Electrical feedthrough

Abstract

An electrical bushing (2) is provided, comprising a base body (10) with at least one opening (12) and an electrical conductor (30) passing through the opening (12), wherein the conductor (30) is held in the opening (12) by a fixing material (20) and the fixing material (20) seals the opening (12), and wherein the base body (10) has a shape with a longitudinal side of length L, a transverse side of width D and a thickness D, where the length L is greater than the width B and the width B is greater than the thickness D. Furthermore, it is provided that the base body (10) is made of a metal material whose fiber orientation (16) is aligned parallel to the longitudinal side and that the base body (10) is provided, at least along the edges of the longitudinal side, with a rounding (18) having a radius r in the range of 0.5 mm to 2 mm.

Description

[0001] The invention relates to an electrical feedthrough comprising a base body with at least one opening and an electrical conductor passing through the opening, wherein the conductor is held in the opening by a fixing material and the fixing material seals the opening, and wherein the base body has a shape in which its length is greater than its width and its width is greater than its thickness. A further aspect of the invention relates to a method for manufacturing such an electrical feedthrough. State of the art

[0002] Enclosures for electrical or electronic components typically require numerous electrical feedthroughs to allow electrical connections from the outside into the interior of the enclosure, which may contain, for example, parts of an electric compressor (E-compressor). These electrical feedthroughs must be liquid-tight or even hermetically sealed to protect the components inside the enclosure from the environment and / or to contain gases or liquids. To achieve such liquid-tight or hermetically sealed feedthroughs for an electrical conductor located in an opening of the enclosure, metal-fixed feedthroughs can be used. A fixing material, such as a glass material, is used to seal the opening and hold the conductor in place. The fixing material also provides electrical insulation between the conductor and the enclosure.

[0003] In known bushings, a substantially plate-shaped element forms a base body through which the electrical conductors pass. This base body can then be inserted into an opening in the housing of an electrical or electronic device, such as an electric compressor. To ensure a seal between the base body and the housing, the sealing surfaces on the base body must be flat. Accordingly, the base body must not bend when it is attached to the housing, for example, via a screw connection.

[0004] From EP 3936722 A1, an electric compressor connection terminal in the form of a plate-shaped element with several through-holes for electrical conductors is known. The plate-shaped element has several through-holes, with the conductors passing through each through-hole and held with a glass or glass-ceramic material, thus forming a glass-metal seal. To increase the bending stiffness of the plate-shaped element, a raised or thickened edge is provided at the perimeter and / or a raised or recessed area is formed by embossing.

[0005] The familiar base bodies for electrical bushings are typically cut or punched from a strip of material and then punched and formed in several steps until they reach their final shape. Cutting or punching from the strip material generates waste, which can amount to up to 50% of the original material. In a typical punching process, where the base body is manufactured from a rolled flat strip, the outer contour of the base body is punched out of the strip in several steps. The punching process also creates a burr and a draw-in edge on the base body, and the burr must be deburred after punching.

[0006] Furthermore, the known basic shapes require reinforcement structures, such as raised and reinforced edges. These must be provided in further complex forming steps and require additional material.

[0007] It is therefore an object of the invention to provide an electrical feedthrough with a base body, wherein the base body is to be manufactured in a material-saving manner and has a high bending stiffness. Disclosure of the invention

[0008] An electrical bushing is proposed, comprising a base body with at least one opening and an electrical conductor passing through the opening, wherein the conductor is held in the opening by a fixing material and the fixing material seals the opening, and wherein the base body has a shape with a longitudinal side of length L, a transverse side of width B and a thickness D, where the length L is greater than the width B and the width B is greater than the thickness D. Furthermore, it is provided that the base body consists of a metal material whose fiber orientation is oriented parallel to the longitudinal side and that the base body is provided with a rounding, at least along the edges of the longitudinal side, which has a radius r in the range of 0.1 mm to 2 mm, preferably in the range of 0.5 mm to 1.5 mm, and particularly preferably from 0.75 mm to 1.0 mm.

[0009] The base body is preferably plate-shaped with a substantially rectangular shape. The longitudinal side, and thus the longitudinal edges of the base body, are straight. The transverse side of the base body can also be straight, but curved shapes and combinations of straight and curved sections are also possible. For example, the transverse side can have an arc shape whose radius corresponds substantially to half the width B / 2 of the base body. Furthermore, a straight section in the middle with curved transitions to the longitudinal sides can be provided. Another example is a curved section in the middle of the transverse side that transitions into the longitudinal side via two short straight sections or chamfers.

