Electrical capacitor composed of a consolidated winding or consolidated stack of metallized plastic plies layered to one another and method for the manufacture thereof

A method for manufacturing an electrical capacitor, comprising:

• providing a wide band with regenerably thin metal layers as coatings on both sides;
• applying an extremely thin plastic layer to a surface of at least one of said metal layers:
• dividing said wide band into individual bands by cuts proceeding in a longitudinal band direction, said individual bands being of a width for drum winding;
• providing two of said individual bands with intermittent metal-free insulating strips by laser beams, said insulating strips being in regions of edges of said individual bands and spaced at intervals in a winding direction so that said insulating strips lie in a plane perpendicular to a winding axis when wound on a drum, ends and beginnings of said insulating strips extending into an incision region;
• guiding said individual bands during winding onto a drum so that centers of said insulating strips of an upper one of said individual bands are symmetrically arranged over centers of intermediate spaces between said insulating strips of a lower one of said individual bands;
• layering said individual bands on said drum to form an initial capacitor;
• providing at least end faces of said initial capacity formed by said edges of said individual bands with a metal layer by metal spraying while still on said drum and after winding;
• producing incisions in said incision region perpendicular to the winding direction proceeding from both sides of said initial capacitor in a center between two respective cut lines, said incisions forming projections due to a width and depth of said incisions;
• separating said initial capacitor into individual capacitors by insulating saw cuts along said cut lines which proceed through the centers of said insulating strips and by an insulating saw cut along a cut line lying parallel to said edges and in a center of said initial capacitor;
• and
• applying power leads to finish said electrical capacitor.

An electrical capacitor, comprising:

• a consolidated stack of plastic plies layered against one another and provided with regenerably thin layers of valve metal as coatings on both surfaces of each and every plastic ply, said coatings alternately extending up to ends of said two projections from layer to layer,
• two projections formed by an incision of which proceeds in the direction of the thickness of the stack and roughly in the center of one side thereof;
• metal layers provided on surfaces formed by the ends of said projections in the consolidated stack serving the purpose of electrical contacting, said metal layers being formed by metal spraying, said metal layers connecting the coatings to one another;
• external power leads fastened to said two projections by said metal layers;
• said valve metal coatings covering surfaces of said plastic plies practically up to edges at long sides of said consolidated stock as well as up to both ends of said two projections;
• said two projections being alternately provided with metal-free insulating strips and residual metal strips from plastic ply to plastic ply;
• said incision having a depth greater than a width of said residual metal strips;
• and
• an extremely thin plastic layer is present as a dielectric on both of said coatings on every second plastic ply, said extremely thin plastic layer completely covering said coating and extending up to a region of said residual metal strips and being at least partially removed above said insulating strips.