Etching a substrate: processes – Masking of a substrate using material resistant to an etchant
Reexamination Certificate
2005-05-27
2011-12-06
Ahmed, Shamim (Department: 1713)
Etching a substrate: processes
Masking of a substrate using material resistant to an etchant
C216S047000, C216S058000, C216S083000, C430S005000, C430S311000, C430S312000, C430S313000
Reexamination Certificate
active
08070971
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.
REFERENCES:
patent: 6387774 (2002-05-01), Yoo
patent: 7037626 (2006-05-01), Dirksen et al.
Dijkstra Paul
Kloosterman Jan
Ahmed Shamim
NXP B.V.
LandOfFree
Etch method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Etch method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Etch method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4314511