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Patent Searching and Data


Title:
ELECTROSTATIC ULTRASONIC TRANSDUCER AND METHOD OF MAKING THE SAME
Document Type and Number:
WIPO Patent Application WO2000072631
Kind Code:
A3
Abstract:
The present invention provides a transducer and a method of making the same. The transducer is comprised of a plurality of transducer cells (200A, 200B, 200C), and conductive interconnects (220, 230) between the cells. Each transducer cell contains a bottom electrode (320A, 320B, 320C) formed on a layer of insulator material, a lower insulating film portion (320A) formed over the bottom electrode, a middle insulating film portion (320B) that includes an air/vacuum void region (340A, 340B, 340C), and an upper insulating film portion (320C) that includes a top electrode (350A, 350B, 350C) formed within a portion of the upper insulating film portion. A first layer of interconnects (230) electrically connect the bottom electrodes of each transducer cell and a second layer of interconnects (220) electrically connect the top electrodes of each transducer cell. The top and bottom layers of interconnects (220, 230) are patterned to avoid overlap between them, thus reducing the parasitic capacitance. Further, as noted, the top electrode (350A, 350B, 350C) is preferably formed within the upper insulating film portion, (320C), closer to the air/vacuum void than to the top surface of the insulating film, to increase the electric field for a given voltage. Still furthermore, the electrodes within each transducer cell are preferably formed to have dimensions that are smaller than the overall surface area of the membrane that they excite.

Inventors:
LADABAUM IGAL
Application Number:
US0013634W
Publication Date:
May 03, 2001
Filing Date:
May 17, 2000
Export Citation:
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Assignee:
SENSANT CORPORATION
International Classes:
B06B1/02; G01H11/06; H02N1/00; H04R19/00; H04R31/00; (IPC1-7): B06B1/02; H04R19/00; G01H11/06
Foreign References:
DE2444023A11975-03-20
US5619476A1997-04-08
Other References:
KENICHIRO SUZUKI ET AL: "A SILICON ELECTROSTATIC ULTRASONIC TRANSDUCER", IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS AND FREQUENCY CONTROL,US,IEEE INC. NEW.YORK, vol. 36, no. 6, 1 November 1989 (1989-11-01), pages 620 - 627, XP000099883, ISSN: 0885-3010
PATENT ABSTRACTS OF JAPAN vol. 014, no. 114 (P - 1015) 2 March 1990 (1990-03-02)
PATENT ABSTRACTS OF JAPAN vol. 013, no. 173 (E - 748) 24 April 1989 (1989-04-24)
PATENT ABSTRACTS OF JAPAN vol. 014, no. 344 (E - 0955) 25 July 1990 (1990-07-25)
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