Shin-etsu Chemical Co., Ltd.

Tokyo Electoron Limited

Takaaki Nagao

Dai Inoue

Hiroyuki Koide

Tadakatsu Shimada

Hideo Hirasawa

Nobuo Kawada

Masami Terashima

Yuichi Matsunaga

Junichi Arami

Kenji Ishikawa

Hideki Fujii

Toshihiko Shindo

Soichiro Kemmochi

Shoji Hoshino

Ryoji Nakajima

Kazuhiko Urano

Toshihiko Shindoh

An optical fiber base material manufacturing method includes: supplying oxygen, hydrogen, and silicide to a core deposition burner; depositing silicon dioxide; adjusting a drawing up speed so that a deposition tip position remains at the same position in accordance with growth of a porous base material; calculating an average of the drawing up speed at each preset time interval; calculating a difference of the calculated average from a preset value of the drawing up speed; correcting a flow rate of silicon tetrachloride when the supplied hydrogen is hydrogen produced or stored at normal temperature, and correcting a flow rate of hydrogen when the supplied hydrogen is hydrogen obtained by vaporizing liquid hydrogen, where when correcting the flow rate of hydrogen, a flow rate of hydrogen supplied to a cladding deposition burner is also corrected in a ratio of before and after the correction of the flow rate of the hydrogen.

Optical fiber preform manufacturing method and optical fiber preform manufacturing device

An optical fiber base material manufacturing apparatus including a reaction chamber; a burner that has a portion thereof inserted into the reaction chamber through an insertion opening that creates a connection between the inside and outside of the reaction chamber, and emits a flame toward a starting member positioned within the reaction chamber; and a seal connection member that creates an air-tight seal between the burner and the reaction chamber at the insertion opening. One end of the seal connection member firmly contacts the burner inserted therethrough, another end of the seal connection member firmly contacts the reaction chamber and has a through-hole formed therein through which the burner is inserted without contacting the seal connection member, and the seal connection member includes a connecting portion that connects the one end to the other end, while preventing transfer of stress between the one end and the other end.

Optical fiber base material manufacturing apparatus

Provided is a quartz glass manufacturing method that involves using one or more burners, supplying hydrogen and oxygen to the one or more burners to generate an oxyhydrogen flame, introducing a silicide into the oxyhydrogen flame, forming a porous base material by depositing silicon dioxide generated from a flame hydrolysis reaction with the silicide, and heating and sintering the porous base material to form transparent glass, the method comprising supplying hydrogen that is stored or made at a normal temperature to the one or more burners; controlling a hydrogen flow rate using a measurement apparatus or control apparatus that performs measurement based on heat capacity of a gas; vaporizing liquid hydrogen stored in a low-temperature storage chamber, and supplying the vaporized liquid hydrogen to the one or more burners as backup hydrogen; switching from the hydrogen to the backup hydrogen; and when switching, adjusting the hydrogen flow rate to a value obtained by multiplying the hydrogen flow rate immediately after switching by a predetermined correction coefficient.

Quartz glass manufacturing method using hydrogen obtained by vaporizing liquid hydrogen

A method of manufacturing an optical fiber base material includes: forming a porous glass base material by depositing glass particles; providing a synthetic quartz glass vessel at least partly made of quartz glass which contains aluminum equal to or less than 0.01 ppm; introducing dehydration reaction gas and inert gas into the vessel; heating a portion made of quartz glass which contains aluminum equal to or less than 0.01 ppm in the vessel that contains the dehydration reaction gas and the inert gas; and inserting the porous glass base material into the heated vessel to dehydrate and sinter the porous glass base material.

Method of manufacturing optical fiber base material and apparatus of the same

There is provided an apparatus for supplying a hydrogen gas to a quartz glass manufacturing apparatus including a burner that generates an oxyhydrogen flame when supplied with the hydrogen gas, where the apparatus includes: a first hydrogen supply system that supplies a hydrogen gas in which isomers are in equilibrium; a second hydrogen supply system that supplies a hydrogen gas in which isomers are out of equilibrium; a flow rate control section that includes: a valve that changes a flow rate of the hydrogen gas to be supplied to the burner; a first flow rate measuring section that measures the flow rate of the hydrogen gas to be supplied to the burner by measuring a heat capacity; and a control section that controls the valve in such a manner that a measured value obtained by the first flow rate measuring section approaches a set value input from outside; a second flow rate measuring section that measures the flow rate of the hydrogen gas to be supplied to the burner by measuring a different factor than the heat capacity; and a set value compensating section that compensates the set value by multiplying the set value by a ratio between the measured value obtained by the first flow rate measuring section and a measured value obtained by the second flow rate measuring section.

