Etching apparatus for accurately making small holes in thick materials
US4013498A · kind A · utility
22Cited by
4References
1Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1975 |
| Grant date | Mar 22, 1977 |
| Priority date | — |
| Expiry date | Sep 29, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2209/015
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A sheet of metallic material having a thickness T is covered on one side by an etchant resist and on the opposite side by an etchant resist and a removable shield. Etching is first performed on the side with only the etchant resist layer. Next, the shield is removed and the material is etched from both sides to produce an opening having a minimum dimension less than the thickness T of the material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.