Abstract: A method of manufacturing a ceramic multilayer component, comprising electrically conductive and electrically insulating layers which are stacked in alternate arrangement in a multilayer structure, which method comprises the following steps:providing three extrudable polymeric mixtures, each mixture comprising a binder and a particulate filler, whereby:(a) a first mixture comprises a ceramic filler;(b) a second mixture comprises a metallic filler and a first binder;(c) the third mixture comprises a metallic filler and a second binder;with the aid of an extrusion device having an extrusion channel which is provided with a layer-multiplication element, manufacturing an extruded multilayer stack comprising a plurality of the basic units abac, in which layers a,b,c correspond respectively to the first, second and third mixtures, the stack having two oppositely situated side walls along which part of each layer is exposed;with the aid of a first solvent, dissolving away part of each layer b exposed along a first s

Abstract: A polycarbonate copolymer of a spirobisindan (6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindan) and bisphenol-A in which the mole fraction of the spirobisindan .alpha. ranges between 0.844 and 0.887 is provided. Such a copolymer has a stress-optical coefficient C.sub.m in the melt which is equal to zero or substantially equal to zero, so that the sensitivity of the polymer to orientation birefringence is very small. Such a copolymer can be rendered optically isotropic and is very suitable for use in optical components in which birefringence is undesirable. Examples of such optical components are lenses and substrates for optical information media.

Abstract: A method of manufacturing a silicon-on-insulator semiconductor body is characterized by the steps consisting in that a carrier body is temporarily connected to a supporting body with accurately flat and parallel major surfaces and having a thickness of at least 1/8 of the largest dimension of the carrier body, in that the free major surface of the carrier body is mechanically polished to a precision of at least 1/2 .mu.m flatness, in that the carrier body is detached from the supporting body and the polished major surface is temporarily connected to the supporting body and the other major surface of the carrier body is mechanically polished to a precision of at least 1/2 .mu.m flatness and a parallelism between the major surfaces of at least 1/2 .mu.m whereupon a semiconductor body is connected through a major surface permanently to a major surface of the carrier body, in that then the semiconductor body is mechanically ground to a thickness of at least 50 .mu.