Siemens Aktiengesellschaft

Manfred Schnoeller

Ernst W Haas

Wolfram Wersing

Karl Lubitz

Jutta Mohaupt

Joachim Martin

Konrad Reuschel

Wolfgang Keller

Karl Platzoeder

Gunter Raab

Werner Baumgartner

Eberhard Spenke

Joachim Burtscher

Heinz-Herbert Arndt

Gustav Fischer

Alfred Muehlbauer

The invention is directed to a piezo-electric transducer having electrodes that adhere well both to ceramic as well as to plastics and that are composed of intrinsically conductive plastic. The invention is also directed to a method for the manufacture thereof. A conductive polymer layer is produced on the surface of a piezo-ceramic component by chemical or anodic oxidation of a monomer. The monomers are selected from the class of 5-member heterocycles containing sulfur or nitrogen as heteroatom, or aniline, azuline, or derivatives of the said compounds. The components provided with the economical electrodes can be advantageously composed to form sandwich-like transducers having plastic intermediate layers that exhibit good electro-acoustical properties.

Piezo-electric transducer having electrodes that adhere well both to

The invention provides an electrode for piezoelectric composites having high acoustic attenuation. The electrode is composed of a first layer having high elasticity and lower conductivity and of a second layer lying thereabove that has higher conductivity. The invention also provides a method for the manufacture thereof. The first layer is an intrinsically conductive plastic directly deposited on the ceramic whose polymerization is initiated by chemical or anodic oxidation of the corresponding monomers. The second layer is fashioned of adequately conductive metal and is preferably first sputtered on or vapor-deposited in a thinner layer and is then subsequently electrolytically reinforced. Piezoelectric composites that exhibit high acoustic attenation and, thus, prevent an acoustic crosstalk between the individual transducer elements can be manufactured from piezoelectric ceramic lamina or foils provided with such electrodes. Such composites also withstand higher mechanical distortion (for example, due to thermal expansion), even if the ceramic is highly porous.

Electrode for piezoelectric composites

A method for the manufacture of a linear or annular ultrasonics antenna array for the megahertz range, which consists in providing a laminate of alternating layers of unsintered ceramic and spacing layers, the spacing layers being composed of a filler material which is heat fugitive at the sintering temperature of the ceramic, the spacing material also including refractory grains distributed therein of a size which corresponds to the spacing desired between the ceramic layers, sintering the laminate to thereby liberate the filler material and leave voids between the refractory grains, impregnating the resulting laminate with a polymerizable resin to bond the sintered ceramic layers together, and separating the resulting laminate into individual transducer elements.

Method for the manufacture of an ultrasonics antenna array

A method is disclosed for the production of n-doped silicon single crystals, each having a dish-shaped specific electrical resistance profile in a radial direction about a central axis of the crystal. A silicon single crystal is exposed to a pattern of radiation with neutrons according to the reaction 30.sub.Si (n,.gamma.) 31.sub.Si .sup..beta.-.fwdarw. 31.sub.P. The neutron radiation causes a weaker doping concentration in marginal regions of the crystals due to the production of fewer phosphorus atoms. Either p-conductive silicon crystals or n-conductive silicon crystals may be utilized as an initial material for exposure to the neutron radiation.

Method for the production of n-doped silicon with a dish-shaped profile

Method and apparatus for forming silicon U-shaped carrier members from straight silicon rods using a combination of rod movement, zone heating, and controlled bending.

Technique for making silicon U-shaped members

An apparatus for doping a semiconductor crystalline rod by nuclear or radiogenic reactions comprised of a hollow irradiation housing having axially and rotatably movable rod support means within the chamber thereof and a neutron conductive sleeve connected with the housing and providing communication between a neutron source and the housing chamber. Accurate and controlled doping of a semiconductor crystalline rod mounted on the rod support means within the housing chamber occurs via controlled rod movement in relation to the neutron source.

Apparatus for doping a semiconductor crystalline rod

Si monocrystals of the n-type are produced by zone melting polycrystalline Si rods under conditions sufficient to produce monocrystal rods, measuring the specific conductivity of such monocrystal rods and subjecting such monocrystal rods to a controlled radiation by thermal neutrons based on the measured conductivity to produce a desired degree of n-conductivity in the ultimately attained rods.

Method of producing homogeneously doped n-type Si monocrystals by

Homogeneously doped Si monocrystals of the n-type are produced from p- or n-type Si crystals having a random dopant concentration in radial and axial directions of the crystal and the dopant concentration within such crystals is adjusted by subjecting such crystals to controlled thermal neutron radiation.

Method of producing homogeneously doped n-type Si monocrystals and

Hollow semiconductor bodies are formed from a gaseous phase by deposition on a heated mandrel and end zones of a so-produced body are doped so as to be conductive at room temperature.

Method of producing directly heatable hollow semiconductor bodies

A semiconductor layer, such as an epitaxial layer on a suitable substrate is subjected to controlled bombardment by neutrons whereby the atoms of the semiconductor layer are converted via nuclear reaction into doping material atoms.

Growing community of inventors

Haimhausen, Germany

Manfred Schnoeller