Proximity printing
US3944419A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1975 |
| Grant date | Mar 16, 1976 |
| Priority date | — |
| Expiry date | Jan 30, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/2041
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
To avoid damaging photolithographic masks and photoresist coatings on articles during selective exposure of the photoresist coatings, the mask is held very near to, but not in contact with, the photoresist coating during the selective exposure. Because of the close spacing involved, such a technique is commonly termed "proximity printing." To provide suitable spacers for holding a mask in uniform proximity with a photoresist coating, a plurality of droplets of a liquid acrylic resin are dispensed onto the mask and cured in air to harden them. For proximity printing, the mask is simply pressed against the photoresist coating with the droplets therebetween and light of sufficient wavelength and intensity is directed selectively onto the coating through the mask for a sufficient time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.