US4962776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for surface and fluid cleaning
Assignee: University of Minnesota System
•
Filing: 1988-05-03
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Granted: 1990-10-16
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Expires: 2008-05-03
Abstract
Abstract A cleaning system of the apparatus utilizing the effect of surface tension forces (4) and phase changes between a liquid and gas. In one embodiment the surface (21) to be cleaned is submerged within a vessel (30), the pressure within the vessel being increased. A rapid depressurization of the vessel causes a plurality of bubbles (12) to form around undesired particulate matter (13) on the surface (14) of the article to be cleaned, the bubbles rising to the surface of the liquid (27) within the chamber, thereby cleaning the article. A second embodiment utilizes a cleaning fluid (52) which is applied to the surface of the article (49) to be cleaned. The fluid being subsequently frozen on the surface, thereby reducing the adhesion force between the surface of the article and undesired particulate matter. The surface of the article (49) is subsequently heated, and the undesired particulate matter is removed through the medium of the cleaning fluid (52).
Inventors
- 👤 Benjamin Y. H. Liu
- 👤 Kang H. Ahn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:59
CPC Classifications
B; B08; B08B; B08B3/00; B08B3/04; B08B3/10; H; H10; H10P; H10P70/00; H10P70/10; B08B3/102; B08B7/00; B08B7/0064; C; C02; C02F; C02F1/00; C02F1/24; H10P70/15; H10P72/00; H10P72/04; H10P72/0402; H10P72/0406; H10P72/0411; H10P72/0414; H10P72/0416
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
77 words
A method for cleaning a surface of a precision manufactured component, comprising the steps of: (a) exposing the surface to a cleaning fluid in the vaporous state; (b) forming a film of liquid cleaning fluid on the surface; (c) freezing said film to entrap microparticles present on the surface, said microparticles having a minimum particle size of at least as small as 0.05 microns; and (d) removing the frozen film and said entrapped microparticles from the surface.
Claim 2
Independent Claim
77 words
A method for cleaning a surface of a precision manufactured component, comprising the steps of: (a) exposing the surface to a cleaning fluid in the vaporous state; (b) forming a film of liquid cleaning fluid on the surface; (c) freezing said film to entrap microparticles present on the surface, said microparticles having a minimum particle size of at least as small as 0.05 microns; and (d) removing the frozen film and said entrapped microparticles from the surface.
Claim 3
Dependent Claim
23 words
The method according to claim 1 wherein the film is formed by exposing the fluid vapor to the cooled particles and the surface.
Claim 4
Dependent Claim
34 words
The method according to claim 1 wherein the freezing step is accomplished by contacting the surface with a second fluid maintained at a temperature below the freezing point of the fluid to be frozen.
Claim 5
Dependent Claim
17 words
The method according to claim 3 wherein the second fluid is air, nitrogen or an inert gas.
Claim 6
Dependent Claim
32 words
The method according to claim 1 wherein the removing step is accomplished by contacting the frozen fluid with additional fluid maintained at a temperature above the freezing point of the frozen fluid.
Claim 7
Dependent Claim
16 words
The method according to claim 1 wherein the removing step is accomplished by heating the surface.
Claim 8
Dependent Claim
17 words
The method according claim 6 wherein the surface is warmed from its side opposite the frozen coating.
Claim 9
Dependent Claim
18 words
The method according to claim 1 wherein the fluid is water, an alcohol, a fluorocarbon or a hydrocarbon.
Claim 10
Dependent Claim
18 words
The method according to claim 1 wherein the freezing step is accomplished by conductive cooling of the surface.
Claim 11
Dependent Claim
18 words
The method according to claim 1 wherein the freezing step is accomplished by convective cooling of the surface.
Claim 12
Dependent Claim
23 words
The method according to claim 1 wherein the freezing and removing steps are respectively accomplished by conductive cooling and heating of the surface.
Claim 13
Dependent Claim
18 words
The method according to claim 1 wherein the removing step is accomplished by radiative heating of the surface.
Claim 14
Dependent Claim
13 words
The method according to claim 1 wherein the surface is a semiconductor material.
Claim 15
Dependent Claim
11 words
The method according to claim 1 wherein the fluid is water.
Claim 16
Dependent Claim
20 words
The method according to claim 13 wherein the removing step is accomplished by spraying warm water onto the frozen fluid.
Claim 17
Independent Claim
78 words
A method for cleaning a surface of a precision manufactured component, comprising the steps of: (a) introducing a vaporous fluid into a chamber containing the surface, such that the vaporous fluid contacts the surface to be cleaned; (b) freezing the vaporous fluid onto the surface to entrap microparticles present on the surface said microparticles having a minimum particle size at least as small as 0.05 microns; and (c) removing the frozen fluid and the microparticles from the surface.
Claim 18
Independent Claim
78 words
A method for cleaning a surface of a precision manufactured component, comprising the steps of: (a) introducing a vaporous fluid into a chamber containing the surface, such that the vaporous fluid contacts the surface to be cleaned; (b) freezing the vaporous fluid onto the surface to entrap microparticles present on the surface said microparticles having a minimum particle size at least as small as 0.05 microns; and (c) removing the frozen fluid and the microparticles from the surface.
Claim 19
Dependent Claim
21 words
The method according to claim 16, wherein the freezing step lessens the adhesion force between the surface and undesired particulate matter.
Claim 20
Dependent Claim
34 words
The method according to claim 16 wherein the freezing step is accomplished by contacting the surface with a second fluid maintained at a temperature below the freezing point of the fluid to be frozen.
Claim 21
Dependent Claim
17 words
The method according to claim 16 wherein the second fluid is air, nitrogen or an inert gas.
Claim 22
Dependent Claim
16 words
The method according to claim 16 wherein the removing step is accomplished by heating the surface.
Claim 23
Dependent Claim
13 words
The method according to claim 14 wherein the surface is a semiconductor material.
Claim 24
Dependent Claim
11 words
The method according to claim 16 wherein the fluid is water.
Claim 25
Dependent Claim
22 words
The method according to claim 16, wherein the removing step is accomplished by causing the frozen fluid to at least partially melt.
Claim 26
Dependent Claim
17 words
The method according to claim 16, further comprising the step of spinning the surface within the chamber.
Claim 27
Dependent Claim
32 words
The method according to claim 16, wherein the removing step is accomplished by contacting the frozen fluid with additional fluid maintained at a temperature above the freezing point of the frozen fluid.
Claim 28
Dependent Claim
27 words
The method according to claim 16, further comprising the step of introducing a gas into the chamber after the removing step, such that the surface is dried.
Claim 29
Dependent Claim
17 words
A method according to claim 11 or 16 wherein the precision manufactured component is a semi-conductor chip.
Claim 30
Dependent Claim
17 words
A method according to claim 11 or 16 wherein the precision manufactured component is a computer disk.
Claim 31
Dependent Claim
17 words
A method according to claim 11 or 16 wherein the precision manufactured component is an optical component.
Claim 32
Dependent Claim
20 words
A method according to claim 11 wherein the vaporous fluid forms the liquid film without intermediate formation of vapor droplets.
Claim 33
Dependent Claim
21 words
A method according to claim 16 wherein the vaporous fluid is frozen onto the surface without intermediate formation of vapor droplets.
Claim 34
Dependent Claim
27 words
A method according to claim 11 or 16 wherein the fluid on the surface wets the surface and microparticles and is substantially free of entrapped air bubbles.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |