What is the effect of bright tin plating process on resistance?

What is the effect of bright tin plating process on resistance?

Tue Feb 06 09:48:51 CST 2024

The effect of bright tin plating on the electrical resistance of electronic components is usually small, but it still depends on the thickness and quality of the coating. Bright tin plating is the application of a layer of tin or tin alloy to a conductive part of an electronic component (such as the conductive path of a printed circuit board, component pins, etc.), which serves several purposes:

1. Anti-corrosion: tin and its alloys can effectively prevent the oxidation of copper and other base materials.

2. Improve weldability: Tin has good weldability, which can improve the reliability of components during welding.

3. Increase electrical conductivity: Pure tin is a good conductor, covering the oxidized surface of poor conductors such as copper can improve the overall electrical conductivity.

Bright tin plating usually does not significantly change the resistance of the circuit, which is said for the following two reasons:

1. After electroplating production with tin plating brightener, the tin plating layer on the product is usually very thin, with a thickness of only a few microns to tens of microns, so the cross-sectional area of the conduction path will not be greatly changed.

2. The resistivity of tin and most tin alloys is low, resulting in a negligible increase in resistance relative to the resistivity of the base material (such as copper).

However, if the coating is applied improperly, such as the coating is too thin or cracks, holes and other defects, it is possible to reduce the conductivity, resulting in increased contact resistance. This kind of situation can occur when the quality control of the coating is not good.

In general, the purpose of bright tin plating is to improve the performance and reliability of electronic components, and not to change the resistance, under normal process conditions, the effect of bright tin plating on the circuit resistance is very small. So, in order to improve the performance, what kind of tinning brightener should we use?  Bigely tin plating brightener Sn-807 can be used, which has a balanced consumption and good brightness during electroplating, and does not change color or yellow after high temperature baking test.

If you need tin plating brightener, please feel free to contact us.