US4577465A
Expired / Lapsed
US
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Oil free vacuum system
Assignee: Azenta Inc
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Filing: 1984-05-11
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Granted: 1986-03-25
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Expires: 2004-05-11
Abstract
Abstract An oil free vacuum system 10 which comprises a high thermal capacitance cryopump 12 and air ejector 38. The air ejector 38 is used to reduce load lock chamber 16 pressure to an intermediate vacuum. Cryopump 12 further evacuates chamber 12 to the operating vacuum of a work chamber 14. The work chamber 14 is maintained at high vacuum by a main cryopump 20. The main cryopump can be started in an oil free manner through the use of air ejector 38 and high thermal capacitance cryopump 12. A high themal capacitance, high thermal conductance cryopanel is formed of a lead/copper sandwich.
Inventors
- 👤 Donald A. Olsen
- 👤 Michael J. Eacobacci
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:00
CPC Classifications
F; F04; F04B; F04B37/00; F04B37/06; F04B37/08; Y; Y10; Y10S; Y10S417/00; Y10S417/901
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
89 words
A vacuum system comprising: a. a work chamber; b. a load lock for receiving material to be introduced into and removed from the work chamber; c. a first cryopump for fluid communication with the work chamber; d. a second cryopump for fluid communication with the load lock through a valve; and e. a gas ejector for initial depressurization of said load lock to a cross-over pressure when the valve to the second cryopump is closed and materail is introduced to the load lock for transfer to the work chamber.
Claim 2
Dependent Claim
89 words
A vacuum system comprising: a. a work chamber; b. a load lock for receiving material to be introduced into and removed from the work chamber; c. a first cryopump for fluid communication with the work chamber; d. a second cryopump for fluid communication with the load lock through a valve; and e. a gas ejector for initial depressurization of said load lock to a cross-over pressure when the valve to the second cryopump is closed and materail is introduced to the load lock for transfer to the work chamber.
Claim 3
Dependent Claim
32 words
The vacuum system of claim 1 wherein said second cryopump comprises a high thermal capacitance cryopump to complete evacuation of the load lock after said gas ejector initially depressurizes said load lock.
Claim 4
Dependent Claim
23 words
The vacuum system of claim 2 wherein said high thermal capacitance cryopump comprises a low temperature adsorptive array constructed in part of lead.
Claim 5
Dependent Claim
17 words
The vacuum system of claim 3 wherein said low temperature adsorptive array further comprises a copper layer.
Claim 6
Dependent Claim
18 words
The vacuum system of claim 3 wherein said lead is alloyed with antimony to increase the lead's hardness.
Claim 7
Dependent Claim
23 words
A vacuum system as claimed in claim 2 wherein the capacitance of the high thermal capacitance cryopump is at least about six joules/K.
Claim 8
Dependent Claim
35 words
The vacuum system of claim 6 wherein the capacitance per volume of a material forming at least part of a cold stage cryopanel of the second cryopump is at least about 0.2 joules/cm 3 -K.
Claim 9
Dependent Claim
74 words
A vacuum system comprising a cryogenic refrigerator and a low temperature cryopanel mounted to and cooled by said cryogenic refrigerator, the cryopanel being cooled to cryogenic temperatures for condensing gases thereon and thus creating a vacuum, wherein said cryopanel comprises a sheet of at least two layers, one layer formed of a material of relatively high thermal conductivity and the other layer formed of a material of relatively high thermal capacitance per unit volume.
Claim 10
Dependent Claim
74 words
A vacuum system comprising a cryogenic refrigerator and a low temperature cryopanel mounted to and cooled by said cryogenic refrigerator, the cryopanel being cooled to cryogenic temperatures for condensing gases thereon and thus creating a vacuum, wherein said cryopanel comprises a sheet of at least two layers, one layer formed of a material of relatively high thermal conductivity and the other layer formed of a material of relatively high thermal capacitance per unit volume.
Claim 11
Dependent Claim
18 words
The cryogenic refrigerator of claim 8 wherein said material of high thermal capacitance per unit volume is lead.
Claim 12
Dependent Claim
13 words
The cryogenic refrigerator of claim 9 wherein said highly conductive material is copper.
