Siemens Aktiengesellschaft

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Epcos Ag

Dieter Cramer

Karl Lubitz

Carsten Schuh

Andreas Wolff

Hans Hellebrand

Ulrich Bast

Clemens Scherer

Wolfram Wersing

Christoph Hamann

Thorsten Steinkopff

Martina Vogt

Hans Kaarmann

Gabriele Preu

Joachim Fröhlich

Stefan Rothbauer

Gerald Kainz

Tudor Ionescu

Iris Hahn

A piezoelectric component has a multilayer structure. The piezoelectric component includes piezoelectric ceramic layers, electrode layers arranged among the ceramic layers in a stack such that the electrode layers and the piezoelectric ceramic layers alternate in the stack, and a passivation layer disposed on a lateral surface of the stack. The passivation layer is made from a passivation material that has a crack resistance that is lower than a bond strength of the passivation material.

Multilayer electrical component having a passivation layer

A piezo actuator with an actuator body has at least one electrically conductive multi-layer film with a rigid electrical terminal element. The multi-layer film controls expansion and attraction of the actuator body. An electrical conduction layer of the multi-layer film has at least one recess to increase flexibility. The recesses in the conduction layer are, for example, photolitho-graphically produced.

Piezo actuator with multi-layer conductive film, and method for making same

A piezo actuator (,) is disclosed that has a contact lug (,) for the electrical contacting of an electrode (,) of an actuator member (,). Due to an expansion and contraction of the actuator member, a mechanical stress occurs in the contact lug that is minimized in that the contact lug has a device for adapting the expanse to a dimension of the expansion and contraction. The device is, for example, a deformation material in the form of a wire weave. The piezo actuator is utilized for the drive of an injection valve in an internal combustion engine.

Piezo actuator with improved electrical contacting and employment of such a piezo actuator

A method for manufacturing a monolithic piezoelectric actuator of multilayer design and having a high aspect ratio of more than two built up from a plurality of smaller stacks in a multilayer design, includes alternately layering green piezoceramic films and electrode material, compressing the layers while elevating the temperature to remove the binder and thereby form a composite, stacking several of the composites on one another, and sintering the stack so as to form the monolithic piezoelectric actuator which exhibits an improved mechanical strength with good piezoelectric properties.

Method for producing a monolithic multilayer piezo actuator

A piezoelectric actuator, and method of producing same, wherein electrically conductive contact tabs are applied onto metallization strips in such a way that a projecting region remains, so that in the event of cracks nevertheless occurring, such cracks run in the projecting region of the contact tab and are bridged electrically.

Piezoelectric actuator with a new type of contacting and a method for the production thereof

A piezoelectric component in the form an actuator having a monolithic multi-layer stack is disclosed. The stack comprises a large active cross sectional area and simultaneously exhibits high arc-over resistance between neighboring electrodes of different polarity. For manufacture, only the surface of the stack via which an electrical contacting of the electrode layers ensues is ground after the sintering of a stack composed of piezo ceramic layers and electrode layers arranged on top of one another.

Piezoelectric component and method for the manufacture thereof

A monolithic piezoelectric actuator is made of a stoichiometric PZT ceramic (,) with low A-site doping, and electrode layers (,) containing silver and palladium. It exhibits an improved mechanical strength with good piezoelectric properties. The production process leads to optimum grain sizes and optimum piezoelectric properties irrespective of any B-site doping in the ceramic. Multilayer piezoelectric actuators with high application temperatures up to 150&deg; C. can be obtained.

Process for manufacturing monolithic multilayer piezoelectric actuator

In a method for producing a PZT piezoceramic, an intermediate compound is formed having the formula Zr.sub.x Ti.sub.1-x (O.sub.2 (ZTO) in a hydrothermal process. A ceramic having a desired zirconium/titanium ratio can be produced from two such ZTO powders having respectively different x-values. These powders are blended with lead oxide, and if desired with dopants, and are converted into a PZT powder by calcining. The calcined PZT powder is then sintered to form a high-density PZT ceramic which can be aligned precisely at the morphotropic phase boundary.

Method for producing a piezoceramic

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.

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Munich, Germany

Dieter Cramer