Connection arrangement and method for making a connection arrangement

Abstract

The invention relates to a connection arrangement comprising a metal flat conductor having an at least quadrangular cross-sectional profile and at least two opposing first and second surfaces which extend in parallel with each other at least in part in the longitudinal direction, and at least two parts which are formed as connection lugs, are flat in the region of overlap, rest on the first surface with a lap joint and protrude beyond one or both long edges of the flat conductor, characterised in that a metal friction stir welding joining zone is formed starting from the second surface, extending through the flat conductor towards the first surface and protruding into the connection lugs.

Description

[0001] Connection arrangement and method for producing a connection arrangement

[0002] The subject matter relates to a connection arrangement for electrical flat conductors, particularly in automotive applications, and a method for manufacturing such a connection arrangement.

[0003] Flat electrical conductors, also known as busbars, can be made of aluminum, aluminum alloy, copper, or copper alloy. These flat conductors serve, for example, as energy backbones for distributing electrical power in vehicles, as battery cell connectors, and / or as module connectors. Along the flat conductor, several electrical connections are sometimes required, which are often implemented as terminal blocks.

[0004] If these electrical connections are made of a different metallic material than the flat conductor, the result is a so-called mixed-material flat conductor made of different metallic materials. Joining these different metallic materials, especially if aluminum is one of them, is problematic with regard to the contact resistance at the connection point.

[0005] To achieve an electrically advantageous electrical connection between the flat conductor and the terminal tab, ultrasonic welding is proposed, for example. In ultrasonic welding, welding energy is applied by means of .Ultrasound is introduced into the joining partners via a welding tool. These begin to vibrate, and their relative movement results in the input of welding energy at the interface, leading to the melting of the joining partners and thus the formation of an intermetallic, metallurgical bond. Ultrasonic welding is a preferred welding method for creating intermetallic joints between different metals. However, this method has disadvantages when several intermetallic joints need to be formed spatially adjacent to each other along the flat conductor, between the flat conductor and a terminal tab.Since, after the first connecting tab has been welded on, ultrasonic vibrations are introduced into the joining partners by the sonotrode of the ultrasonic welding tool when welding on a further connecting tab, these vibrations can damage the previously created intermetallic, material-bonded connection between the flat conductor and the connecting tab. The cooled, hardened weld can develop cracks, microcracks, or other damage, so that the previously flawless weld is compromised by the application of welding energy for the next weld.

[0006] For this reason, the subject matter was based on the task of providing a connection arrangement in which a plurality of connecting tabs can be permanently and stably arranged on a flat conductor.

[0007] This problem is solved by a connection arrangement according to claim 1 and a method according to claim 15.

[0008] The connection arrangement in question initially comprises a flat conductor.

[0009] This flat conductor can be made of a metallic metal, for example aluminum or an aluminum alloy, as well as copper or a copper alloy.

[0010] The connection arrangement can be located in a spatially defined area of ​​the flat conductor or extend over the entire flat conductor. Two or more connection arrangements can also be provided side by side on the flat conductor. The flat conductor can be configured as a busbar, particularly as an energy backbone. It can also be configured as a battery cell connector or battery module connector. The flat conductor has a cross-sectional profile that is at least quadrilateral, and in particular a square or rectangular cross-sectional profile. With this cross-sectional profile, the flat conductor has at least two opposing first and second surfaces that are at least partially parallel to each other in the longitudinal direction. In the case of a rectangular cross-sectional profile, the first and second surfaces can be the wider sides.

[0011] Connecting tabs are attached to the flat conductor. These tabs can also be flat and, particularly in the area of ​​the joining surface, have a rectangular or square cross-sectional profile. Alternatively, the connecting tabs can be formed as connecting lugs, crimp terminals, or similar features. Specifically, a connecting tab can consist of a flat section and a profiled section. These sections can be located at the distal ends of the connecting tab. The flat section can also be surrounded on both sides by profiled sections, which can extend beyond the flat conductor. The profiled section can be formed into an arc-shaped recess to accommodate a round cable.

[0012] The connecting tabs can have at least one contact area, particularly adjacent to the profiled area. This contact area serves for contacting a conductor (stranded wire or solid material). For this purpose, the contact area can be coated, for example, nickel-plated and / or tin-plated, so that a conductor can be soldered to it. The conductor can also be welded on, particularly by ultrasonic welding or resistance welding. The contact area can also have a relief surface to optimize the weld. The flat area can be located in the region of overlap with the flat conductor. The connecting tabs are particularly made of sheet metal, especially as a stamped or stamped-bent part.The connecting tabs are placed with an overlap, in particular an overlap edge, on the first surface of the flat conductor. In this overlap, a part (overlap area) of a surface of the connecting tab lies on the first surface of the flat conductor and another part extends over a longitudinal edge of the flat conductor.

