Alkali metal diffusion barrier layer
US5830252A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 1996 |
| Grant date | Nov 3, 1998 |
| Priority date | — |
| Expiry date | Feb 1, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C2218/156
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Amorphous metal oxide barrier layers of titanium oxide, zirconium oxide and zinc/tin oxide are effective as alkali metal ion barrier layers at thicknesses below 180 Angstroms. The amorphous metal oxide barrier layers are most effective when the density of the layer is equal to or greater than 90% of the crystalline density. The barrier layers prevent migration of alkali metal ions such as sodium ions from glass substrates into a medium e.g. electrolyte of a photochromic cell, liquid material of a liquid crystal display device contacting the glass surface. The properties of the medium, particularly electroconductive metal oxide coatings, are susceptible to deterioration by the presence of sodium ions migrating from the glass.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.