GB898582A - Improvements in or relating to methods of applying a protective coating to electrical components - Google Patents

Abstract

898,582. Capacitors. SIEMENS & HALSKE A.G. June 24, 1960 [June 25, 1959], No. 22218/60. Class 37. A protective coating is applied to electrical components (e.g. capacitors) having leads extending therefrom, wherein plural components are spacedly positioned between two longitudinal metallic strips with the leads extending laterally therefrom, and a molten insulating substance which is solid at the working temperature is poured into the space between the strips to contact the exterior portions of the components and bond to the metallic strips ; the components being separable by sawing after solidification of the insulation. Aluminium foils 8, 8<1> exteriorly coated at 5, 5<1>, 5<11> with a synthetic polycarbonate insulating material (e.g. 4-4<1>-dimono-oxyarylalkane) are placed within the side frames 10, 10<1> of a clamp (Figs. 2, 3) and over a central separating sheet 9, and two sets of capacitors 6, 61, 611 and 7, 71, 7<11> are spacedly disposed between the exposed surfaces of the foils; the leads protruding laterally between U-shaped silicone rubber strips 11, 11<1> and 11<11>, 11<111> closing the bottom and sides of the frame and the insulating layer overlapping the longitudinal sides of the foils between the side-frames and the strips, so that a molten casting resin may be poured into the remaining space to bond to the foils, the insulating layer and the capacitor units and form when cold a solid strip containing plural sealed in units which may be separated by sawing (Fig. 1, not shown). The foils may be coated on both sides with a continuous insulating layer (Fig. 4, not shown) or carry rectangular sections of insulating material on their inner faces opposite each capacitor unit (Fig. 5, not shown). The units may be spacedly welded or cemented between two strips of insulating material prior to insertion between the foils in the casting clamp (Figs. 6, 8, not shown) or an additional metal foil may be folded round each capacitor unit before casting with or without the interposition of a further insulating layer (Figs. 7, 9, 10, not shown). Canned capacitor units may be inserted between the metal foils either separately or as a connected chain and embedded in casting resin as above (Figs. 11, 12, not shown). The coated surface of the foils may be initially roughened, or the foils may be produced by depositing metal on an insulating sheet.