Silver Plating of Copper or Copper Alloys – Silver Properties
Silver plating of copper or copper alloys is a highly functional finish for transferring heat and electricity utilized across a wide breath of industries. Silver has been applied since late 1800s onelectrical switchgear and other components that pass electrical current. In recent years silver plating of copper electronic components including connectors and terminals has grown rapidly within the electronic, automotive and electric vehicle (EV) markets. Silver plating has many unique properties that make it desirable for these applications. The primary reason is that silver has the highest electrical and thermal conductivity of any metal, which facilitates the efficient transmission of electricity and heat. In addition, silver is a relatively soft metal which allows the silver deposit to compress and form around a mating connecter filling small voids and micro-roughness. This increases the effective contact area resulting in less overall connector resistance.
Figure 1: Conductivity of Silver as Compared to Copper and Other Metals
Silver has excellent lubricity and resists galling in switching, sliding or rotary applications. However, high pressure wear surfaces such as blade-style stab connectors can be susceptible to silverwear. In applications such as this, a higher deposit thickness of silver is recommended as well as the use of a nickel or electroless nickel underplate. Thinner silver plating without a nickel underplate is best used on static joints or low duty cycle connectors that are mated and unmated relatively infrequently.
