Photoimageable permanent resist
US5178988A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1991 |
| Grant date | Jan 12, 1993 |
| Priority date | — |
| Expiry date | Jul 29, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/027
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Compositions which include an acidified epoxy oligomer, a free radical photoinitiator and a monomer capable of being polymerized by the photoinitiator are used to form aqueous developable, photodefined coatings useful as permanent solder marks for printed circuits and permanent plating resists for additive printed wiring boards. The process for using the compositions include application as a fluid in solvents; drying; exposing to ultraviolet light; developing in an aqueous alkaline solution; and crosslinking the acidified, epoxy oligomers. The articles produced include printed wiring boards with the permanent, photoimaged resist composition thereon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.