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EP-4736270-A1 - CONTACTING ELEMENT FOR ELECTRICALLY CONTACTING AT LEAST TWO ELECTRICAL CONTACT ELEMENTS, ARRANGEMENT, AND METHOD FOR CONTACTING ELECTRICAL CONTACT ELEMENTS BY MEANS OF LASER BEAM WELDING

EP4736270A1EP 4736270 A1EP4736270 A1EP 4736270A1EP-4736270-A1

Abstract

The invention relates to a contacting element (4) for electrically contacting at least two electrical contact elements (2, 3), said contacting element comprising: - a first contacting side (7) for contacting the first electrical contact element (2), - a second contacting side (8) for contacting the second electrical contact element (3), wherein - the first contacting side (7) has a first support region (10) and the second contacting side (8) has a second support region (11), wherein - the first contacting side (7) can be arranged adjacent to a surface (13) of the first electrical contact element (2) by means of the first support region (10), - the second contacting side (8) can be arranged adjacent to a surface (14) of the second electrical contact element (3) by means of the second support region (11), and wherein - the first support region (10) protrudes outward relative to a main extension plane of the first contacting side (7), and the second support region (11) protrudes outward relative to a main extension plane of the second contacting side (8). The invention also relates to an arrangement (1) and to a method.

Inventors

  • GANSTER, AXEL
  • LASCH, MARKUS
  • STEGMEIER, STEFAN
  • WEISBROD, Erik

Assignees

  • Siemens Aktiengesellschaft

Dates

Publication Date
20260506
Application Date
20240730

Claims (14)

  1. 1. Contacting element (4) for electrically contacting at least two electrical contact elements (2, 3), with - a first contacting side (7) for contacting the first electrical contact element (2), - a second contacting side (8) for contacting the second electrical contact element (3), wherein - the first contact side (7) has at least one first support area (10) and the second contact side (8) has at least one second support area (11), wherein - the first contacting side (7) can be arranged by means of the first support area (10) on a surface (13) of the first electrical contact element (4), - the second contacting side (8) can be arranged by means of the second support area (11) on a surface (14) of the second electrical contact element (3), and wherein - the first support region (10) projects outwards in relation to a main extension plane of the first contacting side (7) and the second support region (11) projects outwards in relation to a main extension plane of the second contacting side (8), wherein - a material thickness (dl) of the first support region (10) is smaller than a material thickness (Dl) of the first contacting side (7) and a material thickness (d2) of the second support region (11) is smaller than a material thickness (D2) of the second contacting side (8).
  2. 2. Contacting element (4) according to claim 1, wherein the first support region (10) and the second support region (11) are spherically designed, wherein the first support region (10) is curved towards the first electrical contact element (2) during a contacting process and the second support region (11) is curved towards the second electrical contact element (3) during the contacting process.
  3. 3. Contacting element (4) according to claim 1, wherein the first support region (10) and the second support region (11) are pyramid-shaped, wherein a tip (19) of the pyramid-shaped first support region (10) is directed towards the first electrical contact element (2) during a contacting process and a tip (20) of the pyramid-shaped second support region (11) is directed towards the second electrical contact element (3) during the contacting process.
  4. 4. Contacting element (4) according to claim 1, wherein the first support region (10) and the second support region (11) are designed in a plateau-shaped manner, wherein an outer side (21) of the plateau-shaped first support region (10) parallel to the first contacting side (7) is directed towards the first electrical contact element (2) during a contacting process and an outer side (22) of the plateau-shaped second support region (11) parallel to the second contacting side (11) is directed towards the second electrical contact element (3) during a contacting process.
  5. 5. Contacting element (4) according to one of the preceding claims, wherein the first and second contacting sides (7, 8) each have further support areas.
  6. 6. Contacting element (4) according to claim 5, wherein the support areas of the two contacting sides (7, 8) are each arranged at a distance from one another.
  7. 7. Contacting element (4) according to one of the preceding claims, wherein the contacting element (4) is bent between the first and second contacting side (7, 8) taking into account a bending angle (15), in particular the bending angle (15) is adjustable depending on a positioning of the two contact elements (2, 3).
  8. 8. Contacting element (4) according to one of the preceding Claims, wherein the support areas (10, 11) by means of a punching process, a pressing process, or a rolling process.
  9. 9. Arrangement (1) with a first and a second electrical contact element (2, 3), wherein the two electrical contact elements (2, 3) are electrically contacted by means of a contacting element (4) according to one of the preceding claims.
  10. 10. Arrangement (1) according to claim 9, wherein the first contacting side (7) of the contacting element (4) is coupled to the first contact element (2) by means of the first support region (10), which at least partially rests on the surface (13) of the first contact element (2), and the second contacting side (8) of the contacting element (4) is coupled to the second contact element (3) by means of the second support region (11), which at least partially rests on the surface (14) of the second contact element (3).
  11. 11. Arrangement (1) according to claim 10, wherein the first support region (10) is at least partially materially connected to the first contact element (2) by means of a laser beam welding process and the second support region (11) is at least partially materially connected to the second contact element (3) by means of the laser beam welding process.
  12. 12. Arrangement (1) according to one of claims 9 to 11, wherein the contacting element (4) is contacted at points with the two contact elements (2, 3) by means of the support areas (10, 11).
  13. 13. Method for contacting at least two electrical contact elements (2, 3) by means of a laser beam welding process, comprising: - Positioning a contacting element (4) according to one of claims 1 to 9 such that the first support area (10) of the first contacting side (7) on a surface (13) of the first contact element (2) and the second support area (11) of the second contacting side (8) rest on a surface (14) of the second contact element (3), - Partially melting the material of the first and second support areas (10, 11) by the laser beam welding process, wherein the first support area (10) is materially connected to the first contact element (2) and the second support area (11) is materially connected to the second contact element (3), whereby the first contact element (2) is electrically connected to the second contact element (3).
  14. 14. The method according to claim 13, wherein energy is introduced with a laser unit (12) in the area in which a respective support area (10, 11) rests on a respective surface (13, 14) of the contact elements (2, 3) in order to partially melt the material there.

