JP2010092809A - Flat cable, and method of manufacturing flat cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat cable which is narrowed in a spacing between conductors, prevents a short-circuit between the conductors and is used for an electrical wiring or the like of a vehicle, and to provide a method of manufacturing the same. <P>SOLUTION: In the flat cable in which a plurality of lengthy conductors are arranged nearly in parallel, pinched between two sheets of insulating films 20, 30, and joined with an adhesive agent, the glass transition temperature of the insulating films is higher than the melting point of the adhesive agent. A protrusion 21 which partitions between the conductors 40 is formed by integral molding at least on one side of the insulating films. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a flat cable used for, for example, an electric wiring of a vehicle and a manufacturing method thereof.

Conventionally known is a flat cable in which a plurality of conductors made of copper or copper alloy having a long and flat cross section are arranged in parallel and sandwiched between two insulating films such as PET resin and integrated by an adhesive. In view of the fact that multi-polar electrical wiring is possible in a thin space and that flexibility is good, it is used for electrical wiring in automobiles.

In this flat cable manufacturing process, two insulating films are laminated at high temperature and high pressure, so when passing through the roll, the position of the conductor is shifted due to the flow of the adhesive, causing a short circuit between the conductors. There is.

Therefore, there is a flat cable manufacturing method in which the configuration of the adhesive is devised in order to prevent a short circuit between conductors, and a flat cable manufacturing method in which the adhesive is omitted by melting the insulating film itself by devising the shape of the insulating film. Proposed.
JP-A-6-28935 JP 2002-42589 A

However, if an attempt is made to reduce the space between the conductors in order to save space, the above problem becomes serious, and there is a problem that leakage between the conductors is likely to occur in a short circuit between the conductors or a withstand voltage test. Even when the insulating film is melted without using an adhesive, the position of the conductor may be shifted as in the case of the adhesive.

Therefore, an object of the present invention is to provide a flat cable and a flat cable manufacturing method in which a short circuit between conductors does not occur even when the interval between the conductors is narrow.

The flat cable and the flat cable manufacturing method of the present invention for solving the above-described problems are as follows. In the flat cable in which a plurality of long conductors are arranged substantially in parallel and sandwiched between two insulating films and bonded by an adhesive, the glass transition temperature of the insulating film is as follows. The flat cable is characterized in that it has a melting point that is higher than the melting point of the adhesive, and a protrusion for partitioning the conductors is formed on at least one of the insulating films by integral molding. With this configuration, the protrusions provided on the insulating film are not melted even in the laminating step, and are present in the solid phase as insulating walls that partition between adjacent conductors, so that no conductor deviation occurs. For this reason, even if the space | interval between adjacent conductors is narrowed, between conductors does not short-circuit.

The invention according to claim 2 is the flat cable according to claim 1, wherein the protrusions are formed continuously in the longitudinal direction of the insulating film. With this configuration, insulation between adjacent conductors becomes more reliable.

The invention according to claim 3 is the flat cable according to claim 1 or 2, wherein the height of the projection is lower than the thickness of the conductor. With this configuration, it is possible to avoid an increase in the thickness of the flat cable even though the protrusions are not melted.

Further, in the invention according to claim 4, the width at the top of the projection is narrower than the width at the bottom of the projection, and the flat according to any one of claims 1 to 3. It is a cable. With this configuration, when the conductor is disposed on the insulating film having the protrusions, the conductors are likely to fit between the protrusions, and the conductor can be prevented from riding on the protrusions and coming into contact with the adjacent conductor.

According to a fifth aspect of the present invention, there is provided a flat cable manufacturing method in which a plurality of long conductors are arranged substantially in parallel, sandwiched between two insulating films, and bonded by an adhesive. The transition temperature is higher than the melting point of the adhesive, and at least one of the insulating films is formed with protrusions that partition the conductors, and the plurality of conductors are placed on one of the insulating films. The insulating film is placed between adjacent protrusions, the other of the insulating films is overlapped, and the stacked adhesive, the plurality of conductors, and the insulating film are sandwiched between rolls at a temperature equal to or higher than the melting point of the adhesive. A method for producing a flat cable, wherein the pressure is applied while heating and bonding. With this manufacturing method, the flat cable according to claims 1 to 4 can be manufactured easily and reliably.

The invention according to claim 6 is the method for producing a flat cable according to claim 5, wherein the temperature during the heating is equal to or lower than the glass transition temperature of the insulating film. According to this manufacturing method, since the lamination can be performed while maintaining the original shape of the insulating film, the flat cable according to claims 1 to 4 can be manufactured more easily and reliably.

According to the present invention, even when the distance between adjacent conductors is reduced in order to save the space of the flat cable, the protrusion provided on the insulating film effectively prevents the conductor from being displaced, so the insulation distance is ensured. can do. Therefore, the flat cable which prevented the short circuit between adjacent conductors easily and reliably is obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view schematically showing a state in which an insulating film and a conductor are laminated in the flat cable according to the first embodiment of the present invention. 2 is a partially enlarged view of a cross section viewed from the direction of arrow A in FIG. FIG. 3 is an enlarged partial cross-sectional view showing a state in which the arrangement and lamination of each member are completed. FIG. 4 is an enlarged partial sectional view showing a state in which the flat cable is completed after the bonding is completed.

