Structure Control Theory of Plated Film —Part of Surface Morphology—

Abstract

The author has investigated the relationship between the structure of the plated film and plating conditions for 12 pure metals and 28 binary alloys. The structure of the plated film can be discussed based on metallurgical structure, surface morphology, crystal size, crystallographic orientation, adhesion between the plated film and substrate, retained stress, and anomalous structure. The control mechanisms of these features can be independently explained, since there is an independent control theory for each feature. This paper explains the unique control theory for surface morphology of plated films proposed by the author. In discussing surface morphology, two cases must be considered separately: pure metals and alloys. Discussions of pure metal films can be further subdivided into those with low melting points and those with high melting points. Generally, the crystals of plated alloy films are small, and the surface morphology depends on the crystallographic structure of the alloy film. The roughness of the plated film increases with film thickness and is hardly influenced by current density. When the current density is low, the surface roughness dominates. When current density is high, the surface is relatively smooth for both pure metal films and alloy films. It is not due to over voltage. The type of anion in the plating bath influences the nature of the roughness.

Direct Electrodeposition of Porous Gold Nanowire Arrays for Biosensing Applications

“…The protrusions on the cathode surface make disperse crystallization easier by attaching nuclei of adatoms and offering sites of maximal current density. [32,33] It can be assumed that the concentration polarization and electrochemical polarization at these sites are smaller than in other regions of the cathode. Therefore, they are sites of preferential crystallization of the gold deposit.…”

Fabrication of Electroplated Nickel Composite Films Using Cellulose Nanofibers Introduced with Carboxy Groups as Co-Deposited Materials

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