Abstract: Viaholes are dry-etched into glass fiber reinforced plastic sheets according to a predetermined hole pattern, leaving the glass fiber meshing practically unaffected.The method is used, for instance, to fabricate plastic sheets with unilaterally or bilaterally applied conductor patterns and viaconnectors that are conductively linked to the conductor patterns, and to fabricate multilayer board laminates obtained by several plastic sheets carrying the conductor pattern being alternately packaged, if required, with untreated copper sheets, and by the package thus obtained being subsequently laminated. Such boards and/or plastic sheets bilaterally provided with conductor patterns may be used as connector boards for, say, multilayer ceramic modules carrying semiconductor chips.

Abstract: Viaholes are dry-etched into glass fiber reinforced plastic sheets according to a predetermined hole pattern, leaving the glass fiber meshing practically unaffected.The method is used, for instance, to fabricate plastic sheets with unilaterally or bilaterally applied conductor patterns and viaconnectors that are conductively linked to the conductor patterns, and to fabricate multilayer board laminates obtained by several plastic sheets carrying the conductor pattern being alternately packaged, if required, with untreated copper sheets, and by the package thus obtained being subsequently laminated. Such boards and/or plastic sheets bilaterally provided with conductor patterns may be used as connector boards for, say, multilayer ceramic modules carrying semiconductor chips.

Abstract: For making rails in workpieces for magnetic head sliders for sensors of magnetizable media, anodic oxidation of highly pure aluminum substrates is applied. For that purpose, the respective surface of the substrates is covered with a mask cover which leaves uncovered the zones in the substrate surface area which are intended for the forming of rails. By means of anodic oxidation of the aluminum in the exposed regions, rail layer regions of oxide are formed which after the removal of the mask cover can themselves be used as an etching mask in order to provide a recessed region between two respective rails by means of chemical wet etching.

Abstract: The invention relates to a composite magnetic disk for magnetic recording, which consists of an annular core of polymeric material to which is bonded at least one disk of reaction-bonded silicon carbide with a magnetic recording layer on its outer surface. After its processing, the SiSiC disk surface shows optimum planarity and smoothness so that it can be used as a magnetic disk substrate. Furthermore, the material has a low density and an extremely high specific modulus of elasticity so that numbers of revolution higher than obtainable with formerly known AlMg5 disk substrates can be reached.

Abstract: A method and apparatus for the selective deposition of metal layers on a substrate. At least one metal layer is deposited in a self-aligned manner on conductive regions on the surface of isolating or semiconductive substrates, for which purpose the conductive regions are arranged facing a metal plate having at least one layer of the metal to be deposited, and Tesla currents are generated between the metal plate and the regions to be coated. The apparatus for implementing the method includes a metal plate, a Tesla transformer which is coupled to the metal plate or to a metal grid, spaced apart from the surface of the metal plate away from the conductive regions, having closely adjacent and regularly distributed spikes pointing towards the metal. This method may be used, for example, to produce conductors on or in ceramic modules, circuit cards and semiconductor elements.

Abstract: According to this method, copper is dry etched in a glow discharge containing compounds with at least one methyl or methylene group, particularly at temperatures close to room temperature.The method is applied in particular for making conductors on or in module substrates or circuit cards, solder spots, and the wiring of magnetic thin films.

Abstract: A substrate for a magnetic recording disk employs an annular core of synthetic material having thin metal foils bonded to opposite faces, the metal foils serving to receive a magnetic recording material to form a magnetic recording structure. The inner surfaces of foils which are bonded to the core faces have applied thereto a thin, soft, deformable layer such as copper to prevent irregularities in the core faces from affecting the outer surfaces of the metal foils.