Power electronics device and method of manufacturing the same

Abstract

A power electronic device and a method of manufacturing the same are proposed, the power electronic device having a power converter module comprising a switching device and first and second DC voltage terminal elements, the switching device having a substrate with first and second DC voltage conductor tracks, the first and second DC voltage terminal elements being connected in an electrically conductive manner to the first and second DC voltage conductor tracks with correct polarity, and the device having first and second DC voltage connection elements, wherein the first DC voltage terminal element is connected in an electrically conductive manner to the first DC voltage connection element with correct polarity by means of a materially bonded first connection, wherein the second DC voltage terminal element is connected in an electrically conductive manner to the second DC voltage connection element with correct polarity by means of a materially bonded second connection.

Description

Technical Field

[0001] This invention describes a power electronic device and a method of manufacturing the same. The power electronic device has a power converter module having a switching device and a first DC voltage terminal element and a second DC voltage terminal element. The switching device has a substrate having a first DC voltage conductor rail and a second DC voltage conductor rail. The first DC voltage terminal element and the second DC voltage terminal element are conductively connected to the conductor rail with the correct polarity. The power electronic device also has a first DC voltage connection element and a second DC voltage connection element, wherein the first DC voltage terminal element is conductively connected to an associated DC voltage connection element with the correct polarity, and wherein the second DC voltage terminal element is conductively connected to the second DC voltage connection element with the correct polarity. Background Technology

[0002] DE 10 2009 043 181 A1 discloses a power converter device having multiple power converter assemblies, each power converter assembly having a cooling device, a power semiconductor module, and a capacitor device. In this configuration, the power semiconductor module is arranged adjacent to the capacitor device. DC load terminal elements of the power semiconductor module are connected to the capacitor device via a planar busbar, wherein the planar busbar is formed of first and second metal forming bodies having insulating intermediate layers, and the planar busbar covers the capacitor device in at least one orientation. The buses of two adjacent power converter assemblies can be connected to each other in a low-inductance manner via the first metal forming body and via the second metal forming body, the first metal forming body being connected using a first connector and a first connection device, and the second metal forming body being connected using a second connector and a second connection device. The first connector is further covered by the second connector.

[0003] DE 10 2017 109 706 B3 discloses a power electronic device designed to have a power converter module having first and second DC voltage terminal elements and first and second DC voltage connection elements, which are electrically connected to the conductor rails with the correct polarity, wherein the first and second DC voltage terminal elements and the first and second DC voltage connection elements always form a stack, wherein in each case an insulating device is arranged between them, the first DC voltage terminal element has a first opening in a first main plane that is thereby closed, the second DC voltage connection element has a second opening in a third main plane that is thereby closed and aligned with the first opening, the second DC voltage terminal element and the first DC voltage connection element are arranged in the second main plane and are laterally spaced apart from each other in the opening regions, the second main plane being arranged between the first main plane and the third main plane. In this device, clamping devices extend electrically insulatedly through the first and second openings, thereby forming a conductive clamping connection between the first DC voltage terminal element and the first DC voltage connection element and between the second DC voltage terminal element and the second DC voltage connection element. Summary of the Invention

[0004] In view of the aforementioned prior art, the object of the present invention is to provide a power electronic device having a power converter module and a method for manufacturing the same, wherein the connection between the DC voltage terminal element of the power converter module and the DC voltage connection element for external connection of the power converter module is implemented in a low-inductance manner and by means of material bonding.

[0005] According to the present invention, this objective is achieved by a power electronic device having a power converter module comprising a switching device, a first DC voltage terminal element, and a second DC voltage terminal element. The switching device has a substrate having a first DC voltage conductor rail and a second DC voltage conductor rail. The first DC voltage terminal element and the second DC voltage terminal element are conductively connected to the first DC voltage conductor rail and the second DC voltage conductor rail with the correct polarity. The power electronic device also has a first DC voltage connection element and a second DC voltage connection element, wherein the first DC voltage terminal element is conductively connected to the first DC voltage connection element with the correct polarity via a material-bonded first connection portion, and wherein the second DC voltage terminal element is conductively connected to the second DC voltage connection element with the correct polarity via a material-bonded second connection portion. In each connection region between the DC voltage terminal element and the associated DC voltage connection element, when viewed along the normal direction, the first DC voltage terminal element and the second DC voltage terminal element, as well as the first DC voltage connection element and the second DC voltage connection element, are respectively stacked, wherein an insulating device is arranged between them.

