Electrical contact element and method for manufacturing same
An electrical contact element and a method of manufacturing an electrical contact element having a connecting segment which is formed of a copper sheet and comprising a coating overlaying the copper sheet having at least two layers. A first layer contains at least 60% by weight of tin. A second layer is disposed between the first layer and the copper sheet. The second layer contains a copper-containing alloy. The copper-containing alloy contains 40 to 80% by weight of copper and 20 to 60% by weight of zinc. The combined percentage by weight of copper and zinc in the second layer is at least 90%. A third layer containing tin may be disposed between the second layer and the copper sheet. A fourth layer containing zinc may be disposed on a side of the first layer opposite the second layer.
1. An electrical contact element having a connecting segment which is formed of a copper sheet and comprises a coating, wherein the coating comprises:
a first layer containing at least 60% by weight of tin; and
a second layer disposed between the first layer and the copper sheet and containing a copper-containing alloy, wherein the copper-containing alloy contains 40 to 80% by weight of copper and 20 to 60% by weight of zinc, wherein the combined percentage by weight of copper and zinc is at least 90%.
2. The electrical contact element according to claim 1 , wherein the second layer has a thickness of 0.5 to 5 μm.
3. The electrical contact element according to claim 1 , wherein the second layer consists of the copper-containing alloy.
4. The electrical contact element according to claim 1 , wherein the first layer has a thickness in a range of 1 to 15 μm.
5. The electrical contact element according to claim 1 , wherein the first layer contains up to 40% by weight of zinc.
6. The electrical contact element according to claim 1 , wherein the coating comprises a third layer disposed between the second layer and the copper sheet, wherein the third layer contains tin.
7. The electrical contact element according to claim 6 , wherein the coating comprises a fourth layer disposed on a side of the first layer opposite the second layer wherein the fourth layer contains zinc.
8. A method for manufacturing an electrical contact element, comprising the steps of:
providing a base body;
applying a second layer on the base body, wherein the second layer contains a copper-containing alloy, wherein the copper-containing alloy contains 40 to 80% by weight of copper and 20 to 60% by weight of zinc, and wherein the combined percentage by weight of copper and zinc is at least 90%; and
applying a first layer, containing at least 60% by weight of tin, on a side of the second layer opposite the base body.
9. The method according to claim 8 , further comprising a step of heat treating the electrical contact element, wherein the heat treating step is performed after the step of applying the first layer.
10. The method according to claim 8 , wherein the layers are each applied by a process selected from the group consisting of galvanic technique, vapor coating, sputtering, dip coating, spray coating, and any combinations of the above processes.
11. The method according to claim 8 , wherein the base body is formed of a fire-tinned copper sheet.
12. The method according to claim 9 , wherein the heat treating step is performed in a temperature range of 50 to 350° C. for a time period of 1 second to 48 hours.
13. The method according to claim 12 , wherein the heat treating step is performed in a temperature range of 220 to 270° C. for a time period of 5 seconds to 2 minutes.