ELECTROPLATING FROM ADDITIVE-FREE ELECTROLYTES

Faraday Technology, Inc. proposes to develop an electroplating process fromadditive-free bath for the printed wiring board (PWB) industry and metal platingindustry. Current state-of-the-art metal plating relies on baths containingproprietary additive. These additives were developed empirically and consist ofbrighteners, levelers, and surfactants. These additives affect the platingprocess to yield electrodeposits with the appropriate properties for their givenapplications. During plating, these additives gradually decompose and arereplenished until the bath can no longer be used due to the build up ofdecomposition products. Consequently, the rinse waters cannot be recycled toplating operations. In addition, since the additives and their decompositionproducts build up and adversely effect the rinse operations, the rinse waterscannot be recycled to the rinse operations. Finally, the sensitivity of theelectrodeposition process to the concentration of additives makes it difficultto maintain control of the plating process. They propose to replace the additiveplating bath chemistries with electrodeposition from additive-free electrolytesusing pulse current waveforms. Additive-free electrolytes will allow therecovery and in-process recycle of rinse waters and plating baths enablingclosed-loop environmentally conscious metal plating.