[0006] Here, the normal direction is understood to refer to the normal direction of the main surface of the corresponding terminal element or connecting element in the region of the material bonding joint. These terminal elements and connecting elements have corresponding surface connection segments there, and these surface connection segments are also aligned along this normal direction. Here, the term "along the normal direction" should be understood to refer to both positive and negative normal directions.

[0007] Preferably, the corresponding material-bonded joint is implemented as a welded joint, particularly as a laser-welded joint.

[0008] Preferably, the first connecting portion and the second connecting portion are spaced laterally perpendicular to the normal direction and connect areas that do not overlap.

[0009] It may also be advantageous for the first DC voltage terminal element or the first DC voltage connection element to rest on a support device, which is preferably designed as part of the housing of a switching device or as part of a cooling device, at least in the area of ​​the connection. In this case, the first DC voltage terminal element or the first DC voltage connection element can be arranged on the support device in the area of ​​the first connection, preferably adjacent to the first connection, by a clamping device. In this case, the clamping device can be designed as a screw connection and has an insulating sleeve that at least partially surrounds the screw connection, and thus can pass through an opening in the first DC voltage terminal element in an electrically insulating manner, and preferably also through a second opening in the second DC voltage connection element.

[0010] In particular, it is advantageous that the first DC voltage terminal element is arranged in the first main plane, the second DC voltage terminal and the first DC voltage connection element are arranged in the second main plane, and the second DC voltage connection element is arranged in the third main plane, or wherein the first DC voltage connection element is arranged in the first main plane, the second DC voltage connection element and the first DC voltage terminal element are arranged in the second main plane, and the second DC voltage terminal element is arranged in the third main plane, and the main planes are stacked in the normal direction.

[0011] In principle, it may also be advantageous for the two stacked insulating devices to overlap each other in the area between the first and second connecting parts.

[0012] Each corresponding DC voltage terminal element is advantageously designed as a metal foil or sheet, preferably with a thickness of 300 μm to 2000 μm, particularly preferably 500 μm to 1500 μm. It is also advantageous that the corresponding insulating device is formed of a plastic material with high dielectric strength, particularly of polyimide, ethylene tetrafluoroethylene copolymer, or liquid crystal polymer, preferably with a thickness of 50 μm to 500 μm, particularly preferably 75 μm to 150 μm.

[0013] In principle, the DC voltage connection element can form a DC voltage source for the power converter module and is preferably designed as part of a capacitor device.

[0014] This objective is further achieved by a method for manufacturing the aforementioned apparatus, comprising the following steps:

[0015] a. A power converter module having a first DC voltage terminal element and a second DC voltage terminal element is arranged relative to a capacitor device having a first DC voltage connection element and a second DC voltage connection element in such a way that the surface connection portion of the first DC voltage connection element is placed on the surface connection portion of the associated first DC voltage terminal element, and the first DC voltage terminal element or the surface connection portion of the first DC voltage connection element is accessible to the welding device, with the surface connection portion positioned relative to the associated surface welding portion.

[0016] b. The first connection portion is formed by soldering the first DC voltage connection element to the first DC voltage terminal element;

[0017] c. Arrange the surface connection section of the second DC voltage connection element on the surface connection section of the associated second DC voltage terminal element;

[0018] d. The second connection portion is formed on the second surface welding section by welding the second DC voltage connection element (especially using a laser welding process) to the second DC voltage terminal element.

[0019] In this approach, it is preferable that the laser beams in the two laser welding processes act on the corresponding surface welding sections from the same normal direction, preferably a negative normal direction.

[0020] In this case, it is advantageous that during step a), the DC voltage terminal elements or DC voltage connection elements are spaced apart in the regions of their respective surface connection segments and preferably at an angle relative to each other. In this case, it is advantageous that in step c), the second DC voltage terminal element (52) or the second DC voltage connection element (62) is bent in the bending region.

[0021] The surface connection section defines those portions of the terminal elements and connecting elements where a material bonding connection (i.e., preferably a laser-welded joint) is formed. The corresponding surface welding section defines those portions of the terminal elements and connecting elements to which a laser acts to form a connection.

[0022] Of course, as long as this situation is not inherently or explicitly excluded, the features mentioned in the singular in the device according to the invention, particularly the power converter module, may also exist in multiple forms.

