Patent · US Expired

Apparatus for casting silicon with gradual cooling

US4915723A · kind A · utility

19Cited by
6References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 30, 1989
Grant dateApr 10, 1990
Priority date
Expiry dateJun 30, 2009

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC30B11/003
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

For the continuous casting of silicon, an electrically conductive bottomless crucible is circumferentially divided by axial slits and is positioned within an electrical induction coil. The slits form circumferential gaps of between 0.3 mm and 1.0 mm and the inner wall of the crucible is inclined by between 0.4.degree. and 2.0.degree., so that the crucible expands in the downstream direction of movement of the silicon. In order to reduce the temperature gradient of the solidified silicon to between 20.degree. C./cm and 100.degree. C./cm, an additional heating element is disposed downstream of the boundary surface between the molten and solidified silicon. The crucible may be cooled by forming the crucible as a double walled cylinder and flowing a coolant therethrough.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.