DE10222285C1 - Flat and flexible ribbon cable has the insulation extruded in two stages, to fix the conductor paths in defined positions in relation to each other within the insulation - Google Patents

Abstract

The extruded flat ribbon cable (2) gives a defined position of the two conductor paths (3) within an insulation (6A,6B), using a two-stage extrusion process with two extruders (4A,4B). The conductor paths are directed by a guide system (10A,10B,12). In the first extrusion stage, a cross section zone of the ribbon cable covered by the guide remains free, and a part of the insulation is formed so that the conductor paths are fixed in place in relation to each other. The insulation is completed in the second extrusion stage, with a forced displacement to move the material through the guide until the insulation from the first stage has hardened sufficiently, in a continuous action.

Description

The invention relates to a method for producing a flexible flat band cable and such a ribbon cable, in which several conductor tracks from are surrounded by insulation.

The flexible flat ribbon or foil cable is also generally used as an FFC Cable (FFC = flexible flat cable). The film line runs in individual conductor tracks parallel to each other and are on or in a film-like Insulation and carrier material arranged. For the production of the FFC cable usually either a so-called lamination process or an extru sionsverfahren used. In the lamination process, the individual conductors strips between two insulation layers and these together with to the conductor tracks under the influence of pressure and temperature to the FFC cable sammengefügt. In the extrusion process, conductor tracks run in parallel on an extrusion system with a suitable insulation material composite extruded together.

Manufacturing process for conventional flat cable or flexible ribbon or Foil lines can be found, for example, in DE 24 53 941 A1. The DE 100 20 761 A1 and DE 17 65 690 A. In the case of those to be extracted from this Manufacturing process becomes a connection area for the production Contacting of the individual conductor tracks formed. This is either pre see that partial areas of the conductor tracks remain free (DE 17 65 690 A1) or that the conductor tracks in the connection area are stripped in a simple manner can. This is done, for example, by arranging an intermediate band ensured that the insulation does not adhere to the conductor tracks is bound.  

The FFC cables are used and found in many technical fields also used in the automotive sector. Especially in this area automation to the greatest possible extent due to the high cost pressure aimed at when assembling the FFC cables. Under packaging the preparation for the connection or the connection of the FFC Understand cable to a connector, plug or another FFC cable. When connecting two crossing or T-shaped connected FFC Cables are usually inserted into contact windows in the insulation of the FFC cables brings so that in the area of the contact window the respective conductor tracks open are placed and can be contacted. The contact window who usually by mechanical removal of the insulation material  introduced, for example by milling. In order for an automated pre hen on the one hand to prevent damage to the conductor tracks and other Ensuring that the conductor track is exposed safely is essential of crucial importance that the individual conductor tracks pass exactly on one correct height within the FFC cable. However, this is precisely the case with a conventional extrusion process. Because due to the during the extrusion process, inevitably soft insulation material, the Only after a certain period of time does the conductor tracks move possible within the still soft extrusion mass. This makes the location of the individual conductor tracks within the FFC cable are not exact and sufficient defined to ensure safe and reliable automatic assembly to be able to perform.

The invention has for its object the manufacture of a flexible flat to enable ribbon cable by extrusion, in which the individual conductor tracks take a defined position.

The object is achieved according to the invention by a method with the Merk paint according to claim 1. With this method, the conductor tracks guided by a guide element so that it is at least in one, preferred wise take a defined position relative to each other in two dimensions. in the The area of the guide element remains in a first extrusion step Guide element covered cross-sectional area free and it only becomes a Part of the insulation surrounding the individual conductor tracks and the Conductor will be fixed relative to each other. Only in the second extrusion The insulation is then completed shrilly.

This two-stage process is based on the idea of encasing the lei to carry out sheets with insulation material during the extrusion in two steps, with the first step the conductor tracks through the insulation material in their defined position and can no longer slip. This Two-stage process is based on the knowledge that only one  stage extrusion process the guide element, inevitably before the Introducing the extrusion material must be arranged. This is for the Conductors on the path between the guide element and the loading rich, in which the introduced insulation material is sufficiently hardened Slipping possible. The two-step process with training initially only part of the isolation is still based on the deliberations made by the leader tion element covered cross-sectional area of the ribbon cable at the first Leave the extrusion step free, so that the guide element is almost independent gig of the location of the insulation material in the first extrusion step can be attached. Overall, this measure is a safe me mechanical guidance of the conductor tracks in a defined position as long as possible until the conductors are sufficiently hardened due to the insulation material tracks are held in a defined position by the insulation material.

