Immersion Silver

(Sterling Metallic Solderability Preservative)

Immersion Silver Surface Finish

IPC Code: IAg

Immersion Silver (also called immersion Ag) is a RoHS compliant (lead-free) surface finish that is an ideal choice for flat surface requirements and fine pitch components It’s also an ideal choice for special applications that want to avoid any magnetic materials in the PCB.

Immersion silver is applied directly over copper and provides an excellent solderable surface and as an HASL replacement. It is used commonly for metallic dome contacts, membrane switches, EMI shielding, and aluminum wire bonding.

Diagram illustrating the different applications of Electroplating.

Diagram illustrating the layers of Immersion Silver.

Superior Processing’s Immersion Silver meets the requirements of IPC 4556.

IPC-4556 specifies the thickness of each layer being per the table below but for some applications different thickness are specified by our customer.

Immersion Silver per IPC-4553	micro inches (µin)		micrometers (µm)
	Minimum	Maximum	Minimum	Maximum
Silver (Ag)	5	16	0.130	0.410
Thickness based on measuring on a 0.060″ x 0.060″ pad.