JP2009211979A - Method of manufacturing flat cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a flat cable in which adhesiveness of reinforcing material to insulating resin film is improved. <P>SOLUTION: The flat cable 1 is configured such that on both sides of the arrangement face of a plurality of flat conductors 4, a first insulating resin film 2a and a second insulating resin film 2b are adhered to the flat conductor 4, the flat cable 1 has an exposed part of the flat conductor 4 on the face of the first insulating resin film 2a side, and the reinforcing material 5 is adhered on the opposite position to the exposed part. In manufacturing the cable, when the reinforcing material 5 is adhered, after a step in which the first insulating resin film 2a and a second insulating resin film 2b are adhered to the flat conductor 4, the manufacturing method has a step in which a pair of blocks 16 are pressed of which at least one is a heating block 14 from both sides of the first insulating film 2a and the reinforcing material 5, and has a shim 17 as a spacer to reduce a gap between the exposed part 4a at a block 15 on the first insulating resin film 2a side out of the pair of blocks 16. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a flat cable having a portion in which a plurality of flat conductors are covered with insulating resin films sandwiched from both sides of an arrayed surface arranged in a plane, and the flat conductors are exposed.

  With the reduction in size and weight of electrical equipment and information equipment, there is a demand for downsizing electronic components and wiring components mounted on them. In particular, wiring members for small devices are required to be mounted with high density and high reliability in a limited space. In order to satisfy these requirements, a plurality of flat conductors were covered with insulating resin films from both sides of the array surface arranged in a planar manner, and a terminal portion connected to an electrical connector or the like was provided at the end portion. A flexible flat cable is used.

The end of this type of flat cable has a flat conductor exposed on one side, and a reinforcing material is applied to the opposite side to reinforce the structural strength, facilitating insertion and connection to an electrical connector. (See, for example, Patent Document 1).
JP 2006-49185 A

  Affixing of the reinforcing material to the cable terminal portion is performed on a long cable material that is insulated and covered with an insulating resin film from both sides of an array surface in which a plurality of flat conductors are arranged in a plane. It adheres to the place used as the terminal part of an electrical connection by the space of. In the place to be the terminal portion, the flat conductor is partially exposed in advance, and the reinforcing material is pasted on the opposite side, with the exposed portion of the flat conductor straddling in the longitudinal direction. It is attached and cut at the intermediate position to form a terminal portion.

  The reinforcing material is usually in the form of a tape, has an adhesive layer on its adhesive surface, and presses the adhesive for a certain time while heating with a block pair composed of a heating block and a press receiving block. The layers are fused and bonded to the end of the flat cable. However, when connecting the flat cable terminal portion to the electrical connector, there has been a problem that the reinforcing material is easily peeled off from the insulating resin film.

  This invention is made | formed in view of the said situation, and it aims at providing the manufacturing method of the flat cable which improved the adhesiveness of a reinforcing material and an insulating resin film.

  As a result of intensive studies by the inventors, the reinforcing material and the cable material are sandwiched between a pair of blocks composed of a heating block and a press receiving block, and the reinforcing material is bonded to the opposite surface of the exposed portion of the flat conductor. When affixed to the insulating resin film, the exposed portion has a structure without an insulating resin film, so a space gap is mainly formed between this portion and the block disposed on the exposed surface side, and the space gap It has been found that the adhesion pressure between the reinforcing material and the insulating resin film decreases due to the escape of the insulating resin film, and microbubbles remain at the interface between the reinforcing material and the insulating resin film. And the more micro bubbles are generated, the lower the adhesion between the reinforcing material and the insulating resin film, and the reinforcing material is more easily peeled off from the insulating resin film when connecting the flat cable terminal to the electrical connector. understood.

