Immersion tin board

What is Immersion Tin Plating?

Immersion tin is a coating of tin deposited on the copper layer of a PCB using an electroless chemical process. The tin layer protects the board from oxidation, extending its shelf life. It is usually white after electroplating, so it is called white tin.

What is Immersion Tin PCB?

PCB tinning is the process of covering copper traces with a layer of tin, which will prevent any possible degradation, oxidation or corrosion of them. Tin plating also helps mask copper traces when etching the board itself.
Immersion tin pcb surface finish describes a very thin layer of tin applied to the copper layer of the PCB. This method is a lead-free PCB alternative that produces a consistently flat surface that solders well and is cost-effective. The tin layer is usually mostly white in appearance, so the finish is sometimes called white tin and is applied to the copper using an electroless bath. This tin finish protects the underlying copper from oxidation during the expected shelf life of the PCB.
Immersion Tin PCB finishes have a relatively long shelf life, but do require careful handling during PCB assembly. Due to the potential for handling damage, our full PCB assembly is highly recommended by PCB suppliers for projects that require an immersion tin finish; when PCB fabrication and PCB assembly are performed under one roof, the potential for shipping and handling incidents becomes drop to lowest.
One problem with this finish is the strong affinity of tin and copper for each other, allowing one metal to diffuse into the other. This process results in the formation of "tin whiskers," small diffused tin wires that can cause short circuits and reduce the quality of solder joints, negatively impacting PCB shelf life and performance.
If you still have any questions about dip tin or any other finish, or send your PCB design files for an official quote, feel free to contact us!