WO2023110956A1 - Method for establishing an electrical contact in an electrical machine - Google Patents

Abstract

The invention relates to a method (100) for establishing a contact of a contacting element (20), in particular of a contacting wire and/or a contacting pin, in an electrical machine (10) on an electronic unit (44), in particular a printed circuit board (44a) and/or an intermediate element (44b) which is designed for electrical contact with the printed circuit board (44a). According to the invention, the method has the following steps: d) providing (110) a coupling element (40) for the electronic unit (44), said coupling element (40) having a receiving section (15), e) arranging (120) the contacting element (20) on the receiving section (15) of the coupling element (40), f) melting (130) the contacting element (20) using a laser (64) which emits green or blue laser radiation (210a, 210b) until an electrically conductive integral bond is formed between the contacting element (20) and the coupling element (40).

Description

Description

title

Method for producing an electrical contact in an electrical machine

The invention relates to a method for producing a contact of a contact element in an electrical machine and an electrical machine with an electrical contact.

State of the art

Currently, copper wires from coils of electrical machines for energizing are often realized with cold contacting techniques such as insulation displacement connections, but other forms of contacting are also known, such as resistance welding or soldering connections. Insulation displacement connections have the disadvantage that a clamp with a complex design and a corresponding space requirement, as well as local accessibility for the clamping tool, is required.

A connection using resistance welding also requires space and accessibility for the welding electrodes and the electrode holder. In the case of break-through contacts (pin in a hole) that are connected using selective soldering, there must be free space around the soldering point for accessibility and as a safety distance for neighboring components. In addition, the process control for selective soldering is very complex.

The process of selective soldering is classified as not robust and always requires a subsequent check of the connection quality - optically directly or in combination with an X-ray system. The object of the present invention is to overcome this disadvantage and to provide methods which can also be used when there is little space available. Disclosure of Invention

Advantages

The present invention describes a method for producing contacting of a contacting element, in particular a contacting wire and/or a contacting pin, in an electrical machine on an electronic unit, in particular a printed circuit board and/or an intermediate element which is designed to make electrical contact with the printed circuit board, comprising the following Steps: a) providing a coupling element for the electronics unit having a receiving section, b) arranging the contacting element on the receiving section of the coupling element, c) melting the contacting element with a laser emitting green or blue laser radiation until an electrically conductive, material connection between the contacting element and the Coupling element is formed.

With the method according to the invention, it is possible to provide contacting of a contacting element in an electrical machine that requires a significantly reduced installation space. In addition, the process time for contacting can be advantageously reduced using the method according to the invention, so that a corresponding cost advantage can be achieved. The space required during the joining of the joining partners can be significantly reduced. Due to the selected wavelength, neighboring structures can be prevented from being damaged when there is little space available in the electrical machine. This is ensured in particular by the significantly better absorption of the radiation when it is coupled into the base material.

In the context of the present invention, a coupling element can be understood in particular as an element which has an absorption factor for has "green" or "blue" laser radiation, which is at least greater than 20%, preferably greater than 30%, particularly advantageously greater than 40%.

In the context of the present invention, a laser-emitting green laser radiation-is to be understood as meaning a laser which emits laser light with a wavelength of approximately 512 nm, with approximately a tolerance range of +/-20 nm being understood. Correspondingly, within the scope of the present invention, a laser-emitting blue laser radiation-is to be understood as meaning a laser which emits laser light with a wavelength of approximately 445 nm, with approximately also meaning a tolerance range of +/-20 nm. In the following, a “green” or “blue” laser will be discussed in this context.

An intermediate element of the type in question here can be, for example, a wiring board for electronics. A contacting element can be a contacting wire or a contacting pin, for example. It is conceivable that the contacting wire itself is part of the winding of an electrical machine. Contacting pins are also conceivable for the electrical and/or mechanical contacting of the winding with the control electronics. It is conceivable that such a contacting pin is welded to the printed circuit board by means of the method according to the invention, wherein the contacting pin can have an additional insulation displacement section on the motor side for connection to the windings.

