The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 13, 1991
Filed:
May. 18, 1990
John F Schoeppel, San Rafael, CA (US);
Veriflo Corporation, Richmond, CA (US);
Abstract
A method and apparatus for cleaning surfaces to absolute or near-absolute cleanliness involves spraying jets of heated cleaning solution so that it flows over and scrubs the surfaces to be cleaned. The cleaning solution is continuously recirculated and filtered during cleaning to remove over 99% of all particles having a diameter equal to or greater than 0.02.mu.. The cleaned surface is rinsed with heated, filtered deionized water and dried to provide a surface having absolute or nearly-absolute cleanliness to the limit of the best commercial instrumentation, e.g., .ltoreq. five particles with a diameter of .gtoreq.0.02.mu. per cubic foot of gas flowed over a cleaned surface as detected by a laser particle counter. The method is useful for cleaning gas valves and regulators and components thereof as well as existing gas flow equipment, for example, for use in semiconductor processing equipment. The cleaned surfaces are sterile and therefore also useful in the health and pharmaceutical industries.