Abstract: A tube of ceramic dielectric material having inner and outer electrodes formed thereon is immersed in an alcohol solution of rosin to form a rosin film over the entire exposed surfaces thereof. A pair of metal caps, each having a plurality of circumferentially spaced inward projections and a thin solder layer covering at least each inward projection, are then pressed onto the opposite ends of the ceramic tube, thereby embedding the inward projections of each metal cap in one of the electrodes. The solder layer on each metal cap projection is then melted to establish firm mechanical and electrical contact between electrodes and metal caps. Semiflexible, hermetic sealing joints are then formed at least between electrodes and metal caps by applying an insulating paint while the ceramic tube and metal caps are being heated to partly evacuate the interior thereof. Finally, an external covering comprising one or more insulating layers is formed at least over the sealing joints and a region therebetween.

Abstract: A pair of metal caps pressed onto the opposite ends of a ceramic dielectric tube have each a plurality of circumferentially spaced inward projections which are embedded in either inner or outer electrodes formed on the ceramic tube. Each inward projection of each metal cap is further soldered to one of the electrodes, preferably by melting a thin solder layer which has plated over the metal cap, thereby establishing or reinforcing the mechanical and electrical contact between electrodes and metal caps. Semiflexible sealing joints consisting essentially of epoxy resin of the bisphenol A type are formed at least between electrodes and metal caps to hermetically seal the capacitor. An external covering comprising one or more layers of plastics material is formed at least over the sealing joints at a region therebetween.