Flat flexible cable and method for the production thereof

Abstract

The invention relates to a flat flexible cable and to a method for the production thereof. One embodiment of the flat flexible cable (200) has: at least two data pair elements (100), wherein each of the at least two data pair elements (100) has two parallel electrical conductors and extends in a longitudinal direction; and a woven structure interlaced at least in sections with the at least two data pair elements (100), wherein the woven structure has at least one first thread (7) running at least in sections in the longitudinal direction and at least one second thread (6) running at least in sections transversely, in particular at least approximately perpendicular, to the longitudinal direction, wherein the at least one first thread (7) runs alternatingly along the longitudinal direction in such a way that the at least one first thread (7) secures the at least one second thread (6).

Description

[0001] Flat ribbon cables and methods for their manufacture

[0002] The invention relates to a flat ribbon cable and a method for its manufacture.

[0003] A ribbon cable is a multi-core cable in which the conductors are not bundled in a circular sheath, but rather run parallel to each other. It is primarily, but not exclusively, used to connect multi-core signal lines in electronic assemblies and computers. Ribbon cables can also be shielded, usually with an aluminum or copper foil wrapped or glued around them.

[0004] Furthermore, it is known to surround data pairs or wires within a flat ribbon cable with a laminated foil. Due to the laminated foil, the cable's lateral flexibility is reduced compared to a loose bundled cable. Continuous shielding across all data pairs can also cause inter-pair crosstalk. Laminated foils are often heat-sealed, which in turn can affect the signal integrity (SI) of the data pairs, especially those with polyethylene (PE) insulation.

[0005] Woven flat ribbon cables with coaxial elements, single wires, or stranded / twisted pairs are known from the prior art. These cables traditionally employ weaving processes in which cables / pairs must be moved during shed formation to create an alternating weave pattern. This mechanically induced stress can degrade the signal integrity of the cable assembly, particularly with small cable sizes and foam insulation.

[0006] US Patent 2013 / 0062095 relates to a flat cable with a plurality of parallel wires and a fiber element woven between the plurality of wires in the same direction as the plurality of wires. Each plurality of wires has an inner conductor with a fiber (filament) and a plurality of conductors around an outer circumference of the fiber, and insulation around an outer periphery of the inner conductor. The fiber element comprises an elastic polyurethane fiber. EP 2 685 465 relates to a flat cable and a cable harness. The flat cable has a plurality of electrical wires and an elongated woven fabric. The fabric is provided with crossover sections perpendicular to the plurality of electrical wires, arranged in an ascending and descending order along the plurality of electrical wires according to a specific rule.The fabric is further provided with parallel sections that are continuous with the intersection areas and overlap with the electrical wires positioned at the ends of the multitude of electrical wires. The fabric and the electrical wires are tightly interwoven to prevent the fabric from moving along the longitudinal direction of the electrical wires relative to them.

[0007] There is a need for an improved flat ribbon cable and an improved manufacturing process for it. In particular, there is a need for a flat ribbon cable with the best possible properties and a manufacturing process that is as simple as possible.

[0008] According to a first aspect of the invention, a flat ribbon cable is proposed. The flat ribbon cable has at least two data pair elements. Each of the at least two data pair elements has two parallel electrical conductors. Each of the at least two data pair elements extends in a longitudinal direction. The flat ribbon cable has a woven structure. The woven structure is interwoven with the at least two data pair elements at least partially. The woven structure has at least one first thread. The at least one first thread runs at least partially in the longitudinal direction (of the at least two data pair elements). The woven structure further has at least one second thread. The at least one second thread runs at least partially transversely to the longitudinal direction (of the at least two data pair elements). In particular, the at least one second thread runs at least nearly perpendicular to the longitudinal direction.The at least one first thread runs alternately along the longitudinal direction. The at least one first thread runs alternately along the longitudinal direction in such a way that the at least one first thread fixes the at least one second thread.

[0009] The flat ribbon cable can also be referred to as a flat cable. The longitudinal direction is a direction along the longitudinal axis of the at least two data pair elements and / or a direction along the longest extent of the at least two data pair elements. The at least one first thread and the at least one second thread are separate threads. In particular, the at least one first thread and the at least one second thread can be of different designs and / or have different properties and / or diameters and / or thicknesses. The at least one first thread can run in such a way that the at least one second thread can cross the at least one first thread alternately over and under the at least one first thread along the longitudinal direction.

