Immersion Tin

(White Solderable Tin)

Immersion Tin (White Solderable Tin)

IPC Code: ISn

Immersion Tin is a is a RoHS compliant (lead-free) surface finish that is an ideal choice for flat surface requirements and fine pitch components. White Tin (Immersion Tin) is a deposit of a thin layer of pure Tin on Copper layer of a PCBs. The flatness of this particular coating makes this an ideal surface finish choice for small geometries and components. Immersion Tin has been primarily used as an alternative to a lead-based surface finish. It is also used for its very flat and smooth finish making it ideal for fine geometries and fine pitch surface mount components.

Immersion Tin is deposited directly on copper.

Diagram illustrating the layers of Immersion Tin.

Our Immersion Tin meets the requirements of IPC-4554 and MIL-T-81955.

IPC-4554 specifies the thickness of each layer being per the table below but for some applications different thickness are specified by our customer.

Immersion Tin per IPC-4554	micro inches (µin)	micrometers (µm)
Immersion Tin per IPC-4554	Minimum	Minimum
Tin (Sn)	40	1.016
Thickness based on measuring on a 0.060″ x 0.060″ pad.