The flat cable 10 includes a first insulating film 20 made of PET (polyethylene terephthalate), a second insulating film 30 made of PET, and a plurality of rectangular wire conductors 40, 40,. It is comprised with the polyester-type hot-melt-adhesives 50 and 50 apply | coated to each surface which the 1st insulating film 20 and the 2nd insulating film 30 oppose. In FIG. 1, the hot melt adhesive 50 is omitted.

In the first insulating film 20, a plurality of protrusions 21, 21,... Are integrally formed in a wall shape continuous in the longitudinal direction on the surface facing the second insulating film 30. Further, the height of the protrusion 21 is lower than the thickness of the conductor 40.

A plurality of conductors 40, 40,... Are arranged one by one between the adjacent protrusions 21, 21,... On the first insulating film 20, and a second insulating film 30 is further formed thereon. Cover. These processes are continuously performed while supplying each member with a roll.

FIG. 3 shows a state where the arrangement and lamination of each member are completed in this way. Since the height of the protrusion 21 is lower than the thickness of the conductor 40, the upper surface of the conductor 40 protrudes above the protrusion 21. In addition, although the hot melt adhesive 50 is schematically drawn thick in the drawing, in practice, it is so thin that it can be ignored in the combination of each member.

Furthermore, the members that have been arranged pass between heating rolls (not shown) continuously as they are. Here, during heating, the member is heated to a temperature equal to or higher than the melting point of the hot melt adhesive 50. As a result, the hot melt adhesive 50 is heated and melted, and pressure is applied between the rolls to complete the bonding in a laminated state, and the flat cable 10 is obtained.

In addition, the temperature of the said temperature rise is below the glass transition point of PET resin which comprises the 1st insulating film 20 and the 2nd insulating film 30. FIG. This temperature is naturally lower than the melting point of the PET resin. For this reason, the 1st insulating film 20 and the 2nd insulating film 30 are maintaining the original shape.

FIG. 4 shows a cross-sectional view of the flat cable 10 that has been bonded in a laminated state. Are sandwiched between the first insulating film 20 and the second insulating film 30, and the conductors 40, 40,... Are disposed between the protrusions 21, 21,. Buried. In this way, the flat cable 10 that can prevent occurrence of a short circuit between adjacent conductors can be manufactured satisfactorily.

Here, since the height of the protrusion 21 is lower than the thickness of the conductor 40, the distance between the upper surface of the protrusion 21 and the second insulating film 30 is larger than that of the other part, and the part can be formed without any gap. As filled, the thickness of the hot-melt adhesive 50 is larger than that of other portions.

As a second embodiment of the present invention, in a laminated state when heated and heated to a temperature above the glass transition point and below the melting point of the PET resin constituting the second insulating film 30 by heating. FIG. 5 shows an enlarged sectional view of the flat cable 10 that has been bonded. The second insulating film 30 is flat as shown in FIG. 3 before bonding, but is pressed in a softened state by being heated to a temperature higher than the glass transition point. The upper surface side of the insulating film 30 is recessed, and the lower surface side protrudes toward the protrusion 21.

Here, the heating temperature may be not less than the glass transition point of the PET resin constituting the first insulating film 20 and not more than the melting point, but the first insulating film 20 is reinforced by the protrusions 21 between the conductors 40. So it maintains the original shape. Depending on the relationship between the shape of the film and the applied temperature and pressure, the lower surface side of the first insulating film 20 may be recessed.

Thereby, the space | interval of the upper surface of the processus | protrusion 21 and the 2nd insulating film 30 becomes small, and the thickness of the hot-melt-adhesive agent 50 becomes small in the meantime. Also in this case, the flat cable 10 that can prevent occurrence of a short circuit between adjacent conductors can be manufactured satisfactorily. Further, since the portion where the hot melt adhesive 50 is thick is reduced, the flat cable 10 becomes strong against peeling.

As a third embodiment of the present invention, FIG. 6 shows an example in which second protrusions 31, 31,... Are formed on the second insulating film 30. The protrusion 21 and the second protrusion 31 face each other, and the total height of the protrusion 21 and the second protrusion 31 is slightly smaller than the thickness of the conductor 40.

Thereby, the space | interval of the processus | protrusion 21 and the 2nd processus | protrusion 31 becomes small, and the thickness of the hot-melt-adhesive 50 of the part is small. Also in this case, the flat cable 10 that can prevent occurrence of a short circuit between adjacent conductors can be manufactured satisfactorily. Further, since the portion where the hot melt adhesive 50 is thick is reduced, the flat cable 10 becomes strong against peeling.

