to print the laminated structure pattern consisting of the carbon layer 2b in a comb shape. In forming the connection structure H shown in FIG. 3, if the connection between the connection terminal 5 of the film circuit and the conductor terminal 9 of the flat cable is performed in a manner described later, the connection strength can be increased. It is suitable.

First, in the first embodiment, as shown in FIG. 8, the length of the connection terminals 5 and 5 is made longer than the distance to the end of the flat cable F, and the length of the conductor terminals 9 and 9 is increased. In this embodiment, the length of each conductive film is longer than the distance to the end of the film circuit B, and conductive films 11 and 11 having a length substantially equal to the length of the connection terminal or the conductor terminal are arranged between the terminals. . In the case of the connection structure obtained in this manner, each terminal 5, 9
Are overlapped on the surface of the flat cable F and the surface of the film circuit B, thereby increasing the connection strength. Note that FIG. 8 shows an example in which both ends of both ends overlap the surface of the mating member.
5 overlaps the flat cable F, conversely, the two conductor terminals 9 overlap the film circuit, and one connection terminal 5 overlaps the flat cable F,
Even when one conductor terminal 9 overlaps the film circuit, it is effective in improving the connection strength.

In the second mode, as shown in FIG. 9, a notch 12 having a desired length is formed at the center of the width of the flat cable F.
Is formed, and the insulating film near the base end portion of the cut 12 is partially peeled to expose the conductor 9 on the front and back (the conductor on the back side is not shown). After inserting the locations as indicated by the arrows in the figure, the connection terminals 5 and 5 and the above-described exposed conductors 9 and 9 are overlapped via the conductive films 11 and 11 to form an overlapped portion. The structure is such that an insulating film (not shown) having an adhesive layer is heat-sealed to the upper and lower surfaces.

In this connection structure, the overlapping portion (connection portion) of both terminals is formed near the base end of the cut, the overlapping area of the film circuit B and the flat cable F is large, and the conductor terminal 9 is Since the surface other than the exposed surface is secured with an insulating film, the connection structure is strong against bending and twisting. In the third mode, as shown in FIG. 10, a notch 12 having a desired length is formed at the center of the width of the flat cable F, and the outer insulating film is peeled off while leaving the insulating film at the distal end, and the conductor terminal is removed. 9,9
Is exposed, and the center of the width of the film circuit B is inserted into the cut 12 as shown in the figure, and the connection terminals 5 and 5 of the film circuit B are exposed via the conductive films 11 and 11. , 9 are connected. In this case, the tip of the conductor terminal (the portion where the insulating film remains)
Is connected to the front and back surfaces of the film circuit B, so that the connection strength is increased.

In the fourth embodiment, as shown in FIG. 11, only one of the insulating films of the flat cable F, which is to be connected to the connection terminals 5 and 5 of the film circuit, is peeled off to remove one of the conductors 9. Is exposed, and there is a conductive film 1 there.
In this embodiment, connection terminals 5 and 5 of the film circuit are connected via the terminals 1 and 11. Also in this case, since the other portions of the conductor 9 are secured by the insulating film, the connection strength of the formed connection structure is increased.

At this time, the length of the connection terminals 5 and 5 of the film circuit is increased, and the connection ends are superimposed on the insulation film of the flat cable F as shown in FIG. The connection strength is further improved by increasing the peeling length of the conductor and superposing the exposed long conductor surface on the film circuit. FIG. 12 shows another connection structure I. In this connection structure I, an overlapping portion G is formed by interposing a conductive film 11 between the connection terminal 5 of the film circuit and the conductor terminal 9 of the flat cable, and the overlapping portion G is formed.
Is covered with a self-fusing tape 13, and the outside thereof is further covered with an insulating film 10 having an adhesive layer. This structure can also be manufactured by arranging the self-fusing tape 13 on the upper and lower surfaces of the region including the overlapping portion G, further arranging the insulating film 10 thereon, and then thermocompression bonding the whole.

In the case of the connection structure I, since the self-fusing tape having excellent adhesiveness acts to secure the sealing property with respect to the overlapped portion G, almost complete waterproofness can be obtained. Preferred examples of the self-bonding tape having such a function include F-co tape (trade name) series, C tape (trade name) and Barco tape (trade name) marketed by Furukawa Electric Co., Ltd. Can be.

