Abstract: Multilayer printed circuit boards, foil printed circuit boards and metal-clad laminates for foil circuit boards and a process for the manufacture thereof, with interfacial connections structured in insulator layers, with resist openings of surface structured in resist coatings, with current paths structured in conductor layers and with contact points and in which for reducing the number of photochemical structurings or patternings required the interfacial connections and resist openings are mechanically structured, in that interfacial connection openings preworked in insulator layers are etched according to interfacial connection structures of mask foils, that in the interfacial connection openings are deposited electrically conductive deposition substances for the formation of contact layers in said openings.

Abstract: An orthodontic assembly including an orthodontic appliance and a region composed of a matrix material having a plurality of reinforcement structures distributed throughout, with some of the reinforcement structures being exposed on an exterior surface of the assembly, as well as an associated method of fabrication. In one embodiment, the entire orthodontic appliance is composed of the noted reinforcement structures and matrix material. In another embodiment, the noted region is actually a layer which is attached to a separately formed appliance, such as a bracket. Nonetheless, the reinforcement structures may be exposed in a variety of locations, such as on the base and/or arch slot. Moreover, this region may be formed by forming the appliance from the reinforcement structures and matrix material in a manner which produces skin on its exterior surface, and removing the skin from the desired areas to expose reinforcement structures partially contained within the matrix material.

Abstract: A wide variety of end products may be manufactured from fibers or fiber pulp derived from feathers. Examples of such end products are paper and paper-like products, non-woven and woven fibers, insulation, filters, extrusions, and composite sheets and plates.

Abstract: A multilayer laminated body has a determinate system of hollow passages and is formed by an assembly of flat layers of polymeric materials having major dimensions in orthogonal X and Y directions and a thickness dimension in a Z direction perpendicular to the X and Y directions. Selected ones of the layers have openings extending through in the Z direction, and other layers have canals formed in an X-Y plane. The openings and canals form parts of hollow passages so that assembly of multiple layers joins openings and canals forms complete and continuous passages through the assembled layers. Layers joined in pre-laminate assemblies are assembled together in precise relative positions for desired alignment of the canals and openings. The passages can be filled with optically conductive material or electrically conductive material and electrodes can be appropriately positioned for acting on fluids passing through the body.

Abstract: An electrical insulator coated with electrically insulating material is disclosed. An electrically insulating material is applied on a primer coat, in which the uniformity of the applied primer coat can be checked in a comparatively simple manner. A fluorescent material is dissolved in the primer solution before being applied to the component. Once dry, the primer coat is exposed to ultraviolet light, which causes the fluorescent material to fluoresce. Points on the surface of the component where the primer defectively coats the components are optically detected from the absence of fluorescent material. Primer is then reapplied to these points.

Abstract: In the method according to the invention for the production of multilayer foil printed circuit board from preliminary products (A), with current paths (B) structured in electrical conductive layers (1,3) and with electrically conductive metal platings (C,D) from conductive layer (1) to conductive layer (3) through an insulating layer (2), or for producing semifinished products for such foil circuit boards, in first method steps a structuring means (7,7',13) is applied in controlled, local manner to the preliminary product (A) and resist layers (8,9) are coated with the preliminary product (A), the structuring means (7,7',13) being applied either to the resist layers (8,9) and the resist layer (8,9) is locally removed, or the resist layers (8,9) are applied to the structuring means (7,7',13) and in a further method step the applied structuring means (7,7',13) are removed, so that openings (10,10') are formed in the resist layers (8,9) and extend down to the insulating layer (2) and in a further method step thr

Abstract: The indicating device (3) is used for signalling a faulty condition of an electrical apparatus, in particular of a surge arrester (1). It contains a sensor (resistor 10) which is located in an insulating material housing (6) and is intended for detecting a fault current flowing through the apparatus, as well as a two-piece metal housing (4) surrounding the insulating material housing (6). The sensor (10) and the insulating material housing (6) are part of a switching element (5). This switching element (5) causes the insulating material housing (6) to spring apart, by the formation of compressed gas, when the fault current occurs and displaces the two parts (shells 12, 13) of the metal housing (4), making the indicating element (16) visible and forming a DC connection which carries the fault current.

Abstract: A process for the production of printed circuit boards and film circuit boards includes providing a starting product with a layer of insulating material between layers of metal. Openings are formed at desired locations through the metal and, at selected ones of those openings, openings are formed through the insulating material by plasma etching or chemical etching. The result of this is back-etching leaving projecting webs of metal extending partly across the openings. The projecting edges are removed by subjecting all of the metal surfaces to etching or electrodeplating which also thins the metal layers. The resulting structure is then plated, adding reinforcing thickness to the thinned metal layers and coating the openings through the insulating material with metal, providing interracial connections between the metal layers. The resulting intermediate can then be formed into a circuit board by forming circuit patterns in the metal layers.

Abstract: A surge arrester includes at least two connection fittings and a one-piece frame, the frame holding the connection fittings. The frame is formed of an insulating material. The surge arrester includes at least one block of varistor material clamped between the connection fittings. The surge arrester further includes an insulating material in which the frame, the block of varistor material and at least part of the connection fittings are cast to form a monolithic body. An arrangement is provided for maintaining a contact force between the connection fittings and the block of varistor material.

Abstract: The surge arrester contains two connection fittings (1, 2) which are spaced apart from one another along an axis and between which at least one cylindrical varistor element (7) is arranged. The connection fittings (1, 2) and the at least one varistor element (7) are clamped with one another, accompanied by the formation of contact force, to form a mechanically stable active part of the surge arrester. The active part is surrounded by a cast housing (12) made from insulating material. The clamping of the active part is achieved by at least two loops (5) respectively acting independently of one another on the connection fittings (1, 2). The loops (5) are arranged at a distance from the at least one varistor element (7). The connection fittings (1, 2) contain bearing areas which correspond respectively to the number of the loops (5) and are distributed uniformly about the axis azimuthally and on which a loop end is respectively supported.

