Measurement of complexing agent concentration in an electroless plating bath
US6890758B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 2003 |
| Grant date | May 10, 2005 |
| Priority date | — |
| Expiry date | Oct 14, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/200833
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The concentration of citrate complexing agent in an electroless cobalt or nickel plating bath is determined by titrating a sample of the electroless plating bath containing a small concentration of free fluoride ion with a standard lanthanum nitrate solution. During the titration, La3+ ion first reacts preferentially with the citrate complexing agent and then with fluoride ion, which reduces the free fluoride ion concentration. The endpoint for the titration is indicated by a substantial decrease in the free fluoride ion concentration, which is detected via a fluoride ion specific electrode (ISE). The method can be used for analysis of other complexing agents.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.