Immersion Silver also called immersion Ag, is the standard finish and RoHS compliant finish available on any PCB configuration. It has excellent flatness and can replace Immersion Gold over Electroless Nickel (Au/Ni) for most applications. Immersion silver is well suited to lead-free assembly techniques and less expensive than Electroless-Nickel Immersion Gold (ENIG), safer than immersion tin. This finish is most commonly used for aluminum wire bonding, metallic dome contacts, and EMI shielding.
|Surface Finish||Content||Technological capability|
(According to IPC-4553A)
|Max panel size||406*533mm|
|Board thickness||0.20 – 3.2mm|
|Immersion Ag thickness||0.05-0.3um|
The immersion silver process is between organic coating and electroless nickel/gold plating, and the process is relatively simple and fast. Even if exposed to heat, humidity and pollution, silver can still maintain good solderability, but will lose its luster. Silver does not have the good physical strength of electroless nickel/gold plating because there is no nickel under the silver layer.