Etch method
US8070971B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 2005 |
| Grant date | Dec 6, 2011 |
| Priority date | — |
| Expiry date | Jul 26, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24479
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An improved method of etching a structure and a structure etched by the method is disclosed. The bottom side of a leadframe of an IC-package is an example of a structure, which advantageously may be etched with the disclosed method. The method includes the steps of providing an etch mask to the substrate to be etched. The etch mask comprising at least two sub-mask: a first sub-mask covering the area which substantially should remain after the etching process, and a second sub-mask covering an area to be removed in the etching process. The second sub-mask is a sacrificial mask in the form of a grid. The presence of the second sub-mask increases the etching speed in the area covered by it.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.