plating, anodizing, & finishing Q&As since 1989
Function of Chloride in Acid Copper Plating Bath.
An ongoing discussion beginning back in 2000 ...2000
Q. Being new to the industry (and being a chemist) I am trying to decipher plating processes on a molecular level.
I am trying to find detailed information on the action/function of the chloride ion in an acid copper electroplating bath - is its function as an aid to anode filming only? We use active soluble phosphorised anode balls. Does it aid in the deposition process;that is, will the leveler and brightener work correctly without the presence of chloride? The reason I'm curious is because I've been told several different things by various experts, and I really require a definitive answer. No doubt the answer is quite straightforward but..........?
Help somebody please!John Mason
A. The role of chloride is primarily formation of the film on the anode, but do not discount the importance of that film. That film is necessary to the proper corrosion of the anode. If that film is not properly formed, you will find the anodes polarizing. For further info, you might take a look at Modern Electroplating by Lowenheim.
James Totter, CEF
- Tallahassee, Florida
January 26, 2018
Q. Besides anode filming and corrosion, what is the role of chloride in acid copper plating?David Lubiner
Tanury Industries - Lincoln Rhode Island
January 28, 2018
A. Hi David,
Role of chloride in acid Cu plating as below:
1. Reduce anode polarization.
2. Eliminate striated deposit in high current density area.
3. Improve copper deposit ductility.
4. Act as binding sites for suppressor such as polyethylene glycols to suppress deposition rate and improve copper deposit morphology at high current density area.
February 9, 2018
A. Just a quick addition, the chloride ion is also essential for Cu anode dissolution.Mark Baker
Process Engineering - Phoenix, Arizona USA