Abstract: Electrical connections in multilayer printed circuit boards made from conductor foils are preworked by producing preworked electrical connections on the conductor foils to be subsequently processed and for this purpose photoresist is laminated onto said conductor foils, in such a way that in a photochemical process a freely selectable pattern of recesses in the photoresist is exposed and developed, that in a galvanic plating process metal is plated in said recesses and the photoresist is subsequently removed, that at least two conductor foils are pressed, in such a way that the conductor foils are separated by at least one intermediate adhesive film or foil and that each adhesive foil is laminated onto at least one conductor foil, each of said intermediate adhesive foils engaging on at least one conductor foil with preworked electrical connections in such a way that on pressing at least two conductor foils the electrical connections preworked on at least one of the conductor foils penetrates the intermediate

Abstract: The inventive core for electrical connecting substrates, particularly for printed circuit boards and foil circuit boards, has an inner layer (I) with a columnar structure and on either side, metallic cover layers (A,A'), the columnar structure of the inner layer (I) comprising columns (9.1,9.2), which are regularly arranged, spaced from one another and from the cover layers (A,A'), being directed transversely to the service extension of the core and made from an electrically conductive material in a matrix (6) of an electrically insulating material. The cover layers (A,A') e.g. have electrical terminals (16,16', 17,17') in the form of through-plated blind holes (13,14) on selected columns (9) of the inner layer (I) and are structured in such a way that they have a regular pattern of terminals (16,16') on the facing cover layer and terminals (17,17') on the through-connections insulated from the cover layers, this grid pattern can have a size of approximately 0.5 mm.

Abstract: In a metal-clad laminate the requirements concerning the mechanical strength are functionally separated from the circuit connection requirement, so as to be able to bring the circuit connection, particularly for signals, "closer" to the electrotechnical characteristics of the chips. For this purpose and without taking account of the mechanical strength of the substrate, the layout miniaturization is optimized. In place of a circuit board (MCM), a laminate which can be built up to a circuit board is produced. The inventive laminate comprises an extremely thin foil with a plurality of extremely small holes simultaneously etched in an etching process. The hole diameter can be reduced by almost an order of magnitude (up to 20 .mu.m), which permits a sub-100 .mu.m technology. Such a laminate is not used as a mechanical support and is only provided for signal guidance. The effect of the miniaturization can be seen in the diameter for the plated-through holes.

Abstract: The surface of a metal foil to be used as an intermediate layer in printed circuit boards is chemically roughened. In one embodiment, fine depressions are etched out of the metal coating. In another embodiment, protuberances are plated thereon. The use of the method permits the use of the foil in the production of multilayer printed circuit boards with coatings having different thermal expansion characteristics and improves the adhesion with the next conductor layer applied thereto to a significant extent and prevents delamination.

Abstract: A method for producing aligned passages through substrate materials, in which the projection of the inlet and outlet openings does not coincide, uses displaced application of etching windows on opposite sides and corresponding pronounced under-etching of these windows. By applying displaced etching windows on both sides of the substrate and through-etching the substrate through these windows, `oblique` passages are obtained through the substrate. By a suitable location of the windows it is also possible to produce branched passages with more than one outlet opening.

Abstract: This surge voltage arrester has two connecting fittings (1, 2) which are braced with respect to one another. At least one pellet (7) consisting of varistor material is clamped in between the connecting fittings (1, 2).It is intended to create a surge voltage arrester which can be produced using simple means and which, in addition, can be cast around in a simple manner. This is achieved in that at least two insulating clamping elements, which are arranged symmetrically, are provided for bracing the connecting fittings (1, 2). The clamping elements, the at least one pellet (7) and, partially, the connecting fittings (1, 2) have insulating plastic material cast around them to form a monolithic block.

Abstract: A voltage supply for an electric filter is disclosed. The supply comprises a high-voltage rectifier, a pulsed voltage circuit including a resonant circuit and a parallel circuit of a thyristor and a diode which controls resonance in the resonant circuit. The thyristor is fired to trigger the resonant circuit and generate an oscillation which is delivered to the filter as a pulsed voltage. In order to prevent damage to the thyristor, it is fired whenever the duration of the current flowing through the diode is shorter than the thyristor recovery time.

Abstract: An electrostatic precipitator is supplied with a d-c voltage of variable level upon which is superimposed a series of voltage pulses. For each voltage pulse, the difference between a positive current-time area and a negative current-time area beneath a current-voltage curve is determined and maximized by changing the pulse amplitude, pulse width, pulse repetition frequency and/or the rate of pulse rise. In addition, the d-c voltage is controlled to have a value at a point of maximum slope of the function of precipitator current with respect to the magnitude of the d-c voltage.

Abstract: A combination of a special swab applicator, a containment vial therefor and a cap for the vial is provided. An elongate vial containing a culture preserving media has one open end and a closed end and threads about its circumference at the open end. The cap has a threaded rim for attachment to the vial and a central section closing off the area inside the rim. The central section has an axially extending bore portion that snuggly fits an end of the swab applicator. The swab applicator has a long shaft with a first section having a length corresponding approximately to the length of the vial and a second section joined to the first by a frangible joint. After use of the applicator it is inserted into the vial and the second section is broken off. The cap is then threaded onto the vial to seal it and capture the first section.