FIG. 13 shows still another connection structure J.
This connection structure J is obtained by covering the outside of the connection structure I shown in FIG. 3 with a self-sealing tape 13 in a liquid-tight manner, and also exhibits excellent waterproofness in this case. FIG. 14 is a plan view showing another connection structure K of the present invention. The connection structure K has an insulating film 10 that covers the outside and has an adhesive layer, and four corners at both ends of a self-fusing tape that are curved. This is preferable because, when the connection structure is actually used, even if a stress that causes bending or torsion is applied, the overlapping portion G of both ends is hardly damaged. That is, the connection strength increases.

FIGS. 15 and 16 show still another connection structure L. FIG. This connection structure L is a connection structure in a case where the film circuit B has a multi-pole structure and the conductor of the flat cable F has a large number of conductors corresponding thereto. In the case of this connection structure, as shown in FIG. 15, on one surface of the film circuit B, a plurality of connection terminals (14 in FIG. 15) 5a are exposed at locations slightly recessed from the ends, and the back surface of the film circuit B is exposed. A plurality of connection terminals 5b are exposed at the end. Then, the conductor terminal 9a of one flat cable F1 is superimposed on the connection terminal 5a on the surface via the anisotropic conductive film 11, and
Also, the connection terminal 5b on the back side has the anisotropic conductive film 11 similarly.
The conductor terminal 9b of the other flat cable F2 is superimposed via.

Then, as shown in FIG. 16, the upper and lower surfaces including the overlapped portion G have curved surfaces at the four corners at both ends as shown in FIG. Are arranged and the whole is thermo-compressed. Here, in these connection structures, the surface portions (excluding the connection terminal 5 and the conductor terminal 9) of the film circuit B and the flat cable F in the region covered with the insulating film 10 and the self-fusion tape 13 are: Preferably, a through hole is provided.

In general, the adhesive strength between the film circuit B or the flat cable F and the insulating film 10 or the self-bonding tape 13 is not so strong. The film circuit B may come off. Therefore, after a through hole is formed in the surface portion of the film circuit B or the flat cable F, the region including the overlapping portion G is formed in the insulating film 10.
And the self-fusing tape 13, the insulating films 10, 10 or the self-fusing tapes 13, 13 disposed on the upper surface and the lower surface of the overlapping portion G are firmly adhered to each other through the through holes, and this portion is wedged. Since an effect is produced, even when the film circuit B is pulled, for example, the overlapping portion G
From the film circuit B is less likely to occur.

FIG. 17 shows a connection structure N in which a through hole 17 is formed in the surface portion of the film circuit B, and FIG.
2 is a sectional view taken along line XVIII-XVIII of FIG. FIG.
At 18, the connection structure N is formed in the same manner as the connection structure I by covering the region including the overlapping portion G with the self-fusing tape 13, and further covering the insulating film 10 having an adhesive layer thereon. Can be done. In this case, the through-hole 17 is on the surface of the film circuit B, outside the area covered with the self-fusing tape 13 and on the insulating film 10.
The insulating films 10 are bonded to each other at the interface 10 a through the through holes 17.

The through hole 17 may be formed in any surface portion of the film circuit B or the flat cable F except for the connection terminal 5 and the conductor terminal 9, or may be formed in both. There is no particular limitation on the positions where the holes are formed, except for the connection terminals 5 and the conductor terminals 9.
What is necessary is that it is formed at a position where the members 3 and 13 can be bonded to each other through the through-hole 17. Further, the number of the through holes 17 is not particularly limited.

In the connection structure of the present invention described above, the connection structure between the film circuit and the flat cable has been described. However, the film circuit and the electric wire can be connected in the same manner. FIG. 19 shows a connection structure Q when a film circuit and an electric wire are connected. This connection structure Q is different from the flat cable F in that the electric wire C is used instead of the flat cable F.
It has the same configuration as the connection structure of the present invention described above.
That is, by mechanically connecting the connection terminal 5 of the film circuit B and the conductor terminal 18 of the electric wire C with the terminal jig 19, the connection portion P
Is formed, and the terminal fixing plate 21 is arranged and fixed on the lower surface of the connection portion P, and thereafter, the film circuit B and the electric wire C extend over the region including the connection portion P, specifically, the connection portion P. Insulating films 10 and 10 having an adhesive layer on the upper and lower surfaces of a region including the surface portion are heat-sealed.