[0013] The connecting tabs lie next to each other in the longitudinal direction of the flat conductor, but are preferably spaced apart from each other.

[0014] The connecting tabs can have a connection to a conductor at one or both ends, particularly in the contact area. This existing connection can be established using methods such as ultrasonic welding, friction welding, resistance welding, or laser welding. It is important that the existing connection is not located in the overlap area between the connecting tab and the flat conductor.

[0015] It is now proposed that a metallic friction stir welding zone is formed, extending from the second surface through the flat conductor to the first surface and projecting into the connection tabs. A continuous friction stir welding zone extends through the flat conductor between the two surfaces and into the overlap area where the connection tabs rest on the first surface, also extending into the connection tabs themselves. Thus, a friction stir welding zone extends continuously along the longitudinal direction of the flat conductor and through the flat conductor into the connection tabs. It is therefore possible to bond multiple connection tabs to the flat conductor in a single friction stir welding process. The resulting bond is permanently stable and intermetallic.During the joining process, pressure is applied to the second surface, and together with a rotating welding rod, the flat conductor is plasticized from the second surface towards the first. Stirring also plasticizes at least part of the connecting tabs in contact with the first surface. Thus, both the material of the flat conductor and the material of the respective connecting tab are plasticized, and the materials are partially mixed. This creates a metallurgical bond between the two joining partners.

[0016] In friction stir welding, a special friction stir welding machine or a CNC machine is used to press the flat conductor against the terminals. This can be achieved using the friction stir welding tool and its shaft. A friction welding rod, also called a pin, rotates or oscillates within the shaft and is pressed against the second surface. Alternatively, the entire friction stir welding tool, consisting of a shaft and a pin, can be set into a rotary motion. The friction welding rod transfers the friction welding energy into the flat conductor and the terminal, causing the metallic materials to plasticize and form an intermetallic bond. In a continuous joining zone, only one entry point and one exit point of the rod are formed along the flat conductor across the majority of the terminals.Otherwise, the friction stir welding tool moves in a continuous, preferably transverse motion along the longitudinal axis of the flat conductor on the second surface. However, it is possible to produce several welds side by side even with larger spacing between the tabs within a flat conductor. It should be noted that each weld must connect the flat conductor to at least two terminal tabs.

[0017] According to one embodiment, it is proposed that the friction stir welding joint is formed from the plasticized material of the flat conductor and the connecting tabs during the joining process. In the area along the longitudinal axis of the flat conductor where the connecting tab rests on the first surface, both the material of the flat conductor and the material of the connecting tab are plasticized. In the areas where the connecting tab does not rest, only the flat conductor can plasticize.

[0018] According to one embodiment, it is proposed that the metallic joining zone in the flat conductor is formed continuously along its longitudinal axis over at least two connecting tabs. The connecting tabs rest on the first surface of the flat conductor, spaced apart from one another. Starting from the second surface, the joining zone is introduced into the flat conductor and the connecting tabs. The joining zone extends along the longitudinal axis of the flat conductor over at least two of the connecting tabs. Alternatively, several separate joining zones can be formed along the longitudinal axis of the flat conductor.

[0019] According to one embodiment, it is proposed that the flat conductor is plasticized along its longitudinal axis along the friction stir welding joint zone during the joining process, and that the connecting tabs are positioned at spatial intervals between them on the flat conductor within the joining zone. The joining zone is continuous within the flat conductor and intermittently transitions into one of the connecting tabs. A gap is preferably formed between two connecting tabs.

[0020] As explained at the outset, flat conductors and connection lugs are preferably made of different metallic materials. This can be advantageous, for example, if the flat conductor is made of aluminum or an aluminum alloy and the connection lugs are made of copper or a copper alloy. The connection lugs can provide electrical connections, such as for crimp terminals, screw terminals, solder terminals, or the like. Conventional cables, particularly copper cables, can be connected to the connection lugs. To ensure a homogeneous connection between the connection lugs and the connected cable, the connection lugs, especially in the contact area, are preferably made of the same material as the outgoing cables, which are preferably made of copper.This has the advantage that the contact resistances between the connecting tabs and the cables attached to them are low, since copper has electrical advantages over aluminium in form-fitting joining processes.

