The Role of Organic Additives in the Electroless Nickel Plating Bath

Organic additives to electroless plating baths are shown to affect the surface reaction by changing the catalytic activity of the surface. The presence of a thioketone group in the additive increases the surface activity, which results in acceleration of the target reaction. The presence of the iminogroup favors the formation of complexes and alters the rates of concurrent reactions, which weakens the surface activity. The reaction in the volume is governed by the inhibiting properties of additives dependent on the identity of functional groups. The greater the electron-donor properties of the additive, the higher their adsorbability and the stronger the blocking effect, which stabilizes the electrolyte.