Patent · US Active

Method of making a silica crucible in a controlled atmosphere

US9003832B2 · kind B2 · utility

0Cited by

18References

35Claims

0Family size

Assignees

Heraeus Shin-Etsu America, Inc. · US
HERAEUS QUARZGLAS GMBH & CO. KG · DE

Inventors

Katsuhiko Kemmochi · Camas, US
Thomas Kayser · Leipzig, DE
Robert Joseph Coolich · North Bonneville, US
Walter Lehmann · Leipzig, DE

Key dates

Filing date	Nov 20, 2009
Grant date	Apr 14, 2015
Priority date	—
Expiry date	Dec 21, 2029

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T428/131
WIPO fieldOther special machines
WIPO sectorMechanical engineering

Abstract

A silica crucible is made in a mold cavity of the type in which ambient atmosphere can be drawn through silica grain in the cavity. In one embodiment, a silica grain layer is formed in the mold cavity and gas, which may comprise helium, nitrogen, hydrogen, or a mixture thereof, is introduced into the mold cavity. The silica grain layer is heated while substantially no ambient atmosphere is drawn through the silica grain. Thereafter, at least a portion of the silica grain layer is fused while drawing ambient atmosphere through the silica grain. The gas displaces air in the mold cavity thereby reducing nitrogen oxides and ozone.

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