The Effect of pH on Electroless Copper Deposition

Abstract

Sodium nitrite (8) 355 23.3 • 0.8 9 [NO~-] = 0.02-0.07M; pH = 8.65; temperature = 23 ~ "4" l~ insignificant or undetectable by cyclic voltammetric technique. ConclusionThe cyclic voltammogram of a used copper pyrophosphate solution shows a distinct tail beginning at approximately 0.65V. We have concluded that this tail is due to the oxidation of NOe-ions. The source of NO2-is the reduction of NO3-during electroplating. The concentration of NO2-can be accurately measured by cyclic voltammetric and spectroscopic techniques. Ogden and Tench (4) have found that the effective concentration of the brightener is changed in a used solution. Based upon our study, this change cannot be due to the buildup of NO2-. The effect could be due to organic impurities or to the buildup of orthopyrophosphate ( 14).

Real-time monitoring of metal deposition and segregation phenomena during preparation of PdCu membranes

“…This was accompanied by a noticeable drop of the OH − concentration. Electroless Cu plating rates are very sensitive to pH value exhibiting a sharp maximum around pH 12.5 [14]. At pH 12 the Cu deposition rate declines already to a fraction of the maximum value due to inhibition of the metal surface by products of HCHO oxidation [14].…”

“…Electroless Cu plating rates are very sensitive to pH value exhibiting a sharp maximum around pH 12.5 [14]. At pH 12 the Cu deposition rate declines already to a fraction of the maximum value due to inhibition of the metal surface by products of HCHO oxidation [14]. Although the concentration of the highly reactive HCHO is low in aqueous solutions due to various condensation and disproportionation reactions, most are reversible and depletion of the reducing agent can be excluded as a cause for the deposition rate decline at the HCHO concentrations used here.…”

Electroless Deposition of Copper

“…(17.7), the effect of pH is direct and significant [14,15]. Since OH À ions are reactants in the charge-transfer step, Eq.…”

Metallization Process of a Polyimide Surface with Palladium-Free Activation for Electronic Field Applications

“…The extensive demand for these applications is accelerating the development of copper formulation and plating techniques. [16][17][18][19] Electroless copper coatings have more merits including lower resistivity and smaller charge transfer resistance than other noble metals. In order to achieve initially activated sites on the surface of PI, palladium-free activation (the copper salt activation method) was adopted and then the activated PI was put in the plating solution which consisted of copper sulfate as the main salt and formaldehyde as the reducing agent.…”