The manufacturing method of the flat cable based on this invention made | formed based on the said knowledge is as follows.
(1) A first insulating resin film and a second insulating resin film each having a film layer and an adhesive layer on both sides of an array surface of a plurality of flat conductors arranged in a plane are the adhesive layers. It is bonded and integrated with the flat conductor from the side,
The thickness of the film layer of the first insulating resin film, the adhesive layer of the first insulating resin film, and the adhesive layer of the second insulating resin film are bonded and integrated with the flat conductor interposed therebetween. The value obtained by subtracting the flat conductor thickness from the sum of the thicknesses of the layers to be formed is 60 μm or more, and
It has an exposed portion of the flat conductor on the surface on the first insulating resin film side and corresponds to the exposed portion on the surface opposite to the surface in contact with the flat conductor of the second insulating resin film. A method of manufacturing a flat cable having a reinforcing material bonded to a position,
After the step of bonding the first insulating resin film and the second insulating resin film to the flat conductor, when bonding the reinforcing material, the first insulating resin film side and the reinforcing material side From both sides, pressing a block pair, at least one of which is a heated block,
The method for producing a flat cable, wherein the block on the first insulating resin film side includes a spacer for reducing a gap between the exposed portion and the block.

  According to the flat cable manufacturing method of the present invention, when the reinforcing material is attached to the insulating resin film on the opposite surface of the exposed portion of the flat conductor, the exposure of the block pair composed of the heating block and the press receiving block is performed. By providing a spacer for filling a space gap generated when the exposed portion and the block are in contact with the block disposed on the part side, the reinforcing material and the insulating resin film are bonded with sufficient pressing force, Adhesion can be improved. Thereby, peeling of the reinforcing material from the insulating resin film when the flat cable terminal portion is connected to the electrical connector can be suppressed.

Hereinafter, an example of an embodiment of a flat cable manufacturing method according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of a flat cable obtained by the flat cable manufacturing method according to the present invention, FIG. 1 (A) is an external perspective view, FIG. 1 (B) is a partial sectional side view of the cable, and FIG. C) is a partial cross-sectional side view illustrating a connection state to an electrical connector.

  As shown in FIGS. 1A to 1C, the flat cable 1 covers a plurality of flat conductors 4 arranged in a plane with a first insulating resin film 2a and a second insulating resin film 2b. It is the structure which has the terminal part 3 for a cable connection in the at least one edge part of the cable part 2 made. The terminal portion 3 is formed so as to be detachably connected to, for example, a jack-type electrical connector 6 and the like, and in order to form electrical contact with the electrical connector 6, the exposed portion 4 a where the flat conductor 4 is exposed is formed. It has a configuration in which a reinforcing tape 5 as a reinforcing material for adhering mechanical strength and shape retention is attached to the opposite surface side.

As the flat conductor 4, for example, a tin-plated annealed copper foil or the like having a conductor thickness of about 0.035 mm and a conductor width of 0.3 mm to 0.8 mm is used.
The first insulating resin film 2a and the second insulating resin film 2b constituting the cable portion 2 are, for example, a thermoplastic adhesive layer (not shown) on a film base (film layer) formed of a polyester-based resin. 1) are laminated and integrated. The first insulating resin film 2a and the second insulating resin film 2b are sandwiched from both sides of the plane of the flat conductor 4 so that the adhesive layer is on the flat conductor 4 side. The adhesive layers are fused and integrated with each other to form the arrangement of the flat conductors 4 and electrical insulation.

As shown in FIG. 1 (B), the terminal portion 3 of the cable has an exposed portion 4a where the first insulating resin film 2a is not bonded and the flat conductor 4 is exposed. The exposed portion 4a is a contact portion that forms an electrical connection with the external circuit or the connector contact piece 6a of the electrical connector 6, and the flat conductor 4 of the exposed portion 4a is subjected to gold plating or the like as necessary. . And the reinforcement tape 5 is adhere | attached in the position corresponding to the said exposed part 4a of the insulating resin film 2b on the surface on the opposite side to the exposed part 4a.
In addition, in this embodiment, although it is the structure which has the exposed part 4a only on the single side | surface of the flat cable 1, it is not limited to this, The 1st insulating resin film 2a side, the 2nd insulating resin film 2b side You may have the exposed part 4a on both surfaces.

  The reinforcing tape 5 is preferably a polyester-based resin like the first insulating resin film 2a and the second insulating resin film 2b. For example, the reinforcing tape 5 is formed of polyethylene terephthalate resin (PET) and is attached to one surface thereof. An adhesive layer (not shown) is applied by coating or the like. The reinforcing tape 5 is affixed to the insulating resin film 2b on the outer surface of the cable by pressing the heating block for a predetermined time while heating the adhesive block, thereby melting the adhesive layer.