[0010] The base body preferably has a vertical edge, wherein the edge or the surface of the edge forms an angle of substantially 90° with the top and bottom surfaces of the base body. "Substantially" includes manufacturing tolerances, in particular deviations in the angle of + / - 5°.

[0011] The intended rounding is present at least on the edges of the long side, which form the transition between the top or bottom surface and the vertical edge.

[0012] Metal parts, especially formed metal parts, exhibit a fiber-like structure known as fiber orientation or metallurgical flow lines. The fiber orientation can be visualized, for example, in a cross-section of the metal part using a wet chemical etching process. The fiber orientation, and in particular its direction, is influenced by forming processes such as deep drawing.

[0013] Since the metal material exhibits its greatest mechanical stability parallel to the fiber direction, the longest side of the base body, which is therefore most susceptible to distortion or bending, is designed to be aligned parallel to the fiber direction. This improves the bending stiffness along the longest direction of the base body without the need for additional material.

[0014] Preferably, the base body is made from a wire profile, which can be obtained by rolling a wire. In wire material, the fiber orientation is aligned along the wire direction due to the wire drawing process. By rolling the wire, the cross-sectional shape of the wire material can be adjusted without changing the fundamental orientation of the fiber orientation. Preferably, the base body is obtained from a wire profile whose cross-section has a height equal to the thickness of the base body and a width equal to the width of the base body. By cutting off a piece with a length equal to the length of the base body, the base body with length L, width B, and thickness D is obtained. Since the long side is aligned along the wire drawing direction of the wire profile, the fiber orientation is parallel to the long side of the base body.

[0015] Since the base body is cut from the wire profile at its shorter side with width B, the cutting or punching length is significantly shorter compared to cutting it from a sheet or cutting it from the long side with length L. This allows the base body to be manufactured with a smaller punching machine and with reduced tooling requirements.

[0016] The body of the bushing preferably comprises several openings, each through which an electrical conductor is passed and held by the fixing material. The fixing material seals against the wall of the opening and the conductor. The bushing preferably comprises between two and five conductors; for example, exactly three electrical conductors are passed through it. Alternatively, the bushing can also comprise exactly one electrical conductor.

[0017] The main body may include additional openings that serve as mounting points. These mounting points allow the feedthrough to be attached to a housing component, for example, using screws.

[0018] At least the openings through which an electrical conductor passes and is held by the fixing material preferably have a sharp edge at the transition of an inner wall of the opening to the surfaces of the top and bottom of the base body. An edge is considered sharp, in particular, if it is not rounded or chamfered, or if it has a rounded or chamfered edge with a radius or size of less than 0.1 mm, particularly preferably less than 0.05 mm, and most preferably less than 0.01 mm. Since an abrupt, perfectly sharp transition is not practically feasible, the radius of the sharp edge is generally greater than 50 nm. The sharp edges of the opening can be produced, for example, by punching.

[0019] Sharp edges at the transition to the inner walls of the opening have the advantage that the fixing material and the inner wall abut each other on a straight, vertical surface. With a rounded edge or chamfer, the wall would curve away from the fixing material in the area of ​​its upper edge, thus weakening the connection between them. Under mechanical stress, pieces of the fixing material could chip off in this area, weakening the entire penetration or causing leaks.

[0020] Furthermore, one or more notches can be arranged along the outer edge or contour of the base body. These notches allow for unambiguous orientation of a base body that is otherwise symmetrical along one or more points or along one or more planes. In particular, they make it possible to distinguish the top side of the base body from its bottom side. In stamping processes, a difference between the top and bottom sides of a component typically results from a slight bend or curvature, with the top side being, for example, slightly convex and the bottom side slightly concave. For installing the feedthrough into a housing, one of these orientations may be more advantageous than the other.

[0021] A sealing area may be provided on the top and / or bottom of the bushing's base body. This area is essentially smooth and flat, and in particular free of notches and scratches. A sealing element, such as an O-ring, can seal against this sealing area of ​​the base body and against a sealing area on the housing.

[0022] The openings, in particular the passage openings for the conductors and / or the mounting holes, can be created by punching. It is possible to perform the cutting of the base body from the wire profile and the punching of the openings in a single combined cutting and punching step.

