Glass Master Coating
Original Publication Date: 1980-Jan-01
Included in the Prior Art Database: 2005-Feb-12
It is a common practice to apply a protective coating to the circuitized surface of glass masters which are used to produce miniaturized electronic packages. In the absence of such a protective coating, the circuitized emulsion would be scratched or abraded and ultimately flake off. A protective clear coating consisting of a polyurethane resin, an EPONOL* phenoxy resin solution and a solvent mixture was previously employed to serve the glass master protective function. However, it was found that such coatings would frequently exhibit poor pot life, causing gelation and stringing of the coating. This resulted in scrap losses relative to the glass masters and production interruptions.