Heat treatment apparatus
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsKazuya Uchida, Takashi Koshigai
Life of this patent
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Abstract
A heat treatment apparatus includes: a furnace core tube made of silica glass; a heater provided adjacent to the furnace core tube, the heater heating a heating region; and a moving mechanism supporting a porous glass base material and relatively moving the porous glass base material with respect to the heater in the furnace core tube in a state where the heating region is heated by the heater to make the porous glass base material pass through the heating region. The heat treatment apparatus includes a thin-walled part provided in a region adjacent to a portion located in the heating region in the furnace core tube, the thin-walled part having a thickness of glass less than that of the portion located in the heating region.
Claims5
A heat treatment apparatus comprising:
- a furnace core tube made of silica glass;
- a heater provided adjacent to the furnace core tube, the heater heating a heating region;
- and
- a support rod supporting a porous glass base material and relatively moving the porous glass base material with respect to the heater in the furnace core tube in a state where the heating region is heated by the heater to make the porous glass base material pass through the heating region,
- wherein the heat treatment apparatus includes a thin-walled part provided in a region adjacent to a portion located in the heating region in the furnace core tube, the thin-walled part having a thickness of glass less than that of the portion located in the heating region, and
- wherein the thickness of the thin-walled part is decreased by setting an inner diameter of the thin-walled part to be greater than an inner diameter of the furnace core tube in the heating region.
Dependencies are inferred from the claim text.