[0023] Preferably, the base body is provided with a chamfer and / or a fillet along its entire outer edge, and thus along all edges of the base body's outer contour. The edges of the outer contour or outer edge particularly include those edges that form the transition from the top or bottom of the base body to the vertical edge. The fillet of the remaining edges, i.e., all edges of the outer contour except those on the longitudinal side, but at least those on the transverse side of the base body, preferably has a radius r' in the range of 0.1 mm to 2 mm, particularly preferably in the range of 0.5 to 1.5 mm, and most preferably in the range of 0.75 mm to 1.0 mm. Preferably, the radius r' of the remaining edges, or at least the edges on the transverse side of the base body, is identical to the radius r of the fillet of the longitudinal edges. In the case of a chamfer, a stepped transition between the top or bottom of the base body is created.The chamfer is created between the underside and the vertical edge, with the transition occurring in at least two steps, each less than 90°, instead of an angle of approximately 90°, e.g., 45° each or 30° and 60°. The chamfer size is the distance between these two steps, with the size being in the range of 0.1 mm to 2 mm, preferably in the range of 0.5 mm to 1.5 mm, and particularly preferably from 0.75 mm to 1.0 mm.

[0024] By incorporating rounded edges and / or chamfers that encompass the entire outer edge of the base body, sharp corners and edges are avoided. This ensures a uniform outer edge of the base body, which is mechanically stable. Furthermore, it prevents sharp outer edges from striking and damaging the surfaces or edges of other base bodies or bushings when processing many of them as bulk material. This is particularly advantageous when the base body of the bushing has a flat and smooth sealing area. Notches or undesirable roughness caused by multiple bushings or base bodies striking each other can impair the sealing effect when the sealing area interacts with a sealing element such as an O-ring.

[0025] Preferably, the aspect ratio L / B of the longest side L to the width B of the base body is in the range of 1.5 to 10, particularly preferably in the range of 2 to 5. Larger aspect ratios allow more conductors to be arranged side by side in the same electrical bushing. Since a rolled wire profile is preferably the starting material for the base body in order to achieve the advantageous fiber orientation in the metal material, its size cannot be arbitrarily large.

[0026] Preferably the base body is made of metal, wherein the metal is preferably selected from the group comprising steel, in particular unalloyed steel such as a steel with material number 1.0338 or stainless steel, NiFe, Kovar, titanium and copper.

[0027] Preferably, the base body is provided with a surface coating, in particular a nickel layer. The coating can increase the resistance of the base body material, especially against corrosive environmental influences.

[0028] The surface coating is preferably a nickel layer, which can be deposited electroplated or chemically onto the surface of the metal base material. In the case of electroplating, the coating is preferably obtained by barrel plating. The coating is preferably applied to the entire surface of the base and is preferably free of gaps or defects.

[0029] The electrical conductor consists of an electrically conductive conductor material, such as a metal. Preferably, the at least one electrical conductor consists of a conductor material selected from the group comprising steel, in particular stainless steel, a nickel-iron alloy, and copper. Furthermore, the conductor may have a core made of a highly conductive material, such as copper, and an outer sheath of a different material.

[0030] The fixing material is preferably a glass material, a glass-ceramic material, or a ceramic material. Alternatively, the fixing material can also be a plastic. The fixing material is an electrical insulator. It holds the electrical conductor in the opening of the base body and electrically insulates it from the base body. Furthermore, the fixing material seals the opening against the inner wall and the electrical conductor.

[0031] Preferably, the base body, the at least one conductor, and the fixing material form a metal-fixing material feedthrough in the form of a pressure glazing. Accordingly, a first coefficient of thermal expansion of the base body is preferably selected to be greater than a second coefficient of thermal expansion of the fixing material. To obtain a pressure glazing, the difference between the first and second coefficients of thermal expansion should preferably be at least 2 ppm / K and more preferably at least 5 ppm / K in the temperature range of 300 K to 600 K. A third coefficient of thermal expansion of the conductor material of the electrical conductor is preferably selected such that it is approximately equal to or less than the second coefficient of thermal expansion of the fixing material. Two coefficients of thermal expansion are considered to be approximately equal if the difference is less than 2 ppm / K.

[0032] In conjunction with the design of the feedthrough as a pressure glass feedthrough, in which the fixing material is under compressive pressure through the base body, it is particularly advantageous that the base body described herein, by aligning the fiber orientation or the metallurgical flow lines parallel to the longitudinal side with length L, exhibits particularly high strength with low material consumption and small size.

[0033] As an alternative to pressure glazing, the material of the base body, the fixing material, and the conductor material can be selected such that their respective coefficients of thermal expansion are approximately equal, with a difference of less than 2 ppm / K being considered approximately equal. In this variant, the base body, the at least one conductor, and the fixing material form a customized metal-fixing material bushing.

