Gas separation: apparatus – Electric field separation apparatus – With means to add charged solid or liquid particles to...
Patent
1975-04-30
1976-06-15
Drummond, Douglas J.
Gas separation: apparatus
Electric field separation apparatus
With means to add charged solid or liquid particles to...
96 351, 96 383, 156 11, 156 16, 156 17, H01L 21312
Patent
active
039634892
ABSTRACT:
A method of precisely aligning a pattern on one side of an opaque substrate with a pattern on the opposite side thereof through the use of pattern-defining masks, wherein at least certain pattern areas previously not formed on the substrate, as defined selectively through the masks, are formed while the masks are aligned. The first mask is releasably secured to a first side of the substrate so as to define a particular orientation of a desired pattern therethrough, and is dimensioned such that at least one, but preferably several spaced peripheral areas thereof extend beyond adjacent peripheral edge portions of the wafer, with the extended mask areas including alignment indicia. A second mask is then positioned against a second side of the substrate, and is constructed with one or more outwardly extending peripheral areas and respectively associated alignment indicia corresponding in number, and spatial relationship, with those in the first mask. The second mask is then oriented such that the alignment indicia thereof are brought into precise registry with the corresponding alignment indicia of the first mask so as to ensure that the pattern-defining portions of the masks are in precise alignment on opposite sides of the substrate.
REFERENCES:
patent: 3680205 (1972-08-01), Kravitz
patent: 3759767 (1973-09-01), Walls
patent: 3782942 (1974-01-01), Compare
patent: 3813310 (1974-05-01), Droege et al.
Bergum K. R.
Drummond Douglas J.
Epstein M. Y.
Massie Jerome W.
Western Electric Company Inc.
LandOfFree
Method of precisely aligning pattern-defining masks does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of precisely aligning pattern-defining masks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of precisely aligning pattern-defining masks will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1692843