The terminal jig 19 is not particularly limited as long as it can conduct with the film circuit B and the electric wire C. For example, the same jig as the conventional jig A can be used. . These terminal jigs 19 are electrically connected to the film circuit B or the electric wire C by, for example, crimping. As the terminal fixing plate 21,
For example, a conventionally used terminal fixing plate D1 shown in FIG. 22 or a shape shown in FIG. 19 can be used.

Next, FCO tape (trade name, Furukawa Electric Co., Ltd.)
), A jig A, and a terminal fixing plate were used to assemble the connection structure Q, and its evaluation was performed. In addition, what connected the connection part P using only the insulating film was referred to as connection structure I,
The connection portion P was covered with a self-fusing tape and then covered with an insulating film, and the connection structure II was formed. The connection portion P was covered with an insulating film and covered with a self-fusing tape was formed as a connection structure III. The conventional connection structure shown in FIG. 22 was used for comparison.

For the evaluation of waterproofness, the sample was immersed in hot water at 80 ° C. for 400 hours, and the insulation resistance between terminals of the film circuit was measured. The humidity resistance and the migration resistance were evaluated by applying a voltage of 16 V between the terminals of the film circuit.
After 1000 hours in a constant temperature / humidity chamber in a temperature-85% RH atmosphere, the insulation resistance between terminals of the film circuit was measured. For the connection strength, the tensile strength of the connection part P between the film circuit and the electric wire was determined. Flexibility was evaluated by attaching each sample to a seat cushion with double-sided tape, and the tip was 6 mm in diameter from above.
Was repeatedly pressed against the connecting portion P at a load of 19.2 N at a rate of 35 times / min, and the number of times until the disconnection occurred at the connecting portion P was measured.

The test was completed when the conventional connection structure was immersed in hot water at 80 ° C. for 40 hours. Table 1 shows the above results.

[0050]

[Table 1]

From Table 1, it can be seen that the connection structure of the present invention has better water resistance, moisture resistance and migration resistance, connection strength, and flexibility than the conventional connection structure. In the connection structure of the present invention described above, the connection terminal 5 of the film circuit B and the conductor terminal 9 of the flat cable F, or the connection terminal 5 of the film circuit B and the conductor terminal 18 of the electric wire C are connected. However, if the connection structure of the present invention is applied, it is possible to connect the connection terminals 5 and 5 of the film circuit B or the conductor terminals 9 and 9 of the flat cable F.
The present invention includes such a connection structure.

[0052]

As is clear from the above description, the connection structure of the present invention uses a flat cable or an electric wire as a signal electric wire, and the connection between the film circuit and the flat cable or the connection portion between the film circuit and the electric wire at both ends. Since it is formed by thermocompression bonding of a thin film, it is extremely thin as a whole.

Further, since the connection between the two terminals can be made by laminating the film-like materials and thermocompression bonding of the portions, it is easy to automate the entire manufacturing process, and as a result, the cost is reduced with high productivity. In addition, it is possible to manufacture automobiles that are expected to have a mass production effect because they have excellent flexibility (durability against repeated bending) and connection strength (tensile properties) of the connection part, which indicates the reliability of the connection part. Its industrial value as a connection structure applied to a seating sensor is great.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a basic structure E of a connection structure of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG.

FIG. 3 is a sectional view showing another connection structure H;

FIG. 4 is a schematic perspective view for explaining a method of manufacturing the connection structure H.

FIG. 5 is a schematic perspective view for explaining assembly of still another connection structure M.

FIG. 6 is a partially enlarged view showing a state where a conductive film 11 is attached to the connection terminal 5.

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

FIG. 8 is a schematic perspective view showing a modified example of the overlapping portion in the connection structure I.

FIG. 9 is a schematic perspective view showing another modification of the overlapping portion in the connection structure I.

