Analysis of tin, lead or tin-lead alloy plating solution
US5294554A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1992 |
| Grant date | Mar 15, 1994 |
| Priority date | — |
| Expiry date | Feb 28, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/78
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In electroless or electric tin, lead or tin-lead alloy plating solution which may contain copper, the concentration of a metal ion component selected from divalent tin ion, lead ion, and copper ion is quantitatively determined by taking a sample from the solution, adding a chemical agent, for example, an oxidizing agent to the sample, thereby causing the selected metal ion to develop its color, measuring the absorbance of the sample due to the metal ion by colorimetry, and determining the concentration from the absorbance. A choice of chemical agent depends on a particular metal ion on analysis. When the solution contains more than one metal ion, correction is made by repeating the process using another chemical agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.