To ensure adequate mechanical guidance is in one purpose useful training provided that a in the first extrusion step brought insulation material - based on a feed direction of the conductor lanes - in front of or in the immediate area of the guide element is brought. The guide is seen in the direction of advance of the conductor tracks element on or after an extrusion head for inserting the insulation materials arranged. This takes advantage of the fact that the guide element for the Introducing the insulation material in the first insulation step is not disruptive and that therefore the arrangement of the guide element even after insertion of the insulation material is possible. Especially when arranging the feet Rungselements after the extrusion head, the conductor tracks are forced performed in a defined position until the insulation material is sufficient hardens.

With regard to a good fixation of the conductor tracks relative to one another, the first extrusion step, the insulation material preferably between the conductors webs introduced so that they have a defined side distance to each other take in.  

In order to ensure the most secure position fixation of the conductor tracks, over covers the insulation material introduced in the first extrusion step part of the conductor tracks. The conductor tracks are thus on their ranks which includes the insulation material introduced.

In an expedient embodiment, the guide element is such formed that the conductor tracks at a predetermined distance from an Au be held on the outside of the ribbon cable. In particular, the Conductors held in a common conductor level. With regard the desired automatic assembly, in particular the desired automatic punching or milling of contacting windows is done by this measure the required dimensional accuracy of the position of the individual conductors path relative to at least one and preferably to both outer sides of the Ribbon cable adhered to.

A further guide element is expediently provided, by means of which ches the conductor tracks at a defined lateral distance from each other become. Through the interaction of the two management elements, the Conductors therefore in two dimensions, both with regard to their side liche alignment with each other as well as with regard to their alignment in one defined horizontal plane, held securely.

In order to avoid lateral slippage of the conductor tracks as much as possible, this is additional guide element as close as possible to the location of the insulation materials arranged and preferably integrated directly into the extrusion head.

To secure the position of the conductor tracks as securely as possible using the first A step to ensure extruded insulation material is preferred Training provided that in the first extrusion step, several conductors sheets are covered on one side by the insulation material. Here will assuming that the traces are not necessarily  must be guided on both sides of the guide element, but that also one unilateral leadership is sufficient. In the case of one-sided leadership then there is the possibility of using a conductor on the underside, for example to provide common insulation jacket. In this case it is the first Extrusion step formed part of the insulation seen in cross section preferred designed in the manner of a comb, in which starting from a common several prongs between the individual conductor tracks.

Another insulation material is preferably used in the second extrusion step used, which is the insulation material used in the first step different. The two-stage process creates the opportunity to use a composite of different materials and there with the targeted thermal, mechanical and / or electrical substances to deliver. In particular, the further insulation material used is a filled one or reinforced plastic, so that the mechanical Properties such as the inherent rigidity of the ribbon cable can be set can. In a one-step extrusion process, the use of For example, fiber-reinforced plastic, as with such a plastic only a very poor dimensional stability when fixing the conductor tracks is possible.

The two extrusion steps are expediently carried out in a continuous process process immediately following one another. Immediately is there to understand that the second extrusion step is then made if the insulation produced in the first extrusion step is sufficient hardens so that the conductor tracks are secure in a defined position relative to one another are held. In the continuous process, for example, one common line two extrusion heads in the feed direction of the conductor tracks arranged one after the other. The fer stands at the end of the continuous process trained ribbon cable available.  

Alternatively, there is also the possibility of the first and second extrusion separate step. This can be obtained after the first extrusion step Product kept in stock like a preliminary or raw product, for example and / or moved to another production facility.