Claim 13
Dependent Claim
96 words
A high thermal capacitance cryopump comprising: a cryogenic refrigerator having at least two stages; and a lowest temperature cryopanel mounted to and cooled by the lowest temperature stage of said refrigerator, the cryopanel being cooled to cryogenic temperatures for condensing gases thereon, wherein said lowest temperature cryopanel has a thermal capacitance of at least about six joules/K. and comprises a sheet of sandwiched layers, one layer formed of a material of high thermal conductivity and the other layer formed of a material having a capacitance per unit volume of at least about 0.2 joules/cm 3 -K.
Claim 14
Dependent Claim
96 words
A high thermal capacitance cryopump comprising: a cryogenic refrigerator having at least two stages; and a lowest temperature cryopanel mounted to and cooled by the lowest temperature stage of said refrigerator, the cryopanel being cooled to cryogenic temperatures for condensing gases thereon, wherein said lowest temperature cryopanel has a thermal capacitance of at least about six joules/K. and comprises a sheet of sandwiched layers, one layer formed of a material of high thermal conductivity and the other layer formed of a material having a capacitance per unit volume of at least about 0.2 joules/cm 3 -K.
Claim 15
Dependent Claim
15 words
The cryopump of claim 11 wherein the material of high capacitance per volume comprises lead.
Claim 16
Dependent Claim
17 words
The cryopump as claimed in claim 12 wherein said highly conductive material comprises a layer of copper.
Claim 17
Dependent Claim
18 words
The cryopump of claim 13 further comprising a layer of indium positioned between said copper and lead layers.
Claim 18
Dependent Claim
21 words
The cryopump of claim 11 wherein the material of higher capacitance is sandwiched between two layers of said highly conductive material.
Claim 19
Independent Claim
110 words
A method of continuously processing material in a high vacuum oil free system comprising the steps of: reducing the pressure in a work chamber by means of a first cryopump; placing said material in a load lock; reducing said load lock pressure to a crossover pressure by means of an air ejector device while the load lock is isolated from a second cryopump and the work chamber; further reducing the load lock pressure to a system operating pressure by means of the second cryopump; thereafter connecting said load lock at a system operating pressure to the work chamber; and transferring said material from the load lock to the work chamber.
Claim 20
Independent Claim
110 words
A method of continuously processing material in a high vacuum oil free system comprising the steps of: reducing the pressure in a work chamber by means of a first cryopump; placing said material in a load lock; reducing said load lock pressure to a crossover pressure by means of an air ejector device while the load lock is isolated from a second cryopump and the work chamber; further reducing the load lock pressure to a system operating pressure by means of the second cryopump; thereafter connecting said load lock at a system operating pressure to the work chamber; and transferring said material from the load lock to the work chamber.
Claim 21
Dependent Claim
15 words
The method of claim 16 wherein said second cryopump comprises a high thermal capacitance cryopump.
Claim 22
Dependent Claim
23 words
A vacuum system as claimed in claim 17 wherein the capacitance of the high thermal capacitance cryopump is at least about six joules/K.
Claim 23
Dependent Claim
35 words
The vacuum system of claim 18 wherein the capacitance per volume of a material forming at least part of a cold stage cryopanel of the second cryopump is at least about 0.2 joules/cm 3 -K.
Claim 24
Dependent Claim
22 words
The method of claim 17 wherein said high thermal capacitance cryopump comprises a low temperature adsorptive array constructed in part of lead.
Claim 25
Independent Claim
40 words
A method of starting a first cryopump comprising the steps of: a. evacuating said first cryopump to an intermediate pressure with an air ejector device; b. further evacuating said cryopump with a second cryopump; and c. operating said first cryopump.
Claim 26
Independent Claim
40 words
A method of starting a first cryopump comprising the steps of: a. evacuating said first cryopump to an intermediate pressure with an air ejector device; b. further evacuating said cryopump with a second cryopump; and c. operating said first cryopump.
Claim 27
Dependent Claim
55 words
A vacuum system as claimed in claim 1 wherein the second cryopump comprises a cryopanel cooled to cryogenic temperatures to condense gases thereon, the cryopanel comprising a sheet of at least two sandwiched layers respectively formed of a material of relatively high thermal conductivity and a material of relatively high thermal capacitance per unit volume.
References Cited (Backward Citations)
US3010285A
Cited
US3137551A
Cited
US3262279A
Cited
US3485054A
Cited
US3630051A
Cited
US4406130A
Cited
US4446702A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-24 | 1989-09-23 | 1990-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-24 | 1993-09-23 | 1994-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-24 | 1997-09-23 | 1998-03-25 | $7700.00 | Window Closed / Lapsed |