Etching depth monitor
US4481061A · kind A · utility
7Cited by
2References
15Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 10, 1983 |
| Grant date | Nov 6, 1984 |
| Priority date | — |
| Expiry date | Jun 10, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/163
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A monitor (9) for determining the amount of metal which has been removed during the course of a chemical etching process comprises an etch resistant substrate (10) whereon are affixed a plurality of metal foil areas (12A to 12H) each with its own, known substantially uniform thickness prior to the start of the etching process, indication of the progressive depth of etching being provided by which out of the plurality of areas of foil (12A to 12H) remain at any particular time after the commencement of etching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.