In the context of the present invention, a materially bonded connection is to be understood in particular as a contact that has materially bonded connection sections between the contacting element and the coupling element that are dimensioned in such a way that one satisfies the external loads and requirements for conductivity in an electrical machine of the type in question here Guidance support structure is provided. The laser advantageously has a continuous laser power of between 1 kW and 3 kW. In particular, contacting wires with a diameter between 0.2 mm and 3 mm, particularly advantageously between 0.3 and 2.6 mm, can be advantageously used connect between 0.5mm and 2mm to the electronics unit using laser welding. According to a particularly preferred embodiment of the invention, it is conceivable that the welding process takes place in a protective gas atmosphere.

The production of an electrical contact by means of a “green” or “blue” laser has the advantage that the contacting element with the coupling element can be produced particularly efficiently. At the same time, the formation of spatter, which can be particularly critical in the area of the electronics unit, can be reduced in a particularly advantageous manner. Due to the high degree of absorption for aluminum and copper in these wavelength ranges, the damage to neighboring structures can be reduced in a particularly advantageous manner. "Green" and "blue" laser radiation is very well absorbed by copper compared to the infrared wavelength range. This allows lower use of a laser with lower power and intensities. Compared to lasers in the infrared wavelength range, the use of "green" or "blue" lasers can advantageously minimize the risk of damaging neighboring parts or components through a reflection.

Advantageous developments of the method according to the invention are possible as a result of the features listed in the dependent claims.

According to an advantageous development, the coupling element and, alternatively or additionally, also the contacting element are designed to absorb the green and/or blue laser radiation. In the context of the present invention, an absorption element can be understood in particular as an element that has an absorptivity for “green” or “blue” laser radiation that is at least greater than 20%, preferably greater than 30%, particularly advantageously greater than 40%. According to an advantageous development of the invention, the contacting element and, alternatively or additionally, the coupling element are made of a non-ferrous metal, in particular copper or aluminum. It is also conceivable that the coupling element and, alternatively or additionally, also the contacting element are made of copper. Since copper has a particularly high degree of absorption for "green" and "blue" laser radiation, the coupling of the laser radiation into the base material can be fundamentally improved and damage to surrounding electronic components can thus be advantageously prevented.

An advantageous development of the invention provides that the receiving section has a recess for the contacting element. The receiving section preferably has a through-opening, in particular a through-hole, in which the contacting element is arranged. According to a preferred embodiment of the invention, the diameter of the through hole is larger than the diameter of the contacting element. A particularly optimized contacting can be provided in that the contacting element is pushed through the through-opening to such an extent that it has an overhang, in particular a free melting section, to the surface of the coupling element. The contacting element preferably penetrates both the electronics unit and the coupling element completely. Before the contacting element is melted, it therefore preferably has a free melting section that protrudes beyond the coupling element. The height of the free fusion section preferably correlates with the diameter of the bonding wire and the diameter of the through-hole as follows:

According to a preferred development of the invention, the electronics unit is a board, in particular a printed circuit board or an interconnection board. In the context of the present invention, a plate is to be understood in particular as a substantially flat, preferably substantially planar element, the flat surface of which is very large in relation to its thickness. In this case, the plate extends essentially in a plate plane. After its arrangement in the receiving section, the contacting element has a main extension direction. In the context of the present invention, the main extension direction is preferably to be understood as the axis of symmetry of the contacting wire in the area of the receiving section, in particular in the passage through the through-opening. An advantageous development of the invention provides that the main extension direction of the contacting element is arranged essentially perpendicular to the electronics unit. A particularly advantageous development of the invention provides that the main direction of the laser extension encloses a laser angle of between 1° and 10°, preferably between 3° and 8°, particularly preferably between 5° and 6°, with the main direction of extension of the contacting element.

In this context, a main direction of extension of the laser means the main direction of propagation of the laser radiation, in particular the axis of symmetry of the main direction of propagation of the laser radiation. The laser is thus aligned at a slight angle to the contacting element. Alternatively, the laser is oriented at an appropriate angle to the surface normal of the plane of the circuit board.

