Abstract An electrical device having a pair of projecting leads, such as a capacitor or a capacitor assembly, is encapsulated by forming an inner insulating layer about a body of the device and sections of the leads adjacent the body. A moisture-proof and/or other type protective metal layer then is formed about the inner insulating layer so that it terminates at points short of the ends of the inner insulating layer on the leads, whereby insulated portions of the leads are exposed and the metal layer is electrically insulated from the body of the device and the leads. An outer protective layer, which also may be of insulating material, then is formed about the metal layer and the exposed insulated portions of the leads to entrap the metal layer within the inner and outer layers. The forming of each layer preferably is accomplished by dipping, with the metal layer being formed by dipping in a semi-molten solder composition having a relatively low melting point. Any voids in the solder composition layer then may be sealed by subsequently dipping in a molten metal solution having a melting point on the order of or less than that of the solder composition.
A method of encapsulating an electrical device having a body with a pair of projecting leads in insulating material and a solder composition which does not readily bond to insulating material when in a molten state, which comprises: dipping the electrical device in a solution of resin insulating material which contains an insulating filler material to increase the consistency of the solution and to increase the thickness of the solution which will coat onto the body of the electrical device and the leads, to produce an inner form-fitting layer of insulating material about the body of the electrical device and sections of the leads immediately adjacent the body; then dipping the electrical device in a solution of the solder composition which is at a temperature less than that of the melting point of the inner layer of insulating material, and which is in a semi-solid condition such that the solder composition will solidify rapidly about the electrical device to produce a form-fitting metal protective encasement about the inner layer of insulating material and along sections of the leads when the electrical device is withdrawn from the semi-solid solder solution, with the metal encasement terminating at points short of the inner insulating layer to leave exposed insulated portions of the leads; then sealing any voids in the metal protective encasement by dipping the electrical device in a molten solder solution having a melting point not substantially greater than that of the solder composition used to form the metal protective encasement; and then applying insulating material having a greater melting point than the metal protective encasement, about the metal protective encasement and the exposed insulated portions of the leads in a heated liquid state, with the material fusing to at least the exposed insulated portions of the leads to produce an outer form-fitting protective layer which entraps the metal eNcasement within the inner insulating layer and the outer protective layer.
Claim 2
Dependent Claim
84 words
A method of encapsulating an electrical device having a body with a pair of projecting leads, as recited in claim 1, which further comprises: forming the inner insulating layer by dipping the body of the electrical device and the sections of the leads adjacent the body in a resin solution which contains an insulating filler material to increase the consistency of the solution and to increase the thickness of the solution which will coat onto the body of the electrical device and the leads.
Claim 3
Dependent Claim
66 words
A method of encapsulating an electrical device having a body with a pair of projecting leads, as recited in claim 1, which comprises the additional intermediate step of: sealing any voids in the metal protective encasement by dipping the electrical device in a molten metal solution having a melting point not substantially greater than that of the metal material used to form the metal protective encasement.