[0034] The formed metal-fixing material feedthrough is preferably hermetically sealed, wherein a feedthrough with a He leakage rate of less than 1·10 -7 mbar l / s, preferably less than 1·10 -8 mbar l / s at a pressure difference of 1 bar is considered hermetically sealed.

[0035] The electrical bushings described herein are particularly suitable for compressors. Specifically, they are ideally suited for use in electrically driven compressors, so-called e-compressors, which are used to cool the interior of electric vehicles.

[0036] Accordingly, the electrical feedthrough is preferably designed as a connection terminal for an electric compressor.

[0037] Another aspect of the invention is the provision of a method for manufacturing the electrical bushings described herein. Accordingly, features described in the context of the electrical bushings apply to the methods, and conversely, features described in the context of the methods apply to the electrical bushings.

[0038] A method for manufacturing one of the electrical bushings described herein comprises, in a first step, providing a wire material, wherein the wire material has been formed by rolling into a cross-sectional shape in which the dimension of a long side corresponds to the width B of a transverse side of the base body and the dimension of a short side corresponds to the thickness D of the base body of the bushing.

[0039] Subsequently, a blank is cut from the wire material, wherein the length of one longitudinal side of the blank corresponds to the length L of the longitudinal side of the base body, openings are created in the blank, a fixing material blank and a conductor are inserted into at least one of the openings, and a temperature treatment is carried out to form the fixing material from the fixing material blank.

[0040] Preferably, prior to inserting the fixing material blank and the conductor, a step is taken to introduce chamfers and / or radii with a radius r' on the edges of the blank that were created on the transverse sides by the cutting process. This refers in particular to those edges that transition from a top or bottom surface of the blank to vertical side walls of the blank.

[0041] Preferably, when separating, a straight edge is produced on the transverse side, a curved edge is produced on the transverse side, or a combination of at least one straight and at least one curved section is produced.

[0042] Preferably, the steps of separating the blank, creating the openings and optionally introducing the chamfers and / or rounding on the edges of the transverse sides are carried out in a single work step.

[0043] Preferably, the base body is electroplated with nickel using a barrel plating process after it has received its final shape, i.e., after cutting, forming the openings and, if necessary, rounding the edges, and before carrying out the temperature treatment.

[0044] In drum coating, a conductive drum establishes an electrical contact with the substrates to be coated. The substrates, along with the electrolyte, are located inside the rotating drum, ensuring that all surfaces are coated evenly.

[0045] This process advantageously utilizes the fact that the base bodies each have exclusively rounded or chamfered edges on their outer contours. Within the drum, the base bodies maintain electrical contact with the drum and with adjacent base bodies, enabling electroplating. As the drum rotates, the base bodies move relative to one another and collide, with different parts of each base body being exposed to the electrolyte. Thanks to the rounded or chamfered edges, the surface of the base bodies remains smooth and free of nicks and / or scratches. Sealing surfaces are thus preserved.

[0046] Unlike electroless nickel plating methods, the electrolytically deposited nickel layer contains no phosphorus or is, apart from impurities, free of phosphorus. Compared to galvanic processes, where the components to be coated are individually electrically contacted with an electrode, the coating is completely continuous and has no defects at the point of electrical contact.

[0047] The invention will be described in more detail below with reference to the figures and without limitation thereto. Identical reference numerals denote identical or similar elements.

[0048] They show: Fig. 1: a rolled wire material as a starting product, Fig. 2: a basic body obtained from the wire material in a perspective view, Fig. 3: the basic body of the Fig. 2 in a sectional view from the side, Fig. 4: another embodiment of the basic body in perspective view, and Fig. 5: an electrical feedthrough with a base body.

[0049] Fig. Figure 1 schematically shows a rolled wire material 1. The wire material 1 has a cross-sectional shape which has a length corresponding to the width B of a transverse side 22 of the base body 10 to be produced, compare Fig. 2. The height H of the cross-sectional shape of the wire material 1 corresponds to the thickness D of the base body 10 to be produced.

[0050] The rolled wire material 1 is obtained, for example, by rolling a round, drawn wire. Through rolling, the original circular cross-section is transformed into the... Fig. Figure 1 shows the cross-sectional form as a rectangle with rounded corners. The rounded corners represent a rounding 18 of the longitudinal edges 24 of the rolled wire material 1 with a radius r.

[0051] Fig. Figure 2 shows a basic body 10 with, in this example, three openings 12. The basic body 10 has a substantially rectangular shape with a longitudinal side 24 of length L, a transverse side 22 of width B and a thickness D.

