US 4,288,468 AGranted

Process for encapsulating electrical components by vortex sintering

AssigneeSiemens Aktiengesellschaft

InventorFerdinand Utner

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Abstract

A process for encapsulating electrical components with a continuous layer of synthetic resin material contemplates induction heating of the component by high frequency current with the component leads covered by heat insulating material, and subjecting the heated component to a vortex bath of synthetic resin powder so as to fuse or sinter the powder to the component. Because the leads have not been heated, no resin is sintered thereto, so that scraping or other removal of resin from the leads to make electrical contact therewith need not be undertaken as an additional step. During hardening of the resin the heat insulation may be left in place on the leads to allow the hardened resin to form "feet" on a base of the component, or the heat insulation may be displaced slightly to allow flow of the hardening resin around the lead without forming a fillet.

Claims4

Dependent claims

A process for encapsulating electrical components with hardenable casting resin, said components each having wire leads joined to a component body, said process comprising the steps of:

outwardly bending top edges of a pair of opposed adhesive heat-insulating strips;
placing a component lead between said strips;
gluing said strips to said component lead;
pressing said top edges of the adhesive strips against the lead wires after gluing to cover the lead up to a point at which the lead joins the component body;
heating the surface said component body by induction in a high frequency field;
moving the component through a vortex bath of said resin in powder form to sinter the powder to the surface of the component body;
removing loose resin powder from said insulating material;
smoothing the sintered resin on the surface of the component body by subjecting the body to further heat to melt the resin;
and
allowing the sintered resin to harden.

7 more elements

Dependencies are inferred from the claim text.