If the laser is slightly inclined in relation to the joining partner, a possible "shooting through" of the laser can be advantageously prevented by a corresponding gap between the contacting element and the coupling element. Due to the high absorption of laser radiation from "blue" and "green" lasers in copper, multiple reflections in a gap are not to be expected. This can be the case with infrared lasers, whereby components and parts underneath the electronic unit can be damaged.

An advantageous development of the invention provides that the coupling element is designed as a connecting plate which is arranged on the electronics unit, in particular connected to the electronics unit by means of a solder or is designed embedded in the electronics unit. According to a particularly advantageous development of the invention, the coupling element extends essentially parallel to the electronic unit. In particular, the connecting plate can be understood as a substantially flat, preferably substantially planar element, the planar area of which is very large in relation to its thickness. The connecting plate is preferably aligned parallel to the plane of the printed circuit board. A particularly preferred development of the invention provides that the connecting plate is arranged in the plane of the printed circuit board.

Advantageously, the connecting plate is firmly connected to the coupling element. Preferably the connecting plate has a similar thickness between and , preferably between and, more preferably between and . If the connection plate is embedded in the printed circuit board, it can be of particular advantage for the process if it is flush with the printed circuit board. The extent of the connecting plate in the plane of the board is preferably many times smaller than the extent of the printed circuit board in the plane of the board. The size of the connection plate is preferably adapted to the size of the laser spot. The volume of the connecting plate is preferably dimensioned in such a way that a sufficiently stable, materially bonded, electrically conductive connection can be provided between the coupling element and the contacting element. It is advantageous that such a coupling element can be matched to the wire in terms of its dimensions, ie its material cross section and its thermal absorption, so that the laser evenly heats the contacting element and coupling element and thus provides ideal boundary conditions for particularly fast process management.

As already mentioned, according to an advantageous development of the invention, the coupling element has a through-opening through which the contacting element is passed or pushed through. According to an advantageous embodiment of the invention, the contacting and coupling elements are dimensioned in such a way that after the contacting element has been passed through the through-opening and before the contacting element has been melted with the laser, there is a gap between the coupling element and the contacting element, preferably a circumferential gap, particularly preferably an im Substantially constantly large gap remains circumferentially.

According to an advantageous development of the invention, the diameter of the contacting element in the area of the receiving section is between 10% and 30%, in particular between 15% and 25%, particularly preferably essentially 20% larger than the width of the circumferential gap. With such a correlating area ratio between the contacting element and the gap to be bridged, on the one hand the process of inserting or leading through the contacting element is advantageously optimized and at the same time it is ensured that sufficient Melting volume is provided to bridge the gap, so that a stable contact can be made available.

In order to prevent multiple reflections in the gap and the associated undesired influence on surrounding components, a cover element can be arranged in the area of the circumferential gap. This covering element is preferably also made of aluminum or copper so that it can be melted on with the contacting element and stable contacting can be provided. According to an advantageous development of the invention, the cover element is designed as a sleeve. The cover element is preferably formed in one piece with the coupling element. After the arrangement of the contacting element in the receiving section, the cover element preferably rests against the contacting element in a circumferential contacting manner.

The cover element is preferably designed to be flatter than the coupling element.

It is also conceivable that, in order to avoid multiple reflections in the gap, the receiving section is essentially funnel-shaped. The funnel neck of the essentially funnel-shaped receiving section is preferably arranged facing the laser. When inserting the contacting element, in particular the winding wire, the contacting element is preferably passed through the funnel neck from the funnel opening side, so that the funnel opening can act as an insertion aid for the wire. An advantageous further development of the invention provides that the receiving section is designed essentially in the shape of a tulip. The contour is preferably described by a parabola rotating about a main extension direction. It is also conceivable for the receiving section to have a stripping edge, so that the wire is stripped of insulation when it is inserted into the receiving section at a free end, which can form the fusible section.