[0023] It goes without saying that the various embodiments of the present invention can be implemented individually or in any combination to achieve improvements. In particular, without departing from the scope of the invention and regardless of whether they are disclosed in the context of an apparatus or method, the features mentioned and explained above and below can be used not only in the combinations shown, but also in other combinations or individually. Attached Figure Description

[0024] From Figures 1 to 11 Further explanations, advantageous details and features of the invention will be apparent from the following description of exemplary embodiments of the invention, illustrated schematically, or from the corresponding portions thereof.

[0025] Figure 1 The details of the first design of the power electronics during method step b) are schematically shown in cross-sectional view.

[0026] Figure 2 The power electronic device is shown during method step d).

[0027] Figure 3 A three-dimensional partial view of the power converter module of the power electronics device according to the present invention is shown.

[0028] Figure 4 The details of the second configuration of the power electronics are schematically shown in a cross-sectional view.

[0029] Figure 5A three-dimensional partial view of the power converter module of the power electronics device according to the present invention is shown.

[0030] Figure 6 A capacitor assembly for connection to the power converter module is shown.

[0031] Figure 7 The details of the third design of the power electronics device during method step b) are schematically shown in cross-sectional view.

[0032] Figure 8 The basic steps of the method according to the present invention are shown.

[0033] Figure 9 A three-dimensional view of a power electronic device according to the present invention is shown.

[0034] Figure 10 and Figure 11 The power electronics device during method step b) is shown in different three-dimensional views. Detailed Implementation

[0035] Figure 1 The details of the first design of the power electronics 1 during method step b) are schematically shown in cross-sectional view. Figure 2 The power electronic device 1 is shown during method step d). Two figures show a power converter module 2 having a switching device 4 disposed on a metal base plate 3, which is designed as a liquid-cooled device. To provide electrical insulation from and thermal coupling to the liquid-cooled device 3, the switching device 4 has an insulating material body 40, which is implemented as a ceramic body. On the side facing away from the liquid-cooled device 3, the ceramic body 40 has a plurality of conductor rails 42, which have different potentials during operation of the switching device 4. One of these conductor rails 42, namely a first DC voltage conductor, has a first DC voltage potential, while another second DC voltage conductor rail has a second DC voltage potential. As an example, the switching device 4 forms a power converter circuit.

[0036] On at least one of these conductor tracks 42, a plurality of power semiconductor devices 44 arranged in a standard manner are connected to form a circuit, the conductor track 42 together with the insulating material body 40 forming a substrate of the switching device 4. In this embodiment, the connection is implemented as a standard film composite 46, which is made of alternately stacked conductive films and electrically insulating films.

[0037] For external connectivity, the power converter module 2 has two DC voltage terminal elements 50 and 52, which are conductively connected to one of the DC voltage conductor rails 42 carrying a DC voltage potential. This connection is implemented in a standard manner, but in this unrestricted case, it is implemented as a pressure-bonded connection. These DC voltage terminal elements 50 and 52 are used for connections to associated DC voltage connection elements 60 and 62, which are preferably connected to a capacitor bank (see [link to capacitor bank]). Figure 6 Before and during method step b), the DC voltage connecting elements 60 and 62 are spaced apart from each other in the regions of their respective surface connecting sections 600 and 620, i.e., those sections of the surface connecting sections 500 and 520 to be connected to the assigned DC voltage terminal elements 50 and 52 and which are at an angle relative to each other, for example only, are right angles relative to each other. This angle is formed by bending the second DC voltage connecting element 62 at the bending region 624.

[0038] During method step b), the first DC voltage connection element 50 has been placed on the support surface 240 of the housing 20. The second DC voltage terminal element 52 terminates recessedly relative to the first DC voltage connection element 50, resulting in its surface connection section 500 being accessible from above (i.e., in the negative normal direction, i.e., in the negative z-direction). In method step a), the surface connection section 600 of the first DC voltage connection element 60 is arranged on the surface connection section 500. On the opposite surface of the surface connection section 600 is its surface welding section 602. The first weld joint 70 is formed by the action of the first laser beam 700 of the welding laser on the surface welding section 602, see [link to documentation]. Figure 2 .

[0039] In subsequent method step c), the surface connection segment 620 of the second DC voltage connection element 62 is arranged on the surface connection segment 520 of the associated second DC voltage terminal element 52. For this purpose, in the bending region 624 of the second DC voltage connection element 62, the angled segment is bent in a manner indicated by the dashed curved arrow, such that the two DC voltage connection elements 60, 62 again extend parallel to each other over the entire length shown.