  As shown in FIG. 1C, the flat cable 1 configured as described above has a flat conductor 4 with an exposed portion 4a when the terminal portion 3 is inserted into the electrical connector 6. An electrical connection is made in elastic contact with the contact. The reinforcing tape 5 retains the shape of the terminal portion 3 to facilitate insertion into the electrical connector 6 and has a function to reinforce the flat conductor 4 so as not to be deformed or bent by the connector contact piece 6a. Have. Therefore, the reinforcing tape 5 needs to be firmly bonded to the flat cable 1.

Next, the example of embodiment of the manufacturing method of the flat cable which concerns on this invention is demonstrated based on the flat cable 1 demonstrated above.
2A and 2B are schematic perspective views of a method for manufacturing the flat cable 1.
As shown in FIG. 2 (A), the first insulating resin film 2a and the second insulating resin film 2b constituting the cable portion 2 have an adhesive layer (not shown) on the inner side (the side in contact with the flat conductor 4). )) Continuously. In the first insulating resin film 2a, for example, openings 7a are formed in advance at predetermined intervals.

A large number of flat conductors 4 arranged in a planar shape are sandwiched from both sides of the arrangement surface by the first insulating resin film 2a and the second insulating resin film 2b that are continuously supplied, and the first insulating resin is pressed by the pressure roller 8. The cable material 9 is formed by bonding and integrating the film 2a and the second insulating resin film 2b. In the cable material 9, an exposed portion 4 a of the flat conductor 4 is formed at the opening 7.
The pressure roller 8 may be a heating roller depending on the type of adhesive layer applied to the first insulating resin film 2a and the second insulating resin film 2b.
In this embodiment, as shown in FIG. 2 (A), a cable material 9 having a predetermined number of conductors is prepared in advance wider than the intended cable shape, and is cut along the longitudinal direction by the slitter 10 after crimping. It is said.
And the cable raw material 9 is once wound up and made into a wound body.

As shown in FIG. 2B, the obtained cable material 9 is a cable in which the first insulating resin film 2a and the second insulating resin film 2b are bonded and integrated from both sides of the flat conductor 4 arrangement surface. The partial regions 11 and the terminal partial regions 12 having the exposed portions 4a of the flat conductor 4 are alternately formed.
The terminal portion region 12 is a portion that becomes the terminal portion 3 when the flat cable 1 is cut by the cutting means 13 at the center thereof. After the cable material 9 created as described above is unwound, in this terminal area 12, the reinforcement for reinforcing the mechanical strength in such a manner as to straddle the exposed portion 4 a in the longitudinal direction on the opposite surface of the exposed portion 4 a. Tape 5 is affixed.
For attaching the reinforcing tape 5, a heating block 14 is disposed on the reinforcing tape 5 side, a press receiving block 15 is disposed on the exposed portion 4 a side, and a block pair 16 including the heating block 14 and the press receiving block 15 is provided. The cable material 9 and the reinforcing tape 5 are sandwiched between them and pressed while heating.
In addition, although the aspect by which the cable raw material 9 was wound up once was shown here, you may cut | disconnect continuously, without winding up.

FIG. 3A is a schematic view showing a process of attaching the reinforcing tape 5 to the second insulating resin film 2b (not shown) on the opposite surface of the exposed portion 4a in the terminal region 12. FIG.
The reinforcing tape 5 has a thermoplastic adhesive layer (not shown) on the adhesive surface side, and the adhesive layer is melted and bonded by the heating temperature of the heating block 14 and the pressing time.
The heating block 14 includes a heating member 14b such as a heater, and is configured to be controllable to have a predetermined heating temperature.
The block pair 16 including the heating block 14 and the press receiving block 15 has its pressing surfaces (14a and 15a, respectively) made of an elastic material such as silicon resin so that the reinforcing tape 5 can be pressed with an appropriate pressing force. It is preferable.

