Control process for a monocrystal pulling machine
US4660149A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1984 |
| Grant date | Apr 21, 1987 |
| Priority date | — |
| Expiry date | Oct 10, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1072
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The invention relates to a process for the control of a monocrystal pulling machine. The process consists of recording in a computer memory parameters relating to the geometry of the monocrystal and the growth thereof, signals representative of the weight of the crystal and processed by processing circuits, then recording in said memory a programme so that the computer successively controls the raising to the appropriate temperature of the heating means for successively bringing about the melting of the product for forming the monocrystal, a fast automatic approach of the product bath by a pin carrying a nucleus up to a predetermined distance from the surface of said bath. Finally, the process consists of controlling a slower bath approach until the nucleus is in contact with the bath surface. Following this contact, the temperature of the heating means is automatically regulated for a zero growth of the crystal, the automatic pulling of the crystal and the cooling of the heating means at the end of pulling. Application to the pulling of monocrystals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.