Composite ultrasound transducer and method for manufacturing a structured component therefor of piezoelectric ceramic

US5164920A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Ulrich Bast · Birkenfeld, DE
• Hans Kaarmann · Buckenhof, DE
• Karl Lubitz · Ottobrunn, DE
• Martina Vogt · Mercer Island, US
• Wolfram Wersing · Tauberbischofsheim, DE
• Dieter Cramer · Graz, AT

Key dates

• Filing date: May 28, 1991
• Grant date: Nov 17, 1992
• Expiry date: May 28, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2291/0422
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A composite ultrasound transducer (array) contains piezoelectric ceramic transducer elements which radiate substantially in the longitudinal direction, and are embedded in a polymer matrix. The transducer elements have such a geometrical structure, and are arranged relative to each other, so that the development of oscillation modes perpendicular to the longitudinal direction of the transducer elements is suppressed. A method for manufacturing the composite ultrasound transducer includes the steps of filling a plastic form, having a "negative" of the desired shape of the transducer elements, with ceramic slurry, and pyrolyzing the plastic form after the slurry dries therein. The resulting voids between the hardened ceramic elements are filled with polymer to create the overall composite transducer. The transducer elements can thus be given an arbitrary shape and arrangement, such as hexagonal or irregular square structures, having a trapezoidal cross-section in planes parallel to the longitudinal axis of the transducer elements.