In this embodiment, as shown in FIGS. 2B and 3A, when the reinforcing tape 5 is applied to the second insulating resin film 2b, which is the opposite surface of the exposed portion 4a, in the terminal region 12. Of the block pair 16 composed of the heating block 14 and the press receiving block 15, the press receiving block 15 which is a block disposed on the exposed portion 4a side is brought into contact with the exposed portion 4a and the block 15. A shim 17 is provided as a spacer for filling the generated space gap.
That is, when the cable material 9 and the reinforcing tape 5 are pressed while being sandwiched between the block pairs 16 and heated, the reinforcing tape is filled with the shim 17 by filling a space between the press receiving block 15 and the exposed portion 4a. 5 and the second insulating resin film 2b can be bonded with a sufficient pressing force. As the shim 17, a material such as SUS can be used.

FIG. 4 shows that the reinforcing tape 5 and the second insulation when a flat cable is produced by a manufacturing method in which a spacer is not provided when the reinforcing tape 5 is attached to the second insulating resin film 2b on the opposite surface of the exposed portion 4a. It is the figure which investigated the correlation with the bubble generation rate of the interface with the resin film 2b, and the amount of space gaps.
In FIG. 4, the amount of space gap on the horizontal axis indicates “base material thickness (PET thickness) of first insulating resin film 2 a + adhesive layer thickness after fusion−conductor thickness”. After the cable material 9 is formed, the first insulating resin film 2a and the second insulating resin film 2b are deformed by fusion bonding of the respective adhesive layers. The thickness of the adhesive layer of the second insulating resin film 2b is also included.
In FIG. 4, flat cables A to E shown in Table 1 below are created, the space gap amount is calculated by actual measurement, and the bubble generation rate with respect to the space gap amount is shown.

  As is apparent from FIG. 4, when the space gap amount is 60 μm or more, the bubble generation rate increases rapidly. The more bubbles are generated, the lower the adhesion between the reinforcing tape 5 and the second insulating resin film 2b. Therefore, the flat cable manufacturing method according to the present invention includes the thickness of the film layer of the first insulating resin film 2a, the adhesive layer of the first insulating resin film 2a, and the adhesive layer of the second insulating resin film 2b. Is applied to the manufacture of a flat cable in which the value obtained by subtracting the thickness of the flat conductor 4 from the sum of the thicknesses of layers formed by bonding and integrating the flat conductor 4 is 60 μm or more. The effect is great.

As the spacer, in addition to the shim 17 described above, a heat resistant resin tape such as a Teflon (registered trademark) tape can be used.
The thickness of the shim 17 is appropriately set so that the space gap amount is less than 60 μm.
The length of the shim (the length in the longitudinal direction of the flat cable 1) is preferably about ½ of the length of the conductor exposed portion 4a. On the other hand, when using Teflon (registered trademark), the length (the length in the longitudinal direction of the flat cable 1) is preferably the same as the length of the conductor exposed portion 4a or about -2 mm. Moreover, it is preferable that the width | variety of shim and tehron is substantially the same as the width | variety of the conductor exposed part 4a. In addition, the length of the conductor exposed part 4a is 8-12 micrometers normally. Further, the width of the conductor exposed portion 4 a varies according to the number of cores of the flat cable 1.

  On the other hand, when the pressing surfaces (14a and 15a, respectively) of the block pair 16 are made of an elastic material such as silicon resin, spacers may be provided inside the blocks (FIG. 3B). Also in this case, the thickness of the shim 17 is appropriately set so that the space gap amount is less than 60 μm. For example, if the space gap amount is 70 μm, the thickness of the shim 17 is preferably larger than 10 μm and 70 μm or less.

  Then, as shown in FIG. 2B, the cable material 9 to which the reinforcing tape 5 is bonded is cut at the center of the terminal area 12 by the cutting means 13, so that the flat material as described in FIG. A cable 1 is formed.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, these do not limit this invention.

  The flat cable 1 was created by the same method as the manufacturing method described above, except that the reinforcing tape 5 was attached in any of the following bonding conditions (1) to (3). The prepared flat cable 1 has a base material (PET (polyethylene terephthalate)) thickness of 25 μm for the first insulating resin film 2a, and an adhesive layer for fusion bonding between the first insulating resin film 2a and the second insulating resin film 2b. The thickness (a value obtained by subtracting the conductor) was 60 μm, and the conductor length of the exposed portion 4a was 10 mm.

Adhesion conditions (1)
The reinforcing tape 5 was bonded by pressing with a heating block 14 and a press receiving block 15 having a silicon rubber on the pressing surface, where no spacer was installed.

