Method and apparatus for determining the immersed surface area of one of the electrodes of an electro-chemical bath
US4129480A · kind A · utility
Inventor
Key dates
| Filing date | Dec 20, 1977 |
| Grant date | Dec 12, 1978 |
| Priority date | — |
| Expiry date | Dec 20, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B7/32
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The immersed surface area of one of the electrodes in a conventional electro-chemical bath is accurately determined, so that the bath may be operated at an optimium current density, to obtain high quality electro-plating or electro-polishing. The current density is measured as a certain amount of current over the immersed area of the electrode. For any given area, the current density may be varied by varying the current flow. The potential between the bath and the electrode of interest is measured when no current is being conducted through the bath. A short pulse of current is then passed through the bath from one electrode to the other; and immediately thereafter the potential between the bath and the electrode of interest is again measured. These two potentials are then compared, and the potential difference is used to determine the immersed surface area of the electrode of interest according to a mathematical relationship corresponding to such electro-chemical baths. The immersed surface area of the electrode of interest can also be determined by varying the pulse current amplitude and frequency to obtain a certain predetermined difference between the potential values, measured …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.