Screening seeds for quartz growth
US3976535A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 27, 1975 |
| Grant date | Aug 24, 1976 |
| Priority date | — |
| Expiry date | May 27, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1096
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
z-face quartz of good quality suitable for piezoelectric applications can be grown at rates near 35 mil/da at p-T conditions easily accessible in commercial autoclaves. The growth conditions are predictable from previous systematic studies of growth rate. Cracking of grown crystals either during growth or in crystal processing can be severe and can account for as much as 15-50% yield loss. However, much of this loss can be reduced by carefully screening seeds for strain using the new polariscopic technique of the invention. Strain (and cracking) are severe with growth on highly strained seeds and at high growth rates. Carefully choosing seeds reduces the strain in the grown material for a given growth rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.