Method and apparatus for spatially uniform electropolishing and electrolytic etching
US5096550A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1990 |
| Grant date | Mar 17, 1992 |
| Priority date | — |
| Expiry date | Oct 15, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S204/07
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
In an electropolishing or electrolytic etching apparatus the anode is separated from the cathode to prevent bubble transport to the anode and to produce a uniform current distribution at the anode by means of a solid nonconducting anode-cathode barrier. The anode extends into the top of the barrier and the cathode is outside the barrier. A virtual cathode hole formed in the bottom of the barrier below the level of the cathode permits current flow while preventing bubble transport. The anode is rotatable and oriented horizontally facing down. An extended anode is formed by mounting the workpiece in a holder which extends the electropolishing or etching area beyond the edge of the workpiece to reduce edge effects at the workpiece. A reference electrode controls cell voltage. Endpoint detection and current shut-off stop polishing. Spatially uniform polishing or etching can be rapidly performed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.