[0021] According to one embodiment, it is proposed that at least one of the connecting tabs is arranged in a recess formed on the first surface of the flat conductor, and that ribs are formed on the flat conductor between the recesses. In a longitudinal profile of the flat conductor, it can be formed in a stepped manner with recesses and ribs. The recesses can be formed by punching, pressing, milling, grinding, or the like. The recesses preferably run transversely to the longitudinal direction, and in particular perpendicular to the longitudinal direction, across the first surface of the flat conductor. However, it is also possible to arrange the recesses longitudinally or along the end face at one or both end edges of the flat conductor.In such an arrangement, it is preferred that the flat conductor to be welded also has at least one recess for the transversely arranged tabs in order to weld at least one connecting tab in the transverse direction and at least one connecting tab in the longitudinal direction onto the flat part simultaneously.

[0022] The recesses preferably extend across the entire width of the flat conductor. The connecting tabs can be arranged in the recesses. The longitudinal extent of the recesses along the flat conductor preferably corresponds approximately to the width of the connecting tabs, so that the connecting tabs can be inserted into the recesses, particularly in a clearance fit, transition fit, or press fit. Raised sections, especially ribs, are formed between the recesses.

[0023] As already explained, the recesses in the flat conductor can be formed, for example, without cutting or by cutting. However, it is also possible that plates forming the webs are attached to the flat conductors next to the connecting tabs. These plates have a height equal to the height of the connecting tabs. The plates also have a width equal to the width of the

[0024] corresponds to flat conductor.

[0025] The friction stir welding zone can extend longitudinally along the flat conductor, alternating between the connecting tabs and the plates forming the webs. This allows a connection to be established between the connecting tabs and the flat conductor, as well as between the plates and the flat conductors, during the friction stir welding process.

[0026] According to one embodiment, it is proposed that the connecting tabs rest on the flat conductor with a first surface and are flush with the webs with a second surface opposite the first. The depth of the recesses corresponds, in particular, to the material thickness of the connecting tabs, so that when the connecting tabs are inserted into the recesses, these are flush with the surface of the webs. Thus, after friction stir welding, a uniform first surface of the flat conductor is formed, which is intermittently composed of the connecting tabs and the webs.

[0027] According to one embodiment, it is proposed that at least one of the connecting tabs has a first end face flush with a first longitudinal edge of the flat conductor and projects with a second end face over a second longitudinal axis of the flat conductor opposite the first longitudinal axis. Alternatively, a connecting tab can have an overlap area resting on the flat conductor and projecting beyond a longitudinal edge of the flat conductor on both sides of the overlap area. The width of the connecting tab in the overlap area can be smaller, equal to, or larger than in at least one area projecting beyond a longitudinal edge, in particular a contact area and / or profiled area.

[0028] In the area of ​​the projecting end faces, the connecting tab can have a contact area, in particular in the form of a connecting bore, a connecting bolt, a crimp connection, a welded or soldered connection, or the like.

[0029] The connecting tab can be bare, bimetallic, or coated, and in the area of ​​overlap with the flat conductor, it can be bare or made of a first metallic material or coated, and in the area where the connecting tab projects beyond the second longitudinal edge, it can be bare, bimetallic, or made of a second metallic material or coated. According to one embodiment, it is proposed that the less rigid material, such as the flat conductor made of, for example, aluminum alloy, is plasticized throughout its entire thickness in the friction stir welding joint zone, while the more rigid material, such as connecting tabs made of, for example, copper alloy, is only partially plasticized in the friction stir welding joint zone. In friction stir welding, the flat conductor is preferably plasticized throughout its entire thickness.The connecting tabs, however, only need to plasticize at least partially, since a metallurgical bond is only required in the transition area between the connecting tab and the flat conductor. The connecting tabs can also plasticize only partially across their entire material thickness, and the flat conductor can also plasticize only partially. In this case, the friction stir welding tool is applied to the surface of the connecting tabs. This is particularly relevant if the flat conductor is made of a material with a higher strength than the material of the connecting tabs.

[0030] According to one embodiment, it is proposed that the friction stir welding joint has a width transverse to its longitudinal extent that corresponds at least to the material thickness of the connecting tabs. The rod or pin of the friction stir welding tool is preferably formed with a diameter that corresponds to at least 50% of the material thickness of the connecting tabs. Due to the electrical properties, it is preferred that the material thickness of the connecting tab be substantially aligned with the diameter of the rod or pin.

