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:
Mar. 21, 2000
Filed:
Oct. 21, 1997
Tim Beerling, Corvallis, OR (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A crack or delamination occurring within a thin film structure of a printhead is limited to a local region by strategically locating openings within the thin film structure. The etched openings serve to partially isolate each nozzle chamber. The openings are etched in passivation and other layers of the thin film to limit the propagation of the crack or delamination. As thermal stresses re-occur the crack or delamination extends. In may cases the crack or delamination eventually extends to the etched opening. The crack or delamination then ceases its propagation, in effect being blocked by the etched opening. By including an etched opening within the thin film near each nozzle chamber, a given nozzle chamber is isolated from a crack or delamination in the thin film at an adjacent or nearby nozzle. Reliability of a given nozzle therefore is less dependent upon the reliability of an adjacent nozzle.