FIG. 10 is a schematic perspective view showing another modified example of the overlapping portion in the connection structure I.

FIG. 11 is a schematic perspective view showing still another modified example of the overlapping portion in the connection structure I.

FIG. 12 is a sectional view showing still another connection structure I.

FIG. 13 is a sectional view showing still another connection structure J.

FIG. 14 is a plan view showing another connection structure K of the present invention.

FIG. 15 is a schematic perspective view for explaining assembly of another connection structure L of the present invention.

FIG. 16 is a perspective view showing a state in which an insulating film is arranged on an overlapping portion when assembling the connection structure L.

FIG. 17 is a schematic perspective view for explaining assembly of still another connection structure N of the present invention.

FIG. 18 is a sectional view taken along the line XVIII-XVIII in FIG. 17;

FIG. 19 is a schematic perspective view for explaining assembly of another connection structure Q of the present invention.

FIG. 20 is a cross-sectional view illustrating a cross-sectional structure of a switch unit in the film circuit.

FIG. 21 is a perspective view showing a connection terminal of the film circuit.

FIG. 22 is a perspective view showing a connection structure in a conventional seat sensor.

FIG. 23 is a perspective view of a jig conventionally used for connecting connection terminals of a film circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Insulating film of film circuit B 2a Ag paste layer 2b Carbon coating layer 3 Film spacer 4 Adhesive 5 Connection terminal of film circuit B 9 Conductor terminal of flat cable F 10 Insulating film 11 Conductive film 12 Cut into flat cable F 13 Self Fusing tape 15 Narrow groove 17 Through hole 18 Conductor terminal of electric wire C 19 Terminal jig 21 Terminal fixing plate G Overlap portion of connection terminal 5 and conductor terminal 9 P Connection portion of connection terminal 5 and conductor terminal 18 B Film circuit C Electric wire F, F1, F2 Flat cable

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kyosuke Hashimoto, Inventor 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. No. Furukawa Electric Co., Ltd.

Claims (11)

[Claims] 1. A region including an overlapping portion of a connection terminal of a film circuit and a conductor terminal of a flat cable is covered with an insulating film, and the region and the insulating film are thermally fused to form an integrated structure. A connection structure between a film circuit and a flat cable. 2. The connection structure between a film circuit and a flat cable according to claim 1, wherein a conductive film is interposed between a connection terminal of the film circuit and a conductor terminal of the flat cable in the overlapping portion. . 3. The connection structure between a film circuit and a flat cable according to claim 2, wherein the conductive film is interposed in an area of 4/5 to 1/5 of an area of the overlapping portion. 4. The connection structure between a film circuit and a flat cable according to claim 1, wherein a narrow groove is formed in a longitudinal direction of the connection terminal and / or the conductor terminal. 5. The connection structure between a film circuit and a flat cable according to claim 1, wherein a region including the overlapping portion is covered with a self-fusing tape. 6. The film according to claim 1, wherein the outside of the insulating film is covered with a self-sealing tape, and the insulating film and the self-sealing tape are fused and integrated. Connection structure between circuit and flat cable. 7. A through hole is formed in a surface of the film circuit and / or the flat cable except for the connection terminal and the conductor terminal in a region covered with the insulating film or the self-fusing tape. A connection structure between a film circuit and a flat cable according to any one of claims 1 to 6. 8. The connection structure according to claim 1, wherein the connection terminal of the film circuit and the conductor terminal of the flat cable are connected instead of connecting the connection terminal of the film circuit or the conductor of the flat cable. Film circuit and film circuit, characterized by connecting terminals,
Or connection structure of flat cable and flat cable. 9. A connection portion is formed by connecting a connection end of a film circuit and a conductor end of an electric wire with a terminal jig, a region including the connection portion is covered with an insulating film, and the region and the insulating film are connected to each other. Is a connection structure between a film circuit and an electric wire, which is integrated by heat fusion. 10. The structure for connecting a film circuit and an electric wire according to claim 9, wherein a region including the connection portion is covered with a self-fusing tape. 11. The connection between a film circuit and an electric wire according to claim 9, wherein the outside of the insulating film is covered with a self-sealing tape, and the insulating film and the self-sealing tape are fused and integrated. Construction.