[0031] The friction stir welding tool must be adapted accordingly. The diameter of the rod or pin of the friction stir welding tool can be up to 90% of the material thickness, but at least 50%. This ensures a sufficiently large joining zone.

[0032] According to one embodiment, it is proposed that the friction stir welding joint extends continuously along the longitudinal axis of the flat conductor over at least two connection tabs. Thus, within a weld seam, there is only one entry and one exit point that can be considered weak points, while all other areas exhibit the same joining quality. However, two or more of these weld seams are possible side by side along the longitudinal axis, each connecting two connection tabs to the flat part.

[0033] Another aspect is a method according to claim 15.

[0034] The subject matter is explained in more detail below with reference to a drawing showing an exemplary embodiment. The drawing shows:

[0035] Fig. a1, b Flat conductors according to exemplary embodiments;

[0036] Fig. 2a-d Connection tabs according to exemplary embodiments;

[0037] Fig. 3 shows a flat conductor with welded-on connection tabs according to

[0038] Examples of implementation;

[0039] Fig. 4a-c Views of a connection arrangement according to exemplary embodiments;

[0040] Fig. 5a, b shows a schematic representation of a method for manufacturing a connection arrangement according to exemplary embodiments. Fig. 6 shows a schematic representation of a method for manufacturing a

[0041] Connection arrangement according to implementation examples.

[0042] Fig. 1 shows a flat conductor 2. The flat conductor 2 extends along its longitudinal axis 4 and has a cross-sectional profile transverse to the longitudinal axis 4, which is essentially rectangular. The flat conductor 2 has two opposing, parallel, wide surfaces 2a, 2b, each bounded by longitudinal edges 2c.

[0043] The flat conductor 2 according to Fig. 1a has flat, wide surfaces 2a, b. As can be seen in Fig. 1b, one of the wide surfaces 2a, b can be formed with recesses 6 and ribs 8. The wide surface 2a with the recesses 6 and ribs 8 can be considered the first surface, and the wide surface 2b, which is opposite it, can be flat and considered the second surface.

[0044] The recesses 6 can be formed from the wide surface 2a by milling, upsetting, sawing, cutting (e.g., waterjet cutting, laser cutting), or similar processes. It is also possible to attach plate-shaped elements as webs 8 to the wide surface 2a. The recesses 6 and webs 8 alternate. The longitudinal extent 6 of a recess 6 along the longitudinal axis 4 can correspond to the width of a connecting tab. Connecting tabs and plates can be alternately attached to the flat conductor 2 as webs 8.

[0045] The flat conductor 2 and, if applicable, the material of the webs 8 can be, for example, aluminum or an aluminum alloy. However, it is also possible that copper or a copper alloy is used.

[0046] Connecting lugs 10 are attached to the flat conductor 2, as shown in Figures 2a-c. Figure 2a shows a connecting lug 10 formed from a sheet of metal. The connecting lug 10 can, for example, be stamped or cut from a sheet. The connecting lug 10 can be made of copper or a copper alloy, but it is also possible for the connecting lug 10 to be made of aluminum or an aluminum alloy. The connecting lug 10 can also be bimetallic, with a first region 10a being formed from a first metallic material and a second region 10b being formed from a second metallic material, or being fully or selectively coated. The metallic materials can be those mentioned above.

[0047] In the connecting tab 10 according to Fig. 2a, a connecting bolt 12a is provided in the area 10b.

[0048] In contrast to Fig. 2a, the connecting tab 10 according to Fig. 2b is provided with a through hole 12b in the area 10b.

[0049] The connecting tab 10 can also be formed as a bent section, as shown in Fig. 2c. Fig. 2c shows that section 10b is bent relative to section 10a. In particular, the connecting tab 10 can be bent at a right angle.

[0050] The connecting tab 10 can also be formed as a profiled flat part as shown in Fig. 2d. In an overlap area 10a, the connecting tab 10 can be flat. In a contact area 10c, the connecting tab 10 can be coated or bare to be welded or soldered to a conductor of a cable. In a profiled area 10b, the connecting tab 10 can have an arcuate recess in which a cable, in particular cable insulation, can be inserted.

[0051] The connecting tabs 10 are placed side by side, spaced apart from each other, onto the flat conductor 2, as can be seen in Fig. 3. The flat conductor 2 is fitted with three connecting tabs 10, which are spaced apart from each other. Fig. 3 optionally shows that the flat conductor 2 is formed with recesses 6 and webs 8. The webs 8 space the connecting tabs 10b apart from each other. To create a connection arrangement, it is now proposed that a continuous friction stir welding zone 14 be formed, which extends along the longitudinal axis 4 of the flat conductor 2 over several connecting tabs 10.