Adhesion conditions (2)
As shown in FIG. 3A, the reinforcing tape 5 was bonded by pressing between a heating block 14 having a silicon rubber on the pressing surface and a press receiving block 15 and pressing. However, in the bonding condition (2), instead of the shim 17 instead of the shim 17 on the pressing rubber surface of the press receiving block 15, a Teflon tape (tape length: 10 mm, thickness: 0.16 mm) is positioned to reduce the gap between the exposed portions 4a. installed. In Example 1, one sheet of Teflon tape (tape length 10 mm, thickness 0.16 mm) was used, two sheets were used in Example 2, and three sheets were used in Example 3.

Adhesion conditions (3)
As shown in FIG. 3 (B), the reinforcing tape 5 was bonded by pressing between a heating block 14 having a silicon rubber on the pressing surface and a press receiving block 15. However, under the bonding condition (3), a SUS shim 17 (thickness 0.05 mm, length 5 mm) was placed on the silicon rubber on the pressing surface of the press receiving block 15 at a position to reduce the gap of the exposed portion 4a.

The following tests were performed on the obtained flat cable. The results are shown in Table 2.
(Presence / absence of bubbles)
For the bubble generation rate, the exposed portion 4a was cut at the center in the direction perpendicular to the conductor length direction, and the cross section was observed with a microscope of 30 times or more. When there is at least one space having a width of 0.1 mm or more at the interface where the reinforcing tape 5 having the cross section and the insulating resin film 2b are bonded together, it is determined that “bubbles are generated”.

(Connector insertion / extraction test method)
The obtained flat cable was inserted into the connector at an angle of 45 degrees, and it was confirmed that there was no peeling of the reinforcing plate. The number of samples was checked for peeling of the reinforcing plate in 50 samples.

  As is clear from the above results, in the examples according to the present invention, no bubbles were generated, and the reinforcing plate was not peeled when inserted into the connector.

It is the schematic of the flat cable obtained by the manufacturing method of the flat cable which concerns on invention, FIG. 1 (A) is an external appearance perspective view, FIG.1 (B) is a fragmentary sectional side view, FIG.1 (C) is an electrical connector. It is a fragmentary sectional side view which shows the connection state to. 2A and 2B are schematic views showing an example of a method for manufacturing the flat cable described in FIG. FIG. 3A is a schematic diagram showing a reinforcing tape attaching step in the flat cable manufacturing method described in FIG. 2, and FIG. 3B is a schematic diagram showing a modification of FIG. 3A. . It is a figure which shows the correlation with a bubble generation rate and a space clearance at the time of manufacturing a flat cable with the manufacturing method which does not provide a spacer.

Explanation of symbols

1. 2. Flat cable, 2. Cable part, 2a. First insulating resin film, 2b. Second insulating resin film, 3. Terminal part, 4. Flat conductor, 4a. Exposed portion, 5. Reinforcing material, 7a. 6. opening, Opening, 9. 10. Cable material Cable area, 12. terminal area, 14. heating block, 15. 16. Press receiving block, 16. Block pair, 17. Shim, 18. Teflon tape (registered trademark)

Claims (1)

A first insulating resin film and a second insulating resin film each having a film layer and an adhesive layer on both sides of an array surface of a plurality of flat conductors arranged in a plane are the adhesive layers from the respective adhesive layer sides. Bonded and integrated with a flat conductor,
The thickness of the film layer of the first insulating resin film, the adhesive layer of the first insulating resin film, and the adhesive layer of the second insulating resin film are bonded and integrated with the flat conductor interposed therebetween. The value obtained by subtracting the flat conductor thickness from the sum of the thicknesses of the layers to be formed is 60 μm or more, and
It has an exposed portion of the flat conductor on the surface on the first insulating resin film side, and corresponds to the exposed portion on the surface opposite to the surface in contact with the flat conductor of the second insulating resin film. A method of manufacturing a flat cable having a reinforcing material bonded to a position,
After the step of bonding the first insulating resin film and the second insulating resin film to the flat conductor, when bonding the reinforcing material, the first insulating resin film side and the reinforcing material side From both sides, pressing a block pair, at least one of which is a heated block,
The method for producing a flat cable, wherein the block on the first insulating resin film side includes a spacer for reducing a gap between the exposed portion and the block.

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