Method of Reducing the Formation of Copper Nodules in an Additive Plating Bath
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
The formation of copper nodules on inactive surfaces of nonmetallic substrates during the deposition of copper on activated surfaces and metal substrates is reduced by introducing air into plating bath before the heat exchanger is used. During the deposition of copper in a chemical bath, the following primary reaction occurs: (Image Omitted) . In addition to this reduction of Cu2+ by formaldehyde, there are secondary reactions, such as the incomplete reduction of the Cu2+ to Cu2O and the disproportioning of this Cu-I-oxide to Cu2+ and elementary copper. The copper formed during this process is deposited in the form of nodules at undesired points on the non-metallic surface.