Cryopump and method for regenerating the cryopump using two-stage discharge process

Patent metadata

Field	Value
Publication number	US-9810208-B2
Application number	US-201414206510-A
Country	US
Kind code	B2
Filing date	Mar 12, 2014
Priority date	Mar 12, 2013
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A method of regenerating a cryopump includes a first discharging process that includes alternately evacuating a cryopump housing and supplying a purge gas in a first pressure range, and a second discharging process that includes evacuating the cryopump housing to a low pressure region below the first pressure range. The second discharging process includes making a determination at least once in the low pressure range as to whether the second discharging process should be terminated, and supplying the purge gas to the cryopump housing prior to a first-time determination as to whether the second discharging process should be terminated.

First claim

What is claimed is:

1. A cryopump comprising:
a cryopanel;
a cryopump housing arranged to enclose the cryopanel;
a control unit configured to control evacuation of the cryopump housing and supply of a purge gas to the cryopump housing for full regeneration of the cryopanel,
wherein the control unit is configured to perform:
a first rough-and-purge process that includes alternately performing a first rough-and-purge evacuating of the cryopump housing and a first rough-and-purge supplying of the purge gas in a first pressure range, and
a second rough-and-purge process that includes, subsequent to the first rough-and-purge process, alternately and cyclically repeating a second rough-and-purge evacuating of the cryopump housing to a low pressure region below the first pressure range and a second rough-and-purge supplying of the purge gas to the cryopump housing, and

wherein the second rough-and-purge process includes making a determination at least once in the low pressure region as to whether the second rough-and-purge process should be terminated, and a plurality of cycles of the alternately and cyclically repeating of the second rough-and-purge evacuating of the cryopump housing and the second rough-and-purge supplying of the purge gas to the cryopump housing are performed prior to a first-time determination as to whether the second rough-and-purge process should be terminated.

2. The cryopump according to claim 1 , wherein
the control unit sequentially performs termination of the first rough-and-purge process, the second rough-and-purge evacuating of the cryopump housing from the first pressure range to the low pressure region, and the second rough-and-purge supplying of the purge gas to the cryopump housing.

3. The cryopump according to claim 1 , wherein
the control unit terminates the second rough-and-purge supplying of the purge gas based on a measured pressure in the cryopump housing.

4. The cryopump according to claim 1 , wherein
the control unit performs, prior to the first rough-and-purge process, a temperature-raising process that includes heating the cryopanel to a regeneration temperature, which is higher than a cooling temperature of a cryopump vacuum pumping operation.

5. The cryopump according to claim 1 , wherein
the control unit performs, after the second rough-and-purge process, a cool down process that includes cooling the cryopanel to a cooling temperature of a cryopump vacuum pumping operation.

6. The cryopump according to claim 1 , wherein
the control unit performs, if the first-time determination as to whether the second rough-and-purge process should be terminated is failed, a further plurality of cycles of the second rough-and-purge evacuating of the cryopump housing and the second rough-and-purge supplying of the purge gas to the cryopump housing prior to a second-time determination as to whether the second rough-and-purge process should be terminated.

7. A cryopump full regeneration method comprising:
a first rough-and-purge process that includes alternately performing a first rough-and-purge evacuating of a cryopump housing and a first rough-and-purge supplying of a purge gas in a first pressure range, and
a second rough-and-purge process that includes, subsequent to the first rough-and-purge process, alternately and cyclically repeating a second evacuating of the cryopump housing to a low pressure region below the first pressure range and a second rough-and-purge supplying of the purge gas to the cryopump housing, wherein
the second rough-and-purge process includes making a determination at least once in the low pressure region as to whether the second rough-and-purge process should be terminated, and a plurality of cycles of the alternately and cyclically repeating of the second rough-and-purge evacuating of the cryopump housing and the second rough-and-purge supplying of the purge gas to the cryopump housing are performed prior to a first-time determination as to whether the second rough-and-purge process should be terminated.

8. The method according to claim 7 , wherein
termination of the first rough-and-purge process, the second rough-and-purge evacuating of the cryopump housing from the first pressure range to the low pressure region, and the second rough-and-purge supplying of the purge gas to the cryopump housing are sequentially performed.

9. The method according to claim 7 , wherein
the second rough-and-purge supplying of the purge gas is terminated based on a measured pressure in the cryopump housing.

10. The method according to claim 7 , further comprising:
prior to the first rough-and-purge process, a temperature-raising process that includes heating a cryopanel to a regeneration temperature, which is higher than a cooling temperature of a cryopump vacuum pumping operation.

11. The method according to claim 7 , further comprising:
after the second rough-and-purge process, a cool down process that includes cooling a cryopanel to a cooling temperature of a cryopump vacuum pumping operation.

Assignees

• Sumitomo Heavy Industries

Inventors

• Kimura Toshiyuki

Classifications

• F04B37/08

  by condensing or freezing, e.g. cryogenic pumps · CPC title

• F04B37/085 Primary

  Regeneration of cryo-pumps · CPC title

• B01D8/00

  Cold traps; Cold baffles (pumps for evacuating by condensing or freezing F04B37/08) · CPC title

• F04B37/00

  Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 · CPC title