[0052] The base body 10 has a vertical edge 34, wherein the vertical edge 34, or the surface of the vertical edge 34, forms an angle of substantially 90° with the top surface 32 and the bottom surface of the base body 10, respectively. At the transitions from the top surface 32 and the bottom surface of the base body 10 to the vertical edge 34, the base body 10 has edges 23 and 25.

[0053] The longitudinal sides 24 of the base body 10 are straight, the transverse sides 22 are in the example of the Fig. 2 composed of two curved sections 26 with a radius R and one straight section 28, wherein the two curved sections 26 are arranged adjacent to the longitudinal side 24.

[0054] The basic body 10 was made from the one in Fig. The wire material 1 shown in Figure 1 is obtained by cutting a blank of length L, introducing the openings 12, and rounding the transverse edges 23. The longitudinal edges 25 are already rounded before cutting, since the longitudinal side 24 of the wire material 1 already has corresponding radii 18. In the section shown in Figure 1, the wire material 1 is formed by cutting a blank of length L, making openings 12 and rounding the transverse edges 23. The longitudinal edges 25 are already rounded before cutting, since the longitudinal side 24 of the wire material 1 already has corresponding radii 18. Fig. In the embodiment shown in Figure 2, the same radius r was chosen for rounding the transverse edges 23 as for rounding the longitudinal edges 25. However, it is of course possible to choose a different radius r' for the transverse edges 23 or to provide a chamfer instead of a rounding 18.

[0055] By rounding all edges 23, 25 of the outer contour of the base body 10 with radii 18, the base body 10 has no sharp edges on its outer contour that could damage the surfaces of the base body 10 when a large number of base bodies 10 are handled as bulk material. Thus, surfaces such as the top surface 32 of the base body 10, which can serve, for example, as a sealing surface, remain free of damage such as scratches or notches. Sealing surfaces of the base body 10 remain smooth and free of defects.

[0056] In contrast, edges at the transitions between the walls of the openings 12 and the surface 32 remain free of rounding or chamfering and are therefore sharp-edged. This improves the adhesion of the fixing material 20, compare Fig. 5, to the wall of the opening 12.

[0057] Fig. Figure 3 shows the basic body 10 of the Fig. Figure 2 shows a sectional view from the side. The base body 10 is made of a drawn metal material. In the sectional view, a fiber orientation 16, or the direction of the metallurgical flow lines, is indicated. The fiber orientation 16 runs parallel to the longitudinal side of the base body 10. The metal material exhibits its greatest mechanical stability parallel to the fiber orientation 16. Accordingly, the fiber orientation 16 is advantageously aligned parallel to the longest side of the base body 10, which is most susceptible to distortion or bending. This improves the bending stiffness along the longest direction of the base body 10 without the need for additional material.

[0058] Fig. Figure 4 shows another embodiment of the basic body 10 in perspective view.

[0059] The basic body 10 exhibits in the Fig. The example shown in section 4 again shows an essentially rectangular basic shape with a long side 24 and a short side 22. In contrast to the example shown with reference to the Fig. 2 and Fig. In the embodiment shown in Figure 3, the transverse sides 22 are designed as a curved section 26 with radius R, wherein the curved section 26 transitions into the longitudinal sides 24 via a straight section 28 or a chamfer. The radius R of the curved section 26 corresponds essentially to half the width B / 2 of the base body 10.

[0060] The basic body 10 is essentially symmetrical, so that it appears the same from above and below. To better distinguish a top surface 32 from a bottom surface of the basic body 10, the following is included in the Fig. In the example shown in Figure 4, a notch 19 is provided. The notch 19 eliminates the symmetry of the base body 10.

[0061] Furthermore, the base body 10 of the Fig. 4 in addition to the openings 12 for the passage of ladders 30, compare Fig. 5, two more fastening openings 14. The fastening openings 14 allow the base body 10 or a feedthrough 2 encompassing the base body 10 to be screwed in place, see Figure 5. Fig. 5, with a case.

[0062] Fig. Figure 5 shows an electrical feedthrough 2 with a base body 10 as with reference to the Fig. 4 described in a schematic sectional view from the side.

[0063] In the example of the Fig. An electrical conductor 30 passes through each of the three openings 12. The electrical conductor 30 is held in place by an insulating and sealing element made of fixing material 20, the fixing material 20 tightly sealing the opening 12. Accordingly, the fixing material 20 seals against both the wall of the opening 12 and the conductor 30.