A further advantageous embodiment of the invention provides that the receiving section is designed to nestle against the contacting element. For example, it is conceivable that the receiving section is designed to be elastically deformable in such a way that it yields when the contacting element is passed through and can invest in this. It is conceivable that for this purpose the receiving section is designed to be many times thinner than the coupling element surrounding the receiving section

According to an advantageous development of the method, the coupling element, in particular the receiving section, can be equipped with an embedded solder paste. If this point is sufficiently heated by the laser, a solder joint is created. It is also conceivable that the solder is also supplied laterally as a tubular solder. This is particularly advantageous when the gap to be bridged between the coupling element and the contacting element is very large. By arranging a solder paste or a solder paste prepreg (pressed solder paste, e.g. in the shape of a circular ring that can be placed over the wire) at the gap, this can be bridged particularly reliably by the solder as the filling material. The solder can be arranged on the coupling element either before or after the contacting element is passed through.

The invention also relates to an electrical machine - in particular an electronically commutated electric motor - with a stator having electrical windings with at least one contacting element forming the winding or at least one contacting element for interconnecting the windings, with an electronic unit having a coupling element with a receiving section for energizing the windings , is provided. It is proposed that the electrical contact between the contacting element and the coupling element be produced by melting the contacting element with a laser emitting green or blue laser radiation until an electrically conductive, material connection is formed between the contacting element and the coupling element.

drawings

In the drawings, exemplary embodiments of the method for producing contacting of a contacting element are shown and explained in more detail in the following description. Show it The same parts are given the same reference numbers in the different design variants.

Figure 1 shows a schematic representation of the method,

Figures 2a-2c sectional views of an electronics unit with a contacting element according to one embodiment of the invention, Figure 3 is a schematic sectional view of an electronics unit with a contacting element according to a further embodiment of the invention, Figure 4 is a schematic sectional view of an electronics unit with a contacting element according to a further embodiment of the invention.

FIG. 1 schematically shows the process sequence of a method 100 for producing the contacting of a contacting element 20. Such a contacting element 20 can be, for example, a contacting wire or a contacting pin. In a first method step 110, a coupling element 40 is provided. The coupling element 40 is preferably arranged on a circuit board 44a or an intermediate element 44b, such as a wiring board of an electronic unit 44. The coupling element 40 preferably has a receiving section 15 . The receiving section 15 can be a through-opening in the coupling element 40, for example.

In a second method step 120 the contacting element 20 is arranged on the receiving section 15 . In this method step 120 , the contacting element 20 is thus brought into the vicinity of the coupling element 40 . During method step 120, contacting element 20 is preferably brought closer to coupling element 40 at a distance of more than 1 mm. In a third method step 130, the contacting element 20 is melted with a laser 64 emitting green or blue laser radiation 210a, 210b until an electrically conductive, material connection is formed between the contacting element 20 and the coupling element 40.

In the figures 2a to 2c, the method is shown according to an embodiment of the invention. According to the embodiment of the invention shown in FIG. 2a, the electronics unit 44 is designed as a printed circuit board 44a. The printed circuit board 44a essentially extends in a horizontal plane. The printed circuit board 44a has a through opening 90 . The coupling element 40 is advantageously arranged in the area of the through opening 90 of the printed circuit board 44a. The coupling element 40 is preferably connected to the circuit board 44a by means of a coupling means 42, such as a solder. According to the embodiment of the invention shown in FIG. 2, the coupling element 40 advantageously extends essentially parallel to the printed circuit board 44a.

The coupling element 40 preferably has a connection section 15 . According to the embodiment of the invention shown in FIG. The two through openings 90, 91 of the coupling element 40 and the printed circuit board 44a are preferably arranged essentially collinear, in particular axially parallel to one another. The through-openings 90, 91 are preferably arranged one above the other in such a way that a common through-opening for the contacting element 20 is provided.

According to the embodiment of the invention shown in FIG. 2, the coupling element 40 is preferably designed as a copper plate. After the first method step 110, the provision of the coupling element 40, in particular the arrangement or soldering of the coupling element 40 on the printed circuit board 44a, a contacting element 20, preferably a copper wire or copper pin, is guided through the receiving area 15 of the coupling element 40. According to the embodiment of the invention shown in FIG. 2, the contacting element is passed through the common passage opening of the coupling element 40 and the printed circuit board 44a.

