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:
Feb. 23, 2010
Filed:
Jan. 23, 2007
Takanori Aono, Moka, JP;
Tatsuya Nagata, Ishioka, JP;
Hiroyuki Enomoto, Musashino, JP;
Shuntaro Machida, Kokubunji, JP;
Takanori Aono, Moka, JP;
Tatsuya Nagata, Ishioka, JP;
Hiroyuki Enomoto, Musashino, JP;
Shuntaro Machida, Kokubunji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In an ultrasonic transducer including a gap between an upper electrode and a lower electrode on a silicon substrate, it is made possible to reduce or adjust warpage of an above-gap membrane vibrated by electrostatic actuation due to internal stress. A fourth insulating film and a fifth insulating film of films positioned above the gap which is a cavity required for transmitting and receiving ultrasonic are respectively a silicon oxide film for compression stress and a silicon nitride film for tensile stress. Therefore, compression stress and tensile stress cancel each other, so that warpage of the above-gap membrane is reduced. An amount of warpage can be adjusted by adjusting a film thickness of the fourth insulating film and a film thickness of the fifth insulating film.