As the fourth to seventh embodiments of the present invention, FIG. 7 shows an example in which the shape of the protrusion 21 is changed. As shown in FIGS. 7A to 7D, the width of the top 21a of the protrusion 21 is narrower than the width of the bottom 21b. In either case, when the conductors 40, 40,... Are arranged between the protrusions 21, 21,. Thereby, it can prevent effectively that the conductor 40 adhere | attaches on the processus | protrusion 21, contacts with the adjacent conductor 40, and is short-circuited.

In addition, this invention is not limited to said embodiment, As shown below, a change of a form is possible in the range which does not exceed the main point of this invention. The material of the insulating film is not limited to PET. Polyester resin other than PET, such as PEN (polyethylene naphthalate), polyolefin resin such as polyethylene, PVC (polyvinyl chloride), etc., may be formed into a film, can form protrusions, has insulation, flexibility, etc. Any resin having a function as an insulating coating for a flat cable may be used, and the resin can be appropriately selected from the viewpoints of strength, heat resistance, and the like.

The conductor is not limited to pure copper, but may be a copper alloy or an aluminum alloy. It can select suitably from viewpoints, such as an electric current amount, intensity | strength, and mass.

The hot melt adhesive is not limited to polyester. A modified olefin type or the like can be appropriately selected depending on the adhesiveness to the insulating film. Further, the hot melt adhesive may not be applied to the insulating film, and may be supplied as a separate film. Moreover, as long as it can finally flow into the whole circumference | surroundings of a conductor and it can fill and adhere between gaps without a gap, it may be supplied only to one side instead of both of insulating films. When hot melt adhesive is supplied to only one of the insulating films, it is advantageous in terms of the flow of the adhesive if supplied to the film on which the protrusion is formed, and the adhesive is applied if supplied to a film on which the protrusion is not formed. Is easy.

The protrusion may not be a continuous wall shape, but may be a dotted line or a broken line in a plan view, and the height of the protrusion may not be constant in the longitudinal direction. It is only necessary that the conductor to be applied is positioned and a short circuit between adjacent conductors can be prevented. If the protrusions are continuous and have a constant height, it is easy to manufacture a flat cable that is uniform in the longitudinal direction in terms of appearance and strength. If the protrusion is discontinuous or the height is not constant in the longitudinal direction, the adhesive easily flows over the protrusion, and the influence of uneven supply of the adhesive is reduced.

In the flat cable used as embodiment of this invention, it is a perspective view which shows typically a mode that an insulating film and a conductor are laminated | stacked. In the flat cable used as embodiment of this invention, it is a cross-section part enlarged view which shows a mode that an insulating film and a conductor are laminated | stacked typically. In the flat cable used as embodiment of this invention, it is a cross-section part enlarged view which shows typically the state which lamination | stacking of the insulating film and the conductor was completed. In the flat cable used as embodiment of this invention, it is a cross-section part enlarged view which shows typically the state which adhesion | attachment was completed. In the flat cable used as another embodiment of this invention, it is a cross-section part enlarged view which shows typically the state which adhesion | attachment was completed. In the flat cable used as another embodiment of this invention, it is a cross-section part enlarged view which shows typically the state which adhesion | attachment was completed. In embodiment of this invention, it is the cross-section part enlarged view of a 1st insulating film at the time of changing the shape of the protrusion of a 1st insulating film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Flat cable 20 ... 1st insulating film 21 ... Protrusion 21a ... Top part 21b of protrusion ... Bottom part 30 of protrusion ... 2nd insulating film 31 ... 2nd Protrusion 40 ... Conductor 50 ... Hot melt adhesive

Claims (6)

In a flat cable in which a plurality of long conductors are arranged substantially in parallel and sandwiched between two insulating films and bonded by an adhesive, the glass transition temperature of the insulating film is higher than the melting point of the adhesive. The flat cable is characterized in that a projection for partitioning the conductors is integrally formed on at least one of the insulating films. The flat cable according to claim 1, wherein the protrusion is formed continuously in a longitudinal direction of the insulating film. The flat cable according to claim 1, wherein a height of the protrusion is lower than a thickness of the conductor. The flat cable according to any one of claims 1 to 3, wherein a width at a top portion of the protrusion is narrower than a width at a bottom portion of the protrusion. In the method of manufacturing a flat cable in which a plurality of long conductors are arranged substantially in parallel and sandwiched between two insulating films and adhered by an adhesive, the glass transition temperature of the insulating film is higher than the melting point of the adhesive. High, a projection for partitioning the conductors is formed integrally on at least one of the insulating films, and the plurality of conductors are arranged between adjacent projections on one of the insulating films; The other side of the insulating film is overlaid, and the adhesive, the plurality of conductors, and the insulating film stacked on each other are sandwiched between rolls at a temperature equal to or higher than the melting point of the adhesive, and are heated and pressed to adhere. The manufacturing method of a flat cable. 6. The method for manufacturing a flat cable according to claim 5, wherein the heating temperature is a temperature not higher than a glass transition temperature of the insulating film.

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