According to an advantageous development of the invention, the contacting element 20 is designed as a copper wire and has an optionally insulated section 22 . The stripped free end 21 of the copper wire is preferred carried out in such a way through the coupling element 40 that it stands over the coupling element 40 . After its arrangement on the coupling element 40 (method step 120), the contacting element 20 thus preferably has a free fusible section 54 that protrudes beyond the surface of the coupling element 40. The contacting element 42 preferably has a main extension direction 62 . According to an advantageous development of the invention, the main extension direction 62 is preferably aligned essentially perpendicularly to the extension plane of the printed circuit board 44a.

After the contacting element 20 has been passed 120 through the coupling element 40, the fusible section 54 is melted with a laser 64 emitting green or blue laser radiation 210a, 210b until an electrically conductive, materially bonded connection is formed between the contacting element 20 and the coupling element 40. This results in a very good conductive material connection between the contacting element 20 and the coupling element 40.

According to a particularly advantageous development of the invention, the dimensions and material selection (e.g. thermal absorption) of the coupling element are matched to the contacting element 20 in such a way that the laser 64 heats both the coupling element 40 and the contacting element 20 essentially simultaneously, thereby reducing the cycle time and Quality of the process can be significantly improved. By using a laser 64, which emits green or blue laser radiation 210a, 210b, the laser radiation 210a, 210b can be absorbed particularly well by the coupling element 40 and contacting element 20 (in comparison to the infrared wavelength range). This allows the use of a laser 64 of particularly low power and intensity. On the other hand, the use of green or blue lasers minimizes the risk of damaging neighboring parts or components in such an electric motor through a reflex.

Figure 2a shows a section of an electrical machine 24 before the step of melting 130 and after the steps 110, 120 of arranging the Coupling element 40 and the contacting element 20. Both the coupling element 40 and the contacting element 20 are preferably designed as absorption elements for absorbing the laser radiation 210a, 210b. Both the coupling element 40 and the contacting element 20 preferably have a non-ferrous metal, in particular copper or aluminum. Both the coupling element 40 and the contacting element 20 are preferably made of copper. Both the coupling element 40 and the contacting element 20 are preferably made of copper.

According to the embodiment of the invention shown in FIG. 2a, the coupling element 40 preferably has a through-opening 90 with an opening diameter 50, through which the contacting element 20 is passed or pushed through. Preferably, the contacting element 20 and the through-opening 90 of the coupling element 40 are dimensioned such that after the contacting element 20 has been passed through the through-opening 90 and before the contacting element 40 is melted 130 with the laser 64, a gap 92 remains between the coupling element 40 and the contacting element 20 . Preferably, the gap 92 is circumferential. Preferably, the spacing between the contacting element 20 and the coupling element is equidistant around the circumference.

The contacting wire 20 preferably has a wire diameter of between 0.2 and 3 mm, in particular between 0.3 mm and 2.6 mm, particularly preferably between 0.5 mm and 2 mm. According to an advantageous development of the invention, the fusible section 54 of the contacting element has a length of a few mm. The optimal length of the melting section 54 preferably correlates with the wire diameter of the contacting wire 20 and the opening cross section 50 of the through opening 90. According to an advantageous development of the invention, the circumferential gap is between 0.1 mm and 0.4 mm, particularly preferably 0.2 mm.

The laser 64 is preferably arranged at a laser incidence angle α. As can be seen in FIG. 2a, the main direction of extension of the laser 60 closes a laser setting angle a with the direction of main extension of the contacting element 20 of approximately 5°. However, other angles of incidence are also conceivable, provided these are suitable for advantageously reducing or preventing a corresponding multiple reflection in the gap 92 .