[0010] The at least one first thread can run alternately in the longitudinal direction, at least in sections, between the at least two data pair elements. In other words, the at least one first thread can run in the longitudinal direction in a region between the at least two data pair elements. Additionally or alternatively, the at least one first thread can run along at least one edge of the ribbon cable, at least in sections.

[0011] The at least one first thread can have at least two first threads or be configured as at least two first threads. The at least two first threads can run alternately in the longitudinal direction such that they cross at regular, and in particular constant, intervals. The at least one second thread can be guided or run in the area between the points of intersection. This allows the at least one first thread and the at least one second thread to be interwoven. For example, one of the at least two first threads can run alternately with another of the at least two first threads between the at least two data pair elements. The two alternating first threads can each be crossed by the at least one second thread between their points of intersection.

[0012] The at least one second thread can run perpendicular to the longitudinal direction at regular, and in particular constant, intervals. In this way, a regular, and in particular constant, weave pattern can be created within the woven structure.

[0013] At one edge of the ribbon cable, the at least one second thread can be fixed by a loop of the at least one second thread. For example, the loop can be formed starting from a section of the at least one second thread that runs transversely to the longitudinal direction at a first position. A portion of the at least one second thread, starting from a section of the at least one second thread that runs transversely to the longitudinal direction at a second position, can be passed through the loop and fixed by the loop.

[0014] At one edge of the ribbon cable, the at least one second thread can be crossed with itself, with each other, and / or with the at least one first thread. In particular, the at least one second thread can have at least two threads or be configured as at least two threads. The at least two threads can be crossed with each other and / or with the at least one first thread at the edge of the ribbon cable.

[0015] The first thread (or at least one) can have at least one warp thread or at least one shed thread, or be configured as at least one warp thread or at least one shed thread. The second thread (or at least one) can have at least one weft thread, or be configured as at least one weft thread. In weaving, warp threads are usually the threads that run lengthwise on a loom. Warp threads thus extend from top to bottom, while their counterparts, the weft threads, run from left to right over and under the warp threads. Warp threads are also known by the following names: warp, lead, or lead-in thread. Sheath threads are usually several individual threads running side by side in the same direction. A warp thread can consist of several sheath threads.

[0016] Each of the at least two data pair elements can have two electrically insulated conductors. Optionally, a further, common insulation can be provided / arranged around the respective insulation of the two electrical conductors. Each of the at least two data pair elements can have a shielding film around the insulation, or, if present, the common insulation. Each of the at least two data pair elements can have at least one adhesive film around the shielding film.

[0017] At least one separate single wire, in particular a control wire, and / or at least one further element, in particular a coaxial element, can optionally be interwoven between the data pair elements. The at least one first thread can be arranged longitudinally between the at least one separate wire and / or the at least one element. For example, four data pair elements, eight wires, and four further data pair elements can be arranged side by side and / or consecutively transversely to the longitudinal direction, with a first thread running or being able to run longitudinally between each data pair element, each wire, and each wire arranged next to a data pair element, as well as optionally at both outer edges. Like the data pair elements, the at least one separate element and / or the at least one separate wire are not moved, or substantially not moved, from their initial position when interwoven with the at least one first and second thread.

[0018] According to a second aspect, a method for manufacturing a flat ribbon cable is proposed. Specifically, a method for manufacturing a flat ribbon cable according to the first aspect is proposed. In this method, at least two data pair elements are provided in a home position. Optionally, at least one separate element and / or at least one conductor are also provided in the home position. In the home position, the at least two data pair elements and, optionally, the at least one element and / or at least one conductor extend parallel to each other in a longitudinal direction. In this method, a woven structure is formed from at least one first thread and at least one second thread.In this process, the at least two data pair elements and optionally the at least one additional element and / or the at least one wire are connected to each other by means of the web structure without leaving the basic position, in particular without alternating movement out of the basic position.

