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:
Nov. 14, 2000
Filed:
Feb. 14, 1997
Charles W Bowers, Torrance, CA (US);
ECO-Snow Systems, Inc., Livermore, CA (US);
Abstract
An apparatus and method that enhances removal of contaminating particles from surfaces of a non-electrostatically sensitive components that are cleaned using a carbon dioxide cleaning spray. The apparatus includes a programmable power supply that is connected to ground and to the non-electrostatically sensitive component. The surface charge of the component is determined by cleaning the surface without adding any voltage or charge bias to the component. Then the surface is reversed-biased with a voltage having the opposite polarity by a large amount using the programmable power supply. The surface is then cleaned a second time, which removes the contaminating particles that were bound to the surface by electrostatic forces generated during the first cleaning. Thus, reversing the polarity of the charge on the surface that is to be cleaned removes the strong attraction between the contaminating particles and the surface and enhances removal of the contaminating particles from the surface.