Nickel based finishing coating

The application of chemical nickel (Electroless Ni) as a finishing coating for printed circuit boards is one of the alternatives to HASL. But this method itself is rarely used in the production, due to the essence of Electroless Ni — the formation of an intermediate (barrier) precipitating layer between the dielectric and the metal (immersion silver, palladium, immersion gold, etc.).

Copper plating is used as an effective protection against cementation of printed circuit boards. Also, nickel proved itself to be good in galvanoplasty, when making copies from metals.

Dissolving in a metallized bath, any metal has a certain electrical potential (often positive). Then in the process of long metallization — the flow of special chemicals into the electrons — the potential of the chemical alloy/substance is neutralized.

When applying Electroless Ni, dimethylamine borane or hypophosphate act as neutralizing chemicals. The resulting nickel coating is etched in alkaline copper chloride solutions and further activated. The thickness of the protective layer of precipitation varies from 2.5 to 5 μm.

— High resistance to alkaline conditions, the effects of sudden temperature fluctuations or moisture.
— Special appearance: making a shiny surface.
— It increases hardness, general index of mechanical wear.
— Safe for living organisms, non-toxic.
— Durable appearance.

Characteristics of finishing coating