According to an advantageous development of the invention, the diameter of the contacting element in the area of the receiving section is between 10% and 30%, in particular between 15% and 25%, particularly preferably essentially 20% larger than the width of the circumferential gap. With such a correlating area ratio between the contacting element and the gap to be bridged, on the one hand the process of inserting or leading through the contacting element is advantageously optimized and at the same time it is ensured that sufficient melt volume is provided to bridge the gap, so that stable contacting is provided can. According to the embodiment of the invention shown in FIG. 2a, the laser 64 is oriented at an angle. With a slight inclination of the laser 64 relative to the joining partner, the “shooting through” of the laser radiation 210a, 210b through the gap 92 is advantageously prevented. Due to the high absorption of the blue or green laser radiation 210a, 210b in copper, multiple reflections in the gap 92 can advantageously be prevented.

If the gap 92 between the coupling element 40 and the contacting element 20 is so large that it cannot be safely bridged during welding, it is possible to use a solder paste or a solder paste prepreg (pressed solder paste, e.g. in the form of a circular ring, which is placed over the wire can) to use. This is applied before or after the passage of the contacting element 20 and serves as a filling material. In this case, the contacting element 20 is soldered to the coupling element 40 .

The process control is then coordinated in such a way that the components transfer sufficient heat to the additional material. The further course of the process is shown in FIGS. 2a and 2b. In the following description of these figures, only the changes are discussed, with reference to the drawings and/or the description of FIG.

After the contacting element 20 has been inserted through the coupling element 40, the latter is melted with a laser 64 emitting green or blue laser radiation 210a, 210b. Both the contacting element 20 and the receiving region 15 of the coupling element 40 are melted using a laser 64, which has a laser spot 52, which is preferably larger than the diameter of the contacting element 20 and particularly preferably larger than the opening cross section 92 of the coupling element 40. The contacting element 20 forms a melt head 26 with a diameter 53 which is dimensioned such that the melt volume is sufficient to bridge the gap 92 .

Coupling element 40 and contacting element 20 are now melted until an electrically conductive, materially bonded connection is formed 130 between contacting element 20 and coupling element 40 (see FIG. 2c).

A further exemplary embodiment of the invention is shown in FIG. The following description and the drawing are essentially limited to the differences between the exemplary embodiments, whereby with regard to components with the same designation, in particular with regard to components with the same reference numbers, in principle also to the drawings and/or the description of the other exemplary embodiments, in particular FIG. 2a , can be referenced.

According to the embodiment shown in FIG. 3, the coupling element 40 is funnel-shaped in the area of the receiving section 15 . The coupling element has a peripheral collar 70, which according to a further advantageous development of the invention can rest on the contacting element 20. It is also conceivable for the coupling element 20 to be elastic in the area of the surrounding collar in such a way that it can nestle against the coupling element 20 . It is also conceivable that the funnel-shaped projection is formed by the passage of the contacting element 20 through the coupling element 40 . The tulip-shaped collar 70 preferably protrudes beyond the plane of extent of the coupling element 40 .

According to the embodiment of the invention shown in FIG. 3, the opening cross section tapers from a first opening cross section 56 to a second opening cross section 55. In this way, the insertion of the contacting element 20 into the coupling element 40 can be facilitated. The funnel-shaped cross section of the collar 70 preferably has an opening angle β of between 5° and 45°. The funnel-shaped projection can thus advantageously act as an insertion bevel for the contacting element 20.

Another exemplary embodiment of the invention is shown in FIG. The following description and the drawing are essentially limited to the differences between the exemplary embodiments, whereby with regard to components with the same designation, in particular with regard to components with the same reference numbers, in principle also to the drawings and/or the description of the other exemplary embodiments, in particular FIG. 2a , can be referenced.

According to the embodiment of the invention shown in FIG. 4, a cover element 46 is arranged in the area of the gap 92 . This covering element 46 is preferably also made of aluminum or copper, so that it can be melted on with the contacting element 20 and stable contacting can be provided. According to an advantageous development of the invention, the cover element 46 is designed as a collar. The cover element 46 is preferably formed in one piece with the coupling element 20 . The covering element 46 is preferably in place after the contacting element 20 has been arranged Recording section 15 circumferentially contacting the contacting element 20 at. The covering element 46 is preferably designed to be flatter than the coupling element 40 . Underlying structures can be protected by the covering element 46 and the gap between the contacting element and the coupling element can be bridged.