[0019] In this process, the data pair elements can be moved lengthwise during weaving, allowing them to be interwoven lengthwise. However, they remain in their initial position. This means that the data pair elements are not, or almost not, moved in an alternating fashion relative to each other; that is, they are not, or at least almost not, bent or moved up and down.

[0020] The procedure described in the second aspect offers one or more advantages. For example, since the at least two data pair elements do not leave their initial position when connecting to the web structure, there is hardly any, or at least virtually no, bending stress on the data pair elements. This leads to improved signal integrity of the data pairs / data pair elements. Furthermore, this results in at least a reduction, or even the elimination, of signal dropouts. Alternating movement could cause a reflection peak, which should be avoided.

[0021] The method can further comprise, particularly for forming the web structure, guiding the at least one first thread at least section by section in the longitudinal direction of the data pair elements. The method can further comprise guiding the at least one second thread at least section by section transversely, in particular at least nearly perpendicularly, to the longitudinal direction. The at least one first thread can be guided alternately along the longitudinal direction such that the at least one first thread fixes the at least one second thread.

[0022] The method can, particularly for forming the web structure, include guiding the at least one first thread at least section by section between the at least two data pair elements, alternating in the longitudinal direction. The method can also include guiding the at least one first thread at least section by section along at least one edge of the data pair elements.

[0023] The at least one first thread can have at least two first threads or be designed as at least two first threads. The at least two first threads can be arranged alternately in the longitudinal direction such that they cross at regular, and in particular constant, intervals.

[0024] The at least one second thread can be guided along the longitudinal direction at regular, in particular constant, intervals perpendicular to the longitudinal direction.

[0025] The method may further include fixing the at least one second thread to an edge of the ribbon cable by means of a loop of the at least one second thread.

[0026] The method may further include crossing the at least one second thread at an edge of the ribbon cable with itself or with each other and / or with the at least one first thread. This may, in particular, form the weave structure. Although some of the details described above relating to the ribbon cable have been described according to the first aspect, these details may also be implemented accordingly in the method for its manufacture according to the second aspect, and vice versa. Similarly, although some of the details described above relating to the ribbon cable have been described according to the first aspect and / or the method for its manufacture according to the second aspect, these aspects may also be implemented accordingly in a weaving device that implements the method according to the second aspect for the manufacture of the ribbon cable according to the first aspect.

[0027] The present invention will be further explained with reference to figures. These figures schematically illustrate:

[0028] Figure 1 shows a cross-section of a data pair element;

[0029] Figure 2 shows a cross-section of an embodiment of a flat ribbon cable with four data pair elements from Figure 1;

[0030] Figure 3 shows a principle of a manufacturing process for the flat ribbon cable from Figure 3;

[0031] Figure 4 shows a side view of the principle of the manufacturing process from Figure 3; and

[0032] Figure 5 shows a basic structure of the ribbon cable from Figure 3.

[0033] The following, without limitation, details are set forth to provide a complete understanding of the present invention. However, it is clear to a person skilled in the art that the present invention can be used in other embodiments that may differ from the details set forth below. Furthermore, the figures serve only to illustrate embodiments. They are not to scale and are intended only to exemplify the general concept of the invention. For example, features included in the figures should by no means be considered necessary components. A ribbon cable made of specifically constructed data pair elements is also described below. The construction of the data pair elements is not limited to the specific construction described below. A construction differing from the specific details described below is conceivable and possible.

[0034] Figure 1 shows an exemplary embodiment of a data pair element 100. The data pair element 100 has two conductors, each comprising a wire 1 and insulation 2 surrounding the wire. The insulation can be made of a polyolefin, in particular polyethylene (PE), expanded PE, polypropylene (PP), expanded PP, or a fluoropolymer, in particular fluoroethylene propylene (FEP), expanded FEP, or polytetrafluoroethylene (PTFE). In the exemplary assembly shown in Figure 1, the two conductors are arranged parallel to each other and can be described as parallel data pairs. Optionally, further insulation can be provided / arranged around the two conductors, more precisely around the two insulations 2 of the two conductors, in the form of an inner sheath 3. The inner sheath 3 can be extruded or spun.A shielding foil 4, optionally with two auxiliary wires (which are also referred to as reference 4 for simplicity), is arranged around the inner sheath 3 (if present) or around the insulation 2. The auxiliary wires can be positioned above or below the shielding foil 4. The shielding foil 4 can be wrapped or applied lengthwise. Each data pair element 100 is individually shielded. The shielding foil 4 is surrounded or wrapped with at least one adhesive film 5. The adhesive film 5 serves to fix the data pair element 100.

