Sprague Electric Company

Walter W Schroeder

Clinton E Hutchins

Phyllis M Schmidt

Noel C Sears

Eugene W Kuzia

Joseph C Boni

An aluminum electrolytic capacitor is housed in an aluminum can having one open end. A standard glass-to-metal seal having an outer tantalum ring is seated snugly within the mouth of the can. With the edge of the tantalum ring positioned flush with, or slightly below, the lip of the aluminum can, the beam of a pulsing infra red laser is directed at the interface between the tantalum ring of the seal and the aluminum lip of the can causing the lip of the can to melt, to flow over and to form a continuous annular Al-Ta weld with the tantalum ring and to hermetically seal the ring to the can continuously and completely at a peripheral edge of the tantalum ring.

Hermetically sealed aluminum electrolytic capacitor

A printed-circuit-mountable wet-electrolyte capacitor is housed in a cylindrical can. A disc-shaped plastic cover is fitted in the open end of the can and has a through-terminal sealed therein to which the capacitor anode is electrically connected. Another such terminal, or the can, may serve as the cathode terminal. A groove in the periphery of the cover has a rubber o-ring. The o-ring is compressed by rolling and beading the can inwardly to effect a can/cover seal. Elongate metal pieces are held positioned by cavities provided near the periphery of the cover. The cover is fitted into the can and the elongate pieces are welded to the inner lip of the can to stop outward movement of the cover and to serve as mounting means to a printed circuit board.

Wet-electrolyte capacitor package

A capacitor has a housing of two open-mouth metal cans joined in a non-overlapping arrangement by an insulative bushing that is tapered to provide a self-locking closure when mated with the cans. The electrodes of the capacitance section are electrically connected internally to opposite ends of the housing. If desired, leads are attached externally opposite the internal connections.

Capacitor construction with self-locking closure

A cover-terminal assembly for an electrolytic capacitor is made by placing a gasketed terminal in a counterbored hole in a polyphenylene sulfide cover and upsetting the shank of the terminal by resistance heating under pressure. The portion of the hole adjacent the opposite end of the terminal is also counterbored and then filled in by molten cover material flowed during the hot upsetting operation.

Electrolytic capacitor cover-terminal assembly

A metal termination is formed at the end of a wound capacitor section by rotating the section while spraying a molten metal. A shield plate is placed between the spray nozzle and a portion of the section end so that each incremental surface region of the section end being sprayed is shielded from the molten metal spray during part of each period of rotation. This causes a periodic cooling of each surface region of the section end during spraying so that any desired thickness of termination may be quickly deposited without risk of damaging the section end which may contain plastic or paper dielectric sheet materials that are easily deformed or dissintegrated by conventional molten metal spraying methods.

Growing community of inventors

Williamstown, MA, United States of America

Walter W Schroeder