Online analysis of nickel ion and hypophosphite content in electroless nickel plating baths

In an electroless plating bath, the consumed ingredients have to be regularly replenished to ensure an even layer of nickel-phosphorus alloy. This requires online monitoring of the active bath constituents for the best results. This Process Application Note presents a method to regularly monitor the active bath constituents in an electroless nickel plating bath with the 2060 Process Analyzer from Metrohm Process Analytics. The parameters to be controlled are pH value (4.5–5.0) as well as nickel (NiSO4 < 10 g/L) and hypophosphite concentration (NaH2PO2: 1–12%). Other measurement options include sulfate, alkalinity, and organic additives (via CVS).