[0040] like Figure 2 As shown, the action of the second laser beam 720 of the welding laser on the surface welding section 622 of the second DC voltage connection element 62 now forms the second connection portion 72, see [link to diagram]. Figure 4 Therefore, a second welding joint is formed here, the second connection 72 being between the second DC voltage terminal element 52 and the second DC voltage connection element 62.

[0041] In the region of connection between DC voltage terminal elements 50, 52 and DC voltage connection elements 60, 62, the first DC voltage terminal element 50 and the second DC voltage terminal element 52 are stacked, wherein an insulating device 54 is arranged between the two DC voltage terminal elements 50, 52, and Figure 4 The following is illustrated in an exemplary form. The first DC voltage terminal element 50 rests on the support surface 240 of the housing 20 (shown only partially) of the power converter module 2. In this design, the housing 20 is only implemented as a partial housing 22, and therefore does not completely enclose the switching device 4 as would be possible.

[0042] In the region of the surface connection section 500 of the first DC voltage terminal element 50, its path is defined by the first principal plane HE1. The region of the surface connection section 520 of the second DC voltage terminal element 52 and the region of the surface connection section 600 of the first DC voltage connection element 60 define the second principal plane HE2, which follows the first principal plane in the normal direction N (in this case, the positive z direction). The region of the surface connection section 620 of the second DC voltage connection element 62 defines the third principal plane HE3, which follows the second principal plane in the normal direction N in the direction away from the cooling device.

[0043] The housing 20 of the power converter module 2 is itself formed of a high-temperature resistant plastic, in this case, polyphenylene sulfide (PPS), which also has high bending strength. The DC voltage terminal elements 50, 52 and the DC voltage connection elements 60, 62 are implemented as thin metal sheets with a thickness of 700 μm, more precisely, copper sheets. The insulating devices 54, 64 between the DC voltage terminal elements 50, 52 and between the DC voltage connection elements 60, 62 are both made of a 100 μm thick plastic with high dielectric strength, in this case, ethylene tetrafluoroethylene copolymer or liquid crystal polymer.

[0044] Figure 3 A three-dimensional partial view of the power converter module of the power electronic device according to the present invention is shown, such as Figure 1 and Figure 2 As described herein. Cover element 26 of housing 20 is also shown here.

[0045] Figure 4 The details of the second design of the power electronic device 1 are schematically shown in cross-sectional view. The difference from the first design is that there is also a clamping device 74, which is implemented as a screw connection 740. Figure 5 A three-dimensional partial view of the power converter module 2 of the power electronic device according to the present invention is shown. Figure 6A capacitor device 8 with a capacitor element 80 and DC voltage connection elements 60 and 62 for connection to a power converter module are shown.

[0046] Here, the first DC voltage terminal element 50 has a first opening 500, and the second DC voltage terminal element 52 is recessed relative to the first opening 510 and has a laterally retracted portion. Similarly, the second DC voltage connection element 62 has a second opening 610, and the first DC voltage connection element 52 terminates in a recessed position relative to the first opening 510 and has a laterally retracted portion. Furthermore, the housing 20 also has a third opening 210 aligned with the first opening 510. All openings 210, 510, and 650 are arranged aligned with each other, with screws of the screw connection 740 passing through all openings 210, 510, and 650, and the terminal elements and connection elements are fixed to the housing 20. Alternatively, but not shown, the screws of the screw connection may also engage in another opening of the cooling device 3 fitted with internal threads, thereby additionally fixing the power converter module thereto.

[0047] Figure 7 A cross-sectional view schematically illustrates details of the third design of the power electronics 1 during method step b). (Compared to...) Figures 1 to 3 Compared to the first design, the first DC voltage connection element 60 is placed directly on the cooling device 3 in an electrically insulated manner and therefore with excellent thermal conductivity. For this purpose and purely by way of example, the cooling device has a raised portion 30 with a supporting surface 340.

[0048] The first DC voltage terminal element 50 rests on the surface connection section 600 of the first DC voltage connection element 60 with its surface connection section 500. The action of the first laser beam 700 of the welding laser on the surface welding section 602 is used to form a first weld joint, and the surface welding section is opposite to the surface connection section 600 of the first DC voltage connection element 60.