[0052] Fig. 4a shows the flat conductor 2 from the broad surface 2b. It can be seen that a friction stir weld zone 14 extending longitudinally from the broad surface 2b is formed. The connecting tabs 10 are attached to the surface 2a of the flat conductor 2 opposite the broad surface 2b. The friction stir weld zone 14 extends through the entire flat conductor 2 into the connecting tabs 10. This is clearly visible in Fig. 4b.

[0053] Figure 4b shows a longitudinal section of the flat conductor 2. It can be seen that, starting from the wide surface 2b and extending towards the wide surface 2a, the friction stir welding zone 14 extends through the flat conductor to the connecting tabs 10. The friction stir welding zone 14 can also extend into the webs 8, which are formed, for example, from plate-shaped elements. The friction stir welding zone 14 is a continuous joining zone that extends longitudinally along the longitudinal axis 4 of the flat conductor 2 through a plurality of connecting tabs 10.

[0054] Fig. 4c shows the connection arrangement as seen from the wide surface 2a. It can be seen that the connecting tabs 10 are aligned with a first end face 10' along a longitudinal axis 4 of the flat conductor 2 on the wide surface 2a. The connecting tabs 10 project beyond the opposite longitudinal edge 2c of the flat conductor 2. The friction stir welding zone 14 extends along the longitudinal axis 4 of the flat conductor over several connecting tabs 10 and runs continuously and straight along the flat conductor 2. The connecting tabs 10 are joined to the flat conductor 2 in a single joining process using the friction stir welding zone.

[0055] Fig. 5a shows the flat conductor 2 from the broad surface 2b. It can be seen that two friction stir welding zones 14', 14" extending longitudinally from the broad surface 2b are formed. On the surface 2a of the flat conductor 2 opposite the broad surface 2b, two connecting tabs 10 are attached for each of the joining zones 14', 14". The friction stir welding zones 14', 14" extend through the entire flat conductor 2 into the connecting tabs 10. The connecting tabs 10 in a joining zone 14' can, as can be seen on the left, project beyond one or both longitudinal edges 2c. The connecting tabs 10 in a joining zone 14" can, as can be seen on the right, project beyond only one longitudinal edge 2c.

[0056] Fig. 5b shows the flat conductor 2 from the broad surface 2b. It can be seen that a friction stir weld zone 14 extending longitudinally from the broad surface 2b is formed. Three (of which any two can be selected) connecting tabs 10 are attached to the surface 2a of the flat conductor 2 opposite the broad surface 2b. The friction stir weld zone 14 extends through the entire flat conductor 2 into the connecting tabs 10. As can be seen on the left, one connecting tab 10 can project beyond an end edge 2d of the flat part 2. As can be seen in the middle, one connecting tab 10 can project beyond a longitudinal edge 2c of the flat part 2. As can be seen on the right, one connecting tab 10 can project beyond both longitudinal edges 2c of the flat part 2.

[0057] For this purpose, as schematically shown in Fig. 6, a friction stir welding tool 16 is pressed onto the wide surface 2b. A shaft 16' presses the flat conductor 2 against a work plate 18 and clamps the connecting tabs 10 between the work plate 18 and the flat conductor 2. Either the entire friction stir welding tool 16 or only the friction stir welding pin 16" is driven into the flat conductor 2 in an oscillating or rotating motion in a direction 22 at an angle α < 90° to the surface 2b.

[0058] The high pressure of the shaft 16' and / or the oscillating movement of the tool 16 plasticizes the material of the flat conductor 2. Furthermore, the oscillating movement of the pin 16" or the entire tool 16 mixes the material of the flat conductor 2. The pin 16" penetrates the flat conductor 2 to such an extent that the material of the connecting tabs 10 is also partially plasticized and mixed with the plasticized material of the flat conductor.

[0059] In this welding process, the friction stir welding tool 16 is moved through the flat conductor 2 along the direction of movement 22, which runs parallel to the longitudinal axis 4, whereby the friction stir welding joining zone 14 is formed along the direction of movement 22.

[0060] At the end of the welding process, the pin 16" is moved out of the material of the flat conductor 2 in the direction of 24. During the process, a

[0061] Friction stir welding joint zone 14 through the flat conductor 2 and parts of the connecting tabs

[0062] 10.

