Method of and apparatus for etching
US4017343A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 15, 1975 |
| Grant date | Apr 12, 1977 |
| Priority date | — |
| Expiry date | Jul 15, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23F1/46
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A workpiece is passed through an etching tank, and then through at least an upstream rinsing tank and a downstream rinsing tank. In each of the tanks a respective liquid is pumped up from a sump at the bottom and sprayed over the workpiece as it passes through. Liquid is drawn out of the upstream rinse tank and mixed with regenerator chemicals to replenish liquid lost by the etcher and maintain the liquid in the etcher at full strength. Liquid lost from the upstream rinser in this manner is replenished by introduction into the downstream rinser of fresh water and passage of liquid from the downstream rinser to the upstream rinser through an overflow that maintains a higher liquid level in the downstream rinser than in the upstream rinser.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.