Silicon nitride protective coatings for silvered glass mirrors
US4780372A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 1986 |
| Grant date | Oct 25, 1988 |
| Priority date | — |
| Expiry date | Jun 4, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/0808
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A protective diffusion barrier for metalized mirror structures is provided by a layer or coating of silicon nitride which is a very dense, transparent, dielectric material that is impervious to water, alkali, and other impurities and corrosive substances that typically attack the metal layers of mirrors and cause degradation of the mirrors' reflectivity. The silicon nitride layer can be deposited on the substrate before metal deposition to stabilize the metal/substrate interface, and it can be deposited over the metal to encapsulate it and protect the metal from corrosion or other degradation. Mirrors coated with silicon nitride according to this invention can also be used as front surface mirrors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.