Electrical connection and method of establishing an electrical connection

1. Electrical connection between a flat part and a connecting part wherein

the flat part and the connecting part are arranged one above the other in an overlap area,

a contact surface of the flat part facing the connecting part in the overlap area has a relief-like structure and

the flat part is friction-welded, in particular ultrasonically welded, to the connecting part via the structured contact surface,

wherein

the connecting part has completely penetrated into the relief-like surface of the flat part and a full-surface connection between the connecting part and the contact surface is formed, wherein the contact surface is structured in a longitudinal section of the flat part before and after welding, and wherein the connecting part wraps around the flat part in a U-shape in the overlap area.

2. Electrical connection according to claim 1 ,

wherein the structure is regularly periodic.

3. Electrical connection according to claim 1 ,

wherein the contact surface is free of the structure in one end face area.

4. Electrical connection according to claim 1 ,

wherein in a front end area the contact surface is parallel to a wide surface of the flat part in front of the contact surface.

5. Electrical connection according to claim 1 ,

wherein the flat part has a lower height extent in the area of the contact surface than in an area in front of the contact surface.

6. Electrical connection according to claim 1 ,

wherein the flat part has a smaller width extent in the area of the contact surface than in an area in front of the contact surface.

7. Electrical connection according to claim 1 ,

wherein the connecting part is a flat conductor, the connecting part protrudes beyond the flat part in the width extent in the overlap area and the connecting part is bent around at least one longitudinal edge of the flat part in the overlap area.

8. Electrical connection according to claim 1 ,

wherein the flat part is metallically coated in the area of the contact surface.

9. Electrical connection according to claim 1 ,

wherein the flat part has a terminal console on its side opposite the contact surface in the longitudinal direction.

10. Electrical connection according to claim 9 ,

wherein the terminal console is formed as a connection opening.

11. Electrical connection according to claim 10 ,

wherein the terminal console is metallically coated, in particular the flat part is metallically coated around the connection opening.

12. Electrical connection according to claim 1 ,

wherein the flat part has an S-shaped longitudinal profile.

13. Electrical connection according to claim 1 ,

wherein the flat part is formed from aluminium material and the connecting part is formed from copper material or the connecting part is formed from aluminium material and the flat part is formed from copper material.

14. Electrical connection according to claim 1 ,

wherein the relief-like contact surface is undulated or stepped in a longitudinal section or a cross-section through the flat part.

15. Electrical connection according to claim 14 ,

wherein the structured surface is undulated or stepped in a top view.

16. Electrical connection according to claim 1 ,

wherein the structured surface is formed by recesses in the surface of the flat part.

17. Electrical connection according to claim 16 ,

wherein the recesses are formed by grooves in the contact surface.

18. Electrical connection between a flat part and a connecting part, wherein

the flat part and the connecting part are arranged one above the other in an overlap area,

a contact surface of the flat part facing the connecting part in the overlap area has a relief-like structure and

the flat part is friction-welded, in particular ultrasonically welded, to the connecting part via the structured contact surface,

wherein

the connecting part has completely penetrated into the relief-like surface of the flat part and a full-surface connection between the connecting part and the contact surface is formed, wherein the contact surface is structured in a longitudinal section of the flat part before and after welding, and

wherein the structure in the direction of a longitudinal axis x of the contact surface is formed according to a function

h ( x )= h 0 f ( x )

where h is the amplitude and f(x) is a trigonometric function, especially sin(2πx) or cos(2πx).

19. Electrical connection according to claim 18 ,

wherein the connecting part wraps around the flat part in a U-shape in the overlap area.

20. Method of establishing an electrical connection between a flat part and a connecting part comprising:

providing a flat part,

forming a structured, relief-like structure into the flat part in a contact surface of the flat part,

providing a connection part,

placing the connecting part on the flat part in the area of the relief-like structure,

pressing the connecting part onto the flat part with a welding tool and friction welding, in particular ultrasonic welding between connecting part and flat part,

wherein the welding tool oscillates parallel to the relief-like structure, so that the connecting part has completely penetrated into the relief-like surface of the flat part and a full-surface connection between the connecting part and the contact surface is formed,

wherein the structure is formed by hills and valleys extending in the transverse direction of the flat part and the welding tool oscillates parallel to the hills and valleys.

21. Method according to claim 20 ,

wherein the connecting part and/or the flat part during welding initially plasticize in the region of a protrusion of the relief-like surface as a result of the oscillation introduced and, as the welding duration increases, plasticize the connecting part and/or the flat part down to a bottom of a recess in the relief-like surface.

22. Method according to claim 20 ,

wherein before welding, the connecting part is pressed onto the relief-like structure, this fixes a relative position of the longitudinal axes of the connecting part and flat part with respect to one another, and the flat part and connecting part are then welded together.

23. Electrical connection between a flat part and a connecting part wherein

the flat part and the connecting part are arranged one above the other in an overlap area,

a contact surface of the flat part facing the connecting part in the overlap area has a relief-like structure and

the flat part is friction-welded, in particular ultrasonically welded, to the connecting part via the structured contact surface,

wherein

the connecting part has completely penetrated into the relief-like surface of the flat part and a full-surface connection between the connecting part and the contact surface is formed, wherein the contact surface is structured in a longitudinal section of the flat part before and after welding, and

wherein the connecting part is a flat conductor, the connecting part protrudes beyond the flat part in the width extent in the overlap area and the connecting part is bent around at least one longitudinal edge of the flat part in the overlap area.

24. Electrical connection according to claim 23 ,

wherein the flat part has a terminal console on its side opposite the contact surface in the longitudinal direction.

25. Electrical connection according to claim 23 ,

wherein the structured surface is formed by recesses in the surface of the flat part.

26. Electrical connection between a flat part and a connecting part wherein

the flat part and the connecting part are arranged one above the other in an overlap area,

a contact surface of the flat part facing the connecting part in the overlap area has a relief-like structure and

the flat part is friction-welded, in particular ultrasonically welded, to the connecting part via the structured contact surface,

wherein

the connecting part has completely penetrated into the relief-like surface of the flat part and a full-surface connection between the connecting part and the contact surface is formed, wherein the contact surface is structured in a longitudinal section of the flat part before and after welding,

wherein the relief-like contact surface is undulated or stepped in a longitudinal section or a cross-section through the flat part and wherein the structured surface is undulated or stepped in a top view.

27. Method of establishing an electrical connection between a flat part and a connecting part comprising:

providing a flat part,

forming a structured, relief-like structure into the flat part in a contact surface of the flat part,

providing a connection part,

placing the connecting part on the flat part in the area of the relief-like structure,

pressing the connecting part onto the flat part with a welding tool and friction welding, in particular ultrasonic welding between connecting part and flat part,

wherein the welding tool oscillates parallel to the relief-like structure, so that the connecting part has completely penetrated into the relief-like surface of the flat part and a full-surface connection between the connecting part and the contact surface is formed,

wherein the connecting part and/or the flat part during welding initially plasticize in the region of a protrusion of the relief-like surface as a result of the oscillation introduced

and, as the welding duration increases, plasticize the connecting part and/or the flat part down to a bottom of a recess in the relief-like surface.

28. Method according to claim 27 ,

wherein before welding, the connecting part is pressed onto the relief-like structure, this fixes a relative position of the longitudinal axes of the connecting part and flat part with respect to one another, and the flat part and connecting part are then welded together.