[0035] Figure 2 shows an embodiment of a flat ribbon cable 200. The flat ribbon cable 200 can be configured as a flat ribbon cable for high-speed data transmission. The flat ribbon cable 200 has, by way of example, four data pair elements 100 to illustrate that at least two data pair elements 100 are provided in the flat ribbon cable 200. The four data pair elements 100 are configured by way of example as described by way of example with reference to Figure 1. The four data pair elements 100, as well as the respective two conductors and wires 1 of the four data pair elements 100, extend in a longitudinal direction. The flat ribbon cable 200 further has a woven structure that is interwoven with the four data pair elements 100 at least in sections. The woven structure has at least one first thread 7 and at least one second thread 6. The at least one first thread 7 runs at least in sections in the longitudinal direction.The at least one second thread 6 runs at least partially transversely, and in particular at least almost perpendicularly, to the longitudinal direction. The at least one first thread 7 runs alternately along the longitudinal direction such that the at least one first thread 7 fixes the at least one second thread 6.

[0036] The at least one first thread 7 is exemplified as at least one warp thread and will therefore hereinafter also be referred to as at least one warp thread 7. The at least one second thread 6 is exemplified as at least one weft thread 6 and will therefore hereinafter also be referred to as at least one weft thread 6.

[0037] As can be seen in Figure 2, at least one warp thread 7 runs between each of the four data pair elements 100. More precisely, as shown by way of example in Figure 2, between each pair of data pair elements 100, two warp threads 7 run above a median plane and two warp threads 7 run below a median plane M, which is shown as a dashed line in Figure 2 and divides the ribbon cable 200 into two equal halves. Due to the alternating course, as described later with reference to Figure 3, the warp threads 7 running above and below the median plane M cross at a later point along the longitudinal direction, in order to then exchange their arrangement above and below the median plane M. Figure 2 also shows how a weft thread 6 runs once above and once below the median plane M and forms the outer boundary of the ribbon cable 200.The weft thread 6 can be guided as a single weft thread 6 above and below the mid-level M. Alternatively, at least one weft thread 6 can be guided above the mid-level M and at least one weft thread 6 can be guided below the mid-level M.

[0038] Further details are now described with reference to Figures 3 and 4. The ribbon cable 200 from Figures 3 and 4, as can be seen in Figure 3, has, by way of example, only two data pair elements 100. However, the details described with reference to Figures 3 and 4 apply accordingly to the configuration from Figure 2 and vice versa. Figure 3 shows, by way of example, two alternating warp threads 7. The warp threads 7 run between the two data pair elements 100. The warp threads run alternately in a kind of wave pattern, with the maxima and minima of the respective warp threads 7 being located at the same position in the longitudinal direction. In other words, a maximum of one warp thread 7 is located in the longitudinal direction (and in the transverse direction) at a minimum of the other warp thread 7 and vice versa.Due to the alternating arrangement, the warp threads 7 cross longitudinally at several intersection points 10, one of which is shown in Figure 3 and three in Figure 4. The intersection points 10 run at regular, and in particular constant, intervals in the longitudinal direction.

[0039] Furthermore, Figures 3 and 4 show weft threads 6 running transversely, or more precisely, by way of example, perpendicularly to the longitudinal direction of the flat ribbon cable 200. In the example shown in Figures 3 and 4, two weft threads 6 are provided, one of which runs above the central plane (see central plane M in Figure 2) and the other below the central plane. Alternatively, it would be conceivable to have at least two weft threads 6 above the central plane and at least two weft threads 6 below the central plane. It would also be conceivable to have a single weft thread 6 running both above and below the central plane.