Claims

Expectations 1. Method (100) for producing a contact of a contacting element (20), in particular a contacting wire and/or a contacting pin, in an electrical machine (10) on an electronics unit (44), in particular a printed circuit board (44a) and/or an intermediate element (44b), which is designed to make electrical contact with the printed circuit board (44a), having the following steps: a) providing (110) a coupling element (40) for the electronics unit (44) having a receiving section (15), b) arranging (120) of the contacting element (20) on the receiving section (15) of the coupling element (40), c) melting (130) of the contacting element (20) with a laser (64) emitting green or blue laser radiation (210a, 210b) until an electrically conductive, materially bonded Connection between the contacting element (20) and the coupling element (40) is formed. 2. The method (100) according to claim 1, characterized in that the coupling element (40) and/or the contacting element (20) is designed as an absorption element for absorbing the laser radiation (210a, 210b), in particular the coupling element (40) and/or the contacting element (20) comprises a non-ferrous metal, in particular copper or aluminum, and is in particular made of copper. 3. The method (100) according to any one of the preceding claims, characterized in that the receiving section (15) has a through-opening (90), in particular a through-hole, in which the contacting element (20) is arranged. 4. The method (100) according to any one of the preceding claims, characterized in that the contacting element (20) extends through the electronic unit (44) and the coupling element (40), wherein the coupling element (40) has a free overhanging the coupling element (44). Having melting portion (54). Method (100) according to one of the preceding claims, characterized in that the main extension direction (62) of the contacting element (20) is arranged essentially perpendicular to the electronics unit (44). Method (100) according to one of the preceding claims, characterized in that the laser main extension direction (60) with the main extension direction (62) of the contacting element (20) has a laser setting angle (a) between 1° and 10°, preferably between 3° and 8°, more preferably between 5° and 6°. Method (100) according to one of the preceding claims, characterized in that the laser spot (52) of the laser (64) is larger than the diameter of the contacting element (20) at its melting section (54). Method (100) according to one of the preceding claims, characterized in that the coupling element (40) is designed as a connecting plate which is arranged on the electronics unit (44), in particular connected to the electronics unit by means of a solder or is integrated into the electronics unit (44) is formed embedded. Method (100) according to one of the preceding claims, characterized in that before the melting (130) of the contacting element (20) a circumferential gap (92) is formed between the connection section (15) of the coupling element (40) and the contacting element (20). . Method (100) according to one of the preceding claims, characterized in that the diameter of the contacting element (20) in the region of the receiving section (15) is between 10% and 30%, in particular between 15% and 25%, particularly preferably essentially 20% larger is the width of the circumferential gap (92). Method according to one of the preceding claims, characterized in that a cover element (46), which is preferably made of copper, is arranged in the region of the circumferential gap (92). Method (100) according to one of the preceding claims, characterized in that the coupling element (40) in the region of the receiving section (15) is designed to nestle against the contacting element (20). Method (100) according to one of the preceding claims, characterized in that the receiving section (15) of the coupling element (40) is funnel-shaped, in particular has a tulip-shaped collar (70). Method (100) according to one of the preceding claims, characterized in that in the area of the receiving section (15) of the coupling element (40), in particular in the area of the circumferential gap (92) between the receiving section (15) and the contacting element (20), a solder , Preferably a solder paste, particularly preferably a pressed solder paste element is arranged, wherein the laser (64) during melting (130) of the contact element (20) melts the solder and solders the contact element (20) to the coupling element (40). Electrical machine - in particular an electronically commutated electric motor - with a stator having electrical windings with at least one contacting element (20) forming the winding or at least one contacting element (20) for interconnecting the windings, with an electronic unit (44) having a coupling element for energizing the windings (40) is provided with a receiving section (15), characterized in that the electrical contact between the contacting element (20) and the coupling element (40) is produced by a method according to one of the preceding claims.