Electrical connector and connector system having plated ground shields

1. An electrical connector comprising:

a housing;

signal contacts coupled to the housing and positioned for mating with mating signal contacts of a mating connector; and

ground shields coupled to the housing and at least partially surrounding the signal contacts to shield the signal contacts;

wherein the ground shields are plated with a ground-material composition along one or more contact segments of the ground shields that come into compression engagement with one or more other conductive members, the ground-material composition including a tin-nickel (Sn/Ni) alloy plating layer, and wherein the signal contacts are plated with a signal-material composition that is different than the ground-material composition.

2. The electrical connector of claim 1 , wherein the ground-material composition along a mating contact segment of the ground shields is configured to cause a first low-level contact resistance (LLCR) while mated with mating ground shields of the mating connector during operation, and the signal-material composition is configured to cause a second LLCR while mated with the mating signal contacts of the mating connector during operation, wherein the second LLCR is less than the first LLCR.

3. The electrical connector of claim 1 , wherein the tin-nickel alloy plating layer contains between about 55 wt % and about 75 wt % of tin and between about 25 wt % and 45 wt % of nickel.

4. The electrical connector of claim 1 , wherein the tin-nickel alloy plating layer contains about 65 wt % of tin and about 35 wt % of nickel.

5. The electrical connector of claim 1 , wherein the ground shields lack the ground-material composition along portions of the ground shields outside of the one or more contact segments.

6. The electrical connector of claim 1 , wherein the tin-nickel alloy plating layer is an outermost metal layer of the ground shields along the one or more contact segments.

7. The electrical connector of claim 1 , wherein the ground-material composition includes a nickel plating layer between a base material of the ground shields and the tin-nickel alloy plating layer.

8. The electrical connector of claim 1 , wherein the ground shields include a base material and a nickel plating layer covering the base material along an entire surface area of the ground shields, and wherein the tin-nickel alloy plating layer covers the nickel plating layer only along the one or more contact segments of the ground shields.

9. The electrical connector of claim 1 , wherein the signal-material composition of the signal contacts lacks a tin-nickel alloy plating layer.

10. The electrical connector of claim 1 , wherein the one or more contact segments of the ground shields include one or more of (i) mating segments of the ground shields that engage mating ground shields of the mating connector during mating, (ii) mounting segments of the ground shields that are press-fit into a conductive hole of a circuit board, or (iii) coupling segments of the ground shields that engage adjacent ground shields of the electrical connector.

11. An electrical connector comprising:

a housing;

signal contacts coupled to the housing and positioned for mating with mating signal contacts of a mating connector, the signal contacts having a plating layer that includes a precious metal; and

ground shields coupled to the housing and at least partially surrounding the signal contacts to shield the signal contacts, the ground shields having a plating layer that includes a tin-nickel alloy along one or more contact segments of the ground shields that come into compression engagement with one or more other conductive members,

wherein the ground shields lack the precious metal included in the plating layer of the signal contacts and the signal contacts lack the tin-nickel alloy included in the plating layer of the ground shields.

12. The electrical connector of claim 11 , wherein the tin-nickel alloy in the plating layer of the ground shields contains between about 55 wt % and about 75 wt % of tin and between about 25 wt % and 45 wt % of nickel.

13. The electrical connector of claim 11 , wherein the tin-nickel alloy in the plating layer of the ground shields contains about 65 wt % of tin and about 35 wt % of nickel.

14. The electrical connector of claim 11 , wherein the plating layer of the ground shields that includes the tin-nickel alloy is an outermost metal layer of the ground shields along the one or more contact segments.

15. The electrical connector of claim 11 , wherein the ground shields include a base material and a nickel plating layer covering the base material along an entire surface area of the ground shields, and wherein the plating layer including the tin-nickel alloy covers the nickel plating layer only along the one or more contact segments of the ground shields.

16. The electrical connector of claim 11 , wherein the one or more contact segments of the ground shields that have the plating layer including the tin-nickel alloy include one or more of (i) mating segments of the ground shields that engage mating ground shields of the mating connector during mating, (ii) mounting segments of the ground shields that are press-fit into a conductive hole of a circuit board, and (iii) coupling segments of the ground shields that engage adjacent ground shields of the electrical connector.

17. The electrical connector of claim 11 , wherein the precious metal in the plating layer of the signal contacts is one of gold, silver, platinum, or palladium.

18. A connector system comprising:

a mating connector having mating signal contacts and mating ground shields; and

an electrical connector comprising:

a housing;

signal contacts coupled to the housing and positioned for mating with the mating signal contacts of the mating connector at signal interfaces; and

ground shields coupled to the housing and at least partially surrounding the signal contacts to shield the signal contacts, the ground shields having mating segments positioned for mating with the mating ground shields of the mating connector at ground interfaces;

wherein the mating segments of the ground shields are plated with a ground-material composition and the signal contacts are plated with a signal-material composition that is different than the ground-material composition, the ground-material composition including a nickel plating layer that covers a base material of the ground shields and a tin-nickel (Sn/Ni) alloy plating layer that covers the nickel plating layer.

19. The connector system of claim 18 , wherein the ground interfaces have a first low-level contact resistance (LLCR) and the signal interfaces have a second LLCR, the second LLCR being less than the first LLCR.

20. The connector system of claim 18 , wherein the tin-nickel alloy plating layer contains between about 55 wt % and about 75 wt % of tin and between about 25 wt % and 45 wt % of nickel.