Micro Asperity Contact Mechanics in Millimeter Wave Test Socket Interfaces
Mechanical preload across socket micro asperities defines insertion loss stability and constriction resistance in millimeter wave automated device testing.
Gold Plating
Meaning
Surface treatment involving the application of a thin layer of gold to a conductive base metal. Gold plating provides a stable electrical interface that does not form an insulating oxide layer. It is used in environments where low contact resistance and high corrosion resistance are required for signal integrity.
Barrier Layer
Nickel is usually deposited between the copper base and the gold surface. This layer prevents copper atoms from migrating through the gold and oxidizing on the surface. Without this barrier, the gold plating would eventually lose its effectiveness as the copper reaches the exterior.
Thermal aging tests verify the thickness and quality of this intermediate deposit.
Deposit Porosity
Thickness of the layer determines how many tiny holes exist in the coating. Very thin gold layers are porous, which allows corrosive gases to reach the underlying nickel or copper. Increasing the thickness reduces these pores and makes the part more resistant to salt spray and humidity.
Hardness Grade
Pure gold is soft and wears away quickly during mating cycles. Cobalt or iron is often added to the gold to increase its mechanical durability. This hardened gold survives the friction of repeated connector insertions better than the soft variety.