[0063] Reference symbol list

[0064] 2 flat conductors

[0065] 2a » b wide surfaces

[0066] 2c Longitudinal edge 2d End edge 4 Longitudinal axis 6 Recess 6 Longitudinal extent

[0067] 8 Bridge

[0068] 10 Connecting tab

[0069] 10a, b Area 12a Bolt 12b Through hole 14, 14', 14 Friction stir welding joint zone 16 Friction stir welding tool 16' Shank

[0070] 16" pin

[0071] 18 worktop

[0072] 20-24 Direction of movement

Claims

Patent claims 1. Connection arrangement with a metallic flat conductor having at least a square cross-sectional profile and at least two 5 first and second surfaces, which are at least partially parallel to each other in the longitudinal direction, and at least two connecting tabs, which overlap on the first surface and project beyond at least one edge of the flat conductor, are characterized in that a metallic friction stir welding joining zone is formed extending from the second surface through the flat conductor to the first surface and into the connecting tabs.

2. Connection arrangement according to claim 1, characterized in that the friction stir welding joining zone is formed from material of the flat conductor and the connecting tabs which is plasticized during joining.

3. Connection arrangement according to claim 1 or 2, characterized in that the friction stir welding joining zone in the flat conductor is formed continuously over at least two connecting tabs along the longitudinal axis of the flat conductor, in particular that two separate friction stir welding joining zones with at least two connecting tabs each are formed along the longitudinal axis of the flat conductor.

4. Connection arrangement according to one of the preceding claims, characterized in that the flat conductor is plasticized continuously along its longitudinal axis along the friction stir welding joining zone during joining and the connecting tabs are positioned at intervals to each other on the flat conductor in the joining zone.

5. Connection arrangement according to one of the preceding claims, characterized in that the flat conductor is made of an aluminum material or a copper material and / or that the connecting tabs are made of an aluminum material or a copper material.

6. Connection arrangement according to one of the preceding claims, characterized in that the friction stir welding joining zone is formed from a copper material or an aluminum material, in particular wherein an intermetallic phase is formed in the friction stir welding joining zone between the materials of the flat part and the connecting tabs.

7. Connection arrangement according to one of the preceding claims, characterized in that the flat conductor and the connecting tabs are made of different metallic materials, in particular that the flat conductor is made of a less rigid, in particular less compression-resistant material than the connecting tabs.

8. Connection arrangement according to one of the preceding claims, characterized in that, that at least one of the connecting tabs is arranged in a recess formed on the first surface of the flat conductor and that webs are formed between the recesses.

9. Connection arrangement according to one of the preceding claims, characterized in that the recess of the first surface of the flat conductor is formed from the material of the flat conductor or that plates forming the webs are placed on the flat conductor.

10. Connection arrangement according to one of the preceding claims, characterized in that the connecting tabs rest on the flat conductor with a first surface and are planar with the webs with a second surface opposite the first surface.

11. Connection arrangement according to one of the preceding claims, characterized in that at least one of the connecting tabs has a first end face flush with a first longitudinal edge of the flat conductor and a second The end face projects beyond a second longitudinal edge of the flat conductor opposite the first longitudinal edge, or that at least one of the connecting tabs projects beyond a first longitudinal edge of the flat conductor with a first end face and projects beyond a second longitudinal edge of the flat conductor opposite the first longitudinal edge, or that at least one of the connecting tabs projects beyond an end face of the flat conductor with a first end face.

12. Connection arrangement according to one of the preceding claims, characterized in that, that the flat conductor is plasticized throughout its entire material thickness in the friction stir welding joint zone and that the connecting tabs are only partially plasticized in the friction stir welding joint zone.

13. Connection arrangement according to one of the preceding claims, characterized in that the friction stir welding joint zone has a width transverse to its longitudinal extent which corresponds to at least 50% of the material thickness of the flat parts.

14. Connection arrangement according to one of the preceding claims, - characterized in that the friction stir welding joining zone extends continuously along the longitudinal axis of the flat conductor.

15. Method for producing a connection arrangement comprising the steps of providing a metallic flat conductor with at least a square cross-sectional profile and at least two opposing first and second surfaces that are at least partially parallel to each other in the longitudinal direction, Placing at least two connecting tabs with an overlap on the first surface of the flat conductor, such that the connecting tabs project beyond at least one of the edges of the flat conductor, characterized in that the flat conductor with the connecting tabs is joined through the flat conductor by means of friction stir welding, wherein a friction stir welding joining zone is formed extending from the second surface through the flat conductor to the first surface and projecting into the connecting tabs.