[0049] Immediately thereafter, in method step c), the surface connection portion 520 of the second DC voltage terminal element 52 is arranged on the surface connection portion 620 of the second DC voltage connection element 62. For this purpose, the second DC voltage terminal element 52 is angled in the bending region 524. At the same time, the first insulating device 54 is also angled, and then placed on the first DC voltage terminal element 50 and overlaps with the first DC voltage terminal element 50, such that the first insulating device 54 also partially overlaps with the second insulating device 64.

[0050] In step d), the action of the second laser beam 720 of the welding laser on the surface welding section 622 forms a second welding joint between the second DC voltage terminal element 52 and the second DC voltage connection element 62, with the surface welding section opposite to the surface connection section 620 of the second DC voltage connection element 62.

[0051] Figure 8 The basic steps of the method according to the invention are shown in plan view from the normal direction N, i.e. from the z direction, to the terminal element and the connecting element.

[0052] The top portion of the figure shows a first DC voltage terminal element 50 having a surface connection section 500 and a second DC voltage terminal element 52 having a surface connection section 520.

[0053] At the center, a first DC voltage connection element 60 is additionally shown, which rests on the surface connection section 500 of the first DC voltage terminal element 50 with its surface connection portion. A surface welded section 602 of each first DC voltage connection element 60 opposite to the surface connection section 600 is also shown. A laser track 704 is also shown, which is formed when a first connection is formed on the surface welded section 602 by laser welding.

[0054] Here, in some sections, the second DC voltage connection element 60 protrudes from the drawing plane along the normal direction N, and for this purpose forms an angle in its curved region 624.

[0055] The lower portion of the figure shows the second DC voltage connector 62 after it has been bent at its bending region 624, such that its surface connection segment 620 now rests on the surface connection segment 520 of the second DC voltage terminal element 52. This connection between these surface connection segments is achieved by laser welding. A laser track 724 is also shown, which is created when the second connection is formed on the surface welded segment 622 of the second DC voltage connector 62.

[0056] Figure 9 A three-dimensional view of a power electronic device according to the present invention is shown. Figure 10 and Figure 11 The power electronics device during method step b) is shown in different three-dimensional views. All the basic components shown have been described above.

Claims

1. A power electronic device having a power converter module (2) including a switching device (4), a first DC voltage terminal element (50) and a second DC voltage terminal element (52), the switching device (4) having a substrate having a first DC voltage conductor rail and a second DC voltage conductor rail (42), the first DC voltage terminal element (50) and the second DC voltage terminal element (52) being electrically connected to the first DC voltage conductor rail and the second DC voltage conductor rail (42) in the correct polarity, and the power electronic device (1) having a first DC voltage connection element (60) and a second DC voltage connection element (62), wherein the first DC voltage terminal element (50) is electrically connected to the first DC voltage connection element (60) in the correct polarity through a first connection portion (70) bonded by material; Its features are, The second DC voltage terminal element (52) is electrically connected to the second DC voltage connection element (62) with the correct polarity via a second connection portion (72) bonded by material. In the region of each connection portion (70, 72) between the DC voltage terminal element and the associated DC voltage connection element, viewed along the normal direction (N), the first DC voltage terminal element (50) and the second DC voltage terminal element (52), as well as the first DC voltage connection element (60) and the second DC voltage connection element (62), are respectively stacked, with insulating devices (54, 64) arranged between them. The corresponding material bonding joint is implemented as a laser-welded joint, and the laser beams in the two laser welding processes act on the corresponding surface welding sections from the same normal direction; and The first DC voltage terminal element (50) or the first DC voltage connection element (60) is placed on the support device (20), which is designed as part of the housing (2) of the switching device (4) or as part of the cooling device (3) in at least one of the connection portions (70, 72).

2. The power electronic device according to claim 1, characterized in that: The first connecting portion (70) and the second connecting portion (72) are separated laterally perpendicular to the normal direction (N), and the connecting portions (70, 72) do not have overlapping areas.

3. The power electronic device according to claim 1, characterized in that: The first DC voltage terminal element (50) or the first DC voltage connection element (60) is arranged on the support device (20) in the area of ​​the first connection part (70) by means of the clamping device (74).

4. The power electronic device according to claim 3, characterized in that: The first DC voltage terminal element (50) or the first DC voltage connection element (60) is arranged on the support device (20) adjacent to the first connection portion (70) by means of the clamping device (74).