Apparatus and method for supplying hydrogen gas, and quartz glass manufacturing apparatus

A method of manufacturing an optical fiber base material includes: forming a porous glass base material by depositing glass particles; providing a vessel which employs a composite tube, the composite tube including a portion formed by jacketing a first quartz glass containing aluminum equal to or less than 0.01 ppm with a second quartz glass containing aluminum equal to or more than 15 ppm; introducing dehydration reaction gas and inert gas into the vessel; heating the jacketed portion in the vessel which contains the dehydration reaction gas and the inert gas; and inserting the porous glass base material into the heated vessel to dehydrate and sinter the porous glass base material.

Provided is hydrogen supply equipment that, when switching hydrogen supplied to equipment using hydrogen from (i) hydrogen produced at a normal temperature or hydrogen stored at a normal temperature to (ii) hydrogen stored at a low temperature, supplies the equipment using hydrogen with normal hydrogen obtained by returning the hydrogen at the low temperature to a normal temperature and then passing this hydrogen through equipment for accelerating a conversion from parahydrogen to orthohydrogen.

Hydrogen supply equipment

There is provided an elongation method of an optical fiber base material, by which a base material rod not requiring a process for modifying a bend from base material ingot is obtained. The method for elongating base material ingot to be a base material rod having a diameter smaller than before to manufacture an optical fiber base material, includes the steps of: elongating the base material ingot while controlling a control position so that a neck-down within a horizontal surface of the base material ingot is located at a target position; measuring a bending direction and a bending amount of an elongated base material rod; and adjusting the target position based on the result. In addition, it is preferable to adjust a position of a pendant portion of base material ingot in order to control the position of the neck-down to be the target position. For example, the position of the pendant portion may be moved in an XY direction, more particularly, in a direction in which the measured bend shows convexity.

Method of elongating an optical fiber base material

A method of packing a glass base material (), which is a base material of an optical fiber comprising packing the glass base material () into a cylindrical container (). The packing has: putting the glass base material () into a plastic bag (); and packing the glass base material (), which is put into the plastic bag (), into the cylindrical container (). The packing further has: wrapping the glass base material (), which is put into the plastic bag (), with air packing material (), which contains air inside; and packing the glass base material () wrapped with the air packing material () into the cylindrical container ().

Glass base material packing method

The optical fiber base material heat treatment method can be provided that the first flame polishing heats the surface of the optical fiber base material ( ) with fixing a length of the optical fiber base material ( ) and the second flame polishing heats the surface of the optical fiber base material ( ) by lower temperature than the temperature of the heating of the first flame polishing.

Double flame polishing method for fiber preforms

Proposed is a ceramic-based electrostatic chuck with built-in heater used in high-temperature processing of a semiconductor silicon wafer, which is capable of exhibiting excellent electrostatic attracting force even at a temperature at which conventional ceramic-based electrostatic chucks cannot exhibit high attracting force. The electrostatic chuck with built-in heater of the invention is an integral body comprising: (a) a base body of a sintered mixture of boron nitride and aluminum nitride; (b) a first pyrolytic graphite layer formed on one surface of the base body to serve as a resistance heater element; (c) a first insulating layer of pyrolytic boron nitride on the first pyrolytic graphite layer; (d) a second pyrolytic graphite layer formed on the other surface of the base body to serve as the electrodes for electrostatic chucking; and (e) a second insulating layer on the second pyrolytic graphite layer formed from a pyrolytic composite nitride of boron and silicon of which the content of silicon is in the range from 1% to 10% by weight having an appropriate volume resistivity at a temperature of 500.degree. to 650.degree. C. as deposited by the pyrolysis of a gaseous mixture of ammonia, boron trichloride and silicon tetrachloride.

Ceramic electrostatic chuck with built-in heater

The ceramic electrostatic chuck with built-in heater of the present invention is disclosed having electrodes for electrostatic chuck made from an electroconductive ceramic bonded to a surface of a supporting substrate made from an electrically insulating ceramic, a heat generating layer made from an electroconductive ceramic is bonded to the other surface and the side surface and a covering layer made from an electrically insulating ceramic is provided thereon.

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Ibaraki, Japan

Takaaki Nagao