[0064] The flow lines 16 of the metal material of the base body 10 are again oriented parallel to the longitudinal side 24 of the base body 10, compare Fig. 4. This achieves optimal bending stiffness again without the use of additional material.

[0065] The additional mounting openings 14 remain open, so that the resulting electrical feedthrough 2 can be attached to a housing, for example, using screws. For instance, the feedthrough 2 can be inserted into an opening in the housing of an electric compressor, with an O-ring seal acting between a sealing surface on the housing and a sealing surface on the top 22 of the base body 10.

[0066] Although the present invention has been described using preferred embodiments, it is not limited to these, but can be modified in many ways. Reference symbol list 1 Wire material 2 electrical feedthroughs 10 basic shapes 12 Opening 14 Mounting opening 16 metallurgical flow lines / fiber orientation 18 Rounding 19th notch 20 Fixing material 22 Cross side 23 transverse edge 24 Long side 25 Long edge 26 curved section 28 straight section / chamfer 30 ladders 32 Top 34 vertical side surfaces r Radius Rounding R Radius Corner / Edge D Thickness of base body B Width of base body L Length Base body QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 3936722 A1

[0004]

Claims

[1] Electrical feedthrough (2) comprising a base body (10) with at least one opening (12) and an electrical conductor (30) passing through the opening (12), wherein the conductor (30) is held in the opening (12) by a fixing material (20) and the fixing material (20) seals the opening (12), and wherein the base body (10) has a shape with a longitudinal side (24) of length L, a transverse side (22) of width B and a thickness D, wherein the length L is greater than the width B and the width B is greater than the thickness D, characterized by , that the base body (10) consists of a metal material whose fiber orientation (16) is aligned parallel to the longitudinal side (24) and that the base body (10) is provided with a rounding (18) at least along the edges of the longitudinal side (34), which has a radius r in the range of 0.1 mm to 2 mm. [2] Electrical feedthrough (2) according to claim 1, characterized by, that the base body (10) is provided with a chamfer and / or a rounding (18) along all edges of the outer contour. [3] Electrical feedthrough (2) according to claim 1 or 2, characterized by , that the aspect ratio L / B of the longest side L to the width B of the basic body (10) is in the range of 1.5 to 10. [4] Electrical feedthrough (2) according to any one of claims 1 to 3, characterized by , that the base body (10) is made of a metal selected from the group comprising steel, in particular unalloyed steel such as 1.0338 or stainless steel, NiFe, Kovar, titanium and copper. [5] Electrical feedthrough (2) according to any one of claims 1 to 4, characterized by , that the base body (10) is provided with a surface coating, in particular a nickel layer. [6] Electrical feedthrough (2) according to any one of claims 1 to 5, characterized by , that the electrical feedthrough (2) is designed as a connection terminal for an electric compressor. [7] Method for manufacturing an electrical feedthrough (2) with a base body (10) according to any one of claims 1 to 6, wherein the method comprises - Providing a wire material (1) wherein the wire material (1) has been formed by rolling into a cross-sectional shape in which the dimension of a long side corresponds to the width B of a transverse side (22) of the base body (10) and the dimension of a short side corresponds to the thickness D of the base body (10) - Cutting a blank from the wire material (1), wherein a length of a longitudinal side (24) of the blank corresponds to the length L of the longitudinal side (24) of the base body (10), wherein the wire material (1) is already provided with a rounding (18) with radius r on its edges before cutting the blank, wherein this rounding (18) forms a rounding (18) along the edges on the longitudinal sides (24) of the base body (10) after cutting, - Creating openings (12) in the blank, - Inserting a fixing material blank and a conductor (30) into at least one of the openings (12), and - Execution of a temperature treatment to form the fixative material (20) from the fixative material blank. [8] Method according to claim 7, further comprising the introduction of chamfers and / or roundings (18) with a radius r' on the edges of the blank that have been created on the transverse sides by cutting. [9] Method according to claim 7 or 8, wherein during separation a straight edge is produced on the transverse side (22), a curved edge is produced on the transverse side, or a combination of at least one straight and at least one curved section is produced. [10] Method according to any one of claims 7 to 9, characterized by, that the cutting of the blank, the creation of the openings (12) and optionally the introduction of the chamfers and / or roundings (18) on the edges of the transverse sides (22) is carried out in a single work step. [11] Method according to any one of claims 7 to 10, characterized by , that the base body (10) is electroplated with nickel after the formation of the openings (12) and before the heat treatment is carried out using a barrel plating process.

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