5. The power electronic device according to claim 3, characterized in that: The clamping device (74) is designed as a screw connection (740) and has an insulating sleeve that at least partially surrounds the screw connection (740) and thus passes through the opening (510) in the first DC voltage terminal element (50) in an electrically insulating manner.

6. The power electronic device according to claim 5, characterized in that: The clamping device (74) passes through the second opening in the second DC voltage connection element (62) in an electrically insulated manner.

7. The power electronic device according to claim 1, characterized in that: The first DC voltage terminal element (50) is arranged in the first main plane (HE1), the second DC voltage terminal (52) and the first DC voltage connection element (60) are arranged in the second main plane (HE2), and the second DC voltage connection element (62) is arranged in the third main plane (HE3); or wherein The first DC voltage connection element (60) is arranged in the first main plane (HE1), the second DC voltage connection element (62) and the first DC voltage terminal element (50) are arranged in the second main plane (HE2), and the second DC voltage terminal element (52) is arranged in the third main plane (HE3), and the main planes are stacked in the normal direction (N).

8. The power electronic device according to claim 1, characterized in that: Two stacked insulating devices (54, 64) overlap each other in the area between the first connection and the second connection.

9. The power electronic device according to claim 1, characterized in that: Each DC voltage terminal element (50, 52) is designed as a metal foil or metal sheet.

10. The power electronic device according to claim 9, characterized in that: Each DC voltage terminal element (50, 52) has a thickness ranging from 300 μm to 2000 μm.

11. The power electronic device according to claim 9, characterized in that: Each DC voltage terminal element (50, 52) has a thickness of 500 μm to 1500 μm.

12. The power electronic device according to claim 1, characterized in that: Each insulating device (54, 64) is formed of a plastic material with high dielectric strength.

13. The power electronic device according to claim 12, characterized in that: The plastic material with high dielectric strength includes polyimide, ethylene tetrafluoroethylene copolymer, or liquid crystal polymer.

14. The power electronic device according to claim 12, characterized in that: Each insulating device (54, 64) has a thickness of 50 μm to 500 μm.

15. The power electronic device according to claim 12, characterized in that: Each insulating device (54, 64) has a thickness of 75 μm to 150 μm.

16. The power electronic device according to claim 1, characterized in that: DC voltage connection elements (60, 62) form the DC voltage source of the power converter module (2).

17. The power electronic device according to claim 16, characterized in that: The DC voltage connection elements (60, 62) are designed as part of the capacitor assembly.

18. A method for manufacturing a power electronic device, said power electronic device being the power electronic device according to any one of claims 1-17, characterized in that, It includes the following steps: a. A power converter module having a first DC voltage terminal element (50) and a second DC voltage terminal element (52) is arranged relative to a capacitor device (8) having a first DC voltage connection element (60) and a second DC voltage connection element (62) in such a way that the surface connection section (600) of the first DC voltage connection element (60) rests on the associated surface connection section (500) of the first DC voltage terminal element (50), and the surface connection section (500) of the first DC voltage terminal element (50) or the surface connection section (600) of the first DC voltage connection element (60) is accessible to the welding device (700), and the surface connection section (500, 600) is positioned relative to the associated surface welding section (502, 602); b. The first connection portion (70) is formed by soldering the first DC voltage connection element (60) to the first DC voltage terminal element (50); c. Arrange the surface connection section (620) of the second DC voltage connection element (62) on the surface connection section (520) of the associated second DC voltage terminal element (52); d. A second connection portion (72) is formed on the second surface welding sections (522, 622) by welding (720) the second DC voltage connection element (62) to the second DC voltage terminal element (52). The corresponding welding process is a laser welding process, in which the laser beams in the two laser welding processes act on the corresponding surface welding sections from the same normal direction.

19. The method according to claim 18, characterized in that: During step a), the DC voltage terminal elements (50, 52) or DC voltage connection elements (60, 62) are arranged at a distance in the regions of their respective surface connection sections (500, 520, 600, 620).

20. The method according to claim 19, characterized in that: During step a), the DC voltage terminal elements (50, 52) or DC voltage connection elements (60, 62) are at an angle relative to each other.

21. The method according to claim 19 or 20, characterized in that: In step c), the second DC voltage terminal element (52) or the second DC voltage connection element (62) bends in the bending region (524, 624).

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