Tin plating is used extensively on many different types of metals, both ferrous and nonferrous. Tin is a gray-white, soft, and ductile metal that is not easily oxidized in air. Electrodeposited tin has good conductivity and corrosion resistance while enhancing solderability of substrates that are not otherwise easily soldered to. Tin is generally considered non-toxic and non-carcinogenic and as such its use is generally approved for food contact applications.
Tin plating is provided in two general types of deposits: bright tin and matte tin. Both can be obtained from an alkaline or acidic bath and both are electrolytically applied. The acidic chemistries are most common today.
Uses
Electrical contact applications such as: bus bars, terminals, and switching components that don’t require soldering.
Matte Tin Properties
Solderable
Non-Reflective
Corrosion protection
Electrical enhancements to the substrate
Uses
Electrical contact applications such as: bus bars, terminals, and switching components where soldering is required
For substrates alloyed with zinc it is generally recommended to apply a diffusion barrier or nickel or copper to prevent zinc migration into the tin deposit. Tin deposits can have the potential to form tin “whiskers” on the surface of the deposit. For applications where tin whiskers could negatively impact the function of the product, tin-lead plating is used.
Tin Lead
Tin Lead plating consists of the co-deposition of a layer of tin and lead onto a base part. A wide variety of tin-lead alloy compositions is used depending on the application and desired properties of the final product. Tin-lead alloys are the easiest alloys that can be electroplated. Tin lead is most commonly used in the electronics industry. It can be soldered easily, is corrosion resistant, ductile and offers good electrical conductivity. In addition, the presence of lead can stop the formation of tin whiskers.
Tin is not good for low temperature applications as it changes structure and loses adhesion when exposed to temperature below 40° F.
The Lindgren Group plates tin to the following specifications among others:
Bright Tin
Matte Tin