[0040] In the example shown in Figures 3 and 4, the weft thread 6 running above the mid-plane and the weft thread 6 running below the mid-plane are inserted / shot from the left side / left edge (referring to Figure 3) of the ribbon cable 200 and then run at least almost perpendicular to the longitudinal direction (of the ribbon cable 200) to the right side / right edge. At least almost in the middle of the two data pair elements 100, the two weft threads 6 run between the upper and lower warp threads 7 and can thus be fixed by the two warp threads 7. At the right edge, the upper and lower weft threads 6 are each guided (referring to Figure 3, upwards and then downwards again) so that they each form an upper and a lower loop 9. The weft threads 6 are then guided back from the right edge to the left edge.At least approximately in the middle of the two data pair elements 100, the two weft threads 6 again run between the upper and lower warp threads 7 and can thus be fixed by the two warp threads 7. At the left edge, the two weft threads 6 are guided along the longitudinal direction and crossed at a weft thread crossing point 11, thereby also fixing them at the left edge. If the two weft threads 6 are now guided again from the left edge to the right edge and, on the way there, are fixed at least approximately in the middle between the two data pair elements 100 between the two warp threads 7, the weft threads 6 are each guided through the corresponding loops 9 and fixed by the loop 9 that was previously formed by the respective weft thread 6 itself.After the weft threads 6 have formed a loop 9 again and been led from the right edge to the left edge, the process is repeated as long as necessary to form a desired weave structure.

[0041] The weft thread 6 can run perpendicular to the longitudinal direction at regular, and in particular constant, intervals. In Figure 3, only two such transverse paths are shown, while in Figure 4, three are shown, whereby the rightmost transverse path in Figure 4 is not yet fixed by a further crossing point 10 with the warp threads 7.

[0042] A schematic representation of a flat ribbon cable 200, including its weave structure, is shown by way of example in Figure 5. The flat ribbon cable 200 in Figure 5 has, by way of example, two data pair elements 100. In addition, at least two warp threads 7 extend along the longitudinal direction of the data pair elements 100 between the data pair elements 100. Essentially transverse to the longitudinal direction, except for the respective reversal sections at the edges, a weft thread 6 runs at regular intervals. The warp threads 7 run alternately, offset by 180 degrees from each other. Due to this offset alternating course, in the longitudinal direction of the flat ribbon cable 200, one of the warp threads 7 runs above the weft thread 6 and another of the warp threads 7 runs below the weft thread 6. At the subsequent intersection point between the warp threads 7 and weft thread 6, one of the warp threads runs below the weft thread and the other of the warp threads runs above the weft thread.This sequence continues alternately in the longitudinal direction. Even if only two warp threads 7 are visible, each warp thread shown can represent an alternating pair of warp threads 7. In this case, Figure 5 would show four warp threads 7 as an example, each pair of alternating warp threads 7 in a region between the data pair elements 100. Furthermore, Figure 5 shows an example of a filler thread at the upper edge of the ribbon cable 200.

[0043] Further details, which may apply to all the characters described, are outlined below.

[0044] The elements of the flat ribbon cable 200 can be fed into a weaving machine, particularly side by side. Warp threads 7 are placed between the data pair elements 100. These warp threads 7 are moved up and down during weaving. The data pair elements 100 themselves do not move mechanically. The warp threads 7, which are drawn up / warped during weaving, lie in a space 8 between two data pair elements 100. Weft threads 6 are guided through the raised warp threads 7 and fixed by them. The data pair elements 100 do not need to move during this process.

[0045] Since the data pair elements 100 are not (need to be) moved during this process, no or at least virtually no bending stress is exerted on them. This leads to improved signal integrity of the data pairs / data pair elements 100. Furthermore, this results in a reduction or even a complete elimination of signal dropouts. Alternating movement could cause a reflection peak, which should be avoided.

[0046] The weft threads 6, guided between the warp threads 7 and the data pair elements 100, can be fixed at the end by the loop 9 formed by the weft thread 6 of the previous transverse pass. The alternating movement of the warp threads 7 fixes the weft thread(s) 6 between the data pair elements 100. At an edge, the weft threads 6 are crossed, so that they are also fixed there (at the respective weft thread crossing points 11). Sheave threads (number >= 1) can also be used for the warp threads.

[0047] The elliptical pair shape of the data pair elements 100 and the resulting flat ribbon cable 200 enables a tilt-free product. The method described herein enables the production of a flat ribbon cable suitable for data transmission at frequencies > 25 GHz.

