Temperature-stable composite of a stranded wire having a contact pad
The invention relates to an electrical element having at least one functional region and a contact surface, wherein a connecting element is arranged on the contact surface, wherein the connecting element comprises a stranded wire coated with sintered material, wherein the stranded wire is connected, in particular sintered, to the contact surface by a sintered material. Furthermore, the invention relates to a method for producing the electrical element according to the invention.
1. A method for producing a connecting element on a contact surface, comprising: a. providing a stranded wire, a contact surface, and a sintering agent, b. coating at least a part of the stranded wire with sintering agent to obtain a coated stranded wire, c. positioning the coated stranded wire on the contact surface, d. exerting pressure on the coated stranded wire by means of a heated punch, thereby pressure sintering the coated stranded wire to the contact surface to produce a connecting element, wherein the heated punch comprises a depression with an opening, wherein the depression in the heated punch partially receives the coated stranded wire during the connection process, wherein the opening of the depression is larger than the diameter of the coated stranded wire so that the coated stranded wire is pressed onto the contact surface into the depression in the punch during pressure sintering, and wherein the aspect ratio of the connecting element of height (h) to width (b) is in the range of 0.5 to 3.
2. The method of claim 1 , further comprising providing an electrical element having at least one functional region and the contact surface, and arranging the connecting element on the contact surface.
3. The method of claim 2 , wherein the electrical element is an electrical or electronic component or a sensor.
4. The method of claim 1 , wherein the sintering agent comprises or consists of a precious metal, or silver.
5. The method of claim 1 , wherein the stranded wire outside the connecting element is surrounded at least partially by an insulating layer.
6. The method of claim 1 , wherein the stranded wire contains several individual wires, and wherein the individual wires are each at least partially coated with sintered material.
7. The method of claim 1 , wherein the stranded wire contains several individual wires comprising a material selected from the group consisting of copper, silver, gold, nickel, or aluminum, or alloys thereof or combinations thereof.
8. The method of claim 1 , wherein the contact surface in at least one dimension is at most 20% greater than the height of the connecting element.
9. The method of claim 1 , wherein the contact surface comprises an alloy, or a silver alloy or a silver-platinum alloy.
10. Method according to claim 1 , wherein the aspect ratio between the depth (t) of the depression to the width (w) of the opening of the depression is in the range of 0.5 to 3.
11. Method according to claim 1 , wherein the stranded wire is at least partially surrounded by an insulating layer.
12. Method according to claim 1 , wherein the stranded wire is coated with sintering agent by saturating, in particular by a dip coating.
13. Method according to claim 1 , wherein the stranded wire has a cross-section whose aspect ratio is in the range of 0.5 to 2.
14. Method according to claim 1 , wherein the individual wires of the stranded wire are stranded or braided.
15. Method according to claim 1 , wherein the stranded wire is at least partially saturated with sintering agent so that the individual wires of the stranded wire are coated substantially completely with sintering agent.