Film for applying compressive stress to ceramic materials
US10868899B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 22, 2018 |
| Grant date | Dec 15, 2020 |
| Priority date | — |
| Expiry date | Jun 22, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/1637
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method to provide compressive stress to substrates includes depositing a film on a ceramic substrate at a deposition temperature (Td) to form an article, the film having a difference relative to the ceramic substrate at Td in a coefficient thermal expansion (CTE) of at least 1.0×10−6/K and a difference in a refractive index >0.10. At least a portion of the thickness the film is converted in at least one of composition, phase and microstructure by lowering or raising the temperature from Td to reach a changed temperature (Tc) that is at least 100° C. different from Td. The film converting conditions result in the converted film portion providing a difference in refractive index at the Tc between the converted film and the ceramic substrate of ≤|0.10|. The temperature of the article is then lowered to room temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.