Claims

Patent claims 1. Flat ribbon cable (200) comprising: - at least two data pair elements (100), each of the at least two data pair elements (100) having two parallel electrical conductors and extending in a longitudinal direction; and - a web structure interwoven at least partially with the at least two data pair elements (100), wherein the web structure has at least one first thread (7) running at least partially in the longitudinal direction and at least one second thread (6) running at least partially transversely, in particular at least nearly perpendicularly, to the longitudinal direction, wherein the at least one first thread (7) runs alternately along the longitudinal direction such that the at least one first thread (7) fixes the at least one second thread (6).

2. Flat ribbon cable (200) according to claim 1, wherein the at least one first thread (7) runs at least section by section alternately in the longitudinal direction between the at least two data pair elements (100) and / or runs at least section by section along at least one edge of the flat ribbon cable (200).

3. Flat ribbon cable (200) according to claim 1 or 2, wherein the at least one first thread (7) has at least two first threads (7) or is designed as at least two first threads (7), and the at least two first threads (7) run alternately in the longitudinal direction such that the at least two first threads (7) cross each other at regular, in particular constant, intervals.

4. Flat ribbon cable (200) according to one of claims 1 to 3, wherein the at least one second thread (6) runs along the longitudinal direction at regular, in particular constant, intervals transverse to the longitudinal direction.

5. Flat ribbon cable (200) according to one of claims 1 to 4, wherein at least one second thread (6) is fixed at an edge of the flat ribbon cable (200) by a loop (9) of the at least one second thread (6).

6. Flat ribbon cable (200) according to one of claims 1 to 5, wherein the at least one second thread (6) is attached to an edge of the flat ribbon cable (200). itself or with each other and / or with the at least one first thread (7) crossed.

7. Flat ribbon cable (200) according to one of claims 1 to 6, wherein the at least one first thread (7) has at least one warp thread or at least one shed thread or is designed as at least one warp thread or as at least one shed thread.

8. Flat ribbon cable (200) according to one of claims 1 to 7, wherein the at least one second thread (6) has at least one weft thread or is designed as at least one weft thread.

9. Flat ribbon cable (200) according to any one of claims 1 to 8, wherein each of the at least two data pair elements (100) comprises: two electrically insulated conductors with insulation (2); a shielding foil (4) around the insulation (2); and at least one adhesive foil (5) around the shielding foil (4).

10. Method for manufacturing a flat ribbon cable (200), preferably according to one of claims 1 to 9, wherein - at least two data pair elements (100) are provided in a basic position in which they extend parallel to each other in a longitudinal direction, - a web structure is formed from at least one first thread (7) and from at least one second thread (6) and the at least two data pair elements (100) are connected to each other by means of the web structure without leaving the home position, in particular without alternating movement out of the home position.

11. The method of claim 10, comprising: - Guiding the at least one first thread (7) at least section by section in the longitudinal direction of the data pair elements (100); - Guiding the at least one second thread (6) at least sectionally transversely, in particular at least almost perpendicularly, to the longitudinal direction; wherein the at least one first thread (7) is guided alternately along the longitudinal direction in such a way that the at least one first thread (7) fixes the at least one second thread (6).

12. Method according to claim 10 or 11, further comprising guiding the at least one first thread (7) at least section by section between the at least two data pair elements (100) alternating in the longitudinal direction and / or at least section by section along at least one edge of the data pair elements (100).

13. Method according to one of claims 10 to 12, wherein the at least one first thread (7) has at least two first threads (7) or is designed as at least two first threads (7), and the at least two first threads (7) are guided alternately in the longitudinal direction such that the at least two first threads (7) cross each other at regular, in particular constant, intervals.

14. Method according to one of claims 10 to 13, wherein the at least one second thread (6) is guided along the longitudinal direction at regular, in particular constant, intervals transverse to the longitudinal direction.

15. Method according to any one of claims 10 to 14, wherein the method further comprises: fixing the at least one second thread (6) to an edge of the ribbon cable by means of a loop (9) of the at least one second thread (6); and / or crossing the at least one second thread (6) at an edge of the ribbon cable (200) with itself or with each other and / or with the at least one first thread (7).

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