Description

Description Contacting element for electrically contacting at least two electrical contact elements, arrangement and method for contacting electrical contact elements by means of laser beam welding The invention relates to a contacting element for electrically contacting at least two electrical contact elements. Furthermore, the invention relates to an arrangement with a first and a second electrical contact element, wherein the two electrical contact elements are contacted by means of a corresponding contacting element. The invention also relates to a method for contacting at least two electrical contact elements by means of a laser beam welding method. In electronics or power electronics, electrical contacts or contact elements are connected to one another to create an electrical connection. In addition to the classic methods such as pressing, soldering, wire bonding and gluing, laser welding is now a suitable method, as this method is contactless and can be used with the help of robotics or automated systems. In addition, energy is introduced where it is needed, which plays an increasingly important role in the context of "sustainability". If, for example, two metallic objects, such as electrical contact elements, are to be joined together using a laser beam welding process, it is essential that they are in direct contact, i.e. that there is a zero gap. The volume of material to be melted should be kept as small as possible in order to minimize thermomechanical stresses, which can lead to cracking and thus damage in components such as semiconductors, coils or capacitors. The publication DE202016008092U1, for example, deals with electrical connection elements on flat supports and the problem of mechanical stresses that arise due to different thermal expansion coefficients of the materials, which can lead to cracks or contact failure. For this purpose, a connection element with a fanned-out structure is proposed, which minimizes mechanical stresses caused by thermal expansion differences. There are already numerous methods to enable laser welding of two touching electrical contacts, such as overlap welding, fillet welding, resistance welding, etc. The following points should and must be observed. The coupling of the laser beam into the material must first be ensured. The wavelength of the laser radiation must be adapted to the material in order to achieve the highest possible light absorption. The higher the reflectivity of the material, such as copper, the more problematic the coupling of the laser radiation is. With copper, the coupling can be improved at a wavelength of 1.06 pm by applying a thin, less reflective layer or by changing the surface, for example by tinning or nickel plating. However, this increases the effort and is technically demanding. The roughness of the surface or oxide layers also influence the reflection-absorption behavior of the material. Another factor to consider is the melting of the material. In the case of copper, the reflectivity decreases with increasing temperature. As soon as the copper surface melts, a multiple of the laser power is absorbed compared to a bare copper surface at room temperature. If a sufficiently high laser power or laser power density is used, then the material is first heated, which is accompanied by absorption. With increased coupling of the laser beam, a vapor capillary is formed in the melt, a so-called keyhole. There is then multiple reflection on the keyhole wall, i.e. the laser beam is completely absorbed. As soon as a keyhole has formed, the entire laser power is suddenly coupled into the workpiece. This is the reason why it is almost impossible to weld pure copper using conventional laser types in the near and far infrared range. The process range between "beginning of melting" and "exceeding the threshold intensity for deep welding" is very small. For this reason, the green wavelength is often used because there is higher absorption, particularly for copper. Another point to be observed is the connection of the contact pieces. Both contact pieces must be in contact during the laser welding process and therefore must not have any gap between them. A gap would cause the upper contact partner to melt or lead to too much laser energy being deposited and then to the second contact partner being suddenly welded through. The result is high melting volumes. If these solidify, large tensile stresses arise, which in turn can damage sensitive components such as silicon components, for example by causing cracks. The two contacts must therefore be pressed together, which is complex because special tools are required. An object of the present invention is to improve contacting of electrical contacts by means of a laser beam welding process. This object is achieved by a contacting element, an arrangement and a method according to the independent patent claims. Useful further developments arise from the dependent patent claims. One aspect (first aspect) of