Exemplary embodiments of the description are given below with reference to the figures explained. They each show in a highly simplified and schematic representation ments:

Fig. 1 is a plan trusionsprozesses to a plant for carrying out the two-stage Ex,

Fig. 2 is a side view with an extrusion head and this in front of the thrust direction a downstream guide member,

Fig. 3 is a cross-sectional view in the region of the guide elements,

FIG. 4a, 5a respectively a signal obtained after the first extrusion step, the intermediate product, with only a portion of the insulation in two different variants and

FIG. 4b, 5b, 5a the immersion step of the respective intermediate products according to Fig. 4a to manufacture ribbon cables belonging to the second Extru.

A production system for producing an extruded, flexible ribbon cable with conductor tracks 3 comprises several extrusion tools according to FIG. 1, namely two first extrusion heads 4 A for the extrusion of a first insulation material 6 A in a first extrusion step and a common second extrusion head 4 B for the Extrusion of a second insulation material 6 B in the second extrusion step. The first extrusion heads 4 A are arranged at the same height and between the conductor tracks 3 . The extrusion heads 4 A, 4 B are each supplied with the material to be extruded via a material feed 8 . The system also includes a plurality of guide elements. Namely, first guide elements 10 A, 10 B are provided which guide the conductor tracks at a defined height. A first row of these guide elements 10 A is provided at 4 A directly at the level of the first extrusion heads. A second row of the guide elements 10 B - viewed in the feed direction 14 - is arranged shortly before the second extrusion head 4 B. Furthermore, second guide elements 12 are provided, which are placed between the individual conductor tracks 3 immediately in front of the first extrusion heads 4 A and ensure a defined lateral spacing of the conductor tracks 3 .

In the manufacturing process, the conductor tracks 3 are unrolled, for example, from a roll and fed to the first extrusion tool with the first two extrusion heads 4 A. The conductor tracks 3 by the guide elements 10 A, 10 B; 12 both in terms of their horizontal orientation and in terms of their lateral spacing from one another in a defined position. About the first extrusion heads 4 A, the first insulation material 6 A is introduced and only part of the overall insulation of the ribbon cable 2 is formed. At least the space covered by the first guide elements 10 A, 10 B remains free of the insulation material 6 A. The insulation material 6 A is introduced between the conductor tracks 3 and covered or covers the edges of the conductor tracks 3 . The course of the conductor tracks 3 in the region of the insulation material 6 A, 6 B is shown by a dashed line. The first two guide elements 10 A, 10 B are each aligned with respect to one another on a respective conductor track 3 , so that they cover the same cross-sectional space.

After introducing the first insulation material 6 A, this cools and hardens, so that the conductor tracks 3 are held in place by the insulation material 6 A. The distance between the extrusion heads 4 A and the common extrusion head 4 B is in particular dimensioned such that adequate curing of the first insulation material 6 A is ensured. The intermediate product obtained after the extrusion heads 4 A from conductor tracks 3 and part of the insulation is conveyed further in the feed direction 14 and passes through the second extrusion head 4 B, in which the second insulation material 6 B is applied, so that the insulation of the ribbon cable 2 is completed.

As can be seen in particular in FIG. 2, the first guide elements 10 A, 10 B are formed as rollers or rollers, between which the conductor track 3 is guided on both sides. Alternatively, only one-sided guidance is possible. Due to the position of the first guide elements 10 A, 10 B shown after the extrusion head 4 A, a particularly good positive guidance of the conductor track 3 is achieved until there is sufficient curing of the insulation material 6 A. In contrast to FIG. 1, the second guide element 12 is now arranged directly within the extrusion head 4 A as close as possible in front of an extrusion nozzle 16 . For this purpose, the second guide element 12 is shown dotted in FIG. 2. A lateral positive guidance is thus achieved until un indirectly before the introduction of the first insulation material 6 A via the material supply 8 .

The position of the first guide elements 10 A relative to the conductor tracks 3 and to one another can be seen from FIG. 3, which shows a cross-sectional or frontal view of the area shown in FIG. 2. It can be seen from this that the extrusion nozzles 16 each cover the edges of the conductor tracks 3 , so that the edges are covered by the insulation material 6 A introduced. The second guide element 12 is in turn represented by a dotted line Darge.

A preliminary product 18 can be achieved with the arrangement shown in FIGS. 2 and 3, as can be seen from FIG. 4a. In this preliminary product 18 between the individual conductor tracks 3 , individual insulation blocks 20 each made of the insulation material 6 A are arranged, each of which grips the edges of the conductor tracks 3 by, but are not connected to one another. In the second extrusion step, this intermediate 18 is then completely encased by the second insulation material 6 B with the insulation blocks 20 . Due to the two-stage extrusion process, the conductor tracks 3 of the ribbon cable are at a defined distance from one another and in relation to the two flat or outer sides 22 of the ribbon cable 2 .

As an alternative to this, there is the possibility of guiding the conductor tracks 3 through only a one-way acting first guide element, so that a cross-sectional area that remains free is only covered on their upper side by the guide element. In the case of a first guide element acting only on one side, a preliminary product 18 can be obtained after the first extrusion step, as shown in FIG. 5a. This preliminary product 18 is designed in the manner of a comb or rake, in which the individual insulation blocks 20 are connected by a common base. The individual conductor tracks 3 are therefore completely covered on their underside by the first insulation material 6 A. In the second extrusion step, only the free spaces 24 that remained open after the first extrusion step are then filled with the first insulation material 6 A and the ribbon cable 2 produced is obtained, as shown in FIG. 5b. The previously existing free spaces 24 are indicated here by dotted lines. In contrast to FIGS. 4a, 4b, the outer contour of the ribbon cable 2 is already determined with the first extrusion step in the variant according to FIGS . 5a, 5b.

LIST OF REFERENCE NUMBERS

2

Ribbon cable

3

conductor path

4

A first extrusion head

4

B second extrusion head

6

A first insulation material

6

B second insulation material

8th

material supply
10A, B first guide element

12

second guide element

14

feed direction

16

extrusion die

18

precursor

20

isolation block

22

outside

24

free space

Claims (10)

1. A method for producing a flexible ribbon cable ( 2 ) with conductor tracks ( 3 ) embedded in insulation ( 6 A, 6 B) by extrusion, in which
the conductor tracks ( 3 ) are guided by a guide element ( 10 A, 10 B; 12 ),
In a first extrusion step, a cross-sectional area of the ribbon cable ( 2 ) covered by the guide element ( 10 A, 10 B) remains isolation-free and only part of the insulation ( 6 A) is formed, so that the conductor tracks ( 3 ) are fixed relative to one another , and at the
the insulation ( 6 A, 6 B) is completed in a second extrusion step. 2. The method according to claim 1, in which in the first extrusion step an insulation material ( 6 A) - based on a feed direction ( 14 ) of the conductor tracks ( 3 ) during the extrusion process - introduced before or on the guide element ( 10 A, 10 B) becomes. 3. The method according to claim 1 or 2, wherein in the first extrusion step, the insulation material ( 6 A) is introduced between the conductor tracks ( 3 ). 4. The method according to any one of the preceding claims, in which the conductor tracks ( 3 ) are each partially covered by the insulation material ( 6 A) introduced in the first extrusion step. 5. The method according to any one of the preceding claims, in which by the guide element ( 10 A, 10 B), the conductor tracks ( 3 ) at a predetermined distance to an outside ( 22 ) of the ribbon cable ( 2 ) who who. 6. The method according to any one of the preceding claims, in which the conductor tracks ( 3 ) are guided by a further guide element ( 12 ) at a defined distance from one another. 7. The method according to claim 6, in which in the first extrusion step, the insulation material ( 6 A) - based on the feed direction ( 14 ) of the conductor tracks ( 3 ) during the extrusion process - is introduced immediately after the further guide element ( 12 ), which in particular is integrated in an extrusion head ( 4 A). 8. The method according to any one of the preceding claims, in which in the first extrusion step he several conductor tracks ( 3 ) of the insulation material ( 6 A) are covered. 9. The method according to any one of the preceding claims, in which a further insulation material ( 6 B) is used in the second extrusion step, which differs from the insulation material ( 6 A) used in the first step. 10. The method according to any one of the preceding claims, wherein the two Extrusion steps in a continuous process immediately otherwise carried out.