Press-in pin for an electrical contacting assembly

1. A press-in pin ( 10 ) for an electrical contact-making arrangement ( 1 ), the press-in pin comprising an elastic press-in region ( 12 ) and an electrically conductive coating ( 14 ),

characterized in that the electrically conductive coating ( 14 ) comprises a reactive multilayer ( 14 . 1 ) and a first contact layer ( 14 . 2 ), wherein the reactive multilayer ( 14 . 1 ) is applied to the elastic press-in region ( 12 ) and the first contact layer ( 14 . 2 ) is applied to the reactive multilayer ( 14 . 1 ), and wherein the reactive multilayer ( 14 . 1 ) is configured to be activated by an energy pulse which triggers an exothermic reaction of the reactive multilayer such that heat generated by the exothermic reaction melts the first contact layer ( 14 . 2 ).

2. The press-in pin ( 10 ) as claimed in claim 1 , characterized in that the reactive multilayer ( 14 . 1 ) is applied to an effective press-in length of the elastic press-in region ( 12 ).

3. The press-in pin ( 10 ) as claimed in claim 1 , characterized in that the reactive multilayer ( 14 . 1 ) is constructed from at least two different metal materials which are deposited alternately on the press-in pin ( 10 ).

4. The press-in pin ( 10 ) as claimed in claim 1 , characterized in that the reactive multilayer ( 14 . 1 ) contains aluminum as a first metal material and nickel as a second metal material.

5. The press-in pin ( 10 ) as claimed in claim 1 , characterized in that copper is applied as the first contact layer ( 14 . 2 ).

6. The press-in pin ( 10 ) as claimed in claim 1 , characterized in that the reactive multilayer ( 14 . 1 ) is tin-free.

7. An electrical contact-making arrangement ( 1 ) comprising

a press-in pin ( 10 ), which has an elastic press-in region ( 12 ) and an electrically conductive coating ( 14 ), and

a metallized plated-through hole ( 7 ), which is inserted into a hole ( 5 ) in a printed circuit board ( 3 ) and forms a contact area ( 8 ) for the elastic press-in region ( 12 ) and the electrically conductive coating ( 14 ),

wherein the press-in pin ( 10 ) is pushed into the metallized plated-through hole ( 7 ) and forms an integrally joined connection ( 9 ) between a first contact layer ( 14 . 2 ) of the press-in pin ( 10 ) and a second contact layer ( 8 . 1 ) of the metallized plated-through hole ( 7 ),

wherein the coating ( 14 ) comprises a reactive multilayer ( 14 . 1 ) which is applied to the elastic press-in region ( 12 ) and a first contact layer ( 14 . 2 ) which is applied to the reactive multilayer ( 14 . 1 ), and

wherein the integrally joined connection ( 9 ) is produced by an exothermic reaction of the activated reactive multilayer ( 14 . 1 ).

8. The electrical contact-making arrangement ( 1 ) as claimed in claim 7 , characterized in that dimensions and spring properties of the elastic press-in region ( 12 ) of the press-in pin ( 10 ) are matched to dimensions of the metallized plated-through hole ( 7 ) such that the elastic press-in region ( 12 ) generates a lateral force (Fq) on the metallized plated-through hole ( 7 ) which is less than 25 N/mm 2 .

9. The electrical contact-making arrangement ( 1 ) as claimed in claim 7 , characterized in that the second contact layer ( 8 . 1 ) of the metallized plated-through hole ( 7 ) contains copper.

10. The electrical contact-making arrangement ( 1 ) as claimed in claim 7 , characterized in that the reactive multilayer ( 14 . 1 ) is tin-free.

11. A method for joining a press-in pin ( 10 ) with a metallized plated-through hole ( 7 ), the press-in pin comprising an elastic press-in region ( 12 ) and an electrically conductive coating ( 14 ),

characterized in that the coating ( 14 ) comprises a reactive multilayer ( 14 . 1 ) which is applied to the elastic press-in region ( 12 ) and a first contact layer ( 14 . 2 ) which is applied to the reactive multilayer ( 14 . 1 ),

the method comprising:

inserting the metallized plated-through hole ( 7 ) into a hole ( 5 ) in a printed circuit board ( 3 ) to form a contact area ( 8 ) for the elastic press-in region ( 12 ) and the electrically conductive coating ( 14 ),

pushing the press-in pin ( 10 ) into the metallized plated-through hole ( 7 ) until a desired depth is reached, and

activating the reactive multilayer ( 14 . 1 ) of the coating ( 14 ) of the press-in pin ( 10 ) by an energy pulse which triggers an exothermic reaction of the reactive multilayer ( 14 . 1 ),

wherein heat which is generated by the exothermic reaction melts the adjacent first contact layer ( 14 . 2 ) of the press-in pin ( 10 ) and the second contact layer ( 8 . 1 ) of the metallized plated-through hole ( 7 ) and welds said first contact layer and said second contact layer to one another to form an integrally joined connection ( 9 ).

12. The method as claimed in claim 11 , characterized in that the energy pulse is introduced in a targeted manner into a tip ( 16 ) of the press-in pin ( 10 ) which is pushed into the metallized plated-through hole ( 7 ), said pin protruding out of the metallized plated-through hole ( 7 ).

13. The method as claimed in claim 11 , characterized in that the energy pulse is generated as a laser pulse (ZI) or an electrical pulse.

14. The method as claimed in claim 11 , characterized in that the reactive multilayer ( 14 . 1 ) is tin-free.