Silver-tin coating for electrical connectors, and electrical connectors with siliver-tin coatings
AssigneeWieland Rolled Products North America, LLC
InventorsKelly S. FUNKE, Kon JOHN
Life of this patent
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Abstract
A copper alloy electrical connector component has a coating thereon formed by applying a nickel layer of between about 5 μin and about 20 μin over the copper alloy; applying a copper layer of between about 7 μin and about 18 μin over the nickel layer; applying a total of between about 5 μin and about 15 μin silver layers and about 40 μin and about 80 μin of tin layers over the copper layer: and heating to the coated copper alloy electrical connector component to cause mixing of the silver and tin layers and formation of at least 8 vol % of an Ag3Sn intermetallic.
Claims25
A copper alloy electrical connector component having a coating thereon comprising a nickel layer of between about 5 μin and about 20 μin over the copper alloy;
- applying a copper layer of between about 7 μin and about 18 μin over the nickel layer;
- a total of between about 5 μin and about 15 μin of one or more silver layers and a total of between about 40 μin and about 80 μin of one or more tin layers over the copper layer, wherein subsequent reflow heating of the connector will cause mixing of the silver and tin layers and formation of between about 8 vol % and about 45 vol % of an Ag3Sn intermetallic.
A copper alloy electrical connector component having a coating thereon formed by applying a nickel layer of between about 5 μin and about 20 μin over the copper alloy;
- applying a copper layer of between about 7 μin and about 18 μin over the nickel layer;
- applying a silver layer of between about 5 μin and about 15 μin;
- and applying between about 40 μin and about 80 μin of tin;
- and heating the coated copper alloy electrical connector component to cause mixing of the silver and tin layers and formation of between about 8 vol % and about 45% of an Ag3Sn intermetallic.
A coating over a copper alloy electrical connector component, the coating formed by applying a nickel layer of between about 5 μin and about 20 μin over the copper alloy;
- applying a copper layer of between about 7 μin and about 18 μin over the nickel layer;
- applying a total of between about 5 μin and about 15 μin silver layers and about 40 μin and about 80 μin of tin layers over the copper layer;
- and heating the coated copper alloy electrical connector component to cause mixing of the silver and tin layers and formation of between 8 vol % and 45 vol % of an Ag3Sn intermetallic.
A method of forming a coating on a copper alloy electrical connector component, the method comprising:
- applying a nickel layer of between about 5 μin and about 20 μin over the copper alloy;
- applying a copper layer of between about 7 μin and about 18 μin over the nickel layer;
- applying a total of between about 5 μin and about 15 μin of silver layers and about 40 μin and about 80 μin of tin layers over the copper layer;
- and reflow heating the coating to cause mixing of the silver and tin layers and formation of between 8 vol % and about 45 vol % of an Ag3Sn intermetallic in the resulting silver tin layer.
A method of forming a coating on a copper alloy electrical connector component, the method comprising:
- applying a nickel layer of between about 5 μin and about 20 μin over the copper alloy;
- applying a copper layer of between about 7 μin and about 18 μin over the nickel layer;
- applying a silver layer of between about 5 μin and about 15 μin;
- and applying between about 40 μin and about 80 μin of tin;
- and heating the coated copper alloy electrical connector component to cause mixing of the silver and tin layers and formation of between about 25 vol % and about 45 vol % of an Ag3Sn intermetallic.
A copper alloy electrical connector component having a coating thereon formed by applying a nickel layer of between about 5 μin and about 20 μin over the copper alloy;
- applying a copper layer of between about 7 μin and about 18 μin over the nickel layer;
- applying a total of between about 5 μin and about 15 μin silver layers and about 40 μin and about 80 μin of tin layers over the copper layer;
- wherein the Cu and Ni thickness are further selected to ensure at least 5 μin of free Sn remains after short-time aging so that there is sufficient tin to form at least 8 vol % of an Ag3Sn intermetallic upon reflow heating of the layers.
A method of forming a coating on a copper alloy electrical connector component, the method comprising:
- applying a nickel layer of between about 5 μin and about 20 μin over the copper alloy;
- applying a copper layer of between about 7 μin and about 18 μin over the nickel layer;
- applying a silver layer of between about 5 μin and about 15 μin;
- and applying between about 40 μin and about 80 μin of tin;
- where the Cu and Ni thickness are further selected to ensure at least 5 μin of free Sn remains after short-time aging